Przewlekła choroba nerek – Diagnostyka i diagnoza

Przewlekła choroba nerek
Diagnostyka i diagnoza

Przewlekła choroba nerek (PChN) definiowana jest jako utrzymujące się ponad 3 miesiące uszkodzenie nerek lub obniżenie ich funkcji, potwierdzone obniżonym eGFR (< 60 ml/min/1,73 m²) i/lub albuminurią (uACR ≥ 30 mg/g). Diagnostyka opiera się na łącznej ocenie eGFR, obliczanej najczęściej wzorem CKD-EPI, oraz wskaźniku albumina/kreatynina w moczu (uACR), co pozwala na precyzyjne określenie stadium choroby według klasyfikacji KDIGO (G1-G5 i A1-A3). Wczesne stadia PChN przebiegają bezobjawowo, dlatego badania przesiewowe są szczególnie zalecane u pacjentów z grup ryzyka, takich jak osoby z cukrzycą, nadciśnieniem tętniczym, chorobami sercowo-naczyniowymi, otyłością, wiekiem > 60 lat czy z wywiadem rodzinnym chorób nerek. Regularne monitorowanie eGFR i albuminurii umożliwia ocenę progresji choroby i wdrożenie odpowiedniego leczenia, co jest kluczowe dla spowolnienia postępu PChN i zmniejszenia ryzyka powikłań sercowo-naczyniowych.

Diagnostyka przewlekłej choroby nerek – wprowadzenie

Przewlekła choroba nerek (PChN) to stan długotrwałego uszkodzenia nerek lub obniżenia ich funkcji, utrzymujący się ponad 3 miesiące, mający konsekwencje zdrowotne. Dotyka ona około 15% populacji dorosłych, jednak u wielu osób pozostaje nierozpoznana – szacuje się, że nawet 9 na 10 pacjentów z PChN nie wie o swoim schorzeniu. Wczesne stadia choroby zwykle przebiegają bezobjawowo, co sprawia, że diagnostyka laboratoryjna i obrazowa jest kluczowa dla wczesnego wykrycia i wdrożenia odpowiedniego leczenia.¹²³

Rozpoznanie PChN opiera się na stwierdzeniu nieprawidłowości w strukturze lub funkcji nerek utrzymujących się przez co najmniej 3 miesiące. Kryteria diagnostyczne obejmują obniżony wskaźnik filtracji kłębuszkowej (GFR) lub obecność co najmniej jednego markera uszkodzenia nerek. Do markerów tych należą: nieprawidłowości histologiczne, strukturalne, nieprawidłowy osad moczu, zaburzenia elektrolitowe spowodowane chorobami kanalików nerkowych lub podwyższony poziom albuminy w moczu (albuminuria).⁴⁵

Badania przesiewowe w kierunku PChN

Badania przesiewowe w kierunku PChN są zalecane dla osób z grup ryzyka, do których należą pacjenci z:⁶⁷

Cukrzycą
Nadciśnieniem tętniczym
Chorobami układu sercowo-naczyniowego
Otyłością
Wiekiem powyżej 60 lat
Wywiadem rodzinnym chorób nerek
Przebytym ostrym uszkodzeniem nerek (AKI)
Paleniem tytoniu w wywiadzie
Pochodzeniem etnicznym o zwiększonym ryzyku (np. osoby pochodzenia afroamerykańskiego, Azjaci)

Coroczne badania przesiewowe w kierunku PChN są rekomendowane przez Amerykańskie Towarzystwo Diabetologiczne dla wszystkich pacjentów z cukrzycą, przez National Kidney Foundation dla pacjentów z grupy ryzyka, przez Joint National Committee on Hypertension dla pacjentów z cukrzycą i nadciśnieniem, oraz przez Amerykańskie Towarzystwo Kardiologiczne dla pacjentów z chorobami układu sercowo-naczyniowego.⁶

Podstawowe badania diagnostyczne w PChN

Dwa kluczowe badania diagnostyczne stosowane do wykrywania i oceny PChN to:⁸⁹

Ocena wskaźnika filtracji kłębuszkowej (eGFR)

Wskaźnik filtracji kłębuszkowej (GFR) jest najlepszym miernikiem funkcji nerek. Prawidłowy GFR wynosi około 90-140 ml/min u mężczyzn i 85-115 ml/min u kobiet. W praktyce klinicznej najczęściej stosuje się szacunkowy wskaźnik filtracji kłębuszkowej (eGFR), który obliczany jest na podstawie stężenia kreatyniny w surowicy, wieku i płci pacjenta.¹⁰¹¹

Wartość eGFR poniżej 60 ml/min/1,73 m² utrzymująca się przez co najmniej 3 miesiące może wskazywać na PChN, nawet przy braku innych markerów uszkodzenia nerek. Warto zaznaczyć, że eGFR poniżej 15 ml/min/1,73 m² może sugerować niewydolność nerek wymagającą leczenia nerkozastępczego.¹²¹³

Do obliczania eGFR najczęściej stosuje się wzór CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration). Wzór ten wykorzystuje pomiary stężenia kreatyniny w surowicy, wiek pacjenta (≥ 18 lat) i płeć; obecnie nie uwzględnia się już rasy pacjenta.¹⁰

Ocena albuminurii

Drugim kluczowym badaniem jest ocena albuminurii, najczęściej za pomocą wskaźnika albumina/kreatynina w moczu (uACR – urine albumin-creatinine ratio). Prawidłowa nerka nie pozwala na przechodzenie albuminy do moczu, natomiast uszkodzona nerka przepuszcza pewną ilość albuminy do moczu.⁸³

Wynik uACR wynoszący ≥ 30 mg/g może wskazywać na uszkodzenie nerek. Przedział 30-300 mg/g był wcześniej określany jako „mikroalbuminuria”, a > 300 mg/g jako „makroalbuminuria”. Obecnie rekomenduje się unikanie tych terminów i stosowanie jednolitego określenia „albuminuria” z odpowiednim określeniem wartości.¹⁰⁹

Warto podkreślić, że badanie uACR jest preferowaną metodą oceny albuminurii, a testy paskowe (dipstick) nie są zalecane do pomiaru albuminy ze względu na ich mniejszą czułość.¹⁴

Znaczenie łączonej oceny eGFR i albuminurii

Zgodnie z wytycznymi KDIGO (Kidney Disease: Improving Global Outcomes), ocena eGFR i albuminurii powinna być przeprowadzana łącznie, a nie oddzielnie, w celu poprawy dokładności prognostycznej w ocenie PChN. Warto zwrócić uwagę, że:¹⁵⁹

eGFR może być prawidłowy, podczas gdy uACR jest znacznie podwyższony
uACR może być prawidłowy, podczas gdy eGFR jest znacznie obniżony

Obie wartości razem tworzą tzw. „Profil Nerkowy” (Kidney Profile) zalecany przez National Kidney Foundation do diagnozowania i zarządzania PChN u pacjentów z grupy ryzyka.¹⁶

Dodatkowe badania diagnostyczne

Badania biochemiczne

Oprócz podstawowych badań, w diagnostyce PChN stosuje się również:¹⁷¹⁸

Mocznik (BUN) – podwyższony poziom może wskazywać na upośledzenie funkcji nerek
Elektrolity – dysfunkcja nerek powoduje zaburzenia elektrolitowe, szczególnie potasu, fosforu i wapnia
Równowaga kwasowo-zasadowa – zwykle zaburzona w PChN
Cystatyna C – alternatywny marker funkcji nerek, przydatny szczególnie gdy pomiary oparte na kreatyninie mogą być niedokładne (np. u osób z ekstremalnymi wartościami masy mięśniowej)
Fosforany, 25-hydroksywitamina D, fosfataza alkaliczna i intact PTH – do oceny choroby kości związanej z nerkami
Profil lipidowy – ze względu na zwiększone ryzyko chorób sercowo-naczyniowych u pacjentów z PChN
Albumina w surowicy – pacjenci mogą mieć hipoalbuminemię w wyniku utraty białka z moczem lub niedożywienia

Badania obrazowe

Badania obrazowe odgrywają ważną rolę w diagnostyce PChN, pomagając określić przyczynę choroby i ocenić strukturę nerek:¹⁹²⁰²¹

Ultrasonografia nerek – podstawowe badanie obrazowe w PChN, pozwalające ocenić wielkość i kształt nerek, echogeniczność kory nerkowej oraz wykryć potencjalne nieprawidłowości strukturalne. Mniejsze nerki sugerują, że choroba nerek jest przewlekła.
Tomografia komputerowa (CT) – dostarcza bardziej szczegółowych informacji o strukturze nerek
Rezonans magnetyczny (MRI) – pomocny w ocenie naczyń nerkowych i innych szczegółowych aspektów anatomii nerek
Zaawansowane techniki ultrasonograficzne – nowsze metody, jak ultrasonografia superrozdzielcza czy ultrasonografia z kontrastem (CEUS), mogą umożliwić ocenę mikrokrążenia nerkowego i wczesnych zmian związanych z włóknieniem nerek

Biopsja nerki

Biopsja nerki polega na pobraniu małej próbki tkanki nerkowej do badania pod mikroskopem. Jest to inwazyjne badanie wykonywane zwykle pod kontrolą USG, z miejscowym znieczuleniem. Wskazania do biopsji nerki obejmują:²²¹⁵²³

Niejasną przyczynę choroby nerek pomimo przeprowadzenia innych badań
Podejrzenie kłębuszkowego zapalenia nerek lub śródmiąższowego zapalenia nerek
Białkomocz zbliżający się do zakresu zespołu nerczycowego
Gwałtowne pogarszanie się funkcji nerek
Potrzebę określenia rokowania, np. poprzez ocenę stopnia przewlekłego uszkodzenia tkanki

Klasyfikacja PChN na podstawie badań diagnostycznych

Na podstawie wyników badań diagnostycznych PChN klasyfikuje się według stadiów zaawansowania, co pozwala określić rokowanie, plan oceny i leczenia. Klasyfikacja obejmuje kombinację przyczyny (C), eGFR (G) i albuminurii (A), tworzących akronim CGA.¹⁵¹²

Stadia PChN według eGFR (G)

Choroba nerki dzieli się na 5 stadiów na podstawie wartości eGFR:²⁴²⁵

Stadium 1 (G1): eGFR ≥ 90 ml/min/1,73 m² z innymi oznakami uszkodzenia nerek
Stadium 2 (G2): eGFR 60-89 ml/min/1,73 m² z oznakami uszkodzenia nerek
Stadium 3a (G3a): eGFR 45-59 ml/min/1,73 m²
Stadium 3b (G3b): eGFR 30-44 ml/min/1,73 m²
Stadium 4 (G4): eGFR 15-29 ml/min/1,73 m²
Stadium 5 (G5): eGFR < 15 ml/min/1,73 m² lub dializoterapia

Kategorie albuminurii (A)

Albuminuria jest klasyfikowana w trzech kategoriach:¹⁶

A1: < 30 mg/g – prawidłowa do nieznacznie podwyższonej
A2: 30-300 mg/g – umiarkowanie podwyższona
A3: > 300 mg/g – znacznie podwyższona

Wyższe stadium eGFR i kategoria albuminurii wskazują na bardziej zaawansowaną chorobę nerek. KDIGO stworzyło tzw. „mapę cieplną” (heat map) dla klinicystów, umożliwiającą porównanie eGFR i uACR w celu diagnozy i określenia stadium PChN.¹⁴

Diagnostyka różnicowa

Ważnym elementem diagnostyki PChN jest odróżnienie jej od ostrego uszkodzenia nerek (AKI), które jest potencjalnie odwracalne. Jedną z wskazówek diagnostycznych, która pomaga odróżnić PChN od AKI, jest stopniowy wzrost stężenia kreatyniny w surowicy (przez kilka miesięcy lub lat) w przeciwieństwie do nagłego wzrostu (kilka dni do tygodni).¹⁹

W przypadku nowego, nieoczekiwanego stwierdzenia obniżonego eGFR, badanie należy powtórzyć, aby wykluczyć przyczyny ostrego pogorszenia eGFR (np. ostre uszkodzenie nerek lub rozpoczęcie terapii inhibitorami ACE lub ARB).²⁶

Ocena ryzyka progresji PChN

Dla oceny ryzyka progresji PChN stosuje się różne narzędzia, w tym:²⁷²⁸

Równanie ryzyka niewydolności nerek (KFRE) – równanie zaprojektowane do oszacowania prawdopodobieństwa konieczności dializoterapii w ciągu 2 lub 5 lat
Określenie nachylenia krzywej eGFR – tempo utraty funkcji nerek w czasie, ważny parametr prognostyczny w PChN

Wskazania do konsultacji nefrologicznej

Według wytycznych KDIGO, konsultacja nefrologiczna zalecana jest dla pacjentów z:¹⁵¹¹

GFR < 30 ml/min/1,73 m²
Konsekwentne stwierdzenie znacznej albuminurii
Progresja PChN
Niejasną przyczyną choroby nerek
Trudnościami w kontroli nadciśnienia lub innych powikłań PChN

Znaczenie wczesnej diagnostyki

Wczesna diagnostyka PChN jest kluczowa dla:²⁹³⁰

Spowolnienia lub zatrzymania progresji choroby
Zmniejszenia ryzyka powikłań sercowo-naczyniowych
Poprawy jakości życia pacjentów
Uniknięcia lub opóźnienia konieczności leczenia nerkozastępczego
Zmniejszenia kosztów opieki zdrowotnej

Wczesne wykrycie PChN umożliwia modyfikację stylu życia i wdrożenie odpowiedniego leczenia, które może spowolnić postęp choroby. Regularne badania kontrolne są niezbędne dla określenia tempa progresji choroby u konkretnego pacjenta.³¹

Wyzwania w diagnostyce PChN

Mimo dostępności stosunkowo prostych badań diagnostycznych, PChN pozostaje często nierozpoznana do czasu znacznego uszkodzenia nerek. Głównymi wyzwaniami są:³²³³

Bezobjawowy przebieg wczesnych stadiów choroby
Niskie wskaźniki wykonywania badania moczu, co stanowi barierę dla wczesnej diagnostyki
Obawy klinicystów dotyczące nadmiernej diagnostyki i medykalizacji naturalnego procesu starzenia
Złożoność wytycznych klinicznych
Zarządzanie PChN w kontekście chorób współistniejących
Niewystarczająca edukacja medyczna w zakresie PChN

Nowoczesne podejścia w diagnostyce PChN

Nowoczesne podejścia w diagnostyce PChN obejmują:³⁴³⁵

Algorytmy uczenia maszynowego – mogą pomóc w predykcji PChN i jej stadiów na podstawie danych laboratoryjnych oraz innych parametrów
Zaawansowane metody obrazowania – takie jak ultrasonografia superrozdzielcza, które mogą nieinwazyjnie badać zmiany mikronaczyniowe we wczesnych stadiach włóknienia
Analizy oparte na sztucznej inteligencji – mogą ułatwić odkrywanie nieinwazyjnych biomarkerów obrazowych do oceny funkcji nerek

Podsumowanie

Diagnostyka PChN opiera się na dwóch kluczowych badaniach: ocenie eGFR i albuminurii, które powinny być wykonywane łącznie. Rozpoznanie PChN jest możliwe przy stwierdzeniu obniżonego eGFR (< 60 ml/min/1,73 m²) i/lub albuminurii (uACR ≥ 30 mg/g) utrzymujących się przez co najmniej 3 miesiące. Wczesna diagnostyka i identyfikacja czynników ryzyka są kluczowe dla poprawy rokowania pacjentów z PChN. Regularne monitorowanie parametrów nerkowych u osób z grup ryzyka może przyczynić się do wcześniejszego wykrycia choroby i zapobiegania jej powikłaniom.¹⁶²⁹

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Materiały źródłowe

#1 Chronic Kidney Disease: Prevention, Diagnosis, and Treatment | AAFP
https://www.aafp.org/pubs/afp/issues/2023/1200/chronic-kidney-disease.html
Chronic kidney disease (CKD) affects approximately 15% of the U.S. population, and many people are unaware of their diagnosis. Screening may be considered for patients with cardiovascular disease, diabetes mellitus, hypertension, age 60 years and older, family history of kidney disease, previous acute kidney injury, or preeclampsia. Diagnosis and staging of CKD are based on estimated glomerular filtration rate (eGFR), excessive urinary albumin excretion, or evidence of kidney parenchymal damage lasting more than three months. eGFR should be determined using the CKD-EPI creatinine equation without the race variable. Risk calculators are available to estimate the risk of progression to end-stage renal disease. When possible, serum cystatin C should be measured to confirm eGFR in patients with CKD. […] Interdisciplinary management of patients with CKD is important for reducing morbidity and mortality, and patients at high risk of progression to end-stage renal disease should be referred to a nephrologist.
#2 Chronic Kidney Disease in the United States, 2023 | Chronic Kidney Disease | CDC
https://www.cdc.gov/kidney-disease/php/data-research/index.html
With chronic kidney disease (CKD), kidneys become damaged and over time may not clean the blood as well as healthy kidneys. […] As many as 9 in 10 adults with CKD do not know they have it. […] About 1 in 3 adults with severe CKD do not know they have CKD. […] CKD is more common in people aged 65 years or older (34%) than in people aged 45-64 years (12%) or 18-44 years (6%). […] CKD is slightly more common in women (14%) than men (12%). […] CKD is more common in non-Hispanic Black adults (20%) than in non-Hispanic Asian adults (14%) or non-Hispanic White adults (12%). […] About 14% of Hispanic adults have CKD. […] The Chronic Kidney Disease (CKD) Initiative provides public health strategies for promoting kidney health.
#3 Testing for Chronic Kidney Disease | Chronic Kidney Disease | CDC
https://www.cdc.gov/kidney-disease/testing/index.html
If you have diabetes or high blood pressure, you have a higher risk for chronic kidney disease (CKD). […] Having your kidneys checked regularly gives you the best chance for finding and treating CKD early. […] If you find and treat kidney disease early, you may be able to manage CKD and prevent other health complications. But the only way to know how well your kidneys are working is to get tested. […] One of the earliest signs of kidney disease is when protein leaks into your urine (proteinuria). Urine testing can check for this. […] A urine albumin test result of 30 or above may mean kidney disease. […] If you have kidney disease, your albumin level in your urine helps your doctor determine the best treatment option. […] A serum creatinine blood test measures the amount of creatinine in your blood. If your kidneys aren’t working well, your creatinine level goes up.
#4 Chronic Kidney Disease Diagnosis and Management
https://pmc.ncbi.nlm.nih.gov/articles/PMC7015670/
Chronic kidney disease (CKD) is the 16th leading cause of years of life lost worldwide. Appropriate screening, diagnosis, and management by primary care clinicians are necessary to prevent adverse CKD-associated outcomes, including cardiovascular disease, end-stage kidney disease, and death. […] Defined as a persistent abnormality in kidney structure or function (eg, glomerular filtration rate [GFR] 60 mL/min/1.73 m2 or albuminuria 30 mg per 24 hours) for more than 3 months, CKD affects 8% to 16% of the population worldwide. […] Among individuals diagnosed as having CKD, staging and new risk assessment tools that incorporate GFR and albuminuria can help guide treatment, monitoring, and referral strategies. Optimal management of CKD includes cardiovascular risk reduction (eg, statins and blood pressure management), treatment of albuminuria (eg, angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers), avoidance of potential nephrotoxins (eg, nonsteroidal anti-inflammatory drugs), and adjustments to drug dosing (eg, many antibiotics and oral hypoglycemic agents). […] Diagnosis, staging, and appropriate referral of CKD by primary care clinicians are important in reducing the burden of CKD worldwide.
#5 Laboratory Testing for Chronic Kidney Disease Diagnosis and Management | Test Guide | Quest Diagnostics Laboratory Testing for Chronic Kidney Disease Diagnosis and ManagementLaboratory Testing for Chronic Kidney Disease Diagnosis and Management
https://testdirectory.questdiagnostics.com/test/test-guides/TG_CKD/laboratory-testing-for-chronic-kidney-disease-diagnosis-and-management
Laboratory Testing for Chronic Kidney Disease Diagnosis and Management […] This test guide provides an overview of tests used detect chronic kidney disease (CKD) in adults, as well as monitor CKD progression, comorbidities, complications, and response to therapy. […] Chronic kidney disease (CKD) is defined as abnormalities of kidney structure or function, present >3 months, with implications for health.1 Diagnostic criteria include a decreased glomerular filtration rate (GFR) or presence of 1 or more other markers of kidney damage.1 Markers of kidney damage include a histologic abnormality, structural abnormality, history of kidney transplantation, abnormal urine sediment, tubular disorderâcaused electrolyte abnormality, or an increased urinary albumin level (albuminuria). […] This Test Guide discusses the use of laboratory tests that may aid in identifying CKD and monitoring and managing disease progression, comorbidities, and complications. The tests discussed include measurement and estimation of GFR as well as markers of kidney damage. A list of applicable tests is provided in the Appendix. The information is provided for informational purposes only and is not intended as medical advice. Test selection and interpretation, diagnosis, and patient management decisions should be based on the physician’s education, clinical expertise, and assessment of the patient.
#6 Chronic Kidney Disease: Detection and Evaluation | AAFP
https://www.aafp.org/pubs/afp/issues/2011/1115/p1138.html
Chronic kidney disease affects an estimated 27 million adults in the United States, and is associated with significantly increased risk of cardiovascular disease and stroke. Patients should be assessed annually to determine whether they are at increased risk of developing chronic kidney disease based on clinical and sociodemographic factors. […] Serum creatinine levels can be used to estimate the glomerular filtration rate, and spot urine testing can detect proteinuria. After the diagnosis of chronic kidney disease is made, staging based on estimated glomerular filtration rate determines prognosis, evaluation, and management. […] CKD is defined by the presence of structural or functional abnormalities of the kidney with or without an accompanying reduction in GFR. […] Annual CKD screening is recommended by the American Diabetes Association, by the National Kidney Foundation for patients at risk, by the Joint National Committee on Hypertension for patients with diabetes and hypertension, and by the American Heart Association for patients with cardiovascular disease.
#7 Early Identification and Screening for Chronic Kidney Disease | CKD Toolkits | WCHQ | Health Reporting
https://www.wchq.org/ckd-screening-diagnosis/toolkit
Screen early and often when a patient has type 2 diabetes and/or hypertension. […] Screen with both uACR and eGFR. […] Screen when patients have risk factors for CKD: type 2 diabetes, hypertension, age 60, obesity, family history of kidney disease, history of acute kidney injury (AKI), history of tobacco use, social drivers (i.e.: poverty and/or food insecurity). […] Identifying CKD in early stages of illness progression is important because the risk renal failure and cardiovascular complications is reduced. […] The American Diabetes Association recommends screening all patients with diabetes for CKD and the National Kidney Foundation recommends screening for CKD in all patients with risk factors including diabetes, hypertension, family history of kidney disease, age 60 or older, Race/U.S. ethnic minority status status (i.e.: AfricanAmericans, Hispanics, Asians/Pacific Islander, Native American).
#8 Chronic Kidney Disease Tests & Diagnosis – NIDDK
https://www.niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd/tests-diagnosis
Early kidney disease usually doesnt have any symptoms. Testing is the only way to know how well your kidneys are working. […] To check for kidney disease, health care providers use a blood test that checks how well your kidneys are filtering your blood, called GFR. GFR stands for glomerular filtration rate. […] If you have kidney disease, your health care provider will use the same two tests to help monitor your kidney disease and make sure your treatment plan is working. […] Your health care provider will use a blood test to check your kidney function. The results of the test mean the following: a GFR of less than 60 may mean you have kidney disease. […] If you are at risk for kidney disease, your provider may check your urine for albumin. […] A healthy kidney doesnt let albumin pass into the urine. A damaged kidney lets some albumin pass into the urine. […] A urine albumin result of more than 30 mg/g may be a sign of kidney disease. […] If you have kidney disease, measuring the albumin in your urine helps your provider know which treatment is best for you.
#9 Chronic kidney disease (CKD) – Symptoms, causes, treatment | National Kidney Foundation
https://www.kidney.org/kidney-topics/chronic-kidney-disease-ckd
Chronic kidney disease (CKD) is when the kidneys have become damaged over time (for at least 3 months) and have a hard time doing all their important jobs. CKD also increases the risk of other health problems like heart disease and stroke. […] Checking for CKD is easy with two simple tests: a blood test known as the estimated glomerular filtration rate (eGFR) and a urine test known as the urine albumin-creatinine ratio (uACR). […] Both tests are needed to have a clear picture of your kidney health. Having an eGFR under 60 and/or a uACR over 30 for three months or more is a sign you may have kidney disease. […] The eGFR is an estimate of how well your kidneys are removing waste products from the blood. […] The uACR measures the amount of two different substances in your urine albumin (protein) and creatinine. […] Your uACR number is used to test for albuminuria – a significant risk factor for complications.
#10 Laboratory Testing for Chronic Kidney Disease Diagnosis and Management | Test Guide | Quest Diagnostics Laboratory Testing for Chronic Kidney Disease Diagnosis and ManagementLaboratory Testing for Chronic Kidney Disease Diagnosis and Management
https://testdirectory.questdiagnostics.com/test/test-guides/TG_CKD/laboratory-testing-for-chronic-kidney-disease-diagnosis-and-management
Given that direct measurement of GFR may be problematic, eGFR, using either creatinine- or cystatin Câbased measurements, is most commonly used to diagnose CKD in clinical practice. […] GFR is typically estimated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.4 The CKD-EPI equation uses serum-creatinine measurements, patient age (â¥18 years old), and patient sex; patient race (African versus non-African ancestry) is no longer considered.4 Creatinine-based eGFR is recommended by the Kidney Disease Improving Global Outcomes (KDIGO) 2012 international guideline for initial assessment of GFR.1 […] Cystatin Câbased eGFR provides an alternative when creatinine-based estimates are not appropriate. […] A urine albumin-creatinine ratio result of â¥30 mg/g (albumin excretion rate â¥30 mg/24 hours) is evidence of albuminuria (30 to 300 mg/g was formerly referred to as âmicroalbuminuriaâ and >300 mg/g as âmacroalbuminuriaâ).1
#11 Chronic Kidney Disease: Detection and Evaluation | AAFP
https://www.aafp.org/pubs/afp/issues/2011/1115/p1138.html
CKD is typically detected by measuring serum creatinine levels to calculate the GFR and by measuring the urinary albumin/creatinine ratio to detect proteinuria. […] The GFR is the best measure of kidney function. Normal GFR varies by age, sex, and body size. […] The serum creatinine level is an insensitive marker of GFR early in the course of CKD. […] Nephrology consultation is indicated when the estimated GFR is less than 30 mL per minute per 1.73 m2.
#12
https://www.nhs.uk/conditions/kidney-disease/diagnosis/
Chronic kidney disease (CKD) can be diagnosed with blood and urine tests. […] The main test for kidney disease is a blood test. The test measures the levels of a waste product called creatinine in your blood. […] Healthy kidneys should be able to filter more than 90ml/min. You may have CKD if your rate is lower than this. […] A urine test is also done to check the levels of substances called albumin and creatinine in your urine known as the albumin:creatinine ratio, or ACR. […] Your test results can be used to determine how damaged your kidneys are, known as the stage of CKD. […] Your eGFR results is given as a stage from 1 of 5: stage 1 (G1) a normal eGFR above 90ml/min, but other tests have detected signs of kidney damage. […] For both eGFR and ACR, a higher stage indicates more severe kidney disease.
#13 Testing for Chronic Kidney Disease | Chronic Kidney Disease | CDC
https://www.cdc.gov/kidney-disease/testing/index.html
If your GFR is less than 60, it may mean you have kidney disease. […] If your GFR is less than 15, it may mean your kidneys are failing. […] If your BUN level is higher than normal, this may be a sign that your kidneys aren’t working well. […] Kidney testing helps you and your doctor determine the best treatment plan for you.
#14 Early Identification and Screening for Chronic Kidney Disease | CKD Toolkits | WCHQ | Health Reporting
https://www.wchq.org/ckd-screening-diagnosis/toolkit
Focusing on screening patients with risk factors annually, or more frequently depending on test results, to identify kidney disease early allows for the best possible prognosis and ability to intervene in the course of this chronic illness. […] uACR, the recommended test for albuminuria, gives you the most information and is more sensitive. […] Urine dipsticks are not recommended for measuring albumin. […] uACR measures the protein and creatinine in your urine. […] Rising uACR ( 30 mg/g) detection occurs about 10 years before detectable decline in eGFR; uACR can be the best early indicator of kidney disease in patients with diabetes. […] eGFR, a blood test, is the optimal way to measure kidney function and understand how the kidneys are functioning and cleaning toxins from the blood. […] Use eGFR and uACR to diagnose. […] eGFR can be normal where uACR is severely increased. […] uACR can be normal where eGFR is severely decreased. […] Kidney Disease Improving Global Outcomes (KDIGO) has created a heat map for clinicians to compare eGFR and uACR to diagnose and stage CKD.
#15 Chronic Kidney Disease (CKD): Practice Essentials, Pathophysiology, Etiology
https://emedicine.medscape.com/article/238798-overview
The guidelines define CKD as either kidney damage or a decreased glomerular filtration rate (GFR) of less than 60 mL/min/1.73 m2 for at least 3 months. […] KDIGO advises that GFR and albuminuria levels be used together, rather than separately, to improve prognostic accuracy in the assessment of CKD. More specifically, the guidelines recommended the inclusion of estimated GFR and albuminuria levels when evaluating risks for overall mortality, cardiovascular disease, end-stage kidney disease (ESKD), acute kidney injury, and the progression of CKD. […] KDIGO guidelines recommend referral to a kidney specialist for patients with any of the following: GFR 30 mL/min/1.73 m2, a consistent finding of significant albuminuria, or progression of CKD. […] Early diagnosis and treatment of the underlying cause and/or institution of secondary preventive measures is imperative in patients with CKD. These may slow, or possibly halt, progression of the disease. The medical care of patients with CKD should focus on delaying or halting the progression of CKD, diagnosing and treating the pathologic manifestations of CKD, and timely planning for long-term renal replacement therapy. […] Percutaneous kidney biopsy is generally indicated when kidney impairment and/or proteinuria approaching the nephrotic range are present and the diagnosis is unclear after appropriate workup.
#16 Laboratory Testing for Chronic Kidney Disease Diagnosis and Management | Test Guide | Quest Diagnostics Laboratory Testing for Chronic Kidney Disease Diagnosis and ManagementLaboratory Testing for Chronic Kidney Disease Diagnosis and Management
https://testdirectory.questdiagnostics.com/test/test-guides/TG_CKD/laboratory-testing-for-chronic-kidney-disease-diagnosis-and-management
A GFR <60 mL/min/1.73 m2 for >3 months and/or urine albumin-creatinine ratio â¥30 mg/g for >3 months define CKD.1 Combined, these test results provide a âKidney Profileâ recommended by the National Kidney Foundation for diagnosing and managing CKD in at-risk patients (Figure 1).1,10-12 The results are important independent risk predictors of major adverse cardiovascular events (myocardial infarction or stroke).13 […] Quest Diagnostics offers many tests and panels for diagnosis and management of CKD. Test offerings range from health screenings for abnormal eGFR, proteinuria, and/or albuminuria, to tests for management of CKD and its comorbidities and complications. […] This test is used to assess estimated glomerular filtration rate (eGFR) for the purpose of detecting, monitoring therapy for, and monitoring progression of chronic kidney disease in adults. Cystatin C-based eGFR is less influenced by muscle mass than is creatinine-based eGFR, and therefore more appropriate for patients in whom creatinine-based results may lead to an incorrect diagnosis. […] This test is used to detect chronic kidney disease (CKD), as well as monitor CKD therapy and/or progression in adults. […] This test is used to detect chronic kidney disease (CKD) in adults, as well as monitor CKD progression and response to therapy.
#17 Chronic Kidney Disease (CKD) Workup: Approach Considerations, Kidney Function Formulas, Renal Ultrasonography
https://emedicine.medscape.com/article/238798-workup
The workup for chronic kidney disease (CKD) typically includes a complete blood count (CBC), basic metabolic panel, and urinalysis, with calculation of kidney function. Normochromic normocytic anemia is commonly seen in CKD. Other underlying causes of anemia should be ruled out. […] The blood urea nitrogen (BUN) and serum creatinine levels will be elevated in patients with CKD. Hyperkalemia or low bicarbonate levels may be present. Serum albumin levels may also be measured, as patients may have hypoalbuminemia as a result of urinary protein loss or malnutrition. A lipid profile should be performed in all patients with CKD because of their risk of cardiovascular disease. […] Serum phosphate, 25-hydroxyvitamin D, alkaline phosphatase, and intact parathyroid hormone (PTH) levels are obtained to look for evidence of renal bone disease. Renal ultrasonography and other imaging studies may be indicated.
#18 Chronic Kidney Disease Symptoms, Stages, Causes, Diagnosis
https://www.emedicinehealth.com/chronic_kidney_disease/article_em.htm
Glomerular filtration rate (GFR): The GFR is a standard means of expressing overall kidney function. […] As kidney disease progresses, GFR falls. […] The normal GFR is about 100 to 140 mL/min in men and 85 to 115 mL/min in women. […] Patients are divided into five stages of chronic kidney disease based on their GFR. […] Blood urea nitrogen and serum creatinine are the most commonly used blood tests to screen for and monitor renal disease. […] The level of these substances rises in the blood as kidney function worsens. […] Estimated GFR (eGFR): The laboratory or physician may calculate an estimated GFR using the information from a patient’s blood work. […] It is important to be aware of one’s estimated GFR and stage of chronic kidney disease. […] The physician uses the patient’s stage of kidney disease to recommend additional testing and provide suggestions on management.
#19 Chronic kidney disease – Wikipedia
https://en.wikipedia.org/wiki/Chronic_kidney_disease
Kidney ultrasonography is useful for diagnostic and prognostic purposes in chronic kidney disease. Whether the underlying pathologic change is glomerular sclerosis, tubular atrophy, interstitial fibrosis, or inflammation, the result is often increased echogenicity of the cortex. […] Diagnosis of CKD is largely based on history, examination, and urine dipstick combined with the measurement of the serum creatinine level. Differentiating CKD from acute kidney injury (AKI) is important because AKI can be reversible. One diagnostic clue that helps differentiate CKD from AKI is a gradual rise in serum creatinine (over several months or years) as opposed to a sudden increase in the serum creatinine (several days to weeks).
#20 What Is Chronic Kidney Disease (CKD)? Symptoms, Causes, Diagnosis, Treatment, and Prevention
https://www.everydayhealth.com/urinary-conditions/chronic-kidney-disease/guide/
If blood and urine tests show that you have CKD, your doctor may order any of the following imaging tests to look at the structure and size of your kidneys: Ultrasound, Magnetic resonance imaging (MRI), Computerized tomography (CT). […] Taking a small sample of kidney tissue can help determine what’s going wrong in your kidneys. To do this, your doctor will typically numb the area and insert a long, thin needle through your skin into one of your kidneys. The tissue sample will be sent to a lab for analysis.
#21
#22 Chronic kidney disease – Diagnosis and treatment – Mayo Clinic
https://www.mayoclinic.org/diseases-conditions/chronic-kidney-disease/diagnosis-treatment/drc-20354527
Nephrologist Andrew Bentall, M.D., answers the most frequently asked questions about kidney disease. […] As a first step toward diagnosis of kidney disease, your doctor discusses your personal and family history with you. […] For kidney disease diagnosis, you might also need certain tests and procedures to determine how severe your kidney disease is (stage). Tests might include: […] Kidney biopsy is often done with local anesthesia using a long, thin needle that’s inserted through your skin and into your kidney. The biopsy sample is sent to a lab for testing to help determine what’s causing your kidney problem. […] Your doctor will work to slow or control the cause of your kidney disease. Treatment options vary depending on the cause. […] If your kidneys can’t keep up with waste and fluid clearance on their own and you develop complete or near-complete kidney failure, you have end-stage kidney disease. At that point, you need dialysis or a kidney transplant. […] Your doctor is likely to ask you questions, such as: […] Have you been diagnosed or treated for high blood pressure? […] Have you noticed changes in your urinary habits?
#23 Assessment of patients with a new diagnosis of CKD | UK Kidney Association
https://www.ukkidney.org/health-professionals/information-resources/uk-eckd-guide/assessment-patients-new-diagnosis-ckd
Blood pressure examination is essential in all patients with kidney disease, it is not only important to help identify the aetiology but is a critical component of patient management. […] Good blood pressure control can reduce the risk of CKD progression and cardiovascular complications. […] Any acute decline in eGFR should be repeated within 14 days to exclude an acute kidney injury (AKI) which requires urgent assessment. […] Urine ACR is the first line investigation for proteinuria. […] Haematuria seen in association with proteinuria may be suggestive of an underlying glomerulonephritis. […] Indications include unexplained renal impairment, especially when disease is progressive, to try and identify potentially treatable causes. […] For patients who present with suspected glomerular disease or interstitial nephritis, a biopsy is important to confirm the diagnosis and inform clinical decision making. […] The kidney biopsy can also play an important role in prognostication e.g. by quantification of the extent of chronic tissue damage, when risks associated with some treatment may outweigh potential benefit.
#24 Stages of kidney disease
https://www.kidneyfund.org/all-about-kidneys/stages-kidney-disease
CKD is broken into five stages or categories based on your eGFR value. The five stages of CKD refer to how well your kidneys are working. Kidney disease can get worse in time. In the early stages (Stages 1-3), your kidneys are still able to filter waste out of your blood. In the later stages (Stages 4-5), your kidneys must work harder to filter your blood and may stop working altogether. […] The goal at each stage of CKD is to take steps to slow down the damage to your kidneys and keep your kidneys working as long as possible. […] Stage 4 CKD means you have an eGFR between 15 and 29 and moderate to severe damage to your kidneys. Your kidneys do not work as well as they should to filter waste out of your blood. This waste can build up in your body and cause other health problems, such as high blood pressure, bone disease, and heart disease. You will likely have symptoms such as swelling of your hands and feet and pain in your lower back.
#25 Stages of Chronic Kidney Disease (CKD) | National Kidney Foundation
https://www.kidney.org/kidney-topics/stages-chronic-kidney-disease-ckd
Chronic kidney disease (CKD) is when the kidneys have become damaged over time (for at least 3 months) and have a hard time doing all their important jobs. CKD is evaluated using two simple tests a blood test known as the estimated glomerular filtration rate (eGFR) and a urine test known as the urine albumin-creatinine ratio (uACR). […] Having an eGFR less than 60 and/or a uACR higher than 30 for three months or more is a sign you may have kidney disease. […] Early detection is important CKD often begins without causing any obvious symptoms. Knowing the risk factors can help you know your level of risk and if you should get checked for CKD. […] Having kidney failure means that 85% to 90% of your kidney function is gone and your kidneys don’t work well enough to keep you alive. There is no cure for kidney failure, but it is possible to live a long and full life with treatment.
#26 CKD Pathway – The Pathway
https://www.ckdpathway.ca/
Testing for CKD should not be universal, but should be targeted for individuals at increased risk of developing CKD: […] eGFR 60mL/min/1.73m2 for 3 months is diagnostic for CKD. […] Excess amounts of protein in urine are a marker of kidney damage and increase kidney disease and CVD risk. […] A random urine ACR is preferred to detect proteinuria (ideally first morning void). […] In patients with a new finding of reduced eGFR, retest eGFR to exclude causes of acute deterioration of eGFR (e.g. acute kidney injury, or initiation of ACEi or ARB therapy). […] In patients with a previous finding of an abnormal eGFR and ACR in the past 6 months, you do not have re-test.
#27 Chronic Kidney Disease – Identification, Evaluation and Management of Adult Patients – Province of British Columbia
https://www2.gov.bc.ca/gov/content/health/practitioner-professional-resources/bc-guidelines/chronic-kidney-disease
Renal ultrasound should be undertaken to assess structural abnormalities and aid in diagnosis. […] Risk staging of kidney disease is important for care planning and patient management. Risk is determined based on Cause, eGFR, and uACR, or CGA. […] The Kidney Failure Risk Equation (KFRE) is an equation designed to estimate probability of requiring dialysis within 2 or 5 years.
#28 Advanced ultrasound methods to improve chronic kidney disease diagnosis | npj Imaging
https://www.nature.com/articles/s44303-024-00023-5
CKD is defined as either known kidney disease independent of kidney function (after biopsy, or inherited disease such as Alport syndrome) or impaired kidney function for more than three months independent of a known cause. […] An important prognostic parameter in CKD is the eGFR slope, the rate of loss of kidney function over time. […] Diagnosing CKD non-invasively in early stages would enable preservation of higher kidney function and thereby result in lower cardiovascular disease burden and mortality. […] Recent advances in ultrasound technology, data processing and analysis seem to make it possible to predict organ microcirculatory function. […] Non-contrast-enhanced ultrasound techniques facilitate the indirect and direct assessment of renal microvascular status, either by calculating RI or by imaging slow flow in small vessels.
#29 Chronic kidney disease: early detection and management
https://www.nps.org.au/news/ckd-integrating-kidney-health-into-patient-care
The initial detection of probable CKD is made with a Kidney Health Check. […] It’s recommended to perform the eGFR and ACR tests according to a diagnostic algorithm to confirm a diagnosis of CKD. […] CKD diagnosis is confirmed with: reduced eGFR ( 60 mL/min/1.73 m2) for 3 months and/or elevated ACR (males 2.5 mg/mmol, females 3.5 mg/mmol) for 3 months. […] Targeted screening and detection of probable CKD can enable GPs to confirm a diagnosis and assess the level of risk of cardiovascular disease and progression of CKD. This in turn guides management. Early detection and subsequent timely management can slow down or even prevent deterioration in kidney function and help to improve cardiovascular outcomes.
#30 Chronic kidney disease (CKD) | Kidney Care UK
https://kidneycareuk.org/kidney-disease-information/kidney-conditions/patient-info-ckd-chronic-kidney-disease/
A diagnosis of chronic kidney disease (CKD) means that your kidneys do not work as well as they should. […] CKD is usually diagnosed by blood and urine tests. […] CKD is divided into five stages based on your glomerular filtration rate (GFR). […] Getting an accurate measurement of your GFR is difficult, so your blood test results normally give an estimated filtration rate, or eGFR. […] Most people with CKD stages one to three manage the condition themselves with support from their GP and do not need any specialist care from kidney doctors. […] If your CKD progresses to stage four, you will be referred to a kidney doctor (nephrologist) at a hospital for further treatment. […] Early diagnosis and regular monitoring is therefore very important as lifestyle changes and medical treatment can prevent CKD from getting worse.
#31 Tests for kidney disease
https://www.kidneyfund.org/all-about-kidneys/tests-kidney-disease
Many people with kidney disease don’t know they have it until their kidneys are already damaged because they don’t have any symptoms. This makes early testing important, especially if you’re at increased risk due to factors like diabetes, high blood pressure, or a family history of kidney disease. Early detection and treatment can slow or even stop kidney disease from getting worse. […] Learning about the tests, what they do, and what to expect can help you and your doctor catch kidney disease early when it is most treatable. Doctors can help find the cause of kidney disease through these tests, make a personalized treatment plan, and help you improve your quality of life. […] Blood tests can look for and measure substances (such as antibodies or proteins) that are signs of other health problems that may cause kidney disease, such as lupus.
#32 Chronic kidney disease: detect, diagnose, discloseâa UK primary care perspective of barriers and enablers to effective kidney care | BMC Medicine | Full Text
https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-024-03555-0
Chronic kidney disease (CKD) is a global public health problem with major human and economic consequences. Despite advances in clinical guidelines, classification systems and evidence-based treatments, CKD remains underdiagnosed and undertreated and is predicted to be the fifth leading cause of death globally by 2040. This review aims to identify barriers and enablers to the effective detection, diagnosis, disclosure and management of CKD since the introduction of the Kidney Disease Outcomes Quality Initiative (KDOQI) classification in 2002, advocating for a renewed approach in response to updated Kidney Disease: Improving Global Outcomes (KDIGO) 2024 clinical guidelines. Key enablers of effective CKD care include clinical classification systems (KDIGO), evidence-based treatments, electronic health record tools, financially incentivised care, medical education and policy changes. Barriers to effective CKD care are extensive; key barriers include clinician concerns regarding overdiagnosis, a lack of financially incentivised care in primary care, complex clinical guidelines, managing CKD in the context of multimorbidity, bureaucratic burden in primary care, underutilisation of sodium-glucose co-transporter-2 inhibitor (SGLT2i) medications, insufficient medical education in CKD, and most recently a sustained disruption to routine CKD care during and after the COVID-19 pandemic. Future CKD care in UK primary care must be informed by lessons of the last two decades. Making step change, over incremental improvements in CKD care at scale requires a renewed approach that addresses key barriers to detection, diagnosis, disclosure and management across traditional boundaries of healthcare, social care, and public health. Improved coding accuracy in primary care, increased use of SGLT2i medications, and risk-based care offer promising, cost-effective avenues to improve patient and population-level kidney health.
#33 Improving the outlook for chronic kidney disease
https://www.nature.com/articles/d42473-023-00395-z
Chronic Kidney Disease (CKD), which affects approximately 844 million people worldwide, typically progresses silently for years before it is diagnosed. But by then, in many cases, irreversible damage has already occurred. […] A urine test is needed to diagnose chronic kidney disease when it is in the early stages. […] CKD diagnosis is based on a chronic decline in estimated glomerular filtration rate (eGFR), which is a measure of how well kidneys extract waste from blood. However, in its early stages, CKD cannot be diagnosed by eGFR alone a urine test is required, says Shoichi Maruyama, a professor at the Department of Nephrology, at Nagoya University, in Japan. This test measures the level of protein in the urine, a high level means kidney damage. […] Yet, he says, taking Japan as an example, 90% of stage 3 CKD cases remain undiagnosed.
#34 Chronic kidney disease diagnosis using decision tree algorithms | BMC Nephrology | Full Text
https://bmcnephrol.biomedcentral.com/articles/10.1186/s12882-021-02474-z
Chronic Kidney Disease (CKD), i.e., gradual decrease in the renal function spanning over a duration of several months to years without any major symptoms, is a life-threatening disease. […] Early detection and cure of CKD is extremely desirable as it can lead to the prevention of unwanted consequences. […] The study concluded that it may be used to build an automated system for the detection of severity of CKD. […] CKD is often diagnosed in later stages when dialysis or kidney transplant are the only options left to save the patients life. […] The best way to measure the kidney function or to predict the stages of kidney disease is to monitor the Glomerular Filtration Rate (GFR) on regular basis. […] Machine Learning (ML) has recently played a significant role for the diagnosis of diseases by just analyzing the records of existing patients and training a model to predict the behavior of new patients.
#35 Advanced ultrasound methods to improve chronic kidney disease diagnosis | npj Imaging
https://www.nature.com/articles/s44303-024-00023-5
To increase sensitivity, ultrasound contrast agents have been developed and evolved from free gas bubbles to shell-coated microbubbles in which a polymer or phospholipid shell stabilises the gas core. […] CEUS is superior to conventional Colour Doppler ultrasound in the differentiation of renal infarction and cortical necrosis, and it can characterize kidney lesions, which are indeterminate in CT and MR. […] In conclusion, non-contrast-enhanced ultrasound techniques facilitate the indirect and direct assessment of renal microvascular status, either by calculating RI or by imaging slow flow in small vessels. […] Super-resolution ultrasound imaging of the kidney is evolving and holds a diagnostic potential to study microvascular changes in early stages of fibrosis non-invasively, improving our understanding of disease mechanism and allowing for early diagnosis and timely initiation of progression-delaying therapy. […] AI-based analysis of kidney ultrasound images can facilitate the discovery of non-invasive image-based biomarkers for the assessment of kidney function. […] Ultrasound is already the most widely used non-invasive imaging modality for the assessment of CKD.