Assessment of KDIGO definitions in patients with histopathologic evidence of acute renal disease.
OBJECTIVE
AKI is a clinical syndrome with various causes involving glomerular, interstitial, tubular, and vascular compartments of the kidney. Acute kidney disease (AKD) is a new concept that includes both AKI and the conditions associated with subacute decreases in GFR (AKD/non-AKI). This study aimed to investigate the correlation between AKI/AKD defined by clinical presentation and diffuse histologic criteria for acute abnormalities based on renal biopsy.


METHODS
All 303 patients who were histologically diagnosed as having acute tubular necrosis (ATN), acute tubulointerstitial nephritis, cellular crescentic GN, acute thrombotic microangiopathy, or complex lesions on renal biopsy from January 2009 to December 2011 were enrolled in the study. The 2012 Kidney Disease Improving Global Outcomes AKD/AKI definitions were applied to classify patients as follows: AKI, AKD/non-AKI, non-AKD, or unclassified.


RESULTS
A total of 273 patients (90.1%) met the AKD criteria; 198 patients (65.3%) were classified as having AKI according to serum creatinine (SCr) and urine output criteria. The urine output criteria added 4.3% to the SCr criteria and reclassified 6.7% of the AKI cases into higher stages. Of patients with ATN on pathology, 79.2% met AKI criteria; this was a higher percentage than for those who had other individual pathologic lesions (50%-64%). The major cause of not being defined as having AKI was a slower SCr increase than that required by the definition of AKI (98, 93.3%). Patients with AKI had more severe clinical conditions and worse short-term renal outcome than those in the non-AKI group.


CONCLUSIONS
Diffuse, acute abnormality defined by renal biopsy and AKI defined by clinical presentation are two different entities. Most patients who have diffuse acute histologic findings met the criteria for AKD, whereas only two thirds met the definition of AKI.
Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.
Rong
R
Chu
Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.
Cui
C
Li
Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.
Suxia
S
Wang
Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.
Wanzhong
W
Zou
Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China li.yang@bjmu.edu.cn liugang2003@medmail.com.cn.
Gang
G
Liu
Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China li.yang@bjmu.edu.cn liugang2003@medmail.com.cn.
Li
L
Yang
D058186:Acute Kidney Injury / Q000097:blood / Q000145:classification / Q000473:pathology* / Q000503:physiopathology; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D002681:China; D003404:Creatinine / Q000097:blood; D005260:Female; D005921:Glomerulonephritis / Q000145:classification / Q000473:pathology; D006801:Humans; D007668:Kidney / Q000473:pathology* / Q000503:physiopathology; D007683:Kidney Tubular Necrosis, Acute / Q000145:classification / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000145:classification / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D009626:Terminology as Topic; D057049:Thrombotic Microangiopathies / Q000145:classification / Q000473:pathology; D014554:Urination
D015415:Biomarkers; D003404:Creatinine
acute kidney disease; acute kidney inury; diagnosis; pathology