The Spectrum Of Biopsy-proven Kidney Diseases In 2027patients With Acute Kidney Injury

Objective: To analyze the pathological disease spectrum,etiology,and renal recovery of biopsy-proven acute kidney injury(AKI).Methods: Retrospectively collected clinical and pathological data of AKI patients who were Undertaken renal biopsy during the hospitalization at the National Kidney Disease Clinical Center of Jinling Hospital from January 2013 to December2018.The patients Histopathology mainly presented as interstitial disease were classified into pure AKI group,and those with re-existing glomerular disease were classified as ACKD group.The pathological disease spectrum and renal recovery of the two groups were compared.Results:(1)The study included 2027 AKI patients who had undertaken renal biopsy,which accounting for 6.8% of the total renal biopsy cases and 31.7% of the total hospitalized AKI cases during the same period.The majority of AKI patients were male(65.1%),with an average age of 42 ± 16.5 years,pure AKI and ACKD account for 21.6% and 78.4%.Pure AKI mainly presented as AKI-3(74.8%),while CKD mostly presented as AKI-1(53.5%).The proportion of patients undergoing renal replacement therapy in pure AKI group was significantly higher than ACKD group(29.3% vs 11.9%,P <0.001).(2)In pure AKI group,acute interstitial nephritis(AIN)was most common(56.1%),followed by acute tubular necrosis(ATN)(34.6%).The main cause of AIN was due to drugs(84.9%)and antibiotics was the most common culprit drug(46.6%),followed by a combination of multiple drugs(19.7%),and non-steroidal anti-inflammatory drugs(11.1%)was the third common culprit drug.The main causes of ATN were due to infections(41.7%)and drugs(38.4%),of which infections are mainly caused by Hantavirus(96.8%),and drug-related ATNs was mainly caused by a combination of multiple nephrotoxic drugs.(3)In ACKD group,primary glomerular disease and secondary glomerular disease account for 70.6% and26.9%.Primary glomerular diseases mainly included Ig A nephropathy(22.5%),minimal change disease(17.5%),focal segmental glomerulosclerosis(15.3%),and membranous nephropathy(10.2%).Secondary glomerular diseases mainly include lupus nephritis(11.9%),ANCA-associated vasculitis(4.7%),Henoch-Sch?nlein purpura nephritis(2.6%),and diabetic nephropathy(1.6%).(4)Among the patients who were followed up within 3 months after biopsy(n = 775),the proportions of complete recovery,partial recovery,and non-recovery were 73.2%,13.3%,13.5%,the rate of complete recovery of renal function was higher in pure AKI group than ACKD group(83.5% vs 70.5%,p <0.001).Conclusion: Among AKI patients who underwent kidney biopsy pure AKI was relatively rare while ACKD accounts for the majority.Pure AKI tend to be more serious than ACKD and more patients required dialysis.Among pure AKI patients,AIN was most common,followed by ATN.The main cause of AIN was antibiotics,and the main cause of ATN was infection and drugs.ACKD patients has a wide spectrum of pathological diseases,and the prognosis of renal function is worse than that of pure AKI,suggesting the importance of differential diagnosis of AKI by renal biopsy.