Clinicopathological feature analysis of IgA nephropathy complicated with acute kidney injury in children

Abstract

Objective To investigate the clinicopathological features of IgA nephropathy(IgAN) complicated with acute kidney injury (AKI) in children. Methods The clinical and pathological data of children with biopsy-proven primary IgAN and complicated with AKI from January 2012 to December 2016 in the First Affiliated Hospital of Zhengzhou University were analyzed retrospectively, and the data of macroscopic hematuria (MH) associated AKI(15 cases) and other MH without AKI(99 cases) were compared. Results (1) Among 211 patients diagnosed with IgAN, 21 (9.95%) patients were complicated with AKI.Among the 21 cases, the average age was (9.5±2.1) years old, in which 17 cases(80.9%) were males, 19 cases with MH, and the range of the peak serum creatinine was 93-627 μmol/L.In histology, cellular/fibrocellular crescents were found in 11 cases, while high proportion of tubules filled with red blood cell(RBC) casts were observed in 8 cases, and moderate to severe acute tubular injury (ATI) were observed in 16 cases.In 2 cases, extensively mixed inflammatory cell infiltration with eosinophils was present in the interstitium.(2) According to the clinical and pathological characteristics, the 21 cases were divided into 3 groups: 15 cases with MH related AKI, 4 cases with crescentic glomerulonephritis, and 2 cases with acute interstitial nephritis.Compared with MH without AKI group(99 cases), the MH associated AKI group(15 cases) had significantly longer duration of MH, higher proteinuria level, urinary levels of β2-microglobulin (β2-MG) and N-acetyl-β-D-glucosaminidase (NAG), and greater frequency of RBC casts and ATI, and the differences were statistically significant(all P<0.05). In 2 acute interstitial nephritis cases, one had a history of taking weight loss drug with unknown ingredients, while the specific cause of the other was not clear.(3) None of the patients was on dialysis, but corticosteroid was prescribed in 17 cases (including methylprednisolone pulse therapy in 6), and 3 cases were combined with cyclophosphamide.Almost all patients achieved normal renal function except for one who had no response within 2 months after treatment.The median follow-up period was 24 months, in which 1 patient with crescentic glomerulonephritis progressed to end-stage renal disease. Conclusions AKI is commonly seen in children with IgAN, and complete recovery of renal function was seen in all patients with MH associated AKI and acute interstitial nephritis. Key words: IgA nephropathy; Acute kidney injury; Macroscopic hematuria; Child