A Rare Presentation of Immunoglobulin A Nephropathy: Acute Kidney Injury

Abstract

Background: Acute kidney injury (AKI) is known as an uncommon presentation in immunoglobulin A nephropathy (IgAN). The aim of our study was to analyze the clinical data and biopsy findings in IgAN patients presenting with AKI. Methods: We performed a retrospective analysis of all subjects who had biopsy-proven IgAN and presented with AKI during June 2002 September 2015. The following data were obtained from medical records. Results: A total of 15 patients of 123 patients (12.2%) with primary IgAN admitted with AKI. Patients were generally male (73.3%), with a median age of 38 (interquartile range; IQR, 2,944) years. The serum creatinine at admission was above the normal range (median 2.3 [IQR, 2.14.7] mg/dL]). On histology, cellular/fibrocellular crescents were present in 6 patients. In most cases (53.3%), pathologic abnormalities associated with acute tubular injury/necrosis were defined. Red blood cell casts in tubules were present in 6 cases (40%). In all cases, interstitial mixed inflammatory cell infiltration was observed. In 4 cases, admixed eosinophils were also found. In 3 patients, biopsy specimens showed acute thrombotic microangiopathy lesions (20%). Median follow-up time was 13 (IQR, 346) months. Six patients (40%) progressed to end-stage renal disease (ESRD). Among patients diagnosed with primary IgAN and presenting without AKI, only 4 patients progressed to ESRD. The proportion of patients who progressed to ESRD presenting with AKI was significantly higher than the patients presenting without AKI (p = 0.000). Conclusions: In conclusion, AKI complicates IgAN more often.