Impact of non-immune factors on renal prognosis in adult IgA Vasculitis with Nephritis：A Long-Term Retrospective Cohort Study.

Abstract

Adult Immunoglobulin A vasculitis (IgAV) is documented to be associated with more renal involvement and poorer renal outcome compared to children, but adult IgAV nephritis (IgAV-N) data is rather limited. The present study aimed to describe the characteristics of adult IgAV-N and investigate the long-term prognostic factors. Clinical, morphological data from 106 adult biopsy-proven IgAV-N patients and follow-up data from 94 patients in a single Chinese center were analyzed in this retrospective study. Median follow-up time interval was 102 months. The median age of IgAV-N patients at biopsy was 38 (IQR 24-53) years, and 52.8% were male. The median blood pressure was 126/80 mmHg, and 25.5% of patients were hypertensive at baseline. The median initial proteinuria was 1.4 (IQR 0.7-2.2) g/24h, eGFR was 103 (IQR 84-121) mL/min/1.73 m2. The median time interval of onset to biopsy was eight (IQR 3- 40) weeks. In biopsy, the median percentage of global sclerosis was 5.9% (IQR 0.0-13.8), while 45.3% of patients had interstitial fibrosis and tubular atrophy. Furthermore, during follow-up, 7.4% patients died, 4.3% patients progressed to ESKD and 6.4% patients developed >30% eGFR reduction from baseline. Multivariate Cox proportional analyses revealed hypertension history and higher than 10% global sclerosis at presentation were independent prognostic factors for poor outcome. The present adult IgAV-N cohort revealed a relatively young onset age, fewer nephrotic syndrome and lower incidence of ESKD. Moreover, non-immune factors as history of hypertension and renal chronic histological lesions in biopsy played a crucial role in prognosis of IgAV-N.