Clinical characteristics and outcome of pauci-immune glomerulonephritis in African Americans

Abstract

ObjectivesPauci-immune glomerulonephritis is rare in African Americans (AA) and the clinical presentation and treatment outcomes of vasculitis have not been well described. MethodsWe identified patients who were 2–92 years of age between 1983 and 2011 with a diagnosis of biopsy-proven pauci-immune glomerulonephritis (GN) at any point during their disease course. Comparing AA to Caucasian patients, we examined demographics, clinical features at presentation, treatment and outcomes of relapse, end-stage renal disease (ESRD), and death. ResultsOf the 672 patients, 75 were AA with the remainder being Caucasian. Compared to Caucasians, disease onset in AA was at an earlier age (52 vs. 57 years, p = 0.05) and was more often myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA) positive (71% vs. 54%, p = 0.01). AA patients had a shorter median time between onset of symptoms and biopsy compared to Caucasians [median (IQR): 0.23 (0.00, 1.22) months vs. 0.66 (0.00, 3.62) months, p = 0.003]. Median [Interquartile range (IQR)] follow-up in months was 28 (5, 52) in AA and 26 (10, 55) in Caucasian patients. Median estimated glomerular filtration rate was similar at presentation (21 vs. 22ml/min/m2). Both groups had similar induction treatment regimens. There was less favorable treatment response among AA compared to Caucasians for initial treatment resistance (28% vs. 18%, p = 0.05) and complete remission (72% vs. 82%, p = 0.05). There were no differences in the number of renal relapses or number of deaths between the 2groups. Overall, in multivariable analyses controlling for age, race, ANCA type, and entry serum creatinine, there were not differences by race in treatment response, renal relapse, ESRD, or death over the entire time of follow-up. ConclusionsAA patients with pauci-immune GN are younger and more often MPO-ANCA positive compared to Caucasians. Despite a shorter time to diagnosis for AA patients, there were no differences compared to Caucasians in treatment response, ESRD, renal relapse, or death rates by race over the entire duration of follow-up.