Natural History and Prognostic Factors of IgA Nephropathy Presented with Isolated Microscopic Hematuria in Chinese Patients

Abstract

Background/Aims: IgA nephropathy (IgAN) with isolated microscopic hematuria (IMH) is prevalent in Asian countries including China. However, the natural history of IgAN with IMH has not yet been clarified. The aim of this study was to review the natural course and prognostic factors of IgAN with IMH in Chinese patients. Methods: We retrospectively studied 135 patients (43 males and 92 females) followed up for a mean period of 92 ± 28 months. In order to identify factors associated with renal progression, clinical and pathological data at onset were reviewed. Results: During the follow-up period, hematuria of 16 patients (12%) disappeared while persistent microscopic hematuria was seen in 119 patients (88%), and proteinuria was present in 39 patients (29%). The prevalence of hypertension was 32% (43 patients), and 20% (27 patients) developed renal insufficiency. The prevalence of proteinuria and hypertension in the microalbuminuria group was significantly higher than those in the normoalbuminuria group. Poor renal outcome is usually associated with hematuria, microalbuminuria, and tubulointerstitial lesions. Conclusion: IgAN with IMH may not imply favorable outcome, so early diagnosis and careful follow-up are clinically significant. Hematuria, microalbuminuria, and tubulointerstitial lesions are useful markers to identify those patients at high risk for renal progression.