Clinical and pathological features of IgA nephropathy with macrohematuria in history

Objective To investigate the clinical and pathological characteristics of IgA nephropathy (IgAN) with macrohematuria (MH). Method 1512 consecutive patients with biopsy-proven IgAN diagnosed from January 2006 to December 2011 were enrolled, and divided into MH group and control group respectively, according to whether there existed episodes of MH before renal biopsy. The clinical and pathological characteristics were compared between two groups. Patients in MH group were then divided into three groups according to the interval from the last episode of MH to renal biopsy to clarify the concomitant clinicopathological changes associated with occurrence of MH. Results The rate of MH in history was 22.1%. MH group patients had significantly lower serum creatinine, slighter proteinuria, lower prevalence of hypertension and heavier microhematuria than control group (all P＜0.001). The prebiopsy durations were similar in two groups (P=0.627). In MH group, chronic pathological indicators, including global/segmental sclerosis, tubule atrophy/interstitial fibrosis were all slighter (all P＜0.001), whereas activity indicators, including necrosis lesions, crescents and mesangial proliferation were all more severe compared with control group (all P＜0.05). Those who underwent renal biopsy within 30 days of the last episode of MH had more severe proteinuria and microhematuria, higher prevalence of necrosis lesions, more severe crescents formation, and endothelial proliferation (all P＜0.05). Conclusions IgAN patients with MH in history have relatively milder clinical and chronic pathological manifestations, however more active pathological changes especially in those who suffer episode of MH recently.