Quantitative analysis of mesangial areas in serial biopsied patients with IgA nephropathy.

Clinical courses of 22 patients with IgA nephropathy, who received serial renal biopsies at a mean interval of 36 +/- 11 months, were observed until 2 years after the second biopsy. Of 22 patients, 12 showed no detectable changes in semiquantitatively analyzed mesangial sclerosis between the serial biopsies. By quantitative analysis, on the other hand, mesangial areas decreased between the serial biopsies in 12 patients (group I), and increased in 10 (group II). At the time of the first biopsy, there were no differences between the two groups in sex, age, creatinine clearance (Ccr), urine protein, hematuria, hypertension, treatment and histological parameters. Although Ccr in group I was stable during the 5-year follow-up, group II showed progressive deterioration of Ccr (p less than 0.005). Histologically, mesangial hypercellularity and crescent formation improved in group I (p less than 0.005 and (p less than 0.05, respectively), and tubular atrophy and interstitial fibrosis progressed in group II (p less than 0.05, each). These results demonstrate that changes in mesangial areas evaluated by quantitative analysis between serial renal biopsies are a valuable prognostic indicator in IgA nephropathy.