Primary IgA nephropathy: a nine-year clinicopathologic study in the Veterans General Hospital-Taichung.

IgA nephropathy (IgA N) is the most common type of primary glomerulonephritis (GN) diagnosed in Taiwan. From February 1983 to May 1992, 194 patients with primary IgA N, representing 25.3% of the primary GN, were diagnosed by renal biopsy at this hospital. Clinicopathologic correlation was made in 175 cases of IgA N with adequate clinical and pathologic data including light-(LM), immunofluorescent (IF) and/or electron-(EM) microscopy. Modified classification of Meadow et al. was adopted for the histologic grading of glomerular lesions. Forty-nine biopsies (28.0%) showed Grade IV and V lesions (Grade IV, 10.9%; Grade V, 17.1%, respectively) in association with a high level of serum creatinine and a lower frequency of gross hematuria when compared with lesions of histologic Grades I to III. Patients with Grade V lesions revealed a high frequency of hypertension as compared with those with Grades I to IV. The frequencies of nephrotic range proteinuria in those with various grades of IgA N was not statistically significant in this study. One hundred and thirty patients were followed up for one to eight and half years or until end-stage renal disease (ESRD) developed (mean 3.9 years), excluding the biopsies done at ESRD or from the graft kidney. Forty-two patients (32.3%) had chronic renal insufficiency, of those 25 (19.2%) eventually developed ESRD. Seventy-five percent of the patients with histologic Grades IV and V showed progressive renal disease, while only 16% of patients with Grades I to III lesions revealed progressive disease, the latter indicating a more benign course (P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)