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)