A CLINICOPATHOLOGICAL STUDY OF ADULT JAPANESE IGA NEPHROPATHY PATIENTS - EARLY-STAGE CASES AND CASES WITH EXACERBATION

Most cases of adult type IgA nephropathy (IgAN) have an insidious onse t and asymptomatic course. However, some patients reveal recurrent mac roscopic haematuria following episodes of respiratory or urinary tract infections. In order to clarify che correlation between clinical feat ures and histological alterations or prognosis, 42 cases of early stag e IgAN and 40 cases with acute exacerbation episodes were investigated and compared with a control group. Early stage cases were defined as having had a renal biopsy within 1 year after the first detection of u rinary abnormalities, and had normal urinary findings within the 12 mo nths before the first detection of urinary abnormalities. Acute exacer bation cases were defined as macroscopic haematuria or worsening of ur inary abnormalities after acute infectious episodes and undergoing a r enal biopsy within 120 days after the onset of these episodes. The ear ly stage cases had better renal function and lower systolic and diasto lic blood pressure than that of control group. They also showed milder changes in mesangial cell proliferation, mesangial matrix increase, t otally sclerotic glomeruli, and tubulointerstitial changes. However, i t is important to note that glomerular and interstitial sclerotic chan ges were observed even in early stage cases. Endothelial detachment wa s noticed more frequently in the early stage cases. Acute exacerbation cases revealed lesions of endocapillary proliferation, mesangiolysis and endothelial detachment more frequently, although these changes wer e segmental in each glomerulus. There was no statistical difference in disease prognosis between cases with and without acute exacerbation. These data indicated that there are characteristic histological change s in early stage cases and acute exacerbation cases of IgAN.