Long-term benefits of angiotensin-converting enzyme inhibitor therapy in patients with severe immunoglobulin a nephropathy: a comparison to patients receiving treatment with other antihypertensive agents and to patients receiving no therapy.

Of 531 cases of immunoglobulin A nephropathy in the Toronto Glomerulonephritis Registry, 115 were determined by retrospective analysis to have proteinuria > or = 1 g/d. These patients have been followed a minimum of 3 months (range, 3 to 121 months). Monitoring in the registry included routine blood pressure estimates and renal function status by serum creatinine, creatinine clearance, and proteinuria. These patients were grouped and examined retrospectively into three categories (1) hypertensive on angiotensin-converting enzyme (ACE) inhibitor therapy (ACEi), (2) hypertensive on other medication, and (3) no hypertension (NT). Despite comparable renal function abnormalities, the 27 ACEi patients, when compared with the 55 patients receiving other medication, experienced a significantly slower rate of decline in renal function as measured by slope of creatinine clearance (-0.4 mL/min/mo v-1.0 mL/min/mo; P = 0.007), longer time to a loss of one third of baseline creatinine clearance (P = 0.004), and a higher percentage of remission in proteinuria (18.5% v 1.8%; P = 0.003). A subsequent comparison was made between the NT and ACEi groups and, despite a much lower initial serum creatinine, less severe pathology, and a longer observation period in the NT group, both the rate of decline of creatinine clearance (-0.5 mL/min/mo v -0.4 mL/min/mo; P = 0.9) and the percentage of patients progressing to renal failure (21.2% v 18.5; P = 0.8) were not different. The remission rate of proteinuria was superior in the ACEi-treated group compared with the NT group.(ABSTRACT TRUNCATED AT 250 WORDS)