Retrospective Analysis of Clinical Outcomes in Patients with Immunoglobulin A Nephropathy and Persistent Hematuria Following Renin-Angiotensin System Blockade

BACKGROUND Recent guidelines recommend that patients with immunoglobulin A nephropathy (IgAN) and proteinuria 0.5-1 g/d and >1 g/d be treated with long-term renin-angiotensin system blockade (RASB). This study investigated whether patients with IgAN and persistent hematuria, but without proteinuria, can benefit from RASB. MATERIAL AND METHODS IgAN patients with persistent hematuria at four centers were recruited from January 2013 to December 2018. Patients were divided into those who did and did not receive long-term RASB. The primary outcome was the appearance of proteinuria, and the secondary outcomes were the decreased percentage of hematuria, rate of decline in estimated glomerular filtration rate (eGFR) and final blood pressure. The effects of RASB on these outcomes were assessed by multivariate Cox regression models and propensity score matching. RESULTS Of the 110 eligible patients, 44 (40.0%) received RASB and 66 (60.0%) did not. Treated patients had higher diastolic pressure. The unadjusted primary outcome, the appearance of proteinuria, was significantly less frequent in individuals who were than who were not treated with RASB. Multivariate Cox regression showed that RASB reduced the risk of the primary outcome and the levels of hematuria. The rate of eGFR decline and final blood pressure did not differ in the two groups. CONCLUSIONS RASB reduced the risk of proteinuria development and increased the remission of hematuria in patients with IgAN who presented with persistent hematuria alone. RASB, however, did not affect blood pressure in patients without hypertension and did not affect the rate of eGFR decline.