Clinicopathological characteristics and prognosis of IgA nephropathy patients with hyperuricemia

Abstract

Abstract Objective: To understand the clinical and pathological characteristics of patients with IgA nephropathy (IgAN) complicated with hyperuricemia, and to analyze the effect of serum uric acid on the prognosis of IgAN. Methods: A retrospective analysis of 718 IgAN patients with diagnosis confirmed by renal biopsy and follow-up of more than 1 year was performed. At least two serum uric acid (SUA) levels were recorded measurements of during the follow-up period at intervals of 0.5–1 year. Time-average SUA (TA-SUA) was calculated according to the area under the curve during the follow-up period. The study’s primary end-point was doubling of creatinine or end-stage renal disease. Four groups (Q1–Q4) were divided according to baseline uric acid and TA-SUA quartile spacing from low to and the association of high uric acid level with prognosis in IgAN patients was assessed using Kaplan–Meier survival analysis and Cox proportional hazards models. Results: Compared with the other three groups, the clinical and pathological features of patients in Q4 were more severe in both the SUA and TA-SUA groups. SBP, DBP, MAP, baseline SUA, high SUA and high TS-SUA, eGFR, ALB, 24-hour urinary protein quantification, and renal tubular atrophy/interstromal fibrosis were all identified risk factors for IgA nephropathy progression by univariate Cox regression model analysis. Multivariate results suggested that baseline SUA was not an independent risk factor for renal prognosis in IgAN patients after adjustment for clinical variables such as eGFR. High TA-SUA is an independent risk factor for renal prognosis in IgAN patients. Conclusion: High uric acid levels IgAN patients with high uric acid levels present more severe clinical features and pathological damage. TA-SUA is as an independent risk factor for renal prognosis in IgA nephropathy patients. Baseline SUA level is not an independent risk factor for renal prognosis in IgAN patients after renal function adjustment.