Serum uric acid and renal survival prognosis in primary glomerulonephritis patients in a retrospective single- center cohort

Introduction: The role of serum uric acid (SUA) concentration in primary glomerulonephritis (PGN) aggravation is currently under active discussion. Objectives: This study primarily aimed to analyze the association between SUA concentration and renal survival prognosis in PGN patients and secondarily to determine whether hyperuricemia is an independent risk factor for reduced glomerular filtration rate (GFR) in the presence of nephrotic syndrome. Patients and Methods: We performed a retrospective observational single-center study involving 344 patients with biopsy-proved or clinically diagnosed PGN with the mean follow- up period of 5.3 [3.8-6.2] years. The rate of annual decline in estimated GFR (eGFR) was used to assess chronic kidney disease progression. Primary outcome measures were eGFR decline or transfer to renal replacement therapy (RRT) during the 5-year follow-up period. Results: There were 78/344 (22.7%) patients who eventually progressed to eGFR <15 mL/ min/1.73 m2 or started RRT. In multivariate logistic regression analysis eGFR at diagnosis, proteinuria and hyperuricemia were associated with increased renal risk in PGN patients during the 5-year follow-up period. However, a less significant effect of SUA on rapid eGFR decline was found in the patients with nephrotic-range proteinuria compared with the patients with mild proteinuria. Conclusion: Our study revealed that a higher level of SUA was significantly associated with a greater annual decline in GFR and, consequently, a worse 5-year renal survival prognosis in PGN patients. The effect of hyperuricemia on the risk of rapid CKD progression was greater in PGN patients with mild proteinuria compared with the patients with nephrotic-range proteinuria.