Elevated serum uric acid level correlates with the severity of renal histopathology in IgA nephropathy and establishment of a nomogram model

Background. IgA nephropathy (IgAN), the most common primary glomerulonephritis worldwide, is also a major cause of end stage renal disease (ESRD). We aimed to explore the relationship between the levels of serum uric acidand the degree of renal histopathological damage in patients with IgA nephropathy (IgAN) and build a nomogram model. Methods . It was a retrospective study. The clinical and histopathologicaldata of patients with primary IgAN diagnosed by renal biopsy were collected. Risk factors of severe renal histopathologicaldamage in IgAN patients were identified by logistic regression analysis. A nomogram model was established based on the multivariate logistic regression analysis. The C-index and calibration plots were used for the evaluation of the discrimination and calibration performance, respectively. Results . A total of 594 patients were retrospectively analyzedin the study. Compared with patients without hyperuricemia, patients with hyperuricemia had lower eGFR and higher body mass index, mean arterial pressure (MAP), hemoglobin, serum uric acid, triglycerides, IgA, complement 3, complement 4, proteinuria and severe renal histopathological damage ( p <0.05). Hemoglobin, serum uric acid, eGFR, IgA and proteinuria were identified and entered into the nomogram models. The C-index of this prediction model was 0.689 (95% CI 0.639–0.738). KM survival curve analysis showed that hyperuricemia and severe renal histopathological damage had a higher risk of progression to death or ESRD( p <0.001). Conclusions . Serum uric acid levels are independently associated with severe renal histopathological damage and poor prognosis in IgAN patients.