Hyperuricemia as an independent predictor and prognostic factor in the development of lupus nephritis

Author(s): Ashraf Mahmoud Okba, Mariam Maged Amin, Mai Ahmed El-Deeb & Mohammed Ali Reyad

Background: Lupus nephritis (LN) can increase morbidity and mortality risk in systemic lupus erythematosus (SLE) and 25% of the patients with LN will advance to end-stage renal disease. Objective: To evaluate if hyperuricemia is independently associated with the prediction and prognosis of LN. Methods and finding: This cohort study included 80 SLE patients. SLE patients were divided according to uric acid levels in two groups: “Hyperuricemia SLE” group (n=40) and “No Hyperuricemia SLE” group (n=40). Serum uric acid ≥ 6.0 mg/dL in female and ≥ 7.0 mg/dL in male were indicative of hyperuricemia. SLE Disease Activity Index (SLEDAI) scores, serum level of uric acid, renal activity and chronicity index results were collected and recorded. Median value of serum uric acid level for patients with hyperuricemia was 8.6 mg/dl (4.3-10.4) and for patients without hyperuricemia was 4.2 mg/dl (3.3-5.3). LN was observed in 62.5% of group I (SLE with hyperuricemia) in comparison to 20% of group II (SLE without hyperuricemia)” with p<0.001. A statistically significant relation between hyperuricemia and the occurrence of LN was detected. There was also an inverse correlation between serum level of uric acid and both serum C3 level and estimated glomerular filtration rate (p<0.001); however, there was positive correlation of serum level of uric acid with SLE activity and proteinuria, with statistical significance (p<0.001). Renal activity index in hyperuricemic patients (median=7) was higher than that in patients without hyperuricemia. Conclusion: There is a link to be considered between hyperuricemia and the development of new renal damage in SLE affecting both LN activity and severity.