Relationship between hyperuricemia and serositis in patients with lupus nephritis

To investigate the clinical and pathological characteristics of lupus nephritis (LN) patients with serositis and analyse the relationship between serositis and hyperuricemia (HUA) in LN patients in northeast China.

The data of patients with LN diagnosed by renal biopsy in our hospital from April 2013 to May 2020 were retrospectively analyzed. The differences between the non-serositis and serositis groups were compared by t tests and Chi-square test. Factors with P < 0.05 in the univariate analyses were investigated further using binary logistic regression analysis to investigate the independent risk factors of serositis in patients with LN.

LN patients with serositis were more likely to have fever, hypertension, neuropsychiatric and hematological involvement than those without serositis (P < 0.05). Compared with the non-serositis group, LN patients with serositis were prone to have HUA, high D-dimer, high triglycerides, and had significant differences in the levels of plasma albumin (Alb), estimated glomerular filtration rate (eGFR), erythrocyte sedimentation rate, C-reactive protein, complement C3, 24-h urinary protein, pathological types, pathological score and SLEDAI score. Logistic regression analysis showed that HUA was one of risk factors for serositis in LN patients. The rate of complete remission in LN patients with serositis was significantly lower (P < 0.05) and the rate of no remission and mortality were significantly higher (P < 0.05) than LN patients without serositis.

LN patients with serositis had more severe clinical and pathological manifestations, higher systemic lupus erythematosus (SLE) activity and worse prognosis. Hyperuricemia is associated with serositis in LN patients.