Objective: To explore the relationship between leukocyte count and renal function in patients with lupus nephritis (LN).
Methods: We performed a retrospective cross-sectional study of 100 patients with LN admitted to the Department of Nephrology between 1 January 2015 and 30 December 2023. Based on tertile of leukocyte count, they were allocated to Low, Medium, or High groups. The demographic, clinical, and pathologic characteristics of the groups were compared and the relationship between leukocyte count and renal function was analyzed using multiple linear regression analysis.
Results: After adjustment for age, albumin, 24-hour proteinuria, serum complement factor 3, hemoglobin, blood pressure, systemic lupus erythematosus disease activity index score, and histologic parameters, a linear relationship was identified between leukocyte count and renal function (regression coefficient -2.852; 95% confidence interval: -5.161, -0.543). Therefore, for every 1 × 109/L increase in leukocyte count, the estimated glomerular filtration rate would decrease by 2.85 mL/minute.
Conclusion: There is an independent linear relationship between leukocyte count and renal function. Leukocyte recruitment into the kidney is a critical step in the progression of LN, and as the leukocyte count increases, renal function gradually declines. Leukocyte count may represent a sensitive biomarker of the progression and prognosis of LN.
Keywords: 24-hour proteinuria; Lupus nephritis; estimated glomerular filtration rate; leukocyte; microthrombus; renal function.