Association of monocyte count with rapid renal function decline in nondialysis CKD

Chronic inflammation contributes to chronic kidney disease (CKD) progression. Monocytes, as key inflammatory mediators, have been linked to atherosclerosis, CKD progression, and mortality; however, their clinical relevance in nondialysis CKD remains insufficiently characterized. This study evaluated the association between monocyte count and renal outcomes in nondialysis CKD.

This prospective observational cohort study included 347 patients with nondialysis CKD enrolled between February 2014 and December 2019 and followed until September 2023. Outcomes included rapid renal function decline, defined as an annual estimated glomerular filtration rate (eGFR) decline >3 mL/min/1.73 m², progression to end-stage kidney disease (ESKD) requiring dialysis, and all-cause mortality. Multivariable regression, receiver operating characteristic (ROC), and modified Kidney Failure Risk Equation (KFRE) model analyses were performed.

During a median follow-up of 46.0 months, 156 patients (45.0%) experienced rapid renal function decline, 63 (18.2%) progressed to dialysis, and 40 (11.5%) died. In the final adjusted model, higher monocyte count was associated with rapid renal function decline when expressed per 100 cells/μL increase (odds ratio, 1.35; 95% confidence interval [CI], 1.11-1.82; P = 0.017). Monocyte count was not independently associated with dialysis or mortality. ROC analysis identified 483 cells/μL as a cohort-derived exploratory cutoff for rapid renal function decline. Adding monocyte count to the modified KFRE model improved model fit.

Higher monocyte count was associated with rapid renal function decline in nondialysis CKD and may provide complementary inflammatory information for CKD risk assessment. Further validation is required before clinical application.