Across 11 observational studies enrolling 18,631 individuals with chronic kidney disease (CKD)—ranging from non-dialysis CKD to end-stage renal disease on dialysis—elevated monocyte-to-lymphocyte ratio (MLR) showed strong associations with cardiovascular death (p<0.001 by Fisher's pooled method, n=16,974) and all-cause mortality (p<0.001, n=15,682), with a proposed predictive threshold of 0.63 for all-cause death and 0.43 for cardiovascular events. Evidence for non-fatal cardiovascular events remained inconsistent across six studies.
MLR is an inexpensive, routinely available immune-inflammatory index derived from standard complete blood counts. Its signal in CKD is biologically plausible: monocyte activation drives uremic inflammation and atherosclerotic plaque instability, while lymphopenia—common in dialysis patients—reflects immune exhaustion. Unlike CRP or interleukin-6, MLR requires no additional testing, making it attractive for low-resource clinical settings where CKD burden is disproportionately high.
However, several limitations temper enthusiasm. Follow-up ranged only 1–24 months, thresholds were derived within individual cohorts and may not generalize across ethnicities or CKD stages, and all included studies were observational—causality cannot be inferred. The narrative synthesis without meta-analytic pooling of effect sizes also limits quantitative precision. As a preprint not yet peer-reviewed, these conclusions may be revised. Clinicians should treat proposed thresholds as hypothesis-generating rather than actionable cut-points pending prospective validation in diverse, standardized cohorts.