FP302
INTERMEDIATE MONOCYTES ARE PREDICTORS OF CARDIOVASCULAR BUT NOT OF RENAL EVENTS Free

Introduction and Aims: Monocytes and monocyte-derived macrophages and Dentritic cells (DC) play a central role in both atherogenesis as well as in renal fibrosis. Based on the expression of CD14 and CD16, three different monocyte subpopulations can be differentiated: classical CD14++CD16- monocytes, intermediate CD14++CD16+ monocytes and nonclassical CD14+CD16++ monocytes. In previous studies, intermediate monocytes have been characterized as independent predictors of cardiovascular events in chronic kidney disease (CKD) patients. However, until now no data exist whether distinct monocyte subsets also predict CKD progression.

Methods: 438 CKD patients stage G2 - G4 were recruited in the CARE FOR HOMe study. All patients were followed for the occurrence of a cardiovascular or renal event. The combined cardiovascular endpoint comprised myocardial infarction, coronary, cerebrovascular and peripheral-arterial revascularization, amputation above the ankle, stroke and death. The renal endpoint was defined as reduction of eGFR ≤ 50% or the onset of renal replacement therapy. Counts of monocyte subsets were determined flow-cytometrically on the day of study inclusion.

Results: Within a follow-up time of 3.0 ± 1.3 years, cardiovascular and renal events occurred in 91 and 47 patients, respectively. After stratification of patients into tertiles of baseline monocyte counts, classical (p = 0.006) and intermediate monocyte (p = 0.002) counts predicted cardiovascular events in univariate Kaplan-Meier analysis. After adjustment for classical and CKD-specific cardiovascular risk factors, only intermediate monocytes remained independent predictors of cardiovascular events (p = 0.003; Exp(B) = 1.012; 95% CI: 1.004, 1.019 / per cell/µl).

In contrast, counts of neither monocyte subset predicted renal events.

Conclusions: Intermediate monocytes were confirmed as independent predictors of cardiovascular events in CKD patients. However, despite the central role of monocytes and monocyte-derived macrophages and DCs in renal fibrosis, high counts of distinct monocyte subsets did not predict CKD progression.