Circulating monocyte-platelet aggregates with different monocyte subsets and their association with disease severity in chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is usually considered an immune inflammatory disease. Interaction between platelets and monocytes is associated with immune inflammation. Cross-talk between platelets and monocytes is reflected by formation monocyte-platelet aggregates (MPAs). This study aims to test MPAs and MPAs with the different monocyte subsets to evaluate their association with disease severity in CKD.

METHODS: Forty-four hospitalized patients with CKD and twenty healthy volunteers were enrolled. The proportion of MPAs and MPAs with the different monocyte subsets were tested by flow cytometry.

RESULTS: The proportion of circulating MPAs in all patients with CKD were significantly higher than those of healthy controls (p<0.001). A higher proportion of MPAs with classical monocytes (CM) was found in CKD4-5 patients (p=0.007), while another higher proportion of MPAs with non-classical monocytes (NCM) was found CKD2-3 patients (p<0.001). The proportion of MPAs with intermediate monocytes (IM) in CKD 4-5 group was significantly higher in comparison to CKD2-3 group and healthy controls (p<0.001). Circulating MPAs were found to be correlated with serum creatinine (r=0.538, p<0.001) and eGFR (r=-0.864, p<0.001). The AUC for MPAs with IM was 0.942 (95% CI 0.890-0.994, p<0.001).

CONCLUSIONS: Study results highlight the interplay between platelets and inflammatory monocytes in CKD. There are alterations in circulating MPAs and MPAs with the different monocyte subsets in CKD patients compared to controls which change with CKD severity. The MPAs may have an important role in the development of CKD or as a predictive marker for monitoring disease severity.