Predictive Value of Mean Platelet Volume in Patients Undergoing Conventional Dialysis and Online Hemodiafiltration.

Introduction Patients with end-stage renal disease (ESRD) experience significantly lower survival rates compared to the general population. Despite advances like online hemodiafiltration (OL-HDF), these patients still face high mortality, primarily due to cardiovascular disease (CVD). Mean platelet volume (MPV), an inexpensive and readily available marker of platelet activity and thrombogenesis, may help predict cardiovascular risk (CVR) and poor outcomes, but remains underutilized and under-researched in dialysis patients. The aim of our study is to investigate MPV and the MPV-to-platelet count ratio (MPR) as potential markers for CVR and mortality in patients undergoing conventional hemodialysis and online hemodiafiltration, while also assessing how these therapies impact platelet activity to help improve patient outcomes. Materials and methods This retrospective analysis was carried out at the Clinic of Nephrology and Dialysis at the University Hospital "St. Marina" in Varna, Bulgaria. The study spanned two years, from January 2020 through December 2021, during which the medical records and routine laboratory results of 41 patients who met the study inclusion criteria were reviewed. The study evaluated platelet parameters - MPV, relative platelet count (PLT), and MPR - and their impact on clinical outcomes in two patient groups undergoing OL-HDF and hemodialysis (HD). Outcomes included dialysis adequacy and nutritional status indices, anemia control parameters, and annual mortality. The relationship between platelet parameters and these clinical indicators, as well as their prognostic value, was analyzed. Results The findings show that OL-HDF Group had notably higher levels of dialysis adequacy and nutritional status markers, along with elevated hemoglobin levels obtained using a significantly reduced erythropoietin dose. Regarding the platelet indices studied, a significantly lower MPV, higher PLT, and lower MPR ratio were observed compared to patients on HD. A strong positive correlation between MPV and erythropoietin dose was found in both groups (p<0.05). Data analysis showed that the relative risk of death in patients with MPV >10.5 fL was 5.59 times higher. Discussion PLT contribute not only to thrombogenesis but also to chronic inflammation via thrombokine release. While larger MPV indicates increased platelet reactivity, its predictive value in chronic kidney disease (CKD) remains debated. Some suggest elevated MPV reflects hypervolemia rather than reactivity. Studies have shown a negative correlation between MPV and both hospitalization frequency/duration and clinical outcomes in CKD patients. Conclusion Higher MPV values are significantly linked to clinical deterioration based on the type of dialysis, though not to the dialysis dose itself. Convective therapies lower mortality risk by improving clinical outcomes, enhancing middle molecule clearance, and reducing platelet reactivity and endothelial dysfunction. MPV and MPR are cost-effective, accessible markers for CVR stratification, aiding timely clinical decisions and interventions.