Platelet Count and Platelet Indices as Predictive Markers of COVID-19 Mortality

The aim of the study was to analyze changes in platelet count and function in hospitalized COVID-19 patients and compare them with non-COVID-19 patients, focusing on the association between platelet indices and mortality beyond the known link between neutrophil-to-lymphocyte ratio (NLR) and COVID-19 severity. The study sample consisted of 572 patients, out of which 472 were hospitalized with COVID-19 infection from 15th October 2021 to 30th April 2022 in Louis Pasteur University Hospital Kosice, Slovak Republic and 100 represented the control group without COVID-19 infection. COVID-19 positive patients (n=472) had significantly larger size of platelets (MPV 9.2+/-1.4 vs. 8.8+/-1.2, p=0.002) and therefore a higher percentage of platelets larger than 12 fl (P-LCR 33.7 % vs. 24.8 %, p=0.002) than patients in the control group (non-COVID19). The statistically significant relationship was between mortality in patients with COVID-19 infection (n=122) and the larger size of the platelets (MPV), higher platelet large cell ratio, (P-LCR), higher PLT/MPV ratio, higher platelet distribution width to plateletcrit ratio (PDW/PCT), higher neutrophil-to-lymphocyte ratio (NLR) (p