The role of platelet large cell ratio in determining mortality in COVID-19 patients.

Inflammatory mechanisms have been implicated and have been subject to research in the clinical course of COVID-19 patients. In this study, platelet large cell ratio (P-LCR) has been examined as a novel prognostic and inflammatory parameter. A total of 1992 COVID-19-positive patients admitted to COVID-19 unit of Infectious Diseases were included. In order to identify a potential relationship between P-LCR and mortality, surviving patients were compared with subjects who died as a result of the disease. Although P-LCR levels showed a steady increase in all COVID-19 patients after admission, they were significantly higher in those who eventually died (P < .001), indicating a positive correlation between mortality and P-LCR. The P-LCR levels of patients followed up in the intensive care unit were statistically significantly higher than those followed up in the ward (P < .001). P-LCR levels of patients intubated in intensive care unit were statistically significantly higher than those who were not intubated (P < .001). Also, P-LCR levels were subdivided into 3 categories as normal, low, and elevated. Elevated P-LCR was found to be positively correlated with leukocyte count, neutrophil count, D-dimer, troponin, ferritin, and C-Reactive Protein (CRP) and showed negative correlation with fibrinogen, lymphocyte count, and platelet count. As P-LCR was correlated with the severity of inflammation in all COVID-19 patients, it was significantly higher in those patients who died. Elevated P-LCR was considered to be associated with the risk of severe disease and death. This inexpensive, readily available test may be incorporated into our clinical practice as a novel marker of poor prognosis in addition to other valuable laboratory parameters.