Changes in the hematological cells ratios are associated with death in COVID-19 patients

ABSTRACT

The impaired hematological parameters have been identified as risk factors for critical illness and higher mortality rates in patients with COVID-19. The aim is to analyze the changes in hematological cells ratios and the relationship to death in COVID-19 patients. Method(s) A retrospective study in COVID-19 patients, classified according to the PaO2/FiO2 relation. The plateletto-lymphocyte ratio (PLR), neutrophil-to-lymphocyte (NLR), and monocyte-to-lymphocyte (MLR) were determined during hospitalization, and changes between four observations during hospitalization were analyzed. Of 780 patients included, 464 were discharged by improvement, and 316 died. From deaths, 26.4% were classified as mild or moderate and 14.1% as severe COVID-19 at admission. The PLR, NLR, and MLR values at admission were higher in patients who died than those who survived. The increase of PLR during later hospitalization stages was associated with death in patients with mild or moderate COVID-19 (OR= 2.22, p<0.001) and, in severe disease (OR= 2.01, p=0.004), a similar association showed the increase MLR (OR= 3.07, p<0.001, and OR= 2.2, p<0.001, respectively). Conversely, the increase in NLR from early stages was associated with death outcome;in early stages (OR= 1.54, p=0.024, and OR= 1.60, p=0.04, according to severity category). In late stages (OR= 3.72, p<0.001 and OR= 3.26, p<0.001, respectively). All models were adjusted by age and sex. The positive change on PLR, MLR, and NRL is associated with death regardless of severity at hospital admission;therefore, the monitoring during the hospitalization stay will be useful to patients' management.