Platelet Counts Variation and Platelet Indices According to the Severity and Outcome of COVID-19

Background: Coronavirus disease 2019 (COVID-19), caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, is characterized by various biological changes, notably hematological. The value of platelet count and its indices in the evolution of the disease has been raised by several authors. Our objective was to evaluate the variation in blood platelet counts and indices in relation to the progression of COVID-19. Methods: We conducted this retrospective study between May 12, 2020 and March 20, 2021 at the Epidemiological Treatment Center and Hematology Laboratory of Aristide Le Dantec Hospital. Patients who were tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse transcription-polymerase chain reaction (RT-PCR) and who had undergone at least one complete blood count on admission were included. Excel 2019 and SPSS v.20 were used for data processing. Results: A total of 332 patients were included with a median age of 60 years (12 - 100 years). The male gender was more represented with 58.1%. Forty-nine (49) individuals (14.75%) of the patients included in this study were seriously ill, and 39 (11.75%) of them died. The majority of our 82.8% had normal platelet counts, while only 8.4% had thrombocytopenia. The later was even more frequent in patients with poor prognosis of COVID-19 disease (11.88% versus 7.35%). Platelet indices were significantly higher in the severe group than in the non-severe group. However, only the platelet distribution width (PDW) was significantly increased according to the severity of COVID-19 disease. Conclusion: According to our observations, PDW is an important marker in the risk stratification, the prognosis and unfavorable evolution of COVID-19.