Morphological abnormalities of leukocytes in SARS-CoV-2 infection.

Introduction: The causative agent of COVID-19 (Coronavirus Disease 2019) is an enveloped RNA (ribonucleic acid) virus of the SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) family. The effects of SARS-CoV-2 on the differentiation and maturation of blood cells have been the subject of several studies, we report our experience of an investigation of the morphologic abnormalities of leukocytes observed during COVID-19.

Patients and methods: This is a prospective study of 5 months, from February 2021 to June 2021. Forty COVID-19 patients and 20 healthy controls were included in this study. We performed complete blood count and peripheral blood smear of all patients and control samples. Leukocytes abnormalities were quantified as a percentage of 100 leukocytes of the same lineage.

Results: The morphological abnormalities of the leukocytes found in percentage of patients have been mainly neutrophils bilobed 72,5%, hypogranulation 45%, acquired pseudo Pelger-Huet 35%, vacuolated neutrophils 42,5%, Apoptotic neutrophils 35,5 %, neutrophils with toxic granulations 30%, myelemia 45%, atypical lymphocytes 52,5%, lymphoplasmocytes 60% and vacuolated monocytes 27, 5%.

Conclusion: Our study revealed several morphological abnormalities of the different cells of the leukocyte lineage. The presence of toxic granulations in the cytoplasm of the myelocytes was specific to this study.