ABSTRACT
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection started in Wuhan, China, and spread to the rest of the world to become a pandemic affecting over 385 million people throughout the world to date. Coronavirus disease 2019 (COVID-19) is primarily started as a respiratory tract infection. Recent studies indicate that it should be regarded as a systemic disease involving multiple systems including the hematopoietic system. Complete blood count and its parameters are important investigative tools in its prognosis. However, very few studies highlight the importance of peripheral blood cell morphology in this disease. Aim: To study the hematological parameters (complete blood count and peripheral blood film) of COVID-19-positive patients and to compare the hematological parameters of those admitted in intensive care units (ICUs) with those admitted in non-ICUs of the hospitals. Materials and methods: This retrospective study was carried out at a COVID-19 dedicated tertiary care center over a period of 3 months from July 2020 to September 2020. In our study, all 79 patients had complete blood counts performed at the time of admission. Complete blood count was repeated during the hospital stay for all severe cases. The data which provided information on the age and gender of each patient were obtained from the Laboratory Information System (LIS) of the hospital. Results: The mean age of our study group was 46.05 years. Out of 79 cases, lymphopenia was seen in 16.5% with five patients presenting with severe lymphopenia (<0.5 × 109 /L). All the patients that required ICU care presented with moderate to severe lymphopenia. The patients in the ICU setting showed significant neutrophilia (mean 14.16 × 109 /L) on follow-up complete blood count. Thrombocytopenia was observed in 35.3% of cases. It was observed that the mean neutrophil– lymphocyte ratio was higher in ICU admitted patients as compared to the non-ICU admitted patients. Among the ICU patients, 80% showed a neutrophil–lymphocyte ratio above the baseline cutoff (3.1). A wide array of morphological changes were observed in the peripheral blood smear including toxic-like granules in neutrophils, fetus-like C-shaped nucleus, lymphoplasmacytoid cells, bizarre cells, and apoptotic cells. Conclusion: The study highlights that at the time of admission older age, decreased lymphocyte count, and raised neutrophil–lymphocyte ratio were closely associated with ICU admissions. Also, the morphological changes in peripheral blood film reveal atypical changes predominantly in the white blood cell (WBC) lineage.