Red blood cells injuries and hypersegmented neutrophils in COVID-19 peripheral blood film

In the current investigation, peripheral blood films of 15 COVID-19 patients (44.78±16.55 years), proven by computed tomographic imaging and RT-PCR for coronavirus SARS-CoV-2, were analyzed at the moment of hospital admission. Blood tests showed raised inflammatory markers (C-reactive protein 58.2±61.2 mg/L) with normal values for hemoglobin (126.2±2.6 g/L), WBC (6.8±18.74 10⁹/L) RBC (4.55±0.99 10¹²/L) platelets (262.4±141.8, 10⁹/L) MCV (79.84±8.2 fL) MCH (28±3.31 pg) and MCHC (350.3±1.15 g/L). The results revealed the presence of hypersegmented neutrophils in 66.66%% of the patients. The percentages of neutrophils with 4 and 5 lobes were 46.25 ± 4.83% and 31.5 ± 14.84%, respectively. Three major red blood cells morphological alteration were observed: (1) erythrocytes in “rouleaux” formation represented by linear erythrocytes aggregation, (2) spherocytes with the disappearance of the usual biconcave disk, and (3) echinocytes showing spiky projections. Apparent reorganization of hemoglobin is found in the majority of the analyzed erythrocytes. Rouleaux formation is observed in 33.33% of patients and spherocytes and echinocytes are present at variable levels in the all analyzed patients. The current results revealed erythrocytes injuries in COVID-19 peripheral blood, in association with hypersegmented neutrophils, alterations that could be involved in the respiratory syndrome.