Peculiarities of complete blood count indicators in patients with community-acquired pneumonia during the COVID-19 pandemic

The article presents the literature review data on the community-acquired pneumonia and the survey of patients with community-acquired pneumonia during the pandemic of the new coronavirus infection COVID-19. There are no changes in the rate of leukocytosis detection in patients with mild course of the di­sease within 10 days of hospital stay. There is a tendency to increase the proportion of people with a normal number of leukocytes and lymphocytes from day 4–6 of hospital treatment. Significantly, leukopenia was detected in 9.3 % of patients 1–3 days after hospitalization and was not observed in the future. Lymphopenia was registered in the first 1–6 days of hospital stay and was not observed from day 7–9. Granulocytosis was detected in 27.6 % of patients on day 1–3 in the hospital and in the following days their percentage decreased significantly; at the same time, the number of people with normal range of granulocytes increased significantly. Normal platelet counts were observed in most patients (93.8 %) on day 1–3 of hospital stay, and thrombocytopenia was recorded only in 6.3 % of individuals on day 1–3 after hospitalization. In moderate-to-severe form, 24.7 % of patients had leukocytosis on day 1–3 of hospital stay, and on day 7–9 of treatment, it was detected already in 28.8 % (p > 0.05). The majority of patients (66.7 %) had normocytosis in the first three days, and leukopenia was observed in 8.7 % of people on day 1–3. Significantly, the share of detected lymphocytosis increased, and lymphopenia — decreased from 4–6 days of hospital stay. Granulocytosis was registered in 23.2 % of patients on day 1–3 of hospital stay, followed by a significant decrease in the percentage of granulocytes from days 4–6. Band neutrophils were elevated in the first three days among 51.6 % of patients, and their percen­tage significantly decreased after the fourth day. Most individuals (77.3 %) had a normal platelet count on day 1–3 in the hospital, and thrombocytopenia at this time was found in 16.7 %. The majority of patients aged 20–30 years had a normal number of leukocytes (65.5 %), and 25.5 % had leukocytosis 1–3 days after hospitalization. Lymphocytosis in the first 3 days was registered among 9 % of people and then increased significantly, lymphopenia was observed in 31 % of patients on day 1–3 and subsequently decreased, granulocytosis — in 25 % of cases, elevated levels of band neutrophils — in 43.8 %, thrombocytosis — in 7.3 %, thrombocytopenia — in 10.9 %. Among patients aged 31–40 years in the first 3 days after hospitalization, leukocytosis was registered in 28 % of cases, leukocyte count was normal in 72 %, leukopenia was not detected, 48 % of patients had lymphopenia, 15.8 % — granulocytosis, levels of band neutrophils were elevated in 65.2 %, thrombocytosis was observed in 8 % of cases, thrombocytopenia — in 8 %. Most patients (66.7 %) aged 41–50 years on day 1–3 after hospitalization had normocytosis, 19 % — leukocytosis, 14.3 % — leukopenia, 14.3 % — lymphocytosis, 38.1 % — lymphopenia, 3 (25 %) people had granulocytosis, levels of band neutrophils were elevated in 65 % of cases, thrombocytosis was detected in 4.8 %, thrombocytopenia — in 28.5 %. Among patients aged 51–60 years in the first 3 days after hospitalization, the following indicators of complete blood count were found: 16.1 % of individuals had leukocytosis, number of leukocytes was normal in 83.9 % of cases, leukopenia was not detected, lymphocytosis was found in 16.1 % of people, lymphopenia — in 22.6 %, granulocytosis — in 20 %, elevated levels of band neutrophils — in 39.3 %, thrombocytosis — in 3.2 %, thrombocytopenia — in 16.2 %. Patients older than 60 years on days 1–3 after hospitalization had the following changes: 38.8 % — leukocytosis, white blood cell count was normal in 49 % of cases, 12.2 % of people had leukopenia, 12.2 % — lymphocytosis, 51.1 % — lymphopenia, granulocytosis was not observed, 25 % had granulocytopenia, 60 % — elevated levels of band neutrophils, 8.2 % — thrombocytosis, and 18.3 % — thrombocytopenia.