Immune dysregulation plays a pivotal role in SARS-CoV-2 infection leading to a characteristic pattern of blood leukocytes. Lymphocyte, monocyte, basophil, and eosinophil counts are reduced in proportion to the severity of the disease. Severe lymphopenia is associate with delayed viral elimination and uncontrolled cytokine production, leading to influx of myeloid cells into the lungs. In particular, lung influx of blood eosinophils, mediated by interferon-γ secretion, is the key mechanism of alveolar inflammation. Eosinophil counts are related to the outcome of COVID-19 patients. Basophil depletion in the acute phase of COVID-19 is associated with down regulation of the antibody response to the virus. Several lines of evidence indicate that such leukocyte pattern represents a distinct cellular signature that could allow COVID-19 pneumonia to be identified among patients with CAP of different etiologies.
In conclusion, assessment of blood leukocyte counts at hospital admission in patients with CAP virtually rule out COVID-19 in those cases with basophils and eosinophils greater than 17 and 10 cells/mm3, respectively. Our findings will help to optimize the triage of patients with pneumonia pending the results of NAAT and they will also help to improve the management of false negative results on the first NPS.
community-acquired pneumonia (CAP)
nucleic acid amplification test (NAAT)
nasopharyngeal swab (NPS)
Không có nhận xét nào :
Đăng nhận xét