Cell population data: Could a routine hematology analyzer aid in the differential diagnosis of COVID‐19?

• Published in: International Journal of Laboratory Hematology Vol. 43; no. 2; pp. e64 - e67
• Main Authors: Lapić, Ivana, Brenčić, Tina, Rogić, Dunja, Lukić, Maja, Lukić, Iva, Kovačić, Monika, Honović, Lorena, Šerić, Vatroslav
• Format: Journal Article Web Resource
• Language: English
• Published: England John Wiley & Sons, Inc 01.04.2021; Wiley Subscription Services, Inc
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Automation, Laboratory; Biomarkers - analysis; C-Reactive Protein - immunology; C-Reactive Protein - metabolism; Child; COVID-19; COVID-19 - diagnosis; COVID-19 - immunology; COVID-19 - pathology; COVID-19 - virology; Diagnosis, Differential; Differential diagnosis; Erythrocyte Count; Female; Hematology - instrumentation; Humans; Leukocyte Count; Male; Middle Aged; Monocytes - immunology; Monocytes - pathology; Monocytes - virology; Neutrophils - immunology; Neutrophils - pathology; Neutrophils - virology; Platelet Count; Respiratory Tract Infections - diagnosis; Respiratory Tract Infections - immunology; Respiratory Tract Infections - pathology; Respiratory Tract Infections - virology; Retrospective Studies; SARS-CoV-2 - immunology; SARS-CoV-2 - pathogenicity; Severity of Illness Index; T-Lymphocytes - immunology; T-Lymphocytes - pathology; T-Lymphocytes - virology
• ISSN: 1751-5521; 1751-553X
• DOI: 10.1111/ijlh.13368

Dear Editors, The outbreak of coronavirus disease 2019 (COVID‐19), caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has lately become a major public health concern, in which laboratory diagnostics plays a pivotal role in terms of timely diagnosis, but also monitoring, prognosis, prediction, and detection of underlying complications. Cell population data (CPD) are background parameters derived from optical signals during differential leukocyte count that reflect morphological and functional characteristics of neutrophils (NE), lymphocytes (LY), and monocytes (MO) and are readily available with every routinely performed CBC measurement.3 Hereby, we hypothesized that activation of the immune response triggered by SARS‐CoV‐2 causes cell changes that might be detected and quantified using CPD, and evaluated the potential of CPD parameters in the differential diagnosis of COVID‐19. Description and clinical significance of listed CPD parameters3-6 Parameter Cell morphology Optical signals Clinical significance of increased values NE‐SSC Internal cell complexity Side‐scattered light intensity Presence of greater amounts of granules, vacuoles, or other cytoplasmic inclusions LY‐X MO‐X NE‐WX Side‐scattered light distribution width Greater cell population heterogeneity with respect to NE‐SCC, LY‐X, and MO‐X LY‐WX MO‐WX NE‐SFL Nucleic acid content Fluorescent light intensity Increases in proportion to the amount of cellular DNA or RNA (immature granulocytes, band cells, and activated or blast cells) LY‐Y MO‐Y NE‐WY Fluorescent light distribution width Greater heterogeneity of cell population with respect to NE‐SFL, LY‐Y, and MO‐Y LY‐WY MO‐WY NE‐FSC Cell size Forward‐scattered light intensity Abnormal cell size LY‐Z MO‐Z NE‐WZ Forward‐scattered light distribution width Greater heterogeneity of cell population with respect to NE‐FSC, LY‐Z, and MO‐Z LY‐WZ MO‐WZ Abbreviations: LY, lymphocyte; MO, monocyte; NE, neutrophil. Leukocyte count, absolute and relative neutrophil, lymphocyte and monocyte count, leukocyte subpopulations, cell population data, and C‐reactive protein in COVID‐19‐positive and COVID‐19‐negative cases Parameter (unit) COVID‐19 group (N = 114) Non‐COVID‐19 group (N = 88) P‐value WBC (×109/L) 5.3 (4.5‐6.8) 9.9 (7.1‐13.8) <.001* * Statistically significant P‐values obtained by Mann‐Whitney test. >10 × 109/L (%) 6 (5.3) 42 (47.7) <3 × 109/L (%) 1 (0.9) 5 (5.7) NE (%) 61.1 (52.8‐69.8) 77.7 (69.2‐86.0) <.001* * Statistically significant P‐values obtained by Mann‐Whitney test.