{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,30]],"date-time":"2026-03-30T09:28:44Z","timestamp":1774862924147,"version":"3.50.1"},"reference-count":79,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,3,28]],"date-time":"2026-03-28T00:00:00Z","timestamp":1774656000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Polish Ministry of Education and Science","award":["602\/WIM"],"award-info":[{"award-number":["602\/WIM"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: An unfavorable course of SARS-CoV-2 infection can lead to significant morbidity and mortality. The study aimed to develop a simple, accessible, and reliable tool to anticipate the poor results among COVID-19 pneumonia patients. Methods: This retrospective cohort study involves 306 individuals with severe COVID-19 pneumonia enrolled between March 2021 and June 2021. Each patient had confirmed SARS-CoV-2 infection and required oxygen therapy. Differential blood count and serum CRP were taken on admission day. Medical data were collected from the hospital\u2019s information system. Results: Of 306 patients (133 females, 173 males, aged 66.3 \u00b1 15.2 years), 105 (34.3%) died. Counts of neutrophils, lymphocytes, and eosinophils differed significantly between survivors and deceased (p &lt; 0.001; p = 0.002; p = 0.009, respectively) and had substantially differentiating properties in ROC analysis. Built with the counts of neutrophils, lymphocytes, and eosinophils, the White Blood Cell Score (WBCS) was developed. WBCS robustly predicted mortality (OR = 2.821; CI: 2.037\u20133.906; p &lt; 0.001) in the investigated population. Cumulative risk of death according to WBCS (ranging from 0 to 3 points) was as follows: 0 points\u201410.9%, 1 point\u201423.5%, 2 points\u201433.1%, 3 points\u201434.1%. Conclusions: Based on differential blood count, the proposed WBCS is easy to use and can be helpful in predicting mortality among severe COVID-19 patients.<\/jats:p>","DOI":"10.3390\/jcm15072590","type":"journal-article","created":{"date-parts":[[2026,3,30]],"date-time":"2026-03-30T08:22:36Z","timestamp":1774858956000},"page":"2590","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["New Simplified White Blood Cells Score Improves Mortality Prediction in Severe COVID-19 Patients"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-2950-727X","authenticated-orcid":false,"given":"Kamil","family":"Pary\u017c","sequence":"first","affiliation":[{"name":"Department of Anesthesiology and Intensive Care, Military Institute of Medicine\u2014National Research Institute, Szaser\u00f3w 128 Str., 04-141 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3248-4615","authenticated-orcid":false,"given":"Arkadiusz","family":"Lubas","sequence":"additional","affiliation":[{"name":"Department of Nephrology, Internal Diseases and Dialysis, Military Institute of Medicine\u2014National Research Institute, Szaser\u00f3w 128 Str., 04-141 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-4870-7228","authenticated-orcid":false,"given":"Mateusz","family":"Gutowski","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Intensive Care, Military Institute of Medicine\u2014National Research Institute, Szaser\u00f3w 128 Str., 04-141 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bartosz","family":"Rustecki","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Intensive Care, Military Institute of Medicine\u2014National Research Institute, Szaser\u00f3w 128 Str., 04-141 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrzej","family":"Micha\u0142owski","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Intensive Care, Military Institute of Medicine\u2014National Research Institute, Szaser\u00f3w 128 Str., 04-141 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0195-2022","authenticated-orcid":false,"given":"Jakub","family":"Klimkiewicz","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Intensive Care, Military Institute of Medicine\u2014National Research Institute, Szaser\u00f3w 128 Str., 04-141 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,28]]},"reference":[{"key":"ref_1","unstructured":"(2024, July 18). 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