AUTHOR=Gan Jiahua , Li Jingjing , Li Shusheng , Yang Chunguang 

TITLE=Leucocyte Subsets Effectively Predict the Clinical Outcome of Patients With COVID-19 Pneumonia: A Retrospective Case-Control Study

JOURNAL=Frontiers in Public Health

VOLUME=Volume 8 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2020.00299

DOI=10.3389/fpubh.2020.00299

ISSN=2296-2565

ABSTRACT=Background: 
Clinical characteristics of the coronavirus disease 2019 (COVID-19) have been well studied, while effective predictors for clinical outcome and research on underlying mechanism are scare.
Methods: 
Hospitalized COVID-19 pneumonia patients with definitive clinical outcome (cured or died) were retrospectively studied. The diagnostic performance of the leucocyte subsets and other parameters were compared using the area under the receiver operating characteristic curve value (AUC). Further, the correlations between leucocyte subsets and inflammation related factors associated with clinical outcome were subsequently investigated.
Results: 
Among 95 subjects included, 56 patients were cured and 39 cases died. Older age, higher aspartate aminotransferase levels, lower albumin levels, higher total bilirubin levels, higher serum lactate dehydrogenase levels, higher blood urea nitrogen levels, higher prothrombin time, high D-dimer levels, higher procalcitonin levels, higher serum cytokines (IL2R, IL6, IL8, IL10 and TNF-α) levels, higher leucocyte count or neutrophil count, lower lymphocyte count indicated poor outcome in patients with COVID-19 pneumonia. Lymphocyte subset (Lymphocyte, T cells, helper T cells, suppressor T cells, natural killer cells, T cells+ B cells+ NK cells) count was positively associated with clinical outcome (AUC: 0.777; AUC: 0.925; AUC: 0.900; AUC: 0.902; AUC: 0.877; AUC: 0.918, resp.). Neutrophil-to-lymphocyte ratio (NLR), neutrophil to T lymphocyte count ratio (NTR), neutrophil percentage to T lymphocyte ratio (NpTR) effectively predicted the mortality (AUC: 0.900; AUC: 0.905; AUC: 0.932, resp.). Binary logistic regression showed that NpTR was an independent prognostic factor for mortality. Serum IL6 levels were positively correlated with leucocyte count, neutrophil count and eosinophil count, while negatively correlated with lymphocyte count.
Conclusion:
These results indicate that leucocyte subsets predict the clinical outcome of patients with COVID-19 pneumonia in high efficiency. Non-self-limiting inflammatory response is involved in the development of fatal pneumonia.