Specific Dynamic Variations in the Peripheral Blood Lymphocyte Subsets in COVID-19 and Severe Influenza a Patients: A Retrospective Observational Study

Abstract

Background: Both COVID-19 and influenza A contribute to increased mortality among the elderly and those with existing comorbidities. Changes in the underlying immune mechanisms determine patient prognosis. This study aimed to analyze the role of lymphocyte subsets in the immunopathogenesisof COVID-19 and severe influenza A, and examined the clinical significance of their alterations in the prognosis and recovery duration. Methods: By retrospectively reviewing of patients in four groups (healthy controls, severe influenza A, non-severe COVID-19 and severe COVID-19) who were admitted to Ditan hospital between 2018 to 2020, we performed flow cytometric analysis and compared the absolute counts of leukocytes, lymphocytes, and lymphocyte subsets of the patients at different time points (weeks 1–4). Results: We reviewed the patients’ data of 110 healthy blood donors, 80 Non-severe-COVID-19, 19 Severe-COVID-19 and 43 severe influenza A. We found total lymphocytes (0.93 × 109/L, 0.84 × 109/L vs 1.78 × 109/L, P < 0.0001) and lymphocyte subsets (T cells, CD4+ and CD8+ T cell subsets) of both severe patients to be significantly lower than those of healthy donors at early infection stages. Further, significant dynamic variations were observed at different time points (weeks 1–4). Conclusions: Our study indicates lymphopenia to be associated with disease severity and suggests the plausible role of lymphocyte subsets in disease progression, which in turn affects prognosis and recovery duration in patients with severe COVID-19 and influenza A.

Evaluation of peripheral lymphocyte subsets' alteration and IL6 serum level correlated with Severity and outcome in Corona virus disease 2019 (COVID-19)

“…Qian et al [17] agrees with the current study as they reported association between COVID-19 severity and old age.…”

“…Qian et al [17] and Khamiss et al [19] also studied comorbidities among COVID-19 patients; hypertension and diabetes were the most frequent co-morbidity followed by COPD and cardiovascular diseases which was similar to the present study.…”

Smaller reaction volume of triplex taqman real‐time reverse transcription‐PCR assays for diagnosing coronavirus disease 2019

“…Several studies have shown that the majority of the COVID‐19 patients can present with fever, cough, fatigue, headache, myalgia, and severe respiratory disease 6–8 . The most common manifestations of COVID‐19 patients are almost similar to SARS and MERS 9 .…”