ABSTRACT
How to cite this article: Vadi S, Pednekar A, Suthar D, Sanwalka N, Ghodke K, Rabade N. In Response to Author: COVID-19 and T Cells: Do T Cells Really Matter? Indian J Crit Care Med 2023;27(1):76.
ABSTRACT
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes pneumonia and lymphopenia. We investigated the predictive value of T-lymphocyte subset absolute counts for outcomes following coronavirus disease-2019 (COVID-19)-associated acute respiratory failure (C-ARF). Patients and methods: A retrospective chart review of adult patients with C-ARF was undertaken from 23 March 2020 to 20 November 2021 to obtain relevant data. Patients were divided into two groups based on survival. The T-lymphocyte subsets were determined by flow cytometric analysis. A binomial logistic regression was performed to ascertain factors affecting survival. Cut-off values to differentiate between survivors and non-survivors were identified with the receiver operating characteristic (ROC) analysis. Results: A total of 379 patients were analyzed. Age was negatively correlated with survival. Non-survivors had significantly lower T-lymphocyte subset absolute counts than survivors. Serum ferritin levels were significantly higher in non-survivors. Baseline lymphocyte (%) and a subset were predictive of survival in patients [lymphocyte (%) <5.65%, CD3+ <321 cells/µL, CD4+ <205 cells/µL, CD8+ <103 cells/µL]. Conclusions: Lower T-lymphocyte subsets were associated with higher mortality in patients with C-ARF. Monitoring trends may help in identifying patients at increased risk of poor outcomes. How to cite this article: Vadi S, Pednekar A, Suthar D, Sanwalka N, Rabade N, Ghodke K. Association of Mortality with Lymphocyte Subset in Patients with COVID-19-associated Acute Respiratory Failure: A Subgroup Analysis. Indian J Crit Care Med 2023;27(1):52-56.
ABSTRACT
Background: Of the factors influencing severity and outcomes following coronavirus disease-2019 (COVID-19), cellular immune response has a strong impact. The spectrum of response varies from over-activation to hypo-functioning. The severe infection leads to reduction in numbers and dysfunction of T-lymphocytes/subsets. Patients and methods: This retrospective, single-center study aimed to analyze the expression of T-lymphocyte/subsets by flow cytometry and inflammation-related biomarker, serum ferritin in real-time polymerase chain reaction (RT-PCR) positive patients. According to oxygen requirements, patients were stratified into nonsevere (room air, nasal prongs, and face mask) and severe [nonrebreather mask (NRBM), noninvasive ventilation (NIV), high-flow nasal oxygen (HFNO), and invasive mechanical ventilation (IMV)] subgroups for analysis. Patients were classified into survivors and nonsurvivors. Mann-Whitney U test was used to analyze differences in T-lymphocyte and subset values when classified according to gender, the severity of COVID, outcome, and prevalence of diabetes mellitus (DM). Cross tabulations were computed for categorical data and compared using Fisher's exact test. Spearman correlation was used to analyze the correlation of T-lymphocyte and subset values with age or serum ferritin levels. p <0.05 values were considered to be statistically significant. Results: A total of 379 patients were analyzed. Significantly higher percentage of patients with DM were aged ≥61 years in both nonsevere and severe COVID groups. A significant negative correlation of CD3+, CD4+, and CD8+ was found with age. CD3+ and CD4+ absolute counts were significantly higher in females as compared to males. Patients with severe COVID had significantly lesser total lymphocyte (%), CD3+, CD4+, and CD8+ counts as compared to those with nonsevere COVID (p <0.05). T-lymphocyte subsets were reduced in patients with severe disease. A significant negative correlation of total lymphocyte (%), CD3+, CD4+, and CD8+ counts was found with serum ferritin levels. Conclusions: T-lymphocyte/subset trends are an independent risk factor for clinical prognosis. Monitoring may help in intervening in patients with disease progression. How to cite this article: Vadi S, Pednekar A, Suthar D, Sanwalka N, Ghodke K, Rabade N. Characteristics and Predictive Value of T-lymphocyte Subset Absolute Counts in Patients with COVID-19-associated Acute Respiratory Failure: A Retrospective Study. Indian J Crit Care Med 2022;26(11):1198-1203.