Dados do Trabalho

Título

Lymphopenia in Critical Care COVID-19 Patients: Unveiling an Unprecedented Immunological Conundrum

Objetivo

Lymphopenia has been recognized as a hallmark in critically ill COVID-19 patients, potentially associated with multiorgan dysfunction and disease severity. However, its true influence on patient survival remains elusive. We aim to determine lymphopenia's impact on critical COVID-19 patient outcomes.

Métodos

Multicenter prospective cohort study performed in 5 hospitals in Portugal and Brazil between 2020-2021, electing adult patients admitted to ICU with SARS-CoV-2 pneumonia. Patients were categorized based on lymphocyte counts within 48 hours of ICU admission: Lymphopenia group (Lymphocyte serum count<1 x109/L) and non-Lymphopenia group. Linear regression, propensity score matching, Kaplan-Meier survival curves, and Cox proportional hazards regression analysis were used.

Resultados

912 patients were included, 191 patients in the non-Lymphopenia group and 721 (79.1%) in the Lymphopenia group. Patients with lymphopenia exhibited significantly higher disease severity indexes (SOFA score and SAPS III at ICU admission (p=0.001 and p<0.001 respectively)), augmented proinflammatory profile (maximum registered C-reactive Protein 7.4 (4.7; 16.5) vs 6.4 (2.9; 14.9), p=0.005), heightened vasopressor support requirement (p=0.045) and longer ICU and in-hospital length of stay (both p<0.001). Although Kaplan-Meier curves yielded no disparity between groups in non-matched analysis (log-rank test p=0.092), propensity score matching exposed increased mortality rates at 28 days within the lymphopenia group (log-rank test p=0.031). Cox regression modeling revealed age and SOFA score at admission as primary mortality contributors (HR 1.068 (1.028-1.11) and 1.185 (1.026-1.369), p=0.001 and p=0.021, respectively).

Conclusão

Lymphopenia in COVID-19 patients is associated with higher disease severity and higher risk of mortality and should promote prompt support to critically ill high-risk patients.