Correlation between NRS-2002 scores and PD-1/CTLA-4 expression levels in patients with community-acquired pneumonia

This study aimed to investigate the association between nutritional status, T cell-mediated immunosuppression involving PD-1 and CTLA-4, and the prognosis of patients with community-acquired pneumonia (CAP). Following the enrollment protocol, 60 participants were recruited, and their medical records were collected. Blood samples were obtained to assess the expression of PD-1 and CTLA-4 across different T-cell subsets. Logistic regression analysis revealed no significant association between PD-1/CTLA-4 expression and severe CAP (SCAP) or 28-day mortality. However, elevated levels of PD-1 and CTLA-4 on CD4 + T cells correlated with higher Pneumonia Severity Index (PSI) scores. Patients identified as being at malnutrition risk (Nutritional Risk Screening [NRS-2002] score ≥ 3) exhibited a higher proportion of SCAP and experienced prolonged hospital stays compared to those without nutritional risk. Furthermore, higher expression levels of PD-1 and CTLA-4 were observed in the malnutrition risk group. Malnutrition was associated with longer hospitalization and an increased risk of severe CAP. Elevated PD-1 and CTLA-4 expression on CD4 + T cells was linked to higher PSI scores. These findings suggest that nutritional status may influence the development of immunosuppression, potentially through pathways involving PD-1 and CTLA-4.