Evaluating Immunological Markers and Procalcitonin Expression in Elderly Athletes: Insights into Health Management and Prognosis Following Bacterial Infections

Abstract

Objective: To examine the dynamics of blood lymphocytes and serum Procalcitonin (PCT) expression in elderly athletes with bacteremia, and assess their correlation with short-term health outcomes to better understand immune function in this active population. Methods: This study involved 65 elderly patients with suspected bacteremia at Gulou Hospital affiliated with Nanjing University from January 2017 to March 2021. These included former and current athletes, with data collected on demographics, medical history, and clinical scores. Blood samples were taken at specific intervals post-admission to analyze lymphocyte counts, PCT levels, and CRP via immunochemiluminescence and immunoturbidimetry. Patients were categorized based on blood culture results into a bacteremia-positive group and a control group, and further divided based on 28-day treatment outcomes into effective and ineffective groups. The study primarily aimed to link lymphocyte and PCT levels with patient prognosis. Results: Among the 42 confirmed cases of bacteremia, lymphocyte counts including CD4+ T cells and NK cells were significantly lower in the bacteremia-positive group compared to controls (p<0.05). PCT levels were notably higher in the bacteremia group (p><0.05). Patients in the effective treatment group showed an increase in lymphocyte counts and a decrease in PCT levels over 7 days, indicating a positive response to treatment. Conversely, the ineffective > <0.05). PCT levels were notably higher in the bacteremia group (p<0.05). Patients in the effective treatment group showed an increase in lymphocyte counts and a decrease in PCT levels over 7 days, indicating a positive response to treatment. Conversely, the ineffective treatment group showed a decline in lymphocytes and an increase in CRP, suggesting ongoing immune challenges (p<0.05). Conclusion: Elderly athletes with bacteremia exhibit suppressed immune function, as indicated by reduced lymphocyte counts. Recovery in lymphocyte levels post-treatment correlates with better prognosis, highlighting the importance of monitoring these parameters in managing health outcomes. Regular physical activity may influence these dynamics, suggesting that maintaining fitness could play a role in immune resilience. PCT serves as a sensitive marker for differentiating bacterial infection severity and monitoring recovery, essential for early intervention and tailored treatment strategies in this population.