C-reactive Protein Variation and Its Usefulness in the Prognostication and Monitoring of Patients With Pneumococcal Pneumonia.

Background and objective Community-acquired pneumonia (CAP) is a prevalent and life-threatening infection that causes significant morbidity and mortality. Biomarkers, such as C-reactive protein (CRP), can help to diagnose, monitor, and prognose patients with this condition. This study aimed to analyze the disease course, the CRP peak concentration, its relationship with prognosis, and its variation in hospitalized patients with pneumococcal CAP. Methodology This study included 797 patients diagnosed with pneumococcal CAP and admitted over four years to four different Portuguese hospitals, either to the ICU or the general ward. Results Although CRP peak concentration was not a good predictor of overall hospital mortality, higher peak concentration in older patients (>60 years) was associated with a dismal hospital prognosis. In contrast, younger patients who survived hospital discharge had a non-significant higher peak CRP concentration. A faster time until CRP decreased to at least half of its peak value also correlated with favorable outcomes after adjusting for age and bacteremia [failure to achieve a 50% decrease was associated with an adjusted hazard ratio (HR) for hospital mortality of 6.45; 95% confidence interval (CI): 4.30-9.69]. Conclusions Based on our findings, CRP may be a useful biomarker in the hospital setting for diagnosing and monitoring patients with pneumococcal CAP. Clinicians must be aware of its unique properties, clinical applications, and varying behaviors according to patient age groups.