Clinical utility of serum procalcitonin in adult patients admitted with community-acquired pneumonia in Ilorin, Nigeria

Abstract

Objectives: The usefulness of biomarkers in community acquired pneumonia (CAP) has been under the research light with limited reports from Africa. This study aimed at evaluating the clinical usefulness of serum procalcitonin (PCT) in patients admitted with CAP in a tertiary hospital in Ilorin, Nigeria. Materials and Methods: This was prospective single center observational study of 102 admitted patients with clinical and radiologic features of CAP. All the patients had serum PCT assay, complete blood count, blood culture, sputum microbiology, and serological evaluation for atypical pathogens. Repeat PCT assay was done following 1 week of antibiotic therapy. The patients were classified into one of two diagnostic groups: Those with microbiologically confirmed bacterial CAP and those without bacterial CAP. Results: Over half (58/102; 56.8%) of the patients had microbiologically confirmed bacterial CAP. The baseline serum PCT concentrations were significantly higher in patients with bacterial CAP when compared to the non-bacterial CAP group (2.55 ± 0.14 vs. 0.94 ± 0.61 ng/ml; P < 0.001). There was also a statistically significant difference between the pre- and post-treatment serum PCT concentrations in the bacterial CAP group (P < 0.001) and the non-bacterial CAP group (P = 0.006). The area under the receiver operating characteristic (AUC) for pre-treatment PCT in diagnosing bacterial CAP was 0.795 (95% confidence level [CI]: 0.709–0.881) with a sensitivity of 67.2% and specificity of 79.5% at an optimal cutoff of 1.5 ng/ml. Overall, the biomarker was independently associated with white cell counts >10 × 109/L (AOR = 6.28; 95% CI: 1.30–30.32, P = 0.02). The baseline mean serum PCT levels were also significantly higher in patients admitted for 7 or more days (P = 0.010). Conclusion: Serum PCT had good diagnostic strength in patients admitted with bacterial CAP in Ilorin. The biomarker can also assist clinicians with predicting the pathogenic group and monitoring clinical progress of CAP.