Several biomarkers have been checked and verified for use in improving risk rating and management resolutions in cases of community-acquired pneumonia (CAP) alongside the well-established severity scores.
Objective Our objective was to evaluate the veracity of the serum total cortisol level as a biomarker for assessing the severity of CAP.
Patients and methods Our research was a descriptive and prospective study of patients who have been diagnosed with CAP. All were admitted in the Chest Department of Assiut University Hospital between October 2017 and January 2019. The CAP severity was assessed for all enrolled patients by application of the pneumonia severity index (PSI). Serum total cortisol level was measured once in the morning (between 7 a.m. and 8 a.m.) within the first 24 h after admission. All of the patients were followed up until being discharged. The outcome variable was the intrahospital mortality.
Results This research enrolled 94 patients with CAP; of them, 62 (56%) patients survived, whereas the health of 32 (44%) patients deteriorated and they died. The nonsurvivors had significantly higher cortisol level in the serum compared with the survivors (34.15±9.78 vs. 24.90±8.89; P=0.04). Of the study population, 37 (39.4%) patients had normal cortisol level, whereas 57 (60.6%) had high cortisol level. It was noticed that patients with high cortisol level had a significantly higher PSI (140.75±48.31 vs. 103.56±43.57), and 87.2% of them had PSI class V. The serum cortisol level had a positive significant correlation with PSI points (r=0.45, P=0.01). In terms of the diagnostic performance of serum cortisol, it was noticed that serum cortisol at cutoff point more than 43 µg/dl had 80% sensitivity and 91% specificity to predict the intrahospital mortality in patients with CAP.
Conclusion The serum cortisol could be considered as a promising biomarker that is able to predict the severity and outcome of CAP. However, we recommend further larger studies with different aspects to investigate the accuracy of serum cortisol in assessing the severity of CAP and its potential effect on the treatment plan.