Aim of the Work: To study the role of procalcitonin as a predictor for severity and etiology of
community acquired pneumonia (CAP).
Subjects and Methods: This study was carried out on 60 hospitalized adult patients with CAP
classified into; group I included 30 mild and moderate (15 atypical and 15 typical CAP) and group II included 30 patients with severe CAP (15 atypical and 15 with typical CAP). All subjects were submitted to full history, full clinical examination, chest X-ray (postero-anterior and lateral views) and CT chest in some cases, routine laboratory investigations (complete blood count, liver function tests, kidney function tests and fasting blood sugar), arterial blood gases, microbiological workup, H1N1 and Corona viruses were performed for all patients according to policy of ministry of health, Kingdom of Saudi Arabia. Procalcitonin (PCT) measured within 24 hours of admission.
Results: The study revealed significant higher level of PCT levels in patients with severe CAP regardless atypical or atypical-with no significant difference between severe atypical and typical CAP. Significant higher PCT levels in patients with severe CAP than patients with mild and moderate CAP. Significant higher level of PCT levels in patients with mild and moderate typical CAP than mild and moderate atypical CAP. The X-Ray and CT findings in relation to typical and atypical CAP revealed that the highest PCT level was recorded in consolidation pattern CAP followed by peri-bronchial pattern then ground glass pattern while the lowest level was recorded in random nodular pattern. Positive correlation between Severity of pneumonia according to pneumonia severity index and PCT level .
Conclusions: PCT measurement may provide an important predictor for severity of CAP, while
play a little role as a predictor of etiology.