Comparison of serum procalcitonin and c-reactive protein in diagnosis of bacterial meningitis

ABSTRACT

The diagnostic accuracy of Procalcitonin [PCT] as compared with C - reactive protein [CRP] for early diagnosis of bacterial meningitis in children was evaluated. Descriptive diagnostic study. This study was conducted in Pathology department of Army Medical College Rawalpindi from September 2007 to September 2008. Descriptive diagnostic accuracy study was conducted in Pathology Department of the Army Medical College, Rawalpindi. Total 77 subjects consisted of 31 patients of bacterial meningitis and 46 healthy children were included as controls from the Military hospital, Rawalpindi. The patients comprised of 18 [58%] male and 13 [42%] female with mean age 6 years. Patient's investigations including cerebrospinal fluid [CSF] examination and culture were carried out at admission. PCT and CRP were analyzed on Vidas analyzer and Immulite 1000 respectively. PCT levels were significantly high median [range] of 4.5 ng/ml [0.10-19.00] ng/ml than controls 0.45 ng/ml [0.10-3.00]. Serum CRP levels were moderately elevated with median [range] 11 mg /L [0.30 - 23.00] as compared with 0.30 mg/L [0.30-9.5] controls. The Area under receiver characteristic curve of PCT 0.86 [95% CI 0.76-0.93] was significantly higher than CRP 0.72 [95% CI 0.61-0.82]. The optimum diagnostic cutoff point for PCT and CRP were 2 ng/ ml and 6 mg/L respectively by ROC analysis. PCT had maximum sensitivity 74% and specificity 84% at cutoff > 2 ng/ ml while CRP revealed sensitivity 58% and specificity 83% at cutoff > 6mg/ L. This study has demonstrated PCT as a more reliable diagnostic marker than CRP for early diagnosis of bacterial meningitis and can be used in combination with clinical evaluation for proper management of the seriously ill children