Nyamande K, Lalloo U G
Department of Medicine, Nelson R Mandela School of Medicine, Faculty of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.
Int J Tuberc Lung Dis. 2006 May;10(5):510-5.
Procalcitonin (PCT), a propeptide of the hormone calcitonin, is a novel marker of the inflammatory response to infection. It has been used to discriminate between infectious and non-infectious causes of inflammation, and as a marker of severe sepsis in the intensive care unit.
To evaluate the utility of PCT in distinguishing community-acquired pneumonia (CAP) due to common bacteria, Mycobacterium tuberculosis and Pneumocystis jirovecii in a high human immunodeficiency virus (HIV) prevalence setting.
Two hundred and sixty-six patients admitted with a diagnosis of CAP were investigated. Serum samples for PCT were collected on admission. PCT levels were measured using a commercial immunoluminometric assay.
A microbiological diagnosis was obtained in 169/266 patients: 44 pulmonary tuberculosis (PTB), 31 P. jirovecii pneumonia (PJP), and 35 bacterial pneumonia. The PCT levels were PTB 4.16 ng/ml (SEM 1.197; 95% CI 1.749-6.579); PJP 1.138 ng/ml (SEM 0.2911; 95% CI 0.543-1.734); and bacterial pneumonia 19.48 ng/ml (SEM 5.64; 95% CI 8.021-30.938, P < 0.0004). Thirty-six had co-infections.
PCT levels differ significantly in patients with CAP due to TB, PJP and bacteria. PCT may be important in distinguishing M. tuberculosis and PJP in a high HIV prevalence setting where atypical presentations often confound the empirical clinical diagnosis.
降钙素原（PCT）是降钙素激素的前肽，是感染炎症反应的一种新型标志物。它已被用于区分炎症的感染性和非感染性病因，并作为重症监护病房严重脓毒症的标志物。
在人类免疫缺陷病毒（HIV）高流行率的情况下，评估PCT在鉴别由常见细菌、结核分枝杆菌和耶氏肺孢子菌引起的社区获得性肺炎（CAP）中的作用。
对266例诊断为CAP的住院患者进行调查。入院时采集PCT血清样本。使用商业免疫发光分析法测量PCT水平。
169/266例患者获得微生物学诊断：44例肺结核（PTB），31例耶氏肺孢子菌肺炎（PJP），35例细菌性肺炎。PCT水平分别为：PTB 4.16 ng/ml（标准误1.197；95%可信区间1.749 - 6.579）；PJP 1.138 ng/ml（标准误0.2911；95%可信区间0.543 - 1.734）；细菌性肺炎19.48 ng/ml（标准误5.64；95%可信区间8.021 - 30.938，P < 0.0004）。36例有合并感染。
因结核病、PJP和细菌导致CAP的患者PCT水平有显著差异。在HIV高流行率的情况下，非典型表现常使经验性临床诊断混淆，PCT在鉴别结核分枝杆菌和PJP方面可能很重要。
