From the *Division of Pediatric Emergency Medicine; †Department of Child and Adolescent Medicine, Geneva University Hospitals and University of Geneva, Geneva; ‡Child and Adolescent Department, University Hospital, Lausanne, Switzerland; §Sanofi Pasteur, Marcy l'Etoile, France; and ¶Sanofi Pasteur, Toronto, Canada.
Pediatr Infect Dis J. 2013 Nov;32(11):1175-9. doi: 10.1097/INF.0b013e31829ba62a.
Our objective was to evaluate procalcitonin (PCT) and C-reactive protein (CRP) as predictors of a pneumococcal etiology in community-acquired pneumonia (CAP) in hospitalized children.
Children requiring hospitalization for CAP were prospectively enrolled. The following indices were determined: antibodies against pneumococcal surface proteins (anti-PLY, pneumococcal histidine triad D, pneumococcal histidine triad E, LytB and pneumococcal choline-binding protein A), viral serology, nasopharyngeal cultures and polymerase chain reaction for 13 respiratory viruses, blood pneumococcal polymerase chain reaction, pneumococcal urinary antigen, PCT and CRP. Presumed pneumococcal CAP (P-CAP) was defined as a positive blood culture or polymerase chain reaction for Streptococcus pneumoniae or as a pneumococcal surface protein seroresponse (≥2-fold increase).
Seventy-five patients were included from which 37 (49%) met the criteria of P-CAP. Elevated PCT and CRP values were strongly associated with P-CAP with odds ratios of 23 (95% confidence interval: 5-117) for PCT and 19 (95% confidence interval: 5-75) for CRP in multivariate analysis. The sensitivity was 94.4% for PCT (cutoff: 1.5 ng/mL) and 91.9% for CRP (cutoff: 100 mg/L). A value≤0.5 ng/mL of PCT ruled out P-CAP in >90% of cases (negative likelihood ratio: 0.08). Conversely, a PCT value≥1.5 ng/mL associated with a positive pneumococcal urinary antigen had a diagnostic probability for P-CAP of almost 80% (positive likelihood ratio: 4.59).
PCT and CRP are reliable predictors of P-CAP. Low cutoff values of PCT allow identification of children at low risk of P-CAP. The association of elevated PCT or CRP with a positive pneumococcal urinary antigen is a strong predictor of P-CAP.
我们的目的是评估降钙素原（PCT）和 C 反应蛋白（CRP）作为社区获得性肺炎（CAP）中肺炎球菌病因的预测因子。
前瞻性纳入需要住院治疗 CAP 的儿童。测定以下指标：肺炎球菌表面蛋白抗体（抗 PLY、肺炎球菌组氨酸三肽 D、肺炎球菌组氨酸三肽 E、LytB 和肺炎球菌胆碱结合蛋白 A）、病毒血清学、鼻咽培养和 13 种呼吸道病毒的聚合酶链反应、血培养肺炎球菌聚合酶链反应、肺炎球菌尿抗原、PCT 和 CRP。假定肺炎球菌 CAP（P-CAP）定义为血培养或聚合酶链反应阳性的链球菌肺炎球菌或肺炎球菌表面蛋白血清学反应（≥2 倍增加）。
共纳入 75 例患者，其中 37 例（49%）符合 P-CAP 标准。在多变量分析中，PCT 和 CRP 值升高与 P-CAP 密切相关，PCT 的优势比为 23（95%置信区间：5-117），CRP 的优势比为 19（95%置信区间：5-75）。PCT 的灵敏度为 94.4%（截断值：1.5ng/mL），CRP 的灵敏度为 91.9%（截断值：100mg/L）。PCT 值≤0.5ng/mL 可排除 90%以上的 P-CAP 病例（阴性似然比：0.08）。相反，PCT 值≥1.5ng/mL 与阳性肺炎球菌尿抗原相关时，对 P-CAP 的诊断概率几乎为 80%（阳性似然比：4.59）。
PCT 和 CRP 是 P-CAP 的可靠预测因子。PCT 的低值可识别低风险 P-CAP 的儿童。升高的 PCT 或 CRP 与阳性肺炎球菌尿抗原相关是 P-CAP 的强烈预测因子。
