Rezk Ahmed, Bakry Nehad, Elfiky Samar, Metawaa Maha, Ibrahim Ahmed
Department of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Department of Pediatrics, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
Front Pediatr. 2025 Sep 11;13:1627451. doi: 10.3389/fped.2025.1627451. eCollection 2025.
Effective biomarkers are essential for improving the diagnosis and risk stratification of pediatric pneumonia. This study aimed to evaluate the diagnostic and prognostic utility of salivary and serum interleukin (IL)-6, interleukin (IL)-10, and procalcitonin (PCT) in children diagnosed with pneumonia.
A prospective case-control study was conducted involving 50 children under five years of age with community-acquired pneumonia (CAP) and 50 age- and sex-matched healthy controls. At admission, serum and saliva samples were collected, and levels of PCT, IL-6, and IL-10 were measured using ELISA. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance of each biomarker in distinguishing children with pneumonia from healthy controls. Multivariate logistic regression was then applied to identify independent predictors of disease severity.
All three biomarkers demonstrated exceptional diagnostic accuracy in distinguishing pneumonia from healthy controls. Salivary PCT (>68.5 pg/ml, AUC = 1.000) and serum IL-10 (>73.18 pg/ml, AUC = 1.000) achieved perfect diagnostic performance with 100% sensitivity and 100% specificity. Serum IL-6 (>18.06 ng/L, AUC = 0.994) and serum PCT (>86.66 pg/ml, AUC = 0.962) also demonstrated excellent accuracy with 96% sensitivity and 100% specificity. The neutrophil-to-lymphocyte ratio (>0.8, AUC = 1.000) similarly achieved 100% sensitivity and specificity. Severe pneumonia was associated with higher IL-10 and PCT levels (both serum and saliva), younger age, elevated heart rate, and higher CRP. IL-6 did not correlate with severity. In multivariate analysis, age <6 months (OR: 3.85), neutrophil-to-lymphocyte ratio (OR: 3.40), serum IL-10 (OR: 5.75), and salivary PCT (OR: 4.25) independently predicted severe pneumonia.
Salivary and serum IL-6, IL-10, and PCT show promising diagnostic potential for pediatric pneumonia when compared to healthy controls. IL-10 and PCT also demonstrate prognostic value for severity stratification, with salivary measurements closely mirroring serum results. While these findings suggest potential for saliva-based diagnostics as non-invasive tools for early detection and severity assessment in pediatric pneumonia, validation in clinical settings with symptomatic controls is needed to establish their practical diagnostic utility in differentiating pneumonia from other febrile illnesses.
有效的生物标志物对于改善儿童肺炎的诊断和风险分层至关重要。本研究旨在评估唾液和血清白细胞介素（IL）-6、白细胞介素（IL）-10和降钙素原（PCT）在诊断为肺炎的儿童中的诊断和预后效用。
进行了一项前瞻性病例对照研究，纳入50名5岁以下社区获得性肺炎（CAP）儿童和50名年龄及性别匹配的健康对照。入院时采集血清和唾液样本，采用酶联免疫吸附测定法（ELISA）测量PCT、IL-6和IL-10水平。采用受试者工作特征（ROC）曲线分析评估每种生物标志物在区分肺炎患儿与健康对照方面的诊断性能。然后应用多因素逻辑回归确定疾病严重程度的独立预测因素。
所有三种生物标志物在区分肺炎与健康对照方面均显示出卓越的诊断准确性。唾液PCT（>68.5 pg/ml，AUC = 1.000）和血清IL-10（>73.18 pg/ml，AUC = 1.000）实现了完美的诊断性能，敏感性和特异性均为100%。血清IL-6（>18.06 ng/L，AUC = 0.994）和血清PCT（>86.66 pg/ml，AUC = 0.962）也显示出优异的准确性，敏感性为96%，特异性为100%。中性粒细胞与淋巴细胞比值（>0.8，AUC = 1.000）同样实现了100%的敏感性和特异性。重症肺炎与较高的IL-10和PCT水平（血清和唾液）、年龄较小、心率升高及较高的C反应蛋白相关。IL-6与严重程度无关。在多因素分析中，年龄<6个月（OR：3.85）、中性粒细胞与淋巴细胞比值（OR：3.40）、血清IL-10（OR：5.75）和唾液PCT（OR：4.25）独立预测重症肺炎。
与健康对照相比，唾液和血清IL-6、IL-10及PCT在儿童肺炎诊断方面显示出有前景的潜力。IL-10和PCT在严重程度分层方面也显示出预后价值，唾液测量结果与血清结果密切相似。虽然这些发现提示基于唾液的诊断作为儿童肺炎早期检测和严重程度评估的非侵入性工具具有潜力，但需要在有症状对照的临床环境中进行验证，以确定它们在区分肺炎与其他发热性疾病方面的实际诊断效用。
