The primary objective was to compare serum interleukin-1 receptor antagonist (IL-1RA) levels in cases of community acquired pneumonia (CAP) and healthy age-gender-matched controls. The secondary objective was to compare serum IL-1RA levels in cases which were positive or negative for Streptococcus pneumoniae in the blood by real-time-polymerase chain reaction (RT-PCR). Hospitalized children with World Health Organization defined CAP, aged 2-59 months, were included as cases. Healthy controls were recruited from the immunization clinic of the hospital. Enzyme-linked immunosorbent assay (ELISA) test was used to detect serum IL-1RA levels. Identification of S.pneumoniae in blood was done by RT-PCR. From October 2019 to October 2021, 330 cases (123, 37.27% female) and 330 controls (151, 45.75% females) were recruited. Mean serum IL-1RA levels (ng/ml) were 1.36 ± 0.95 in cases and 0.25 ± 0.25 in controls (p < 0.001). Within cases, serum IL-1RA levels were significantly higher in those whose RT-PCR was positive for S.pneumoniae. Thus serum IL-1RA levels may be evaluated as a surrogate marker of S.pneumoniae in future studies.

中文翻译：

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评估患有和不患有社区获得性肺炎的儿童中白细胞介素 1 受体拮抗剂 (IL-1RA) 水平：一项以医院为基础的病例对照研究。

主要目的是比较社区获得性肺炎 (CAP) 病例和年龄性别匹配的健康对照者的血清白介素 1 受体拮抗剂 (IL-1RA) 水平。次要目标是通过实时聚合酶链式反应 (RT-PCR) 比较血液中肺炎链球菌阳性或阴性病例的血清 IL-1RA 水平。世界卫生组织定义的2-59个月的CAP住院儿童被纳入病例。健康对照是从医院免疫门诊招募的。采用酶联免疫吸附试验（ELISA）检测血清IL-1RA水平。通过RT-PCR 鉴定血液中的肺炎链球菌。2019年10月至2021年10月，招募了330例病例（123例，女性37.27%）和330例对照者（151例，45.75%女性）。病例中平均血清 IL-1RA 水平 (ng/ml) 为 1.36 ± 0.95，对照组为 0.25 ± 0.25 (p < 0.001)。在病例中，RT-PCR 肺炎链球菌阳性患者的血清 IL-1RA 水平显着较高。因此，在未来的研究中，血清IL-1RA水平可以作为肺炎链球菌的替代标志物进行评估。