Department of Pediatric Pulmonology, Faculty of Medicine, Gazi University, Ankara, Turkey.
Department of Pediatric Pulmonology, Meram Medicine Faculty, Necmettin Erbakan University, Konya, Turkey.
Eur J Pediatr. 2022 Aug;181(8):3093-3101. doi: 10.1007/s00431-022-04528-2. Epub 2022 Jun 16.
The exact immunological mechanisms of post infectious bronchiolitis obliterans (PIBO) in childhood are not fully known. It has been shown that the inflammasome and IL-18 pathway play important roles in the pathogenesis of lung fibrosis. We aimed to investigate the role of caspase-1, IL-18, and IL-18 components in PIBO. From January to May 2020, children with PIBO, children with history of influenza infection without PIBO, and healthy children were asked to participate in the study in three pediatric pulmonology centers. Serum caspase-1, IL-18, IL-18BP, IL-18R, and INF-γ levels were measured by ELISA and compared between the 3 groups. There were 21 children in the PIBO group, 16 children in the influenza group, and 39 children in the healthy control group. No differences in terms of age and gender between the 3 groups were found. IL-18 and IL-18BP levels were higher in the healthy control group (p = 0.018, p = 0.005, respectively). IL-18R was higher in the PIBO group (p = 0.001) and caspase-1 was higher in the PIBO and influenza group than the healthy control group (p = 0.002). IFN-γ levels did not differ between the 3 groups. IL-18BP/IL-18 was higher in the influenza group than the PIBO group and the healthy control group (p = 0.003).
Caspase-1 level was increased in patients with PIBO which suggests that inflammasome activation may have a role in fibrosis; however, IL-18 level was found to be low. Mediators other than IL-18 may be involved in the inflammatory pathway in PIBO. Further immunological studies investigating inflammasome pathway are needed for PIBO with chronic inflammation.
• Post infectious bronchiolitis obliterans (PIBO) is a rare, severe chronic lung disease during childhood which is associated with inflammation and fibrosis which lead to partial or complete luminal obstruction especially in small airways. • The exact immunological mechanisms of PIBO in childhood are not fully known.
• Inflammasome activation persists even years after acute infection and may play a role in fibrosis in PIBO. • Mediators other than IL-18 may be involved in these inflammatory pathway.
研究半胱天冬酶-1（caspase-1）、白细胞介素-18（IL-18）及其成分在闭塞性细支气管炎后（PIBO）中的作用。
2020 年 1 月至 5 月，在 3 个儿科呼吸中心邀请患有 PIBO 的儿童、患有流感感染但无 PIBO 的儿童和健康儿童参加研究。通过 ELISA 测定血清 caspase-1、IL-18、IL-18BP、IL-18R 和 INF-γ 水平，并比较 3 组间的差异。
PIBO 组 21 例，流感组 16 例，健康对照组 39 例。3 组间年龄、性别无差异。健康对照组的 IL-18 和 IL-18BP 水平较高（p=0.018，p=0.005）。PIBO 组 IL-18R 较高（p=0.001），PIBO 组和流感组 caspase-1 均高于健康对照组（p=0.002）。3 组间 IFN-γ 水平无差异。流感组 IL-18BP/IL-18 高于 PIBO 组和健康对照组（p=0.003）。
PIBO 患者 caspase-1 水平升高提示炎症小体激活可能在纤维化中起作用，但 IL-18 水平较低。PIBO 中炎症途径可能涉及其他介质而非 IL-18。需要进一步进行免疫炎症小体通路研究以了解慢性炎症的 PIBO。
