Oderda Giuseppina, Vivenza Daniela, Rapa Anna, Boldorini Renzo, Bonsignori Ilaria, Bona Gianni
Department of Pediatrics, Clinica Pediatrica,Università del Piemonte Orientale, Novara, Italy.
J Pediatr Gastroenterol Nutr. 2007 Sep;45(3):301-5. doi: 10.1097/MPG.0b013e3180ca8960.
A protective effect of Helicobacter pylori infection against allergic diseases has been reported. The increasing incidence of childhood allergy in developed countries may be a result of reduced stimulation of the immune system by early chronic infections, with the protective effect of gastrointestinal microbes being mediated by regulatory T lymphocytes and production of interleukin (IL)-10. To elucidate a possible mechanism involved in protecting against the development of atopy, we measured expression of IL-10 in gastric mucosa of children with H pylori gastritis.
Gastric biopsies were performed during endoscopy in 48 children (median age, 9 years), 32 of whom had H pylori gastritis and 16 of whom served as controls. Interferon-gamma (IFN-gamma), interleukin-1beta (IL-1beta), and IL-10 were measured in tissue homogenate by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The amounts of IFN-gamma, IL-1beta, and IL-10 transcripts were quantified via competitive RT-PCR with use of dilution series of specific competitors.
Expression of IFN-gamma and IL-10 were significantly higher in H pylori-infected children. No direct correlation with age was found, but a further increase in IL-10 expression was found in H pylori-infected children older than 4 years, whereas in control subjects, IL-10 expression tended to be lower in older children. IL-1beta expression was similar in infected children and control subjects. In H pylori-infected children, the prevalence of allergy was significantly higher in children with lower cytokine expression in gastric mucosa.
In children, H pylori-induced inflammatory response is associated with development of cell-mediated immunity of T-helper 1 type, as demonstrated by increased IFN-gamma expression. The significantly increased expression of gastric IL-10 in H pylori-infected children and its further increase in older children suggest that this chronic infection may influence IL-10 production even beyond the age of 4 years. H pylori may be one of the infections with the potential to modulate immune responses.
已有报道称幽门螺杆菌感染对过敏性疾病具有保护作用。发达国家儿童过敏发病率的上升可能是由于早期慢性感染对免疫系统的刺激减少，胃肠道微生物的保护作用由调节性T淋巴细胞和白细胞介素（IL）-10的产生介导。为了阐明预防特应性疾病发生的可能机制，我们检测了幽门螺杆菌胃炎患儿胃黏膜中IL-10的表达。
对48名儿童（中位年龄9岁）进行了内镜下胃活检，其中32名患有幽门螺杆菌胃炎，16名作为对照。通过定量逆转录聚合酶链反应（RT-PCR）检测组织匀浆中的干扰素-γ（IFN-γ）、白细胞介素-1β（IL-1β）和IL-10。通过使用特定竞争物的稀释系列进行竞争性RT-PCR来定量IFN-γ、IL-1β和IL-10转录本的量。
幽门螺杆菌感染儿童中IFN-γ和IL-10的表达显著更高。未发现与年龄有直接相关性，但在4岁以上的幽门螺杆菌感染儿童中发现IL-10表达进一步增加，而在对照受试者中，年龄较大的儿童IL-10表达往往较低。感染儿童和对照受试者中IL-1β的表达相似。在幽门螺杆菌感染儿童中，胃黏膜中细胞因子表达较低的儿童过敏患病率显著更高。
在儿童中，幽门螺杆菌诱导的炎症反应与1型辅助性T细胞介导的细胞免疫的发展相关，如IFN-γ表达增加所示。幽门螺杆菌感染儿童胃中IL-10的表达显著增加，且在年龄较大的儿童中进一步增加，这表明这种慢性感染甚至可能在4岁以后影响IL-10的产生。幽门螺杆菌可能是具有调节免疫反应潜力的感染之一。
