Animal experiment and clinical research on the immunological involvement in pathological formation of sick building symptoms

通过临床观察和动物实验，探讨了免疫系统在病态建筑物症状（SBS）形成中的作用。在动物实验中，取甲醛暴露后的脾细胞和外周血细胞，（8小时/天，每周6天，6周）雌性B6 C3 F1小鼠用于免疫学分析（淋巴细胞的亚群分析，生物活性因子或生物反应的mRNA表达，实验诱导的立即变态反应，以及与Th 1/2细胞比例相关的免疫平衡）。HCHO染毒小鼠CD 4细胞增加，CD 8细胞减少，CD 4/CD 8比值升高，IFN-γ阳性细胞减少。干扰素-g mRNA也呈同样的下降趋势。暴露组小鼠白细胞介素4（IL-4）mRNA表达降低，IL-4/IFN-γ mRNA表达比值升高。其他参数无显著变化。尽管上述数据表明，甲醛暴露通过抑制Th 2细胞而驱动免疫显性立即过敏，但未观察到明显的过敏增强。嗅球催乳素mRNA表达增强。分析北里研究所医院诊断为SBS的患者外周血单个核细胞（PBMC）上生物活性因子或生物反应的mRNA表达。在SBS患者PBMC中发现8个基因被抑制。但与5名健康志愿者相比，22名患者中这些基因的表达无显著性差异。虽然有几例患者的血浆催乳素水平较高，但患者与健康志愿者之间无显著性差异。未发现免疫系统参与SBS形成的明显证据。

We evaluated the ivolvement of immune system on the formation of sick building symptoms (SBS) by clinical observation and animal experiment. In animal experiment, splenocytes and peripheral blood cells obtained from formaldehyde exposed (8 hours/day, 6 days per week, 6 weeks) female B6C3F1 mouse were used for immunological analyses (subpopulation analysis of lymphocytes, mRNA expression of biological active factors or biological response, experimental induced immediate allergy, and immunological balance relating to Th1/2 cell ratio).Fluctuation of mRNA expression was evaluated. Increase of CD4 cells and decrease of CD8 cells, and elevation of CD4/CD8 cell ratio were observed in HCHO exposed mice.Interferon-gamma (IFN-g) positive cell was reduced in exposed mice. Interferon-g mRNA also showed same tendency to decline. Interleukin4 (IL-4) mRNA was reduced in exposed mice.Expression ratio of IL-4/IFN-g mRNA inclined to elevate in exposed mice. There were no significant changes in other parameters. Although above data indicated that HCHO exposure drove immune dominant to immediate allergy by association of suppression of Th2 cells, obvious enhancement of allergy was not observed. Enhancement of prolactin mRNA expression in olfactory bulb. Expression of mRNA of biological active factors or biological response on the peripheral blood mononuclear cells (PBMCs) was analyzed in the patients diagnosed as SBS from Kitasato Institute Hospital. Eight gene were identified suppressed in the PBMCs of SBS patients. But there was no significant difference in expression of those genes with the comparison between 22 patients and 5 healthy volunteer. Although several patients showed high level of prolactin in their plasma, there was no significance between patients and healthy volunteer. Finally we could not find the significant evidences that immunological system was responsible for the formation of SBS.