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

2007 Fiscal Year Final Research Report Summary

• Project/Area Number: 18390177
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Hygiene
• Research Institution: Asahikawa Medical College
• Principal Investigator: YOSHIDA Takahiko Asahikawa Medical College, School of Medicine, Professor (90200998)
• Co-Investigator(Kenkyū-buntansha): ITO Toshihiro Asahikawa Medical College, School of Medicine, Assistant Professor (20271760) ; SUGIOKA Yoshihiko Asahikawa Medical College, School of Medicine, Assistant (30398747) ; NAKAGI Yoshihiko Asahikawa Medical College, School of Medicine, Assistant (90322908) ; SAKABE Kou Kitasato University, School of Pharmacy, Professor (70162302) ; KOJIMA Hiroyuki Hokkaido Public Health Institute, Researcher (10414286)
• Project Period (FY): 2006 – 2007
• Keywords: sick building syndrome / multiple chemical sensitivity / immunological test / DNA micro allay analysis / formaldehyde / patients / experimental animars

Research Abstract

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.