Tohru Nakabayashi

Up-regulated expression of Fas antigen (CD95) by peripheral naive and memory T cell subsets in patients with systemic lupus erythematosus (SLE): a possible mechanism for lymphopenia.

Fas antigen (CD95) is a membrane‐associated molecule that mediates apoptotic cell death and may play a role in the induction and maintenance of T cell tolerance. To elucidate the involvement of Fas antigen in human autoimmune diseases, we analysed Fas antigen expression by peripheral T cells from patients with SLE and rheumatoid arthritis (RA), using three‐colour flow cytometry. Both CD4+ and CD8+ T cell from SLE patients expressed Fas antigen in a higher density than did these cell from healthy donors and from RA patients. Enhancement of Fas antigen density was noted in Fas+CD45RO+ memory T cell from SLE patients. More remarkably, a significant expression of Fas antigen was observed in CD45RO− naive T cells from SLE patients CD4+CD45RO− T cells from SLE patients co‐expressed Fas antigen and early to intermediate activation antigens such as CD25 and CD71, and late activation antigen HLA‐DR in only FashiCD4+ naive T tells. Such up‐regulation of Fas antigen expression in SLE patients seems to be clinically meaningful, because mean fluorescence intensity (MFI) of Fas antigen on CD4+ T cell subsets inversely correlates with the absolute size of CD4+ T tell subsets in peripheral blood of SLE patients. These results suggest that T cells with increased Fas antigen expression may be highly susceptible to apoptotic cell death, in vivo. A putative mechanism for lymphopenia in SLE patients is discussed.

Studies on farmer's lung - With special reference to clinical pictures and incidence of the disease.

13例の確実例と2例の強い疑い例計15例の農夫肺を経験したので,その臨床像と発症率について報告する. 1)二つの地域で行なつた農夫肺検診より北海道における農夫肺の推定発症率は1～2%であつた. 2)胸部X線写真所見と病理組織像を比較すると,スリガラス状陰影は肉芽腫の病理組織像,小粒状陰影は貧弱な肉芽腫の病理組織像,微細粒状陰影は間質性肺炎の病理組織像に対応していた. 3)免疫学的検査および病理組識像より発症機序としてGell and Coombs分類でIII型およびIV型アレルギーが関与していることが示唆された. 4)農炎肺の予防方法として牛舎内での防じんマスクの着用が有用であると思われた.