Objective. To investigate whether anticardiolipin antibodies (aCL) in patients with systemic lupus erythematosus (SLE) bind to β2‐glycoprotein I (β2GPI), and to search for a relationship between the presence of IgG and/or IgM anti‐β2GPI antibody and clinical manifestations in SLE patients. Methods. IgG and IgM anti‐β2GPI in 308 Japanese SLE patients were measured using phospholipid‐independent enzyme immunoassays. Relationships to clinical histories and to various laboratory data were examined. Results. The values of anti‐β2GPI and aCL, as measured by conventional enzyme immunoassay, showed a strong correlation, but the anti‐β2GPI assay was more useful in distinguishing β2GPI‐dependent aCL from β2GPI‐independent aCL. The presence of IgG anti‐β2GPI was associated with an increased frequency of a history of thrombosis. Comparisons of various laboratory data suggested that the titer of anti‐β2GPI may fluctuate with disease activity. Conclusion. The results suggest that pathogenic aCL is directed against structurally altered β2GPI and that enzyme immunoassay for anti‐β2GPI may prove useful in evaluating the risk of thrombosis and monitoring the clinical course in patients with SLE.

SUMMARYThere are two major forms of the Fas molecule, membranous Fas and soluble Fas (sFas). To clarify the clinical significance of sFas in autoimmune diseases, we designed a sandwich ELISA to determine serum concentrations of sFas and its molecular structure, and we then analysed the correlation between levels of sFas and laboratory findings in patients with SLE and other autoimmune diseases. The levels of serum sFas were significantly higher in SLE patients than in subjects with other autoimmune diseases and in healthy donors, and the frequency of a positive serum sFas was much greater in SLE patients with high SLE disease activity index scores than in those with low scores. In addition, sFas-positive SLE patients showed a significant difference in various laboratory parameters from sFas-negative SLE patients. Serial measurements of serum sFas levels in SLE patients with active disease revealed that the elevated level of sFas dramatically decreased with improvement in clinical and laboratory findings, following corticosteroid therapy. We propose that the serum level of sFas can serve as an appropriate marker for evaluating SLE disease activity. Serum sFas is heterogeneous with respect to molecular structure, thus several mechanisms are involved in the generation of sFas.

For the first time, we performed an epidemiological study of SSc in Japan to study the factors influencing prognosis, survival rate and cause of death of Japanese SSc patients and to compare our data with those from foreign countries. Prognosis of 496 Japanese patients with progressive systemic sclerosis (SSc) was analyzed based on clinical data described in case cards provided by the members of the Scleroderma Research Committee of the Japanese Ministry of Health and Welfare. The essential observation period was from 5 to 20 years, at ending in 1994. Ninety patients died (males 11, females 79). The age of onset of the deceased patients was significantly higher than that of surviving patients (deceased, 45.6 yrs, surviving 41.3 yrs). Statistically significant factors for a poor prognosis were as follows: Barnett type III > type II > type I, positive for anti-Scl-70 antibody, negative for anti-centromere antibody. The survival rate at 5 years after the onset of the disease was 0.937, followed by 0.82 at 10 years, 0.567 at 20 years and 0.40 at 30 years after the onset. Sex was not a predictor for prognosis, although male patients died at an earlier stage of the disease. The most common causes of death were heart failure, pulmonary insufficiency, lung fibrosis, and renal failure. Twenty-four patients had cancer of which 13 were lung cancers. The current status of the survival rate and prognostic factors of 496 Japanese SSc patients is summarized. In future, more well-controlled studies using the same criteria should be performed for the better understanding and management of SSc.

SUMMARY 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.