Fetal microchimerism in rheumatic autoimmune diseases *
Some clinical features of rheumatic autoimmune diseases (RAD), such as systemic sclerosis (SSc), Sjogren's syndrome (Sjs) and systemic lupus erythematosus (SLE) resemble chronic graft-versus-host disease (GVHD). Recent studies have shown fetal DNA to be found in post-maternal peripheral blood. This observation has led to a hypothesis that persistent fetal cells in the maternal circulation (fetal microchimcrism) could mediate a graft-versus-host reaction, resulting in autoimmune disease. In this study, we examined frequency of fetal microchimerism in Asian-Japanese female patients with RAD who have a son by detection of the Y-chromosome specific sequence (DZY 1) in peripheral blood cells. As a result, DZY 1 was detected in 10 of 20 SSc patients (50. 0%), 6 of 18 Sjs patients (33, 3%), arid 8 of 41 healthy volunteers (19, 4%). No DZY 1 was detected in 21 SLE. In an analysis of HLA class Ⅱ genotypes, DRB 1*0101 and DQB 1*0501 were more frequently detected in SSc patients than in unrelated Japanese. However there were no differences between the DYZ 1 positive and negative groups. In a comparison of clinical features, DYZ 1 was detected in patients with a severe internal complication such as primary hiliary cirrhosis, Scleroderma kidney, and pulmonary hypertension. These findings suggest that fetal microchimerism is a phenomenon strongly related to SSc but not in SLE or Sjs. Patients with fetal microchimerism showed the clinical features resembling those of GVHD. (Accepted on April 4 , 2001) Kawasaki Igakkaishi 27 (2) : 111-121, 2001
