Chimerism in children with juvenile dermatomyositis

Juvenile dermatomyositis is a disease with similarities to chronic graft-ve rsus-host disease. To identify whether chimerism is present in Juvenile der matomyositis, we investigated the families of 15 children with the disorder . Chimerism was identified by PCR in 13 of the 15 affected children, compar ed with five of 35 siblings (p<0<bullet>0001). Maternal cells among periphe ral-blood mononuclear colts were detected in 11 of the 15 boys, compared wi th five of 17 unaffected controls (p=0 . 02), and in muscle tissue of 12 of 15 compared with two of ten unaffected siblings (p=0 . 005). These results suggest that chimerism may be involved in juvenile dermatomyositis.