IDENTIFICATION OF FETAL DNA AND CELLS IN SKIN-LESIONS FROM WOMEN WITHSYSTEMIC-SCLEROSIS

Background Systemic sclerosis is a disease of unknown origin which oft en occurs in women after their childbearing years. It has many clinica l and histopathological similarities to chronic graft-versus-host dise ase. Recent studies indicate that fetal stem cells can survive in the maternal circulation for many years post partum. This finding suggests that fetal cells persisting in the maternal circulation or tissues co uld be involved in the pathogenesis of systemic sclerosis by initiatin g a graft-versus-host reaction. Methods We used the polymerase chain r eaction (PCR) to identify Y-chromosome sequences in DNA extracted from peripheral-blood cells and skin lesions from women with systemic scle rosis of recent onset. To confirm the PCR findings, we used fluorescen ce in situ hybridization of peripheral-blood cells and cells within ch ronic inflammatory-cell infiltrates in biopsy specimens of affected sk in. Results Y-chromosome sequences were found in DNA from peripheral-b lood cells in 32 of 69 women with systemic sclerosis (46 percent), as compared with 1 of 25 normal women (4 percent, P<0.001), and in T lymp hocytes from 3 women with systemic sclerosis who had male offspring. F urthermore, Y-chromosome sequences were identified in skin-biopsy spec imens from 11 of 19 women with systemic sclerosis (58 percent); 9 of t he 11 were known to have carried male fetuses. Nucleated cells contain ing Y chromosomes were detected by fluorescence in situ hybridization in paraffin-embedded sections of skin lesions from all seven women we tested whose skin-biopsy specimens contained Y-chromosome sequences. C onclusions Fetal antimaternal graft-versus-host reactions may be invol ved in the pathogenesis of systemic sclerosis in some women. (C)1998, Massachusetts Medical Society.