Microchimerism in a female patient with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a serious multisystem disease that ha s a striking propensity to affect women. The cause of SLE remains elusive. Fetomaternal cell trafficking, or the passage of fetal cells into the mater nal circulation, is now a well-established phenomenon. In addition, fetal c ells have been implicated in the development of preeclampsia and in the pat hogenesis of scleroderma. We undertook this study to determine whether feto maternal cell trafficking might also be involved in pathogenic processes in SLE. Fluorescence in situ hybridization analysis was performed using X and Y chromosome-specific probes on affected and unaffected tissue obtained at autopsy from a woman who had previously given birth to 2 males and who had died of complications of SLE. The goal of the analysis was to detect the p resence of male cells of putative fetal origin. Male cells were found in ev ery histologically abnormal tissue type that was examined, but were not fou nd in histologically normal tissue. These data suggest that fetal cells may be associated with SLE. It is unclear whether their presence may be relate d to disease causation, an effect of disease progression, or unrelated to d isease pathology. However, this case study is an important step toward unde rstanding the potential relationship between fetomaternal cell trafficking and SLE pathology.