RESUMEN
To identify the association of Y chromosome microchimerism with systemic lupus erythematosus [SLE] and investigate its relation to pregnancy history, clinical and laboratory variables. The presence of Y chromosome microchimerism was screened in 90 females including 35 women with renal lupus, 25 patients with cutaneous lupus and 30 healthy control females using real time polymerase chain reaction. Demographic parameters, reproductive history, clinical and laboratory data were recorded. The percentage of Y chromosome microchimerism was significantly higher in SLE patients compared to healthy women and in females with renal lupus versus those with cutaneous lupus. Among patients with renal lupus, Y chromosome microchimerism was strongly associated with disease activity and damage indices as well as with number of pregnancies, while this association was absent regarding number of pregnancies in cutaneous lupus females. A significant increase in disease activity and severity scores was detected in microchimeric renal lupus females when compared to microchimeric cutaneous lupus patients. Healthy control and cutaneous lupus women with microchimerism experienced significant decrease in number of pregnancies and abortions against microchimeric renal lupus group. These results may provide a preliminary suggestion that Y chromosome microchimerism could have a pathogenic role in SLE and it may be related to inflammation, the extent of disease damage and reproductive history. Further studies are needed among SLE patients with different clinical presentations, as fetal microchimerism is a promising field of investigation which may lead to novel strategies in treatment