Fetal microchimeric cells in blood of women with an autoimmune thyroid disease.

Abstract

ContextHashimoto's thyroiditis (HT) and Graves' disease (GD), two autoimmune thyroid diseases (AITD), occur more frequently in women than in men and show an increased incidence in the years following parturition. Persisting fetal cells could play a role in the development of these diseases.ObjectiveAim of this study was to detect and characterize fetal cells in blood of postpartum women with and without an AITD.ParticipantsEleven patients with an AITD and ten healthy volunteers, all given birth to a son maximum 5 years before analysis, and three women who never had been pregnant, were included. None of them had any other disease of the thyroid which could interfere with the results obtained.MethodsFluorescence in situ hybridization (FISH) and repeated FISH were used to count the number of male fetal cells. Furthermore, the fetal cells were further characterized.ResultsIn patients with HT, 7 to 11 fetal cells per 1.000.000 maternal cells were detected, compared to 14 to 29 fetal cells in patients with GD (p=0.0061). In patients with HT, mainly fetal CD8(+) T cells were found, while in patients with GD, fetal B and CD4(+) T cells were detected. In healthy volunteers with son, 0 to 5 fetal cells were observed, which was significantly less than the number observed in patients (pConclusionThis study shows a clear association between fetal microchimeric cells and autoimmune thyroid diseases.