Fetal microchimerism in Hashimoto’s thyroiditis: a quantitative approach

Abstract

Objective: Fetal microchimerism (MCH) has been implicated in the etiology of autoimmune diseases such as autoimmune thyroiditis. The goal of the study was to reliably estimate the number of fetal engrafted cells and to further investigate factors influencing the development of MCH. Methods: Quantitative real-time PCR amplification using Y-chromosome specific (DYS14) and autosomal (b-globin) loci was performed on thyroid gland specimens. Furthermore, we compared the distribution of ABO and rhesus systems in mothers with and without blood MCH in relation to the blood groups of the children. Results: MCH was detected in eight of 21 Hashimoto patients in a frequency range of 15 to 4900 male cells per 100 000 total cells (median 97 cells), but in none of 17 healthy thyroid glands. In a third group, consisting of 18 nodular goiters, only one sample was positive (182 male cells/100 000 total cells). No woman who had not had a prior pregnancy with a male fetus showed MCH. Mothers both with and without MCH showed the same rate of mother/child incompatibilities for the ABO and rhesus systems. Conclusions: The percentage of microchimeric cells varies to a great extent in Hashimoto's thyroiditis, and this phenomenon can occur in nodular goiter in rare instances, but it appears to be absent from normal thyroid glands. Nevertheless, the biological significance of MCH remains unclear. Moreover, we have concluded that the tested blood group systems (as opposed to their role in graft vs host disease after transplantations) have no effect on fetal MCH.European Journal of Endocrinology 154 237-241

Autoimmune Disease During Pregnancy and the Microchimerism Legacy of Pregnancy

“…(Davies 1999), (Ando et al 2002;Klintschar et al 2001) Recently, using a quantitative PCR assay, fetal Mc was detected in 8 of 21 thyroid samples from women with Hashimoto's disease compared to 0 of 17 healthy thyroid glands. (Ando et al 2002;Klintschar et al 2001;Klintschar et al 2006) In thyroidectomy and autopsy specimens from women with multiple thyroid disorders, male cells were found using fluorescence in situ hybridization (FISH) in thyroids from more than half of women with a thyroid disease compared to none in autopsy controls. (Klintschar et al 2006) A large community-based study showed no association between parity and presence of thyroid antibodies or thyroid dysfunction and suggested a lesser role for fetal Mc in autoimmune thyroid disease.…”

“…(Ando et al 2002;Klintschar et al 2001;Klintschar et al 2006) In thyroidectomy and autopsy specimens from women with multiple thyroid disorders, male cells were found using fluorescence in situ hybridization (FISH) in thyroids from more than half of women with a thyroid disease compared to none in autopsy controls. (Klintschar et al 2006) A large community-based study showed no association between parity and presence of thyroid antibodies or thyroid dysfunction and suggested a lesser role for fetal Mc in autoimmune thyroid disease. (Walsh et al 2005) However, the number of pregnancies may be a less important risk factor than HLA relationships between fetal and maternal cells, as suggested by studies in systemic sclerosis.…”

Fetal cell microchimerism: a protective role in autoimmune thyroid diseases

“…By this and other methods, FCM has been extensively studied in autoimmune diseases, particularly systemic ones, because they are more often observed in females and appear to be modulated by pregnancy (5,6,7,8). As far as autoimmune thyroid disease (AITD) is concerned, FCM has been documented in Hashimoto's thyroiditis (HT) and Graves' disease (GD) (9,10,11,12,13). These diseases occur more frequently in women, with a peak incidence during the fertile age.…”

“…They appear to be related to pregnancy and often have a spontaneous resolution after delivery and an onset or exacerbation in the postpartum period, although their relation with parity is still controversial (14,15,16). In the few available series, which include a limited number of cases, FCM was found to be represented more at the tissue level in HT and GD as compared to non-AITDs (4,9,10,11,12,13,17). Even at the peripheral level, scanty and discrepant results have been reported.…”

Fetal Microchimerism in Cancer Protection and Promotion: Current Understanding in Dogs and the Implications for Human Health

“…Male microchimeric cells have been demonstrated in higher frequency in normal and benign breast tissues than in malignant breast lesions [19]. Similarly, lower frequency of chimerism detected in peripheral blood was identified in women with papillary thyroid cancer and hematological malignancies, including non-Hodgkin lymphoma (nHL) [6,[20][21][22][23]. Evidence of lower frequency or degree of chimerism has been interpreted as a protective effect of the chimeric cells against these cancers in women.…”