Autoimmune diseases, in which a person’s immune system mistakenly attacks healthy tissue, can damage organs vital to normal bodily functions. These diseases occur more frequently among women than among men.
To explore possible reasons for the differences in autoimmune diseases between men and women, researchers in the Unit on Genetics of Puberty and Reproduction, within the Division of Intramural Research Program in Developmental Endocrinology and Genetics, studied women with primary ovarian insufficiency (POI), a condition marked by lower pregnancy rates and reduced estrogen production. The researchers compared women with POI caused by Turner syndrome, a genetic condition in which a woman has only one normal X chromosome, to women with two normal X chromosomes and POI from other causes. The researchers also compared both POI groups to women in the general U.S. population.
The results of the study showed that women in both POI groups were more likely than other women to have at least one autoimmune disease. This finding indicates that neither higher estrogen levels nor pregnancy is likely to increase the risk for autoimmune diseases.
The researchers also identified which autoimmune conditions were most common in the POI groups and found that both populations had high rates of a thyroid condition called Hashimoto’s thyroiditis. In addition, women with Turner syndrome had even higher rates of several autoimmune diseases than did other women with POI. This finding suggests that the absence of a normal second X chromosome may increase the likelihood of autoimmune diseases.
This study not only advances understanding of which factors contribute to increased autoimmunity risk among women, but also points to the need to screen women with POI for certain autoimmune diseases (PMID: 22342295).