Selective Theca Cell Dysfunction in Autoimmune Oophoritis Results in Multifollicular Development, Decreased Estradiol, and Elevated Inhibin B Levels

Abstract

We describe the clinical course of three women with presumptive autoimmune oophoritis who developed multiple follicles but very low to undetectable estradiol levels. Multiple follicles developed spontaneously in all subjects and during pulsatile GnRH treatment for ovulation induction in subject 1. The development of multiple dominant follicles was accompanied by LH levels in the postmenopausal range and FSH levels at the upper limit for premenopausal women. Serum inhibin B levels were elevated appropriately in the setting of multifollicular development, but estradiol levels remained low. Measurement of estradiol precursors demonstrated androstenedione and estrone levels below the 95th percentile in normal women. Adrenal cortical antibodies, and antibodies to 21-hydroxylase and P450 side chain cleavage enzymes were identified in all subjects. All subjects met the criteria for premature ovarian failure during follow-up. Subject 1 later developed adrenal failure, whereas subject 3 had adrenal failure at the time of the study. These subjects elucidate the hormonal pattern in autoimmune oophoritis, before the full criteria for premature ovarian failure are met. The elevated inhibin A and B levels, which accompany the development of multiple small and dominant follicles in these women, suppress FSH relative to LH levels, virtually independent of estradiol. These data provide further evidence for an important role of inhibin B and inhibin A in the negative feedback control of FSH. In addition, the normal inhibin A and inhibin B production in the absence of estradiol precursors and estradiol provide insight into the selective dysfunction of the theca cells in autoimmune oophoritis.