Endocrine Abstracts

Introduction: Premature ovarian insufficiency (POI) is a rare cause of primary amenorrhea (1,2). We report a 16-year-old girl with normal secondary sexual characteristics, but no menses due to an autoimmune POI and associated with autoimmune gastritis. This is the first report of such constellation in an adolescent – both conditions separately already being rare in the pediatric population.

Case presentation: A 16-year-old girl was referred to our department with primary amenorrhea and hyperprolactinemia. She had breast development for 2 years. She had no other complaints, i.e. no galactorrhea, hirsutism, hot flushes or mood changes. No recent weight loss, excessive weight gain or monthly abdominal pains were noted. Her medical history was unremarkable and she took no drugs or food supplements. There was no family history of autoimmune or endocrine diseases, early menopause, or fragile X syndrome. At physical examination, her weight was 50kg (Z score -0.84), height 171cm (Z score 0.67), and blood pressure 130/94mm Hg. She was at Tanner IV for breast and pubic hair development. Thyroid palpation was normal. Skin pigmentation and nails were normal. No dysmorphic features were noted. Hormonal analysis one month before referral showed elevated prolactin (56.2μg/L) levels, high-normal FSH (23.3IU/L), normal LH (13.6IU/L) levels, normal estradiol (62.5ng/L), and normal thyroid function. Repeat laboratory investigations confirmed a lower but still elevated prolactin of 48.1μg/L (ref 3.71 - 23.12μg/L) with a normal monomeric recovery, and elevated morning cortisol (312μg/L), a high FSH (97.3IU/L), a high-normal LH (56.7IU/L) and SHBG (98nmol/L) with unmeasurable estradiol and AMH, suggesting an incipient POI. Genetic investigations including karyotype, CGH-microarray, and FISH of chromosome X were normal. FMR1 triplet repeat analysis showed a heterozygous intermediate expansion allele with 52 repeats. Screening for anti-ovarian, anti-adrenocortical, and anti-21-hydroxylase antibodies was repeatedly negative, but anti-TPO antibodies and anti-parietal cell antibodies consistently elevated. Abdominal ultrasound showed normal-sized ovaries without follicles and a uterus with an endometrial thickness of 5 mm. Pelvic MRI confirmed normal ovarian size and revealed only one follicle cyst in the right ovary (9 mm in diameter). By brain MRI a hypointense lesion (2.8mm in diameter) was found in the posterior part of the anterior pituitary. Spinal bone mineral density was normal (DEXA, Z-score of -0.2). Hematology tests showed a normal erythrocyte sedimentation rate and white blood cell count but revealed an iron deficiency anemia. Serum gastrin was elevated while tissue transglutaminase IgA and fecal occult blood tests were negative. Endoscopic-histologic evaluation confirmed the presence of atrophic gastritis.

Discussion: We report on an adolescent girl with autoimmune POI associated with autoimmune gastritis. The initial transient ovarian failure during immune attacks complicate the diagnosis of autoimmune POI and in this case probably explains the absence of hot flashes, the initially normal estradiol levels, and the normal bone mineralization (3). Furthermore, diagnosing autoimmune POI is also difficult due to low sensitivity and specificity of anti-ovarian antibody testing - frequently false negative as seen in our patient (3). In this girl, the diagnosis was further complicated by elevated prolactin and cortisol levels, which were likely related to stress or transient FSH induced hyperestrogenism. The diagnosis of atrophic gastritis and thyroid autoimmunity and the exclusion of other diagnoses allowed us to diagnose autoimmune POI. Diagnosing autoimmune forms of POI is important in view of the incipient risk of autoimmune adrenal insufficiency and need for follow-up (4).

Conclusion: Autoimmune POI can present with primary amenorrhea in adolescent women. Thorough immune evaluation is needed to diagnose autoimmune POI when anti-ovarian antibodies are negative. Full autoimmune screening, including not only anti-adrenocortical and anti-thyroid antibodies but also anti-parietal cell antibodies should be done in unexplained POI, especially when iron deficiency is present.

References: 1. Baker VL. Primary ovarian insufficiency in the adolescent. Curr Opin Obstet Gynecol. 2013;25(5):375–81.

2. Gruber N, Kugler S, de Vries L, Brener A, Zung A, et al. Primary ovarian insufficiency nationwide incidence rate and etiology among israeli adolescents. J Adolesc Health. 2020;66(5):603–609.

3. Bakalov VK, Anasti JN, Calis KA, Vanderhoof VH, Premkumar A, et al. Autoimmune oophoritis as a mechanism of follicular dysfunction in women with 46XX spontaneous premature ovarian failure. Fertil Steril. 2005;84(4):958–65.

4. Szeliga A, Calik-KSepka A, Maciejwska-Jeske M, Grymowicz M, Smolarczyk K, et al. Autoimmune disease in patients with premature ovarian insufficiency- our current state of knowledge. Int J Mol Sci. 2021 Mar 5;22(5):2594.