Endocrine Abstracts

Hypoparathyroidism (HPT) is the most common autoimmune endocrine involvement of APECED syndrome (autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy, 79-96% cases). HPT is associated with reduced bone remodeling, abnormalities in microarchitecture and bone strength, thus low-energy fractures occur despite normal or even high bone mineral density (BMD). Other APECED components (hypogonadism, malabsorption, growth hormone deficiency etc.), may also affect bone metabolism.

Case Report: A 48-year-old male patient N. was admitted with periodic seizures, decreased libido and mood lability. HPT was diagnosed at the age of 7 years, when seizures and episodes of loss of consciousness appeared. Initially he received Ca and cholecalciferol, at 15 years old alfacalcidol was added to therapy. Further, the patient did not particularly monitor Ca and P levels. In adolescence N. was diagnosed with Fahr’s syndrome (CT signs of basal ganglia calcification, cranial hyperostosis), later – bilateral cataracts. Hypogonadotropic hypogonadism was diagnosed in childhood. He received courses of gonadotropins until the age of 18 years. The secondary sex characteristics appeared at the age of 25 years. In adulthood, androgen therapy was periodically prescribed. At admission he irregularly received alfacalcidol 2.0 mg, Ca carbonate 2000 mg and cholecalciferol. Laboratory tests revealed hypocalcemia – 1.9 mmol/l (2.15–2.55), hyperphosphatemia – 2.15 mmol/l (0.74–1.52), hypocalciuria – 1.52 mmol/d (2.5–8). Therapy was corrected (alfacalcidol 2.5 mg, Ca carbonate 2500 mg) with normocalcemia achievement – 2.2 mmol/l, however mild hyperphosphatemia persisted – 1.63 mmol/l. BMD at the lumbar spine, femoral neck and distal third of the radius by DXA were within the expected range for age but the patient had a height loss of 5 cm. X-ray revealed multiple vertebral compression fractures (Th7, Th10, L2-3, L5). HPT and hypogonadotropic hypogonadism allowed us to suspect APECED. We excluded adrenal insufficiency, hypothyroidism and autoimmune gastritis but diagnosed esophageal candidiasis for the first time. Genetic analysis showed homozygous mutation in the AIRE gene. Because of hypogonadotropic hypogonadism, mixed testosterone esters were added. Considering the combination of severe osteoporosis with HPT, teriparatide became the drug of choice. This also allowed us to reduce the dose of alfacalcidol, Ca supplements while maintaining target Са and Р values. X-ray 6 months after did not reveal vertebral fractures progression.

Conclusions: Achievement of HPT compensation in APECED patients is challenging due to polypragmasia and malabsorption. Autoimmune hypogonadism, including hypogonadotropic, is found in 14-60% cases and affects bone metabolism. Prescribing teriparatide presumably has benefits in HPT patients with osteoporosis.