[Hypophysitis and reversible hypopituitarism developed after COVID-19 infection - a clinical case report].

Aim: To present a clinical case of reversible hypopituitarism due to hypophysitis developed after COVID-19 infection.

Materials and methods: A patient with residual clinical manifestations of hypopituitarism underwent clinical evaluation at the time of symptoms of hypopituitarism and in follow-up. Morning serum cortisol (171-536 nmol/l) was measured by electrochemiluminescence immunoassay. Morning ACTH (7.2-63.3 pg/ml), prolactin (66-436 mU/l), TSH (0.25-3.5 mIU/L), fT4 (9-19 pmol/l) and fT3 (2.6-5.7 pmol/l) were measured by chemiluminescence immunoassay. Data were analyzed throughout the course of the disease.

Results: A 35-year-old female developed clinical symptoms of hypopituitarism two months after recovery from a confirmed COVID-19 infection. Laboratory investigation confirmed hypocorticism, hypothyroidism, hypogonadism and the patient was prescribed appropriate hormonal therapy in January 2021. Four months later the symptoms were alleviated (April 2021) and there were signs of recovery shown by imaging and hormonal: morning serum cortisol 227 nmol/l, morning ACTH 33.96 pg/ml, prolactin 68.3 mU/l, TSH 2.626 mIU/L, fT4 10.75 pmol/l, fT3 3.96 pmol/l. Thyroid hormone was discontinued, but hypogonadism and hypocorticism persisted with estradiol - 51.48 pmol/l, 24h urine cortisol level - 41.8 nmol/day. MRI results showed that the signs of hypophysitis were alleviated in comparison with MRI from January 2021. Full recovery of pituitary axis was reported in October 2021, with recovery of normal menstrual cycle. Furthermore, hormonal profile was likewise normal.

Conclusion: This report provides evidence of delayed damage to the pituitary gland after infection with the COVID-19, with recovery of its function and structure. To date, the mechanisms of such an impact are not entirely clear; further collection of data on such cases and analysis is required.