Endocrine Abstracts

Background: GnRH is the first key hormone of reproduction. GnRH analogs are extensively used in IVF, and treatment of sex hormone-dependent cancers due to ability to bring about ‘chemical castration’. Recent studies have demonstrated that GnRH and sex steroids exert not only hormonal effects but play an important role in the immune system modulation.

Case report: We report a case of vasculitis and severe polymyositis developed 5 days after GnRH administration in infertility patient. Symptoms included progressive and symmetric muscle weakness, myalgias, diffuse arthralgias, effort dyspnea. On physical examination muscular tenderness, tachycardia, normal size liver and spleen were found.

Results: Laboratory findings revealed elevated CK 198.6 μkat/l, increased CK-MB isoenzyme 6.05 μkat/l, elevated LDH 11.0 μkat/l, myoglobin 543.20 μg/l and elevation of troponin T. Moderate elevation of hepatic enzymes was detected. Positivity of ANA was found, while other antibodies were negative. Serum Ig demonstrated higher levels of IgE 374 IU/ml. All remaning findings were within normal range. Muscle biopsy demonstrated changes consistent with diagnosis of myositis and vasculitis. After treatment with prednisone 30 mg daily, aspirin and pentoxyphyllin with rehabilitation an amelioration of muscle impairment was observed.

Conclusions: Autoimmune diseases could be induced by two mechanisms: firstly due to immunostimulating effect of GnRH and subsequent increased release of estrogens. Secondly, GnRH administration might unmask an underlying disease or might aggravate of subclinical disease. Nevertheless, our patient had neither previous history of autoimmune disease nor any symptoms of mild course of the autoimmune disease such as polymyositis or vasculitis.