Endocrine Abstracts

Introduction: Type B insulin resistance syndrome is an autoimmune disorder characterized by the production of autoantibodies against the insulin receptor. It leads to glucose metabolism disorders, extreme insulin resistance, hyperandrogenism and is associated with other features of autoimmunity.

Case report: A 27-year-old man, with a 2-years history of psoriasis, was admitted to our Department because of loss of weight (20 kg in 1 year) and fatigue. He also reported Raynaud’s phenomenon. One year earlier the patient underwent careful haematological assessment because of peripheral lymphadenopathy and enlarged parotid glands, which showed changes characteristic for viral infection. Screening for cancer was negative. On admission, physical examination revealed malnutrition (BMI 16.4 kg/m²), acanthosis nigricans, sclerodactyly, psoriatic lesions, enlarged parotid glands, palpable cervical and axillary lymph nodes, tachycardia. Laboratory analyses revealed anaemia, leucopaenia with lymphopaenia, thrombocytopaenia, blood glucose concentration – 361 mg/dl with tendency to morning hypoglycaemia, HbA1c – 12.4% and glycosuria. Fasting C-peptide concentration was normal and increased adequately in glucagon stimulation test (0′ 2.87 ng/ml, 6′ 4.56 ng/ml). Fasting insulin concentration was extremely high (>300 μIU/ml). In hyperinsulinaemic euglycaemic clamp insulin sensitivity index was decreased (M-2.1 mg/kg FFM/min). We confirmed the presence of anti-insulin-receptor antibodies, indicating type B insulin resistance syndrome. Anti-GAD, IAA, IA2 antibodies were negative. Based on the clinical features, presence of antinuclear antibodies, anti-RNP/Sm antibodies, and positive direct Coombs test diagnosis of mixed connective tissue disease/lupus erythematosus was made. Tumour of blood cells was excluded. Firstly patient was treated with insulin and metformin and then with metformin, prednisone and chloroquine phosphate, which resulted in weight gain, normalization of blood glucose levels (HbA1c – 7.3%) and improvement of blood cell counts and skin lesions. Currently the patient is under metformin and hydroxychloroquine therapy.

Conclusion: We presented a case of severe type B insulin resistance syndrome, associated with another autoimmune disease. Anti-insulin-receptor antibodies are crucial to recognize the syndrome. The treatment is challenging and requires multidisciplinary approach.