Hashimoto’s thyroiditis, hypoparathyroidism and coeliac disease: lessons from a rare association

Résumé

We present the case of a 36 years old woman, affected by euthyroid Hashimoto’s thyroiditis (HT) from the age of 20. She reported the following symptoms for three years: weight reduction, abdominal pain, alternate constipation and diarrhoea, tiredness, paresthesias and cramps. Biochemical evaluation revealed low iron levels (21 ug/dl, with microcytic anemia) and hypocalcemia (6.6 mg/dl), first attributed to coeliac disease (EMA IgG, AGA IgG-A and tTG IgA positivity; Marsh-Oberhuber 3a/3b type at duodenal biopsy). TSH, PTH and 25-OHD3 were in the normal range. Although the patient was on a gluten-free diet for the second year, cramps persisted and facial spasms and tetanic crises appeared. One year later she came to our attention with severe hypocalcemia (Ca 5.1 mg/dl, Ca++ 0.6 nmol/L) and low PTH (2.5 pg/ml). A diagnosis of primary hypoparathyroidism was made and conventional treatment was started. In the following months, symptomatic hypocalcemia persisted (6.7 mg/dl, Ca++ 0.7 nmol/L), despite the gradual increase of calcium and calcitriol supplements. Gastro-intestinal re-evaluation demonstrated gluten contamination, so as to hypothesize that the scarce dietary compliance had caused persistent malabsorption and had made the hypocalcemia difficult to manage. The observation of these three disorders coexisting in a single patient, never reported by the literature, warns us about the virtually unlimited possibilities of autoimmune disease clustering. Clinicians should be aware of the increased risk of developing additional AIDs in patients with one autoimmune disorder.