Celiac disease and autoimmune thyroid disease.

Celiac disease (CD) or gluten sensitive enteropathy is relatively common in western populations with prevalence around 1%. With the recent availability of sensitive and specific serological testing, many patients who are either asymptomatic or have subtle symptoms can be shown to have CD. Patients with CD have modest increases in risks of malignancy and mortality compared to controls. The mortality among CD patients who comply poorly with a gluten-free diet is greater than in compliant patients. The pattern of presentation of CD has altered over the past three decades. Many cases are now detected in adulthood during investigation of problems as diverse as anemia, osteoporosis, autoimmune disorders, unexplained neurological syndromes, infertility and chronic hypertransaminasemia of uncertain cause. Among autoimmune disorders, increased prevalence of CD has been found in patients with autoimmune thyroid disease, type 1 diabetes mellitus, autoimmune liver diseases and inflammatory bowel disease. Prevalence of CD was noted to be 1% to 19% in patients with type 1 diabetes mellitus, 2% to 5% in autoimmune thyroid disorders and 3% to 7% in primary biliary cirrhosis in prospective studies. Conversely, there is also an increased prevalence of immune based disorders among patients with CD. The pathogenesis of co-existent autoimmune thyroid disease and CD is not known, but these conditions share similar HLA haplotypes and are associated with the gene encoding cytotoxic T-lymphocyte-associated antigen-4. Screening high risk patients for CD, such as those with autoimmune diseases, is a reasonable strategy given the increased prevalence. Treatment of CD with a gluten-free diet should reduce the recognized complications of this disease and provide benefits in both general health and perhaps life expectancy. It also improves glycemic control in patients with type 1 diabetes mellitus and enhances the absorption of medications for associated hypothyroidism and osteoporosis. It probably does not change the natural history of associated autoimmune disorders.

Acute intermittent porphyria associated with hyperthyroidism.

The differential diagnosis of abdominal pain with associated hyponatraemia should include acute intermittent porphyria. Development of hyperthyroidism in a patient with latent porphyria may precipitate an acute attack and increase disease severity. Treatment of hyperthyroidism may prevent recurrent episodes.

Prospective screening for coeliac disease in patients with Graves' hyperthyroidism using anti-gliadin and tissue transglutaminase antibodies.

INTRODUCTION: Coeliac disease (CD) is associated with autoimmune thyroid disease (AITD) although its prevalence among those with Graves' hyperthyroidism in the UK is unknown. We determined the prevalence and evaluated the role of screening for CD prospectively in a consecutive cohort of patients with Graves' hyperthyroidism using IgA class antibodies to gliadin (AGA) and tissue transglutaminase (anti-tTG). METHODS: All patients with Graves' hyperthyroidism attending the thyroid clinic over a 9-month period were offered screening for CD using AGA (normal < 3 mg/l) and anti-tTG (normal < 15 micro/ml). Comparison was made with an age- and sex-matched healthy control group from the local population whose sera were tested for anti-tTG. In patients with borderline or raised anti-tTG (> 7 micro/ml) endomysial antibody (EmA) was measured. Serum IgA was also measured to exclude IgA deficiency. Patients with raised AGA, raised or borderline anti-tTG, positive EmA, IgA deficiency or haematinic deficiencies were offered endoscopic duodenal biopsy. RESULTS: A total of 115 patients (97 female and 18 male) with Graves' hyperthyroidism were offered screening tests and 111 accepted. AGA was raised in 15 patients, anti-tTG was raised in two (both positive for EmA) and equivocal in six (one positive for EmA). IgA deficiency was present in three. Four patients were known to have haematinic deficiencies. Twenty-five patients were invited and 19 agreed to have endoscopic duodenal biopsy. Three new patients were found to have CD while two patients were already known to have CD, thus five of 111 patients with Graves' hyperthyroidism had CD. One of 115 healthy controls had a strong positive anti-tTG (> 200 micro/ml) and EmA indicating probable CD. CONCLUSIONS: Screening 111 consecutive patients with Graves' hyperthyroidism revealed AGA in 14%, anti-tTG in 2% and IgA deficiency in 3%. Two patients were known to have CD. Screening detected three new cases. The prevalence of CD in patients with Graves' hyperthyroidism was 4.5% as compared with 0.9% in matched healthy controls. Routine screening for CD should be considered.