PREVALENCE OF ANTIMITOCHONDRIAL ANTIBODIES IN WOMEN WITH HASHIMOTOS-THYROIDITIS

Objectives: Thyroid antibodies are present in more than 15% of patient s with primary biliary cirrhosis. Inversely, the prevalence of antimit ochondrial antibodies in patients with thyroid antibodies is still unk nown. The aim of the present study was to evaluate the prevalence of a ntimitochondrial antibodies in women positive for thyroid microsomal a ntibodies. Methods: Anti-thyroid microsomal positive sera were collect ed from 351 selected female patients (age range 40-70 years) then stor ed at -20 degrees C from September 91 to September 92. Anti-mitochondr ial auto-antibodies were determined in all sera with enzyme-linked sor bent assay (ELISA) using purified antigen. Results: M2 antimitochondri al antibodies were found positive in 7 cases (2%). On immunoblots, the pattern of antimitochondrial reactivity visualized for the 7 sera was similar to pattern of classical primary biliary cirrhosis sera. Six o f the 7 patients were asymptomatic and 4 had normal liver function tes ts. Liver biopsy was carried out in 2 patients and fulfilled diagnosis criteria for primary biliary cirrhosis. Six out of the 7 patients had Hashimoto's thyroiditis (2 biopsy proven, 4 clinical and biological d iagnosis). Conclusion: Patients with Hashimoto's thyroiditis would be a population at high risk of primary biliary cirrhosis. It would be in teresting to screen these patients in order to ascertain the significa tion of antimitochondrial antibody positivity, especially when there i s no apparent liver disease.