Limited usefulness of antithyroperoxidase and antithyroglobulin assays in Jamaicans with Graves' disease

ABSTRACT

The clinical usefulness of commercially prepared haemagglutination kits for thryro peroxidase (TPO) antibody and thyroglobulin (TG) antibody was evaluated in 145 consecutive Jamaicans with Graves' disease. Sixty two (43 percent) of the patients were newly diagnosed, 12 (8 percent) were in remission and 71 (49 percent) had relapsed. Sera from 65 (45 percent) patients were positive for thyroid antibodies. The TPO antibodies were found in 43 percent (63/145), thyroglobulin antibodies in 12 percent (17/145) fifteen (10 percent) patients had both anti-TPO and TG antibodies. Similar prevalences of TPO antibody were found in newly diagnosed patients and those who had relapsed (44 percent v. 41 percent) but the prevalence in the patients in remission was significantly higher (75 percent; X2 = 4.8, P <0.05). The prevalence of TPO antibody increased significantly with age at onset before age 35 years compared to later onset (56 percent v. 32 percent; X2 = 8.09, P <0.005). The presence of both TPO antibody (64 percent v. 31 percent; X2 = 13.1, P <0.001) and TG antibody (22 percent v. 6 percent; X2 = 8.8, P <0.005) correlated positively with Graves' opthalmopathy. Neither of the tests was adequately sensitive in detecting GD in Jamaicans. (AU)