Serum thyroglobulin autoantibody titres and immunoglobulin concentrations in Nigerians with goitre.

Using the tanned turkey red blood cell haemaglutination test, blood samples from 327 Nigerians with goitre were screened for the presence of thyroglobulin autoantibody. 15 (4.6%) were found to have significantly positive autoantibody titres while none of the 50 age and sex-matched normal controls and autoantibody. Of the 15 with significantly positive thyroglobulin autoantibody titres, only 2 were males, giving a male:female ratio of 1 to 6.5. The mean serum concentration of IgG in the positive cases (4,163 +/- 53.5 mg/100 ml) was significantly higher than either that of normal controls (3,044 +/- 147.6 mg/100 ml) of goiterous subjects with no thyroglobulin autoantibody (2,196 +/- 116.5mg/100ml). It was found that thyroglobulin autoantibody is an IgG immunoglobulin. It is concluded that autoimmune thyroid disease occurs in Nigerians with goitre and that females are affected more than males.