FAILURE TO FIND AN ASSOCIATION OF BLOOD GROUP-P1 WITH THYROID-ASSOCIATED OPHTHALMOPATHY

OBJECTIVE Genetic factors have been proposed to account for the development of ophthalmopathy in a proportion of patients with Graves' disease. The aim of this study was to confirm the previously reported association between blood group P1 and thyroid-associated ophthalmopathy. DESIGN A prospective study of sequential Caucasian patients. PATIENTS We studied 169 patients with Graves' disease, 84 of whom had grade 3,4 or 6 ophthalmopathy and 85 had no eye signs. MEASUREMENTS Blood group P(t) was measured by a standard serological technique. RESULTS The frequency of the P1 blood group was 74.1% in the patients without eye signs and 77.4% in those with ophthalmopathy (chi2 = 0.25, P > 0.1). By Woolf's method there was no significant difference in the test for heterogeneity of estimates between the present and the previously reported series of Graves' patients. Combining the results (n = 279), the pooled relative risk for ophthalmopathy with blood group P1 did not differ significantly from 1.0 (chi2 = 2.33, P > 0.1). CONCLUSIONS The presence of blood group P1 in patients with Graves' disease does not appear to be associated with an increased risk of developing thyroid-associated ophthalmopathy.