title: Failure to find an association of blood group P1 with thyroid-associated ophthalmopathy.
abstract: 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.
  
  
  METHODS
  A prospective study of sequential Caucasian patients.
  
  
  METHODS
  We studied 169 patients with Graves' disease, 84 of whom had grade 3, 4 or 6 ophthalmopathy and 85 had no eye signs.
  
  
  METHODS
  Blood group P1 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 (chi 2 = 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 (chi 2 = 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.
authors: Department of Medicine, University of Sheffield, Northern General Hospital, UK.
authors: A P
authors: AP
authors: Weetman
authors: J
authors: J
authors: Poole
mesh_terms: D006111:Graves Disease / Q000097:blood*; D006801:Humans; D010127:P Blood-Group System / Q000235:genetics*; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D010127:P Blood-Group System