Secretor status and human leucocyte antigens in coeliac disease

Background: The ability to secrete blood group antigens into body fluids and secretions is controlled by a single gene on chromosome 19. By means of erythrocyte Lewis (Le) antigen phenotype secretor status can be inferred. An increased prevalence of non-secretors of blood group antigens among coeliac patients has recently been described. Methods: Blood was collected from 112 coeliac patients and 103 controls and tested for secretor status. Secretor status was correlated with human leucocyte antigens (HLA) in coeliac patients, thus evaluating a proposed interaction of susceptibility genes - that is, the secretor gene on chromosome 19 and HLA-linked genes on chromosome 6. Case notes for coeliacs were reviewed with regard to clinical outcome. Results: Of 112 coeliacs who had either Le(a) or Le(b) antigens, 36 (32%) were non-secretors Le(a+, b-), compared with 27% (28) of 103 disease-free controls (P = 0.313). Recessive Lewis phenotype Le(a-, b-) was found in 9% of coeliacs versus 2% of controls. Prevalence of HLA-A1, B8, DR3, and DQ2 was unrelated to secretor status in coeliac patients. An increased prevalence of complications and coeliac-associated abnormalities was found in the non-secreting and recessive coeliac groups. Conclusion: this study shows no firm relationship between the non-secretor state and coeliac disease, nor any difference in the distribution of HLA markers among secretor and non-secretor coeliacs. It is unlikely, therefore, that the secretor gene is the much sought-after second coeliac gene.