Human leucocyte antigen determinants of susceptibility to Barrett's oesophagus in Asians - A preliminary study

Background: Characteristic immune profiles have been demonstrated in gastro-oesophageal reflux disease. However, the genetic basis of gastro-oesophageal reflux disease remains unclear. Aim: To investigate whether certain human leucocyte antigen genes are associated with Barrett's oesophagus. Methods: Asian patients of Malay, Chinese and Indian descent with Barrett's oesophagus (n = 59) and those without reflux symptoms and a normal oesophagus (n = 60) were recruited prospectively using endoscopic and histopathological criteria. Human leucocyte antigen class I and II typing was performed using a polymerase chain reaction sequence-specific primers method. Results: The HLA-B 7 allele was present in 17% (10 of 59) of patients with Barrett's oesophagus when compared with 0% (zero of 60) of controls [P = 0.0006, corrected P = 0.0171, OR = 25.67]. Subgroup analysis revealed that the HLA-B 7 allele was confined almost exclusively to Indians with Barrett's oesophagus, 43% (nine of 21) vs. 0% (zero of 19) Indian controls (P = 0.0014, corrected P = 0.0406, OR = 29.64). No class II associations, protective human leucocyte antigens or extended haplotypes for disease susceptibility were identified. Conclusions: Barrett's oesophagus in Asians, particularly Indians, is strongly positively associated with HLA-B 7; reinforcing a genetic component to gastro-oesophageal reflux disease. A larger sample size and different ethnic populations should be genotyped to further confirm this association and identify possible additional risk factors in the human leucocyte antigen locus.