Coeliac disease (CD): The effect of HLA antigens on the age of diagnosis and the presence of autoimmune thyroid disease

Aims: To study the frequency of HLA-B8 in coeliacs, and to determine if coeliacs with an atypical HLA profile are less likely to develop ATD than those with the typical HLA-B8, DR3, DQ2 haplotype.

Methods: Age at diagnosis of CD was stratified into A (≤5 yr), B (6–15 yr), C (16–30 yr), D (31–45 yr), E (46–60 yr), and F (>60 yr); and thyroid status into 1 (overt ATD), 2 (euthyroid, TA+), and 3 (euthyroid, TA-). The frequencies of the HLA-B8, DR3, and DQ2 were examined separately and as a complete haplotype. HLA typing was performed by serological methods; thyroid function and thyroid antibody by routine methodology. Χ² tests were used to assess significance.

Results: HLA-B8 positivity are found in groups E (90.8%, 89/98) and A (75.0%, 96/128) respectively (p=0.043). A similar pattern is found with the full haplotype, E (76.8%, 53/69): A (58.35, 48/82), p=0.036). The frequencies of HLA-DR3 and DQ2 were not significantly different. As regards ATD the frequency of complete coeliac haplotype was: group 1 (26/35), group 2 (12/17), and group 3 (150/201). These differences are not statistically significant.

Conclusion: There is an increasing trend of HLA-B8 with increasing age. An atypical HLA haplotype does not protect against the development of ATD.