[Gluten enteropathy in Croatian children is primarily associated with the HLA-DR3-DQ2 haplotype]

Coeliac disease (CD) has one of the strongest class II HLA association of any human disease. The goal of this study was to establish the frequency of HLA-DR and DQ antigens, as well as common HLA-DR-DQ haplotypes among CD patients. No similar study has previously been done in Croatian patients.

There were 58 biopsy proven patients with CD. The control groups comprised 502 and 118 healthy person for HLA-DR and HLA-DQ typing, respectively.

The class II HLA-DR and DQ antigens typing were carried out by standard microcytotoxicity assay for B cells. Only antisera to three specificities (DQ1, 2 and 3) were available to us at the time of the study.

We confirmed the high frequency of HLA-DR3 (84.48%; RR = 23.7; p < 0.00001) in our patients with CD. As reported in other populations, most of the patients negative for DR3, were heterozygous for DR7 and DR5 (10.34%) or DR4/DR5, DR4/DR6 (3.44%). CD was significantly correlated with the presence of HLA-DQ2 (96.55%, RR = 75.9; p < 0.00001). Correlation with CD was strongly dependent on homozygosity, 15 out of 58 (25.86%) of the patients and 4 (2.87%) of the controls being homozygotes for DQ2 (RR = 11.9; p < 0.00001). The remaining two patients were DR4-DQ3 positive. Among extended haplotypes only DR2-DQ1 was under-represented (RR = 0.3; p < 0.0033).

The results suggest that in Croatia CD is primarily associated with HLA-DQ2 specificities on the DR3-DQ2 haplotype.