Association of MICA Alleles and Human Leukocyte Antigen B in Turkish Patients Diagnosed With Behçet's Disease.

OBJECTIVES

This study aims to investigate whether or not MHC class I polypeptide-related sequence A (MICA) polymorphisms are associated with the susceptibility to Behçet's disease (BD) in a Turkish population.

PATIENTS AND METHODS

The study included 38 Turkish BD patients (20 males, 18 females; mean age 34±10.9 years) and 51 ethnically matched healthy controls (30 males, 21 females; mean age 36±12.8 years). MICA and human leukocyte antigen B (HLA-B) alleles were determined in all subjects by using the Luminex technology. LABType sequence-specific oligonucleotide MICA test (One Lambda) and sequence-specific oligonucleotide B locus tests (Gene-Probe) were used for the typing studies.

RESULTS

A total of 16 MICA alleles were found in BD patients as well as in control subjects. The gene frequency of MICA006 was significantly higher in the BD patients compared to controls (14.5% vs. 0.9%; odds ratio [OR]: 17.092 95% confidence interval [CI] [2.155~135.554]; p<0.05). When haplotypes were evaluated, an association was found between the haplotypes HLA-B51-MICA006 (11.8% and 0.9%; OR: 13.567 95% CI [1.679~109.577]; p<0.001) and HLA-B51-MICA009 (27.6% and 13.7%; OR: 2.4 95% CI [1.127~5.109]; p<0.05). Frequencies of HLA-B49-MICA004 (0% and 6.8%) and HLA-B52- MICA*009 (0% and 10.7%) were significantly higher in controls compared to BD patients (p<0.05).

CONCLUSION

Our study shows that the MICA006 (MICA-A6) and the MICA009 alleles are associated with BD susceptibility in HLA-B51 positive Turkish population, particularly in HLA-B51 patients with MICA*006, which might be considered as a diagnostic biomarker for BD in the future.