Association of HLA-DQB1 allelic sequence variation with susceptibility to systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease in which polymorphisms within the human leukocyte antigen (HLA) region have been associated to its etiology. We conducted this study to compare the HLA-DQB1 allelic sequence variation among SLE patients and controls in the northeast of Iran. Genomic DNA of 40 SLE patients and 83 healthy controls were amplified by Polymerase Chain Reaction with Sequence-Specific Primers technique (PCR-SSP). Seven serological subclasses of the HLA DQB1 were detected. Allele distribution comparison showed in the SLE group a significant increase of HLA DQ6 (*0601-*0609) (p=0.006); whereas alleles HLA DQ7 (*0301-*0304) were significantly decreased (p=0.005). Combination of DQ5 (*0501-*0504)-DQ6 (*0601-*0609) was increased in patients. These results suggest that DQ6 is the dominant HLA DQB1 allele probably associated with genetic susceptibility to SLE in the northeast of Iran. The association supports the importance of ethnic background and indicates the importance of various genes that has been observed in different SLE populations.