Association of HLA Class II Genes with Systemic Sclerosis in Spanish Patients

Objective. To examine the role of HLA-DRB1 and HLA-DQB1 alleles in the susceptibility to systemic sclerosis (SSc) and its clinical expression in a Spanish population. Methods. One hundred Spanish Caucasian patients with SSc and 130 controls were Studied. Molecular HLA-DRB1 and HLA-DQB1 typing was performed by polymerase chain reaction (PCR) sequence-based typing and PCR sequence-specific oligonucleotide. Results. HLA-DRB1*11 was associated with genetic susceptibility to SSc, whereas HLA-DRB1*07 (HLA-DRB1*0701) showed a protective effect. A significant increase in the frequency of the DRB1*1104 allele was observed in patients with anti-topoisomerase I autoantibodies (anti-Topo I) while HLA-DRB1*01 and HLA-DQB1*05 alleles were significantly increased in patients with anti-centromere antibodies (ACA). The HLA-DRB1*11 allele was more frequent in patients with pulmonary fibrosis; however, no significant association with any HLA-DRB1 or DQB1 alleles was identified in patients with pulmonary arterial hypertension. Conclusion. HLA alleles play a role in genetic susceptibility to SSc in Spanish patients. Some alleles are more prevalent in patients with pulmonary fibrosis and in patients with certain SSc-specific autoantibodies (anti-Topo I and ACA). (First Release Nov 1 2009; J Rheumatol 2009;36:2733-6; doi: 10.3899/jrheum.090377)