DQA1*05, a risk factor previously identified in adult men with SSc, was increased in patients with juvenile-onset SSc versus controls (57.9% versus 44.1%; OR 1.76, P = 0.027), as was DRB1*03 (34.2% versus 22.5%; OR 1.79, P = 0.031).
To determine human leucocyte antigen-class II (HLA-class II) (DRB1, DQB1, DQA1 and DPB1) alleles, haplotypes and shared epitopes associated with scleroderma (systemic sclerosis (SSc)) and its subphenotypes in a large multi-ethnic US cohort by a case-control association study.
The frequency of the HLA-DRB1*03-DQA1*05-DQB1*02 haplotype was significantly increased in the JDM-SSc (P = 0.003) and anti-PM-Scl antibody (P = 0.002) positive groups.
We were unable to demonstrate that DQA1*0501 is associated with microchimerism in T lymphocytes or in whole peripheral blood DNA in patients with SSc or juvenile IIM or in healthy individuals.
An extended HLA DR2 (DRB1*1602, DQA1*0501, DQB1*0301, DPB1*1301) haplotype that includes the class I and III regions was identified which was significantly associated with scleroderma in the Oklahoma Choctaw.