The effect of cigarette smoking on the clinical and serological phenotypes of polymyositis and dermatomyositis.

Objective: Cigarette smoking is associated with immune-mediated disorders. We explored the contribution of smoking to polymyositis (PM) and dermatomyositis (DM) phenotypes and attempted to determine whether cigarette smoking effects differ by race and genotype.

Methods: Associations of tobacco smoking with disease features, autoantibodies, HLA types, and race were evaluated using multiple logistic regressions in 465 patients.

HLA-DQA1 is not an apparent risk factor for microchimerism in patients with various autoimmune diseases and in healthy individuals.

Objective: Microchimeric cells have been identified in lesions and peripheral blood of patients with systemic sclerosis (SSc) and idiopathic inflammatory myopathies (IIM), and HLA-DQA1*0501 is a risk factor for these diseases in some populations. Furthermore, DQA1*0501 has been associated with T lymphocyte microchimerism in SSc. To better define the strength of this association, we assessed the relationship among DQA1 alleles and microchimerism.