Also, no associations were found between MP concentrations and the following variables: autoantibodies, pulmonary arterial hypertension (PAH), digital ulcers neither present at enrolment nor only in the past, disease duration, smoking status, age, hypertension, IgM rheumatoid factor, C-reactive protein, or use of the following medications: low dose aspirin, calcium channel blockers and/or statins. The gene discussed is CD40LG; the disease is pulmonary arterial hypertension.