No significant association was found between SSc-specific autoantibodies (anti-centromere, anti-Scl-70, anti-RNA polymerase III and anti-RNP) status and the risk of depression.
We then examined anti-RNPC-3-positive cases and negative SSc controls from the University of Pittsburgh and the University of Pittsburgh Medical Center (UPMC) scleroderma cohort to confirm our findings and to examine whether specific GI features were associated with anti-RNPC-3 antibodies.
Antinuclear antibodies, anti-centromere antibodies, antiphospholipid antibodies, anti-U3 RNP antibodies and anti-Th/To antibodies would appear to show a particularly important prevalence in scleroderma patients with pulmonary hypertension, appearing in about 8/10 (antinuclear), 1/ 2 (anti-centromere, anti-phospholipid), and 1/4 (anti-U3RNP, anti-Th/To) of patients.
We identified a specificity for the minor spliceosome complex containing RNA Binding Region (RNP1, RNA recognition motif) Containing 3 (RNPC3) that is found in patients with scleroderma without known specificities and is absent in unrelated autoimmune diseases.
As expected, antitopoisomerase I antibody (Ab, n=64), anti-RNA polymerases (RNAP) Ab (n=12) and anti-U3 RNP Ab (n=5) were associated with diffuse cutaneous SSc, whereas anticentromere Ab (ACA, n=75), anti-Th/To Ab (n=7) and anti-U1 RNP Ab (n=10) were frequently detected in patients with limited cutaneous SSc.
Twenty-four sera had autoantibodies to defined nucleolar antigens by IP (seven Pm-Scl, ten RNA polymerase (pol) I, four U3 RNP, three Th RNP), and all were from patients with SSc (38.7%).