Objectives: To study immunoreactivity against human cytomegalovirus (HCMV) in systemic sclerosis (SSc), since HCMV has been put forward as a candidate infectious cause.
Methods: Eighty four patients with SSc (67 females; median age 60 years, range 25-81), 30 patients with multiple sclerosis (MS) (23 females; median age 44, range 20-69 years) and 28 healthy controls (NCs), all pre-tested positive for IgG anti-HCMV antibodies, were studied. IgG anti-UL83 HCMV antibodies were tested by western immunoblotting and expressed in arbitrary units (AUs). Reactivity to UL83 HCMV was assessed in relation to clinical manifestations and SSc-related autoantibodies (autoAbs), tested by an IgG SSc autoantibody profile line immunoassay (Euroimmun) that detects autoAbs against Scl-70, CENPA, CENPB, RNA polymerase III subunit 11 (RP11), RP155, fibrillarin, NOR90, Th/To, PM-Scl100, PM-Scl75, Ku, PDGFR and Ro-52.
Results: Fifty patients (59.5%) were anti-UL83 clear positive (UL83+), including 21/40 (52.5%) lcSSc and 29/44 (65.6%) dcSSc, compared to 15/30 (50%) patients with MS (SSc vs MS, p=ns and 11/28 (39.29%) of NCs (SSc vs NC, p=ns MS vs NC, p=ns). Anti-UL83 antibody AU levels (mean±SD) were higher in SSc (64.3 ± 26) compared to MS (49.1±21.6, p=0.05) or NCs (40.4±13.7, p<0.001; MS vs NCs, p=ns) and were associated with pulmonary fibrosis.
Conclusions: Immunoreactivity to UL83 HCMV is frequent and strong in patients with SSc, implying a possible pathogenic role for this disease.