Increased serum type I interferon activity in early systemic sclerosis patients is associated with antibodies against Sjögren's syndrome antigens and nuclear ribonucleoprotein antigens.

Abstract

OBJECTIVE:

To study serum type I interferon (IFN) activity in patients with early systemic sclerosis (SSc).

METHOD:

Serum type I IFN activity was measured in 33 consecutive patients with SSc and a disease duration of < 2 years and in 13 healthy individuals by calculating a type I IFN score according to the induction of six IFN-α regulated genes in a reporter cell line.

RESULTS:

Twenty-seven per cent of the SSc patients had an increased type I IFN score compared to none of the healthy individuals (p < 0.05). The clinical SSc phenotype associated with high serum type I IFN activity did not differ from patients with low serum type I IFN activity regarding the presence of skin or lung fibrosis, pulmonary hypertension, or digital complications. Patients with high serum type I IFN activity were younger (p < 0.01) and had a lower frequency of cardiac involvement (p = 0.053), lower leucocyte count (p < 0.001), higher immunoglobulin (Ig)G levels (p < 0.05), and a higher amount of antibodies against extractable nuclear antigens (p < 0.01) than patients with low serum type I IFN activity. The presence of antibodies against topoisomerase I, Sjögren's syndrome antigen, and nuclear ribonucleoprotein antigens was associated with higher type I IFN activity (p < 0.05 for all comparisons).

CONCLUSIONS:

Our study indicates that increased serum type I IFN activity in early SSc patients is associated with an antibody and laboratory profile that may reflect a subclinical overlap of SSc with other type I IFN-driven connective tissue diseases (CTDs).

• Authors: D M Wuttge, C Lood, E Tufvesson, A Scheja, L Truedsson, A A Bengtsson, R Hesselstrand
• Journal: Scandinavian journal of rheumatology (Scand J Rheumatol) Vol. 42 Issue 3 Pg. 235-40 ( 2013) ISSN: 1502-7732 [Electronic] England
• PMID: 23379597 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Autoantibodies
• Interferon Type I
• Ribonucleoproteins

Topics

• Adult
• Aged
• Autoantibodies (blood)
• Case-Control Studies
• Female
• Humans
• Interferon Type I (blood)
• Male
• Middle Aged
• Ribonucleoproteins (immunology)
• Scleroderma, Systemic (blood, immunology)
• Sjogren's Syndrome (immunology)