Anti-agalactosyl IgG antibodies in Thai patients with rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis.

Abstract

This study was performed to determine the prevalence of anti-agalactosyl IgG antibodies in Thai patients with RA, systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), and determine the sensitivity and specificity of anti-agalactosyl IgG antibodies in the diagnosis of RA in comparison with IgM-rheumatoid factor (IgM-RF) and anti-cyclic citrullinated peptide (anti-CCP) antibodies. Serum samples were obtained from 100 patients with RA, 50 cases of SLE, 50 cases of SSc, and 100 healthy controls and analyzed for the presence of anti-agalactosyl IgG antibodies, IgM-RF and anti-CCP antibodies. A serum value greater than mean + 2 standard deviation of normal value of anti-agalactosyl IgG antibodies and anti-CCP antibodies was considered positive. The prevalence of anti-agalactosyl IgG antibodies in RA, SLE, and SSc patients was 88.0%, 14.0%, and 12.0%, respectively. The serum level of anti-agalactosyl IgG antibodies in patients with RA (227.10 +/- 353.64 AU/mL) was significantly higher than those in SLE (11.84 +/- 52.04 AU/mL), SSc (18.85 +/- 99.60 AU/mL), and healthy controls (2.14 +/- 1.97 AU/mL), (p < 0.001). There was a good correlation between the log serum level of anti-agalactosyl IgG antibodies and IgM-RF (r = 0.92, p < 0.001), anti-CCP antibodies and IgM-RF (r = 0.49, p < 0.001), and anti-agalactosyl IgG antibodies and anti-CCP antibodies (r = 0.55, p < 0.001). The sensitivity and specificity in the diagnosis of RA was 88.00% and 96.00% for anti-agalactosyl IgG antibodies, 90.00% and 99.00% for anti-CCP antibodies, and 91.00% and 95.00% for IgM-RF, respectively. The serum level of anti-agalactosyl IgG antibodies was significantly higher in RA than in SLE, SSc, and healthy controls. There was a good correlation between serum levels of anti-agalactosyl IgG antibodies, anti-CCP antibodies, and IgM-RF. These three tests had comparable sensitivity and specificity.

• Authors: Worawit Louthrenoo, Nuntana Kasitanon, Ramjai Wichainun, Suparaporn Wangkaew, Waraporn Sukitawut, Shoji Kuwata, Fujio Takeuchi
• Journal: Clinical rheumatology (Clin Rheumatol) Vol. 29 Issue 3 Pg. 241-6 (Mar 2010) ISSN: 1434-9949 [Electronic] Germany
• PMID: 20091076 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Anti-Idiotypic
• Immunoglobulin G
• Immunoglobulin M
• Peptides, Cyclic
• agalactosyl IGG
• cyclic citrullinated peptide
• Rheumatoid Factor

Topics

• Adult
• Antibodies, Anti-Idiotypic (blood, immunology)
• Antibody Specificity
• Arthritis, Rheumatoid (epidemiology, immunology)
• Female
• Humans
• Immunoglobulin G (immunology)
• Immunoglobulin M (blood, immunology)
• Lupus Erythematosus, Systemic (epidemiology, immunology)
• Male
• Middle Aged
• Peptides, Cyclic (immunology)
• Rheumatoid Factor (blood, immunology)
• Scleroderma, Systemic (epidemiology, immunology)
• Seroepidemiologic Studies
• Thailand (epidemiology)
• Young Adult