Anti-agalactosyl IgG antibodies in sera from patients with systemic sclerosis.
OBJECTIVE
To determine the prevalence and clinical correlations of anti-agalactosyl IgG antibodies (anti-AG IgG) in patients with systemic sclerosis (SSc).


METHODS
Serum samples from patients with limited cutaneous SSc (lSSc; n = 49), diffuse cutaneous SSc (dSSc; n = 21), rheumatoid arthritis (RA; n = 10), systemic lupus erythematosus (SLE; n = 20), and healthy individuals (n = 20) were examined by lectin-enzyme immunoassay using human agalactosyl IgG as antigen.


RESULTS
Anti-AG IgG were detected in 52 (74%) of 70 patients with SSc, which was much higher than the frequency of rheumatoid factor positivity in SSc (16%). Levels of anti-agalactosyl IgG antibodies were significantly higher than in healthy controls or patients with SLE, but lower than patients with RA. Levels of anti-AG IgG in patients with dSSc were significantly higher than in lSSc. SSc patients with anti-topoisomerase I antibodies had significantly higher levels of anti-AG IgG than SSc patients with anticentromere antibodies. Concerning clinical correlation, patients with pulmonary fibrosis showed elevated levels of anti-AG IgG compared to those without pulmonary fibrosis. Patients with decreased %VC or %DLCO showed increased levels of anti-AG IgG. Elevated levels of anti-AG IgG were associated with the presence of contracture of phalanges or cutaneous calcinosis, but not the presence of arthritis/arthralgia.


CONCLUSIONS
The results suggest that anti-agalactosyl IgG antibody is frequently detected in SSc and is a serological indicator for more severe SSc.
Nishijima
C
C
Department of Dermatology, Kanazawa University School of Medicine, Japan.
Sato
S
S
Takehara
K
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D002114:Calcinosis / Q000453:epidemiology / Q000276:immunology / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003286:Contracture / Q000453:epidemiology / Q000276:immunology / Q000473:pathology; D005260:Female; D005385:Fingers / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000453:epidemiology / Q000276:immunology / Q000473:pathology; D012595:Scleroderma, Systemic / Q000453:epidemiology / Q000276:immunology* / Q000473:pathology; D016036:Seroepidemiologic Studies
D000888:Antibodies, Anti-Idiotypic; D007074:Immunoglobulin G; C064155:agalactosyl IGG; C048844:anti-IgG