Abstract | OBJECTIVES: To study the clinical, biological and radiological characteristics of RA with a predominant increase of IgA isotype rheumatoid factor ( IgA-RF) over IgM-RF. METHODS: The presence of IgA-RF was determined by a sandwich-type ELISA with an antibody against the human IgA used to capture the immunoglobulin. Associated RF activity was revealed with a peroxidase-conjugated human IgG Fc fragment. Forty-nine RA patients were studied, of whom 19 had an increase in IgA-RF (38%). The control group comprised 30 RA patients without IgA-RF. RESULTS: None of the patients had isolated IgA-RF. In the selected 19 RA patients, the OD of IgA-RF (0.971 +/- 0.62 U) was higher than the IgM-RF (mean OD: 0.675 +/- 0.522 U). A statistically significant correlation was found between IgA-RF and IgM-RF (r = 0.64, p < 0.0001). No correlation was noted between the IgA concentration and the IgA-RF titer. The two groups were comparable for age, disease duration, sex ratio and previous DMARD use. We observed that patients with RA associated with increased IgA-RF more often had the sicca syndrome, but no other extra-articular features. RA patients with IgA RF also had more erosive disease: the mean Larsen score at the hand and wrist was 76 (SD = 68) versus 54 (SD = 60) in the controls, p < 0.02. Replacement surgery for the hip or knee was necessary in 47% of the RA patients with IgA-RF, versus 13% in the controls, p < 0.01. No association of IgA-RF with disease activity was noted. CONCLUSION: Our study showed that RA patients with a predominant increase of IgA-RF had a more erosive disease and a high frequency of associated sicca syndrome.
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Authors | C Jorgensen, M C Legouffe, C Bologna, J Brochier, J Sany |
Journal | Clinical and experimental rheumatology
(Clin Exp Rheumatol)
1996 May-Jun
Vol. 14
Issue 3
Pg. 301-4
ISSN: 0392-856X [Print] Italy |
PMID | 8809445
(Publication Type: Journal Article)
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Chemical References |
- Immunoglobulin A
- Immunoglobulin M
- Rheumatoid Factor
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Topics |
- Arthritis, Rheumatoid
(diagnostic imaging, immunology, physiopathology)
- Disease Progression
- Female
- Humans
- Immunoglobulin A
(blood, immunology)
- Immunoglobulin M
(blood, immunology)
- Male
- Middle Aged
- Radiography
- Rheumatoid Factor
(blood)
- Sjogren's Syndrome
(immunology)
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