Rheumatoid factor by laser nephelometry and Waaler-Rose assay: prognostic value in patients with recent-onset rheumatoid arthritis.

Abstract

OBJECTIVE:

To evaluate the prognostic value of rheumatoid factor (RF), detected in the Waaler-Rose agglutination assay and by nephelometry, in patients with recent-onset rheumatoid arthritis (RA).

METHODS:

Consecutive patients with new-onset RA between 1993 and 1997 were followed for a median period of 4.7 years. Clinical data at baseline and drug use during the disease course were recorded. Outcome parameters studied were disease process, damage (erosions, joint surgery, extra-articular manifestations, and new co-morbidity), and death. Cut-off levels for RF were >40 IU/mL (nephelometry) and titres 1:160 (Waaler-Rose haemagglutination).

RESULTS:

RF tests were negative by both methods in 22% of RA patients (RF- group), while 33% were RF positive by nephelometry only (RF+ group) and 45% were positive by Waaler-Rose and nephelometry (RF++ group). Baseline clinical and laboratory findings as well as the number of subsequently used disease-modifying anti-rheumatic drugs (DMARDs), the number of patients starting and the time spent on steroid therapy were similar in the three RF groups. Odd ratios for death (n = 23), erosions (n = 62), and serious extra-articular disease manifestations (EAMs) (n = 13) as well as patient survival, erosion-free or surgery-free survival rates did not differ between the RF groups. Only rheumatoid nodules were more frequent in RF++ patients.

CONCLUSION:

The baseline presence of RF by either Waaler-Rose or nephelometry was not associated with differences in drug therapy, morbidity other than rheumatoid nodules, or mortality in RA patients in the first 5 years of disease. Being immunoglobulin M (IgM) RF positive thus had little impact on RA patient outcome.

• Authors: C Nikolaisen, O P Rekvig, H C Nossent
• Journal: Scandinavian journal of rheumatology (Scand J Rheumatol) 2005 Jul-Aug Vol. 34 Issue 4 Pg. 269-76 ISSN: 0300-9742 [Print] England
• PMID: 16195159 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antirheumatic Agents
• Biomarkers
• Rheumatoid Factor

Topics

• Adult
• Aged
• Aged, 80 and over
• Agglutination Tests (methods)
• Antirheumatic Agents (therapeutic use)
• Arthritis, Rheumatoid (diagnosis, drug therapy, mortality)
• Biomarkers (analysis)
• Cohort Studies
• Confidence Intervals
• Disease Progression
• Female
• Humans
• Logistic Models
• Male
• Middle Aged
• Multivariate Analysis
• Nephelometry and Turbidimetry (methods)
• Norway
• Prognosis
• Retrospective Studies
• Rheumatoid Factor (analysis)
• Rheumatoid Nodule (diagnosis, drug therapy, mortality)
• Risk Factors
• Sensitivity and Specificity
• Severity of Illness Index
• Survival Rate
• Time Factors
• Treatment Outcome