Rheumatoid factor and response to TNF antagonists in rheumatoid arthritis: systematic review and meta-analysis of observational studies.
OBJECTIVE
To systematically analyze literature with the aim of examining whether rheumatoid factor (RF) is a predictor of response to tumor necrosis factor (TNF) antagonists in rheumatoid arthritis (RA).


METHODS
A systematic review and meta-analysis of observational studies were conducted. All studies on the association of baseline RF (titer and/or status) and response to any TNF antagonists, or with enough information to estimate this association were included. Qualitative analysis and meta-analysis using random-effects approach by type of outcome response and RF test was performed. Risk of publication bias was also evaluated.


RESULTS
The systematic review included 18 studies of 4163 identified articles, involving 5703 patients with homogeneous baseline characteristics. The most common outcome to assess response was European League Against Rheumatism (EULAR) response criteria, normally merging good and moderate categories as response. The weighted mean difference (WMD) of baseline IgM RF titer in meta-analysis was higher in the non-responders group [-101.58 (95% CI -156.58,-46.59) I2=0.0]. Combined odds ratios (ORs) of positive IgM RF, positive IgA RF, and positive IgG RF to achieve good/moderate response were 1.08 (0.80, 1.47), I2=40.9%; 0.83 (0.39, 1.73), I2=39.8%, and 1.30 (0.48, 3.51), I2=62.9%, respectively. We did not find an association between a positive IgM RF and EULAR good response or remission.


CONCLUSIONS
This meta-analysis does not support baseline IgM RF titer as a predictor of response to TNF antagonists in RA. However, this conclusion is hampered by high heterogeneity in the studies included in this meta-analysis.
['Salgado|Eva|E|', 'Maneiro|José Ramón|JR|', 'Carmona|Loreto|L|', 'Gómez-Reino|Juan|J|']
D000293:Adolescent D000328:Adult D000368:Aged D000369:Aged, 80 and over D018501:Antirheumatic Agents D001172:Arthritis, Rheumatoid D001685:Biological Factors D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D064887:Observational Studies as Topic D011379:Prognosis D012217:Rheumatoid Factor D016896:Treatment Outcome D014409:Tumor Necrosis Factor-alpha D055815:Young Adult
Rheumatoid factor TNF antagonists Rheumatoid arthritis