Background Since the description of the efficacy of rituximab (RTX) in treating patients with rheumatoid arthritis (RA), the use of this drug has been extended. However it is not clearly established the patient profile in which the administration of RTX may show greater benefit.
Objectives To systematically review the published evidence to date regarding on the difference in efficacy in the treatment of RA with RTX in patients with rheumatoid factor (RF) positive and negative.
Methods A sensitive search of all published studies on the difference in the efficacy of RTX in RA patients with RF positive and negative was performed in Medline, Embase and Cochrane Central databases since its inception until July 2013. We selected all studies involving adult patients with RA seropositive for RF in which intervention was described as treatment with RTX and comparator as the administration of RTX to adult patients with RA seronegative for RF. Any standardized measure of efficacy in RA was considered as outcome measure. Although meta analysis, systematic reviews, clinical trials and cohorts well designed were preferably selected, finally we also included open studies and all studies that showed a methodologically correct subanalysis related to the question even if it had not been his main objective. After removing duplicates, an initial selection by reading titles, a second selection after reading abstracts and, finally, full reading of selected studies, assessing the methodological quality by levels of the Oxford Centre for Evidence Based Medicine Evidence (2001 update) where applicable, was carried out. A manual search of the references of included studies was also performed.
Results A total of 362 citations about the treatment with RTX of RA patients seropositive and seronegative for RF were identified, which were reduced to 54 after removing duplicates and selection by reading titles and abstracts. Of the 54 selected articles, finally 36 were included in the review, one of which is a meta analysis that includes four of the clinical trials included in that review and their conclusions define de result of the same given the highest quality from the methodological point of view. The rest are 5 clinical trials, 7 prospective studies, 7 retrospective and 16 communications to Congresses or sub-analysis of previous studies.
Conclusions RTX shows greater efficacy in the treatment of RA patients seropositive respect to seronegative, both in intensity and response rate (level of evidence 1a, grade of recommendation A). However, despite the level of evidence, due to the modest difference in efficacy between seropositive and seronegative patients and the results obtained after treatment with RTX in seronegative ones, it would be necessary the implementation of studies in this subgroup of patients to define the role of RTX in the treatment thereof.
Acknowledgements This work has been funded by the Spanish Society of Rheumatology.
Disclosure of Interest A. M. Ortiz Grant/research support: Spanish Society of Rheumatology, M. Rosario Lozano: None declared, C. Martínez Fernández: None declared, I. González-Άlvaro Grant/research support: Spanish Society of Rheumatology