BRIGHTON, England -- Patients with early inflammatory polyarthritis who have positive titers of anti-citrullinated protein antibodies (ACPA) appear to be at high risk for disease progression -- and should be considered potential candidates for biologic therapy, a researcher said here.
Among consecutive patients recruited between 1990 and 1994 from a primary care inception cohort, before the widespread use of biologic drugs, the hazard ratio for eventually requiring biologic therapy was 7.58 (95% CI 2.75 to 20.85) among those who were ACPA positive, according to Suzanne Verstappen, MD, from the University of Manchester, and colleagues.
However, among patients recruited between 2000 and 2004 after biologics were in use, the hazard ratio among those who were ACPA positive was 4.66 (95% CI 2.23 to 9.75), Verstappen said during an oral presentation at the annual meeting of the British Society for Rheumatology.
A decade's worth of experience with biologic therapy for rheumatoid arthritis has shown that early treatment can help prevent the articular damage and disability associated with progressive disease.
So Verstappen's group analyzed data from pre- and post-biologic era inflammatory polyarthritis patients enrolled in the Norfolk Arthritis Register to see if any baseline characteristics, or response to a first disease-modifying antirheumatic drug (DMARD) such as methotrexate, were associated with later need for biologic therapy.
Among the baseline characteristics considered in the study were age, disease activity, Health Assessment Questionnaire scores, C-reactive protein, rheumatoid factor, and the presence of shared epitope alleles for HLA-DRB1.
Failure of the first DMARD was defined as stoppage of the drug because of lack of efficacy or starting a second DMARD within six months.
All patients had two or more swollen joints for four weeks or more.