RT Journal Article
SR Electronic
T1 Missing Anticitrullinated Protein Antibody Does Not Affect Short-term Outcomes in Early Inflammatory Arthritis: From the Canadian Early Arthritis Cohort
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 2023
OP 2028
DO 10.3899/jrheum.150260
VO 42
IS 11
A1 Jenny Shu
A1 Vivian P. Bykerk
A1 Gilles Boire
A1 Boulos Haraoui
A1 Carol Hitchon
A1 J. Carter Thorne
A1 Diane Tin
A1 Edward C. Keystone
A1 Janet E. Pope
YR 2015
UL http://www.jrheum.org/content/42/11/2023.abstract
AB Objective. Anticitrullinated protein antibody (ACPA) is as sensitive as, but more specific than, rheumatoid factor (RF) and is detected earlier in rheumatoid arthritis (RA). Although part of the RA classification criteria, ACPA testing is not routinely paid for/accessible in all jurisdictions. The effect of missing ACPA testing was studied to determine whether failure to perform ACPA testing could cause a care gap in early inflammatory arthritis.Methods. Nearly 2000 patients (n = 1998) recruited to an early inflammatory arthritis cohort were allocated into 3 groups: (1) seropositive (either RF+ or ACPA+), (2) seronegative (RF− and ACPA−), and (3) missing ACPA and RF−. Analyses were adjusted for age, sex, symptom duration, and smoking status if p < 0.1. Disease Activity Score at 28 joints (DAS28) at 3 months was studied, because beyond then, disease activity is expected to determine ongoing treatment.Results. More seropositive patients fulfilled the 2010 American College of Rheumatology/European League Against Rheumatism RA criteria than seronegative patients. Group 3 was slightly older and had a smaller percentage of females, as well as shorter symptom duration and less smoking. At 3 months, group 3 was treated with fewer disease-modifying antirheumatic drugs and methotrexate (p < 0.00002) than groups 1 and 2, but there were no significant differences in DAS28, Health Assessment Questionnaire-Disability Index (HAQ-DI), proportion receiving corticosteroids, or physician’s/patient’s global assessments.Conclusion. There was no care gap in the RF-negative, unknown ACPA group because there were no significant differences in the DAS28, 3-month change in DAS28, or HAQ-DI, despite less treatment. Cost-effectiveness of ensuring ACPA testing availability in suspected RA is unknown because early outcomes did not differ, whether or not ACPA was available.