Researchers recently studied the effect of missing anticitrullinated protein antibody (ACPA) – which is typically not paid for or readily accessible – and whether this causes a care gap in early inflammatory arthritis. They assigned a cohort of nearly 2000 patients to 1 of 3 groups:

• seropositive;

• seronegative; or

• missing ACA and rheumatoid factor (RF)

Investigators evaluated disease activity score at 28 joints at 3 months.

More seropositive patients fulfilled American College of Rheumatology/European League Against Rheumatism RA criteria than seronegative patients. At 3 months, the third group – which was slightly older and had fewer females, shorter symptom duration, and less smoking – was treated with fewer agents, but no risk differences were seen.

The authors concluded that there is no care gap in the RF-negative, unknown ACPA group.

Citation: Shu J, Bykerk V, Boire G, et al. Missing Anticitrullinated Protein Antibody Does Not Affect Short-term Outcomes in Early Inflammatory Arthritis: From the Canadian Early Arthritis Cohort. J Rheumatol. 2015; September 1,2015. doi:10.3899/jrheum.150260.