TY - JOUR T1 - Anti-Cyclic Citrullinated Peptide Antibody versus HAQ/MDHAQ: Comparing Apples and Oranges? JF - The Journal of Rheumatology JO - J Rheumatol SP - 1565 LP - 1567 DO - 10.3899/jrheum.090673 VL - 36 IS - 8 AU - VIVIAN BYKERK Y1 - 2009/08/01 UR - http://www.jrheum.org/content/36/8/1565.abstract N2 - Pincus, et al in the this issue of The Journal address the contentious issue of where anti-cyclic citrullinated peptide antibody (anti-CCP) testing belongs, if at all, in routine clinical practice1. The extension of this line of thought is whether or not this test is cost-effective or of real clinical utility to the practicing rheumatologist. The authors address the question whether testing for anti-CCP will improve patient outcomes or be of value in making appropriate clinical therapeutic decisions at the bedside above and beyond the evaluation of function in a systematic fashion. They raise the question whether a composite patient-related non-biologically-based score such as the Health Assessment Questionnaire (HAQ)/Multidimensional (MD) HAQ should trump a laboratory test when evaluating a patient with rheumatoid arthritis (RA). While arguing for the use of this test, the authors note that “Anti-CCP provides a significantly higher hazard ratio than rheumatoid factor (RF) to identify people with early arthritis who will develop progressive disease”2,3, based on greater pooled specificity of 95% in a metaanalysis of 37 studies, compared to 85% in 50 studies of RF for RA3. They also argue that the presence of these antibodies may favor the use of treatments that are proven to be highly effective in subsets of patients who are positive for anti-citrullinated peptide antibodies (ACPA), which include anti-CCP4.Perhaps we should not compare apples with oranges, as anti-CCP is a good biomarker predicting sustained inflammatory arthritis and increased risk of erosions in early disease, whereas the HAQ (or other modified versions of the HAQ) is important for evaluating function and can be done repeatedly by the patient. The HAQ, however, does not necessarily perform well in early disease, given that functional impairment early on may be fully reversible5 and is … Address correspondence to Dr. Bykerk; E-mail: vbykerk{at}mtsinai.on.ca ER -