How well do ACPA discriminate and predict RA in the general population: a study based on 12 590 population-representative Swedish twins

Abstract

Presence of ACPA and especially high titres of anti-CCP2 have a high diagnostic accuracy for an RA diagnosis in a population setting.

Synovial tissue research: a state-of-the-art review

“…7 It is logical to hypothesise that each of these aims can be facilitated by the identification and development of appropriate biomarkers. However, while peripheral blood biomarkers such as rheumatoid factor and anti-citrullinated peptide antibodies (ACPA) have been shown to be relatively specific and may predict development of RA in asymptomatic individuals, 8,9 they may only be found in 70-80% of RA subjects. Indeed, beyond these factors our repertoire of blood biomarkers to assist with diagnosis, disease progression and response to therapy is currently extremely limited.…”

Challenging judgement of a low-positive ACPA test in the context of individuals at risk of RA

“…We thank Bossuyt1 for his letter and the comments related to our previous published study 2. We agree that the calculated test likelihood ratios for low-positive anticitrullinated protein antibody (ACPA) reflect the relative uncommonness of low-titre ACPA in prevalent rheumatoid arthritis (RA) (despite a significant association between).…”

Anticitrullinated protein antibodies: taking into account antibody levels improves interpretation

“…Hensvold et al 1 reported on the discriminatory capacity of anticitrullinated protein antibodies (ACPA) for diagnosing rheumatoid arthritis (RA) 1. A major strength of the study is that it was performed in a population setting and that a large number of controls (n=12 434) were included, thereby allowing a reliable estimate of the specificity of ACPA.…”

“…The unique and large dataset presented by Hensvold et al 1 allows to deduce test-result interval specific LRs. The LRs are 0.35 (95% CI 0.28 to 0.43), 3.4 (95% CI 1.5 to 7.5) and 73.6 (95% CI 58.7 to 92.3) for an anti-CCP2 test result <25 AU/mL, between 25 and 75 AU/mL and ≥75 AU/mL, respectively.…”

“…Only a small fraction (4%) of the patients (in total 156 patients with RA were included) had a low positive anti-cyclic citrullinated peptide antibody (CCP). The data are for prevalent RA at inclusion (based on table 2 in Hesvold et al 1). …”