In patients with rheumatoid arthritis (RA), perfusion patterns from power Doppler sonography differ in those with seropositive and seronegative disease, which may be dependent on anti-citrullinated peptide antibody (ACPA) status, but not on rheumatoid factor (RF) status, according to study results published in Rheumatology International.

A total of 103 patients with active wrist arthritis were recruited from 2 rheumatology centers, 51 of whom were ACPA-positive and 52 of whom were ACPA-negative. All participants were examined using power Doppler sonography. No significant difference in disease activity was reported between ACPA-positive patients and ACPA-negative patients, as assessed by the 28-joint Disease Activity Score (DAS28; median DAS28 score, 4.2 vs 4.5, respectively).

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Among ACPA-positive patients and ACPA-negative patients, significant differences were observed with respect to age (median, 57 years vs 70 years, respectively; P <.0001) and disease duration (median, 13 years vs 6 years, respectively; P <.0001).

Standardized peak-to-peak amplitude (amplitude/maxima [Pmax]) differed significantly between ACPA-positive patients and ACPA-negative patients (median, 20% vs 41%, respectively; P <.0001) and between RF-positive patients and RF-negative patients (median, 24% vs 40%, respectively; P <.0001).

Moreover, in both ACPA-positive patients and ACPA-negative patients, a significant correlation was demonstrated between minima (Pmin) and Pmax (P <.0001). According to multivariate analysis, both the full model and the model choice strategies identified age (full model P <.02; model choice P =.01) and ACPA status (full model P<.0001; model choice P <.0001) as independent predictors of standardized peak-to-peak amplitude. In contrast, RF status, DAS28, and power Doppler grading all demonstrated no statistically significant influence.

The investigators concluded that ACPA-positive and ACPA-negative RA can be distinguished reliably using power Doppler ultrasonography, implying different pathophysiologic or even nosological processes. Study findings also suggest the RF is not of value when determining the RA phenotype. Additional research of other aspects of ACPA-negative RA is also warranted, both in isolation and compared with ACPA-positive RA.

Reference

Gadeholt O, Feuchtenberger M, Wech T, Schwaneck EC. Power-Doppler perfusion phenotype in RA patients is dependent on anti-citrullinated peptide antibody status, not on rheumatoid factor [published online February 26, 2019]. Rheumatol Int. doi:10.1007/s00296-019-04256-1