Ultrasound assessment of enthesis thickening in psoriatic arthritis patients treated with adalimumab compared to methotrexate

The objective of the study was to combine ultrasonographic (US) with clinical findings for comparing the effect of adalimumab (ADA) to methotrexate (MTX) on the thickness of tendons and enthesis in psoriatic arthritis (PsA) patients. Forty-three consecutive PsA patients were examined at baseline and after 6 and 12 weeks of treatment with ADA or MTX. The US assessment included thickness measurement of the extensor (ET) and flexor tendons (FT) of the second and third finger of both hands, plantar aponeurosis (PA) and the Achilles tendon (AT) bilaterally. Disease activity (DA) was assessed by the number of tender (TJ) and swollen joints (SJ), the number of inflamed enthesis (IE), pain assessment (PAI), and patient (PDAI) and physician (PHDAI) disease activity evaluations by visual activity score (VAS). Nineteen patients received MTX and 24 patients received ADA. All DA parameters improved in both groups. A decrease in thickness of tendons and enthesis was observed only in the ADA group, reaching a level of significance for the left AT (p = 0.01), left PA (p = 0.007), the second left FT (p = 0.04) and the third ET (p = 0.04). ADA patients showed a trend towards a better response to treatment compared to MTX patients that reach significance at week 6 of treatment for the thickness of left AT (p = 0.04), left PA (p = 0.03), the number of TJ (p = 0.0136), PAI (p = 0.0028), and PDAI (p = 0.029). ADA treatment for PsA compared to MTX significantly improved signs of DA and several US parameters. US assessment of enthesis can be an additional useful tool in the monitoring of psoriatic enthesopathy.