A prospective, longitudinal monocentric study on laser Doppler imaging of microcirculation: comparison with macrovascular pathophysiology and effect of adalimumab treatment in early rheumatoid arthritis

Abstract

Increased cardiovascular (CV) morbidity and mortality have been found in rheumatoid arthritis (RA). Tumour necrosis factor α (TNF-α) inhibitors may improve vascular function. In the first part of this study, we determined microcirculation during postoocclusive reactive hyperemia (PORH) representing endothelial function. In a nonselected population (n = 46) we measured flow-mediated vasodilation (FMD) of the brachial artery and laser Doppler flow (LDF) by ultrasound. Among LDF parameters, we determined TH1 (time to half before hyperemia), TH2 (time to half after hyperemia), Tmax (time to maximum) and total hyperemic area (AH). We measured von Willebrand antigen (vWF:Ag) by ELISA. In the second part of the study, we assessed the effects of adalimumab treatment on microcirculatory parameters in 8 early RA patients at 0, 2, 4, 8 and 12 weeks. We found significant positive correlations between FMD and LDF Tmax (R = 0.456, p = 0.002), FMD and TH2 (R = 0.435, p = 0.004), and negative correlation between vWF:Ag and Tmax (R = − 0.4, p = 0.009) and between vWF:Ag and TH2 (R = − 0.446, p = 0.003). Upon adalimumab therapy in early RA, TH2 times improved in comparison to baseline (TH2baseline = 26.9 s vs. TH24weeks = 34.7 s, p = 0,032), and this effect prolonged until the end of treatment (TH28weeks = 40.5, p = 0.026; TH212weeks = 32.1, p = 0.013). After 8 weeks of treatment, significant improvement was found in AHa (AHbaseline = 1599 Perfusion Units [PU] vs. AH8weeks = 2724 PU, p = 0.045). The PORH test carried out with LDF is a sensitive option to measure endothelial dysfunction. TH1 and TH2 may be acceptable and reproducible markers. In our pilot study, treatment with adalimumab exerted favorable effects on disease activity, endothelial dysfunction and microcirculation in early RA patients.