Analysis of clinical and anamnestic factors affecting endothelial glycocalyx condition in patients with active rheumatoid arthritis

Abstract

Background . Endothelial dysfunction (ED) involved in the pathogenesis of rheumatoid arthritis (RA) is more associated with the endothelial glycocalyx (EGC) condition. EGC thinning is an independent predictor of cardiovascular complications that is why it is important to determine the risk factors (RF) that most affect EGC in RA. Objective . To study the relationship between the endothelium condition and RF for an RA unfavourable course and cardiovascular risk (CVR). Design and methods . The study involved 103 patients aged 18 to 69 years of both sexes with active RA. A dark-field microscope was used to assess the EGC condition. In the microcirculatory bed, it allows you to evaluate the depth of erythrocyte perfusion in the EGC thickness (PBR), micro vessel density (VMD) and the number of erythrocytes in them (RBC Filling). An increase in PBR indicates EGC thinning and is a marker of ED. A decrease in RBC Filling and VMD indicates a decrease in the functioning vessels number. Circulating syndecan1 (Sdc1) was assessed as a laboratory EGC damage marker. As a result of a two-step cluster analysis, based on dark-field microscopy, two clusters were identified in the study cohort. They were compared in terms of RF for an unfavourable course of RA and CVR. Results . Patients belonging to cluster 1 had thinner EGC (high PBR), low perfusion (low RBC Filling) and density (low VMD) of microvessels, higher levels of Sdc1 than in cluster 2. This indicates a significant impairment of microcirculation in cluster 1. Among the studied RF for an unfavorable course of RA and CVR, cluster 1 differed only in a lower frequency of taking disease-modifying antirheumatic drugs (DMARDs) compared to the other cluster. In the future, it was associated with the 3,6-fold greater need for DMARD therapy modification. Conclusions . The lack of DMARD therapy, compared with the other RF for the unfavorable course of RA and CVR, makes the greatest contribution to EGC damage and microcirculation disorders in patients with active RA. The revealed changes confirm relationship between endothelial disorders and the pathogenesis of this disease and determine the leading role of DMARD therapy in the RA treatment.