The following is a summary of “Citrullinated and carbamylated proteins in extracellular microvesicles from plasma of patients with rheumatoid arthritis,” published in the June 2023 issue of Rheumatology by Ucci, et al.

For a study, researchers sought to investigate the expression of citrullinated and carbamylated proteins in extracellular microvesicles (EMVs) from rheumatoid arthritis (RA) patients.

Twenty healthy donors (HD), matched for age and sex, and 24 RA naïve patients who had never received biological therapy were included in the study. Laboratory and clinical data were recorded for each patient, and clinical indexes were measured, including the Clinical Disease Activity Index, Simplified Disease Activity Index, and DAS28. EMVs were purified from the plasma of RA patients and HD and quantified using nanoparticle tracking analysis (NanoSight). The EMVs were then incubated with anti-citrullinated and anti-carbamylated proteins antibodies and subjected to flow cytometry and western blot analysis to evaluate the expression of citrullinated and carbamylated antigens.

The NanoSight analysis revealed a significant increase in EMVs in RA patients compared to HD. Additionally, the cytofluorimetric examination revealed that the expression of citrullinated antigens on the surface of EMVs was considerably higher in RA patients than in healthy donors. However, the expression of carbamylated antigens did not indicate a significant difference. Vimentin, glycolytic enzyme alpha-enolase 1, and collagen type II were found to be the primary citrullinated and carbamylated proteins transported by EMVs by Western blot analysis. Additionally, a significant correlation between the expression of citrullinated antigens and disease activity was observed.

The study’s findings suggested that EMVs may be involved in the pathogenesis of RA by inducing autoimmunity.

Source: academic.oup.com/rheumatology/article-abstract/62/6/2312/6762857?redirectedFrom=fulltext