Serum proteomics analysis from rheumatoid arthritis patients receiving combination therapy of imrecoxib, total glucosides of paeony and two DMARDs

Background： Rheumatoid arthritis (RA) is a chronic autoimmune disease. Imrecoxib, disease-modifying anti-rheumatic drugs (DMARDs) and total glucosides of paeony (TGPs) are common clinical therapies for RA. However, the exact mechanism of combination therapy for rheumatoid arthritis is still unclear. This study aims to explore the potential mechanism of this combination therapy for RA. Methods： Five RA patients who used this combination drug therapy were enrolled. Serum was collected at the first visit and the second visit after 3 months of continuous use of the combination treatment. Label-free quantitative proteomics was used to perform a comparative analysis of protein expression in serum after depletion of high-abundance proteins. The GO database was used to annotate the functions of differentially expressed proteins (DEPs). Results： A total of 257 reliable proteins were identified. Six proteins (IGKV3-20, TTR, LRG1, SERPINA3, F10 and NMNAT3) were downregulated, and one protein (HBD) was upregulated after three months of continuous combination drug treatment. Bioinformatics analysis showed that DEPs were primarily involved in various biological processes, such as metabolic processes, cellular processes and biological regulation. The identified DEPs have been reported to be involved in inflammation, cell proliferation, angiogenesis and oxidative stress. Therefore, these proteins have played important roles in RA progression. Conclusion： This combination drug therapy could alleviate the symptoms of RA by regulating these DEPs associated with RA in different ways. The DEPs identified may help to predict the treatment outcome of therapy for RA in the future.