P171 Hsp90 in axial spondyloarthritis, psoriatic arthritis and rheumatoid arthritis

Abstract

Career situation of first and presenting authorStudent for a master or a PhD.IntroductionHsp90 is a highly conserved molecular chaperone that regulates activation of innate immunity, antigen presentation, and the induction of proinflammatory cytokines and chemokines. These properties predispose Hsp90 to its potential role in the pathogenesis of autoimmune inflammatory rheumatic diseases.ObjectivesThe aim of this study was to assess plasma Hsp90 in patients with axial spondyloarthritis (axSpA), psoriatic arthritis (PsA), rheumatoid arthritis (RA) and healthy controls (HC) and to determine its potential association with disease activity and clinical features.MethodsA total of 136 patients, that were divided into groups according to the type of a rheumatic disease (SpA, RA, PsA), and age-/sex- matched healthy individuals were included. Plasma Hsp90 levels were measured by ELISA (eBioscience, Vienna, Austria). Data are presented as median (IQR).ResultsPlasma Hsp90 levels were significantly increased in axSpA and in RA patients compared to HC. The increased plasma levels of Hsp90 in PsA compared to HC did not reach statistical significance. Hsp90 concentrations were higher in RA patients with an altered serum lipid profile: low-density lipoprotein (LDL: r=0.352, p=0.048), high-density lipoprotein (HDL: r=−0.349, p=0.046) and atherogenic index (calculated as log (triglycerides/HDL)) (AI: r=0.454, p=0.009). Furthermore, Hsp90 levels in r-axSpA patients positively correlated with the MRI presence of active inflammatory lesions in sacroiliac joints (SPARCC MRI score for SI joints: r=0.594, p=0.020). Increased Hsp90 levels in PsA patients were associated with the count of joint deformities (r=0.526, p=0.025). No further statistically significant associations were found between Hsp90 plasma levels and RA-, axSpA- or PsA-specific clinical features.ConclusionsWe demonstrated elevated plasma concentrations of Hsp90 in RA and in axSpA patients compared to healthy controls. Hsp90 could be associated with early alterations of serum lipids and development of atherosclerosis in RA. Furthermore, in r-axSpA, Hsp90 may represent an independent marker of SI joint inflammation, whereas in PsA, plasma Hsp90 correlates with joint deformities. These data suggest that Hsp90 could become a potential biomarker of structural changes in SpA.ReferenceNone.AcknowledgementsSupported by AZV-16–33542A and MHCR 023728.Disclosure of InterestNone declared.