SAT0021 STRUCTURAL EFFECTS OF LOCAL CRYOTHERAPY IN RHEUMATOID ARTHRITIS: A STUDY IN ADJUVANT-INDUCED ARTHRITIS
Authors: C. Peyronnel, V. Petitcolin, P. Totoson, H. Martin, F. Verhoeven, C. Demougeot
Journal: Annals of the Rheumatic Diseases (2020)

Background: The control of joint destruction caused by rheumatoid arthritis (RA) is a key issue in the treatment of this disease. Recent evidence showed that radiographic progression of joint damage occur despite a sharp decrease in disease activity and the use of aggressive Disease Modifying Anti-Rheumatic Drug (DMARD) therapies [1]. Whether alternative treatments such as cryotherapy may have beneficial effects on joint destruction at the early stages of the disease remains to be demonstrated, but such strategy would be of interest as it would not interfere with DMARDs treatment. Objectives: The aim of this study was to evaluate the effect of a 14-days-treatment of local cryotherapy on radiological outcomes in rat adjuvant induced arthritis. Methods: Adjuvant-induced arthritis (AIA) was induced in 6-weeks old male Lewis rats by injection of Mycobacterium butyricum in Freund’s incomplete adjuvant at the basis of the tail. A control group received saline. At the onset of arthritis, AIA rats were treated or not by application of cryotherapy on paws using either a cold spray or ice, twice a day for 14 days. Arthritis score and paws skin temperature was daily monitored. At the end of treatment, radiological exam of hind paws was performed and a score taking into account (swelling, osteoporosis, cartilage destruction, bone erosion, bone destruction and new bone formation) was assigned, according to Ackerman et al [2]. Circulating levels of cytokines (IL-6, IL-1β, TNF-α) was measured by Magpix Luminex kit. Results: Compared to untreated AIA, local cryotherapy significantly reduced the progression of arthritis score, whatever the modality (p&lt;0.05), and to the same extent (reduction of arthritis score at day 24 post-immunization: -38% with cold spray, p&lt;0.01, -37% with ice, p&lt;0.01). Radiological score was significantly reduced by both treatments with no difference between the two treatments (-33% with cold spray, p&lt;0.01, -44% with ice, p&lt;0.01). All the items of the radiological score were equally reduced by ice and cold spray except swelling that was significantly reduced only by ice. Interestingly, the use of the cold spray induced a greater decrease in the skin temperature than the ice treatment (18.32 ± 0.07 °C vs 20.46 ± 0.08 °C, p&lt;0.001). Conversely, cryotherapy did not significantly change the level of cytokines. No correlation was found between radiological score and arthritis score or cytokine levels. Conclusion: These data demonstrated that local cryotherapy had positive effects on structural damage in adjuvant-induced arthritis. The mechanisms involved remain now to be determined. These results suggest that local cryotherapy would be an interesting complement to conventional DMARDs in early RA. References: [1] Ten Klooster, P. M. et al. Radiographic progression can still occur in individual patients with low or moderate disease activity in the current treat-to-target paradigm: real-world data from the Dutch Rheumatoid Arthritis Monitoring (DREAM) registry. Arthritis Res. Ther. 21 , 237 (2019). [2] Ackerman, N. R. et al. Effects of naproxen on connective tissue changes in the adjuvant arthritic rat. Arthritis Rheum. 22 , 1365–1374 (1979). Disclosure of Interests: Célian Peyronnel: None declared, Valentin Petitcolin: None declared, Perle Totoson: None declared, Hélène Martin: None declared, Frank Verhoeven: None declared, Céline Demougeot Grant/research support from: With an institutional support from Pfizer.