Induced lymphatic circulation decreases IL-17 expression in the lymph nodes of rats in adjuvant-induced arthritis

Abstract

Abstract Rheumatoid arthritis (RA) is an autoimmune disorder characterized by chronic inflammation mediated by Th-17 cells. Rat adjuvant-induced arthritis (AIA) is a Th-17-dependent RA model with dysfunctional lymphatic circulation. We hypothesized that induction of lymphatic circulation would attenuate arthritic inflammation. We utilized Lymphatic Pump Treatment (LPT), an osteopathic lymphatic manipulation, to determine if inducing lymphatic flow would alleviate arthritic inflammation. LPT was accomplished on AIA rats by gradually increasing compression on the chest wall for 5 seconds followed by a rapid release. This technique was performed on the rats for 1 minute 3X/day over 7 consecutive days following the onset of measurable inflammation on day 14 post adjuvant injection. Ankle caliper measurements, articular index scoring, popliteal lymph nodes, peripheral blood, and spleens were collected. The LPT-treated rats fell into two groups. LPT responders and non-responders. LPT responders had significantly reduced inflammation (as determined by both in ankle circumference and index scoring). These therapeutically treated animals also had significantly decreased IL-17 expression in their draining popliteal lymph nodes. These results along with our previous findings indicate that LPT can reduce arthritis, alter lymphocyte trafficking and differentiation in secondary lymphoid organs during inflammation. These data suggest that induced lymphatic circulation using osteopathic manipulation may serve as a therapy for chronic inflammation in autoimmune disorders and may also be an enhancement to current treatments.