Photodynamic therapy for synovial hyperplasia in patients with refractory rheumatoid arthritis: a study protocol for a randomized, double-blind, blank-controlled prospective trial

Background Persistent synovial hyperplasia with inflammation in rheumatoid arthritis is one of the main pathogeneses of refractory rheumatoid arthritis (RRA). Photodynamic therapy (PDT) causes less trauma than steroid injections or arthroscopic synovectomy while providing stronger targeting and more durable curative effects. The aim of this trial was to evaluate the short-, medium-, and long-term clinical efficacy of PDT when applied as a treatment for RRA synovial hyperplasia and synovitis. Methods and analysis This protocol is for a single-center, randomized, double-blind, blank-controlled prospective trial. A sample of 126 RRA patients will be randomly divided into 3 groups: the control group, the "PDT once" group, and the "PDT twice" group, with 42 participants per group. The trial will be conducted by the Rheumatology and Immunology Department of the Integrated Hospital of Traditional Chinese Medicine, Southern Medical University. The Ultrasound Compound Score of Synovitis (UCSS) has been selected as the primary outcome measure. The secondary outcome measures include knee joint clinical assessments, ratio of relapse, duration of remission, Disease Activity Score in 28 joints (DAS28), inflammation indexes, serum concentrations of specific antibodies, and changes in articular structures as detected by X-ray scans in the 48th week. The improvement ratios of the UCSS at the 8th, 24th, and 48th weeks (compared with baseline) reflect short-, medium-, and long-term time frames, respectively. Ethics and dissemination The protocol was approved by the Medical Ethics Committee of the Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, China (Approval No. granted by the ethics committee: NFZXYEC-2017-005) and then entered in the Chinese Clinical Trials Registry under registration number ChiCTR1800014918 (approval date: February 21, 2018). All procedures are in accordance with Chinese laws and regulations and with the Declaration of Helsinki by the World Medical Association (WMA). Any modifications of this protocol during execution will need additional approval from the Ethics Committee of our hospital.