Arthritis is a major cause of disability and chronic pain and has a significant economical impact. Osteoarthritis (OA) is a progressive and degenerative form of arthritis that does not discriminate against age. Osteoarthritis is difficult to treat, with most current medical treatment strategies aimed at pain reduction and/or symptom control rather than biochemical disease modification. Available pharmacological treatments are limited and often bear unwanted side effects. Viscosupplement/hyaluronic acid (HA) intraarticular injections have been used for many years as an adjunctive treatment in conservative management of osteoarthritis. However, the mechanism of action of HA is uncertain, with some studies suggesting little improvement beyond that achieved with placebo injections.
Recent research has focused on the catabolic cytokines involved in destruction of hyaline cartilage and joint degeneration. Interleukin-1 (IL-1) has been identified as a potent mediator of cartilage loss and reciprocally IL-1 receptor antagonist (IL-1RA) has been shown to limit the intra-articular actions of IL-1. Autologous conditioned serum (ACS) is an injectable IL-1RA medium that has been used in Europe for the treatment of osteoarthritis. Research has indicated significant improvement in symptoms of OA post ACS therapy, however, further research is required to determine whether ACS is actually disease modifying. Use of ACS is limited due to cost and logistical hurdles such as incubating the autolgous blood overnight prior to reinjection.
Owing to the limitations of ACS, the research focus has shifted towards platelet-rich plasma (PRP) injections, where reports have demonstrated improved cartilage matrix expression in animal and in-vitro studies, along with the synthesis of hylauronic acid. Platelets, once originally thought to act solely in haemostasis at sites of vascular injury, are now known to contain an abundance of growth factors and cytokines, crucial to soft-tissue healing. In fact, a retrospective cohort study has indicated significant reduction in pain postintrarticular injection of PRP compared with hyaluroinc acid supplements. Similarly, a recent study of patients with grades I–III OA, demonstrated significantly improved pain and function following PRP, when compared with the hyaluronic acid injection control group. Beside PRP, photo-activation therapy has been shown to increase expression of leucocyte-derived anti-inflammatory cytokines (IL-1RA) and also to cause reduction in proinflammatory cytokines (IL-2 and 6). Thus, a combined photo-activated PRP (PAPRP) preparation may offer a novel method for treatment of osteoarthritis that combines the proven benefits of ACS with potentially disease modifying properties of PRP.
Freitag, J. B., & Barnard, A. (2013). To evaluate the effect of combining photo-activation therapy with platelet-rich plasma injections for the novel treatment of osteoarthritis. BMJ case reports, 2013, bcr2012007463.