Knee osteoarthritis (OA) is a common degenerative disease characterized by chronic pain, joint stiffness, reduced function, cartilage degradation, loss of subchondral bone, and synovial inﬂammation. Although symptoms may be alleviated with conservative therapies such as analgesic drugs, lifestyle modiﬁcations, and physical therapy, no disease-modifying treatment is currently available. In the end phase of OA, joint replacement surgery is currently considered the only solution to relieve symptoms.
A single dose of APS for treatment of early to moderate knee osteoarthritis is well tolerated by the patients, and osteoarthritis symptoms can improve significantly as shown in some of the studies. Based on these results, an adequately powered, well-controlled, randomized multicenter clinical study to establish clinical effectiveness is warranted.
New approaches that harness our understanding of early OA may allow for earlier intervention than joint replacement. One mechanism of knee OA progression is a degenerative feed-forward cycle caused by pathological increases in inﬂammatory cytokines and catabolic factors within and adjacent to the synovial space. Inﬂammatory and catabolic proteins such as interleukin-1 beta (IL-1b), tumor necrosis factor alpha (TNFa), and matrix metalloproteinases ( MMPs), for example, have been implicated in cartilage degradation and continued OA progression.
Approaches to block these deleterious proteins could improve patients’ symptoms, and perhaps the progression of the disease may be halted or even reversed. Autologous blood contains a host of proteins, which can block the action or production of inﬂammatory and catabolic proteins. A strategy to overcome the pathologically high levels of proinﬂammatory and catabolic proteins, which contribute to OA, would be to introduce highly concentrated amounts of anti-inﬂammatory and anabolic proteins into the environment.
Treatment depends on the severity of the osteoarthritis. Conservative treatments include analgesics and corticosteroid injections to relieve pain and inflammation, and physiotherapy and prescribed exercise to improve function and mobility. When symptoms are severe, surgery may be indicated: options include upper tibial osteotomy and unicompartmental or total knee replacement.
The nSTRIDE Autologous Protein Solution (APS) kit has been developed to process autologous blood to produce an output (herein referred to as APS) with high concentrations of anti-inﬂammatory cytokines and anabolic growth factors. APS has been shown to block the effects of inﬂammation in chondrocytes, macrophages, and cartilage explants.
The nSTRIDE APS Kit is a cell-concentration system designed to concentrate anti-inflammatory cytokines and anabolic growth factors to significantly decrease pain and promote cartilage health. In an osteoarthritic knee, an increase in inflammatory cytokines results in cartilage degeneration and knee pain. The inflammatory proteins IL-1 and TNFα attack the cartilage. These inflammatory proteins must be stopped simultaneously to decrease pain and slow cartilage degeneration. The nSTRIDE APS output introduces high levels of IL-1ra, sIL-1R, sTNF-RI, and sTNF-RII that block the inflammatory cytokines IL-1 and TNFα which may slow cartilage degeneration. While balance is being restored to the knee, anabolic growth factors (IGF-1 and TGF-ß1) are also introduced for beneficial cartilage health. The nSTRIDE APS Kit creates a therapy to reduce pain in the knee joint, improve joint function and slow the destruction of cartilage.
Safety and Treatment Effectiveness of a Single Autologous Protein Solution Injection in Patients with Knee Osteoarthritis
This study included 11 patients with OA, treated with single intra articular injection of APS. The primary goal of this study was to analyze the safety proﬁle of APS. A secondary goal was to observe potential treatment effects of APS in patients with early to moderate OA. The overall safety proﬁle of the APS was favourable, with minor complications reported. Complications were generally well tolerated by the patient and resolved without treatment. This is consistent with the theoretical idea that, as an autologous product, APS should be highly tolerable by the patient. APS contains high concentrations of leukocytes.
Some authors have suggested that leukocyte-rich solutions may not be ideal for OA treatment. These opinions are based on cell culture models with unmatched donors and clinically insigniﬁcant (low pg/mL concentration range) differences in concentrations of inﬂammatory cytokines in leukocyte-rich and -poor platelet-rich plasma (PRP). The only comparative clinical study between leukocyte-rich and -poor PRP found no differences in outcomes.
Following APS injection, the WOMAC composite and pain, stiffness, and function subscales all showed robust improvements in mean scores over 6 months. Similarly, both patient and physician global assessment of change was positive. The long-term durability of APS treatment persisted for a subset of patients for at least 18 months. The durability of this response could be significant, as steroids and viscosupplementation have typically shown to be effective in relieving pain for up to 6 weeks and 6 months, respectively. Unlike steroids and viscosupplementation, APS contains high concentrations of anti-inﬂammatory cytokines and anabolic growth factors, which could potentially alter the course of disease progression. The short-term pain relief observed could be due to the anti-inﬂammatory effects of APS. The long-term pain relief could be attributed to the potential disease-modifying properties of APS by improving joint homeostasis and cartilage quality. Future clinical trials, including imaging analysis, will be required to demonstrate a disease-modifying effect of APS.
The procedure is performed on an out-patient basis, under real-time ultrasound guidance. Blood is drawn from the patient’s arm, before being processed using a centrifuge to separate the platelet-rich plasma in the blood. The plasma is then further processed with a centrifuge to separate a protein liquid, which is then injected into the knee.
The protein injected into the knee has been shown to protect cartilage cells, and relieve the pain associated with osteoarthritis. The protein has also been shown to block cartilage destruction in osteoarthritis, and also reverse the effects of osteoarthritis in some cases.
Pain relief is usually experienced after around one week, but it is recommended that the knee is rested for two weeks. The benefits of the injections can last up to 12 months or longer following the procedure.
The procedure is generally well tolerated and the adverse effects reported in studies were generally mild. The side effects were largely related to the injection procedure itself, including:
These adverse effects tend to settle spontaneously and generally do not require any specific treatments.