Joint Surgery and Cell Therapies
CURRENTLY BEING UPDATED
CARTILAGE RESEARCH GROUP
Directors: Professor James Richardson and Professor Sally Roberts
Members of the Research Team: Dr Jan Herman Kuiper, Mr P Harrison, Mr A Bhattacharjee, Dr J Wales, Dr K Wright, Dr C Mennan, Dr H McCarthy, Mr J Garcia, Mrs E A Kerr, Mrs B Linklater-Jones and Mr S Ziya
Clinical Support: Mr Peter Gallacher, Dr Bernhard Tins, Professor I McCall
Overview of Cell Therapy for Cartilage Defects
James B Richardson MBChB FRCS MD, Professor of Orthopaedics
Those who have followed developments of this Institute will recall the trial ACTIVE. This arose from the work of Dr Brian Ashton, now our Chairman, Dr Karen Ashton, Dr Jan-Herman Kuiper and Professor Sally Roberts in developing a facility for growing autologous chondrocyte cells to treat patients with early arthritis. One form of early arthritis and the development of chondral defects, potholes in the surface of normally smooth cartilage lining of our joints. New cartilage is slow to form. Only cells can form cartilage and cartilage is a highly evolved solution to providing a smooth lining in our joints with very low friction. In the laboratory nothing beats chondrocytes in forming cartilage and many studies have been undertaken in patients.
Some studies were rather small in numbers, others relatively short in follow-up. The Medical Research Council (MRC) funded us as Principal Investigator in a multi-centre randomised trial which has recruited the largest number of patients in any study internationally. These 390 volunteers have kindly given their time and effort to be randomised to compare different treatments. We chose perhaps the most difficult group which is of patients who have failed previous treatment and been treated in 29 Centres across the UK and Norway, many of which were not particularly specialised in these cell therapies. Long-term studies are challenging in maintaining follow-up of all treated patients and with the hard work of the Trial Manager, Dr Johanna Wales, and her assistant Mrs Samantha Griffith-Norris a significant number have been followed and assessed. The initial analysis has been undertaken at 5 years by an independent centre and this is very promising with all the outcome measures being in favour of autologous chondrocyte implantation and 3 of these reaching statistical significance. In particular the health economic analysis suggests that out to 8 years there is a significant benefit at relatively low cost compared to the alternative controlled treatments.
The National Institute for Clinical Excellence (NICE) has the difficult job of analysing all the evidence and we have attended meetings in London with them and with other cell manufacturers to provide all the evidence needed to come to a firm conclusion on this new treatment.
In this case the only joint being considered in the knee. We have other patients being treated in the hip and the ankle for cartilage loss with autologous cell implantation and a new trial we discussed last year, ASCOT, which compares combined stem cell and autologous chondrocyte therapies.
The next challenge may be to seek support from NICE for treating ankle defects. There are relatively small numbers of these across the UK and so we have the option of requesting from NICE an analysis on the basis of it being an “orphan” treatment. The Institute of Orthopaedics has recently appointed a PhD student, Dr Jessica Sykes, to focus on the cell therapies in the ankle under the supervision of Dr Nikki Kuiper who has joined the Arthritis Centre as a returning researcher funded by Keele University. This will be yet another collaboration between the Trust, the Institute and the University.
Prof. Sally Roberts and Prof. James Richardson
ASCOT : AUTOLOGOUS STEM CELLS, CHONDROCYTES OR THE TWO?
Autologous cell therapy for osteoarthritis: An evaluation of the safety and efficacy of autologous transplantation of articular chondrocytes and/or bone marrow-derived stromal cells to repair chondral/osteochondral lesions of the knee
James Richardson, Sally Roberts, Jan Herman Kuiper, Helen McCarthy, Bernhard Tins, Karina Wright, Claire Mennan, Paul Harrison, Barbara Linklater-Jones, Johanna Wales
This study is funded jointly by the Orthopaedic Institute, Arthritis Research UK and the Medical Research Council
Patients with localised cartilage damage have been treated with cartilage cells (chondrocytes) grown from small samples of their own cartilage for many years, both here at RJAH and other hospitals worldwide. The cartilage cells are implanted into the damaged knee joint, where they regenerate the joint surface. This technique is known as Autologous Chondrocyte Implantation or ACI.
Injury to the knee joint is not restricted to the cartilage but often includes damage to the underlying bone; osteoarthritis is certainly a disorder which involves both tissues.
Mesenchymal stem cells have been used in a similar procedure to ACI in Japan. Stem cells have the potential to develop into many different cell types that carry out different functions. The bone marrow contains a population of such cells known as bone marrow-derived stromal cells (BMSCs) which can develop into either bone or cartilage, and therefore might be better suited to repair or regenerate both cartilage and bone.
In the ASCOT trial, tissue is removed during a surgical procedure from either the bone marrow (contains BMSCs) or healthy cartilage in a non-weight bearing region of the knee joint (contains chondrocytes), or both. These tissues will then be taken to RJAH’s own cell culture facility, OsCell’s John Charnley Laboratory. Here, they will be incubated in specific conditions, ideal for cell multiplication, in order to produce high numbers of BMSCs or chondrocytes. The cells will then be inserted into the damaged/diseased knee joint in a second surgical procedure three weeks later.
The ASCOT trial aims to see if BMSCs will be able to repair the damage to joints better than cartilage cells, or if a combination of BMSCs and cartilage cells is better.
To date we have enrolled 39 participants into the study, and 26 of these have had their allocated treatment (either implantation of BMSCs, cartilage cells or a combination of the two). The participants do not know which type of cells have been implanted. All participants are seen by the consultant surgeon and the research nurse at 2 months (24 participants to date), 12 months (2 participants to date) and 15 months after their surgery. A series of assessments are used to monitor their progress, including measures of pain and function, an arthroscopy and MRI and CT scans to look at the structural quality of the regenerated cartilage and recording of any side effects experienced.
A number of laboratory-based studies are running alongside the clinical aspects of the study. These will investigate the biological processes of the repair, look into identifying predictors of success or failure of the treatment, and assess the characteristics and genetics of both cell types.
CARTILAGE RESEARCH PROJECTS
BIOMARKER DISCOVERY IN ORTHOPAEDICS: MATCHING PATIENTS TO THE BEST TREATMENT
Karina Wright, Heidi Fuller, Annie Kerr, Andrea Bailey, Peter Gallacher, James Richardson, Sally Roberts
Funded by Arthritis Research UK
The pathology of failure in currently used biological treatments (cell therapies and microfracture) for cartilage repair or early osteoarthritis (OA) is poorly understood. We have shown there to be increased aggrecanase type 1 (ADAMTS-4) activity and CD14 (known biological indicators of OA progression and inflammation) before surgery, in those patients that do not improve clinically following autologous chondrocyte implantation (ACI). Further, we have shown that the function of cells implanted into patients’ joints may be directly and deleteriously affected by elevated ADAMTS-4 activity. We have just secured funding from Arthritis Research UK for a project grant to assess whether ADAMTS-4 activity and CD14 are similarly elevated in those patients that fail to benefit from microfracture, or perhaps whether a different selection of markers will indicate likely failure for these patients. Together we hope to identify a reliable panel of biological predictors which can be used in the preoperative setting to optimise patient selection for each intervention as well as therapy efficacy. We will not only investigate biological mechanisms of action for some of the novel predictors we identify but also use them to develop and target individual treatments for patients. The long term aim is to reduce the number of patients who progress to end-stage OA and require knee replacement by making earlier, less invasive treatments more effective.
CHARACTERISATION OF THE CHONDROGENIC POTENCY OF DONOR-MATCHED CHONDROCYTES AND MESENCHYMAL STEM CELLS FROM OSTEOARTHRITIC JOINTS
John Garcia, Dr Karina Wright, Dr Claire Mennan, Profs James Richardson and Sally Roberts
Funded by the EPSRC Centre for Doctoral Training in Regenerative Medicine and Arthritis Research UK
Current research is aimed at investigating the feasibility of using mesenchymal stem cells (MSCs) as a viable alternative to chondrocytes for cell based cartilage repair. This would circumvent the need to harvest healthy cartilage to obtain cells currently, as is the case for autologous chondrocyte implantation. Therefore the aim of this study, carried out by John Garcia as part of his PhD, is to determine which MSCs (obtained from bone marrow, infrapatellar fat pad or subcutaneous fat) form cartilage best, in comparison to chondrocytes themselves. Since cartilage cells exist at low oxygen concentrations (2-5%) in the body, John is also growing them at 2% oxygen in a special incubator (kindly provided by Ruskinn Technology Ltd) in comparison to the 21%, which is normally used in most culture conditions in laboratories, to determine if using a more hypoxic environment.
ISOLATION AND CHARACTERISATION OF MSCS FROM UMBILICAL CORD
Dr Claire Mennan, Helen McCarthy, James Richardson and Sally Roberts
Funded by Arthritis Research UK
Dr Claire Mennan and Mr Atanu Bhattacharjee have established two protocols for isolating and culturing MSCs from different regions of the umbilical cord (UC) as well as an easier, quicker preparation by enzymatic digestion of the whole cord. MSCs obtained in this manner proliferate much quicker in the laboratory than bone marrow derived MSC, although there is variation between individual people. In the last year Dr Mennan has been characterising the UC-MSCs further, determining if they behave more like embryonic than adult stem cells and if they can influence the immune system. (Many MSCs are reported to ‘dampen’ down the immune system, which could be very useful clinically in certain diseases, such as when an arthritic joint has an inflammatory phase). Markers investigated to date include SSEA-3, 4, Nanog, REX-1, TRA-1-60, TRA-1-81 and OCT3/4 for pluripotency, ‘stemness’ and embryonic properties. Immunomodulatory molecules studied include HLA-G, co-stimulatory markers (CD40, 80 and 86), MHC class II (HLA-DR), IDO and TLR-3 and -4 and these were measured before and after stimulation with interferon gamma (IFN- γ).
In general, results to date support the belief that UC-MSCs have both a calming influence on an inflammatory environment and be immune-privileged, so may be suitable for allogeneic therapy.
ARE CELLS GROWN IN NORMOXIA OR HYPOXIA BETTER FOR CARTILAGE REPAIR?
Dr Claire Mennan, John Garcia, James Richardson, Karina Wright and Sally Roberts
Autologous chondrocyte implantation (ACI) involves growing cells in the laboratory at much higher oxygen levels (21% O2) than are found in the body in articular cartilage (2-5% O2). Hypoxic culture conditions could help maintain the chondrocytic phenotype and prevent de-differentiation. In collaboration with Baker Ruskinn Ltd, we have been studying the growth of chondrocytes in the laboratory in hypoxic (2% O2) and normoxic conditions(21% O2) with the long-term aim of finding the best environment for culturing cells destined for cartilage repair and also understanding the mechanism of action of these cells on return to the patient.
Preliminary data shows that growing chondrocytes in hypoxic conditions, helps to retain a chondrogenic phenotype whilst high oxygen levels appear to allow de-differentiation towards an MSC phenotype. In addition, chondrocytes grow much more slowly in hypoxia compared to normoxia. Further work is necessary to determine if hypoxic cell culture systems could have a use for ‘conditioning’ cells previously grown and proliferated in normoxia towards a more chondrogenic phenotype prior to implantation back into the patient.
A: The shape of cartilage cells (chondrocytes) grown in the lab in low oxygen is more like that which you would find in the body (ie more rounded). They also form ‘clumps’ possibly due to them making more matrix molecules as they would in the body. One such matrix molecule is glycosaminoglycans which stains purple with toluidine blue
B: the cells stain more strongly with this when grown in hypoxia.