Autologous Stem Cell transplantation and Rheumatic Diseases Introduction All over the world, Rheumatic Diseases (RD) are today a problem for the social security systems. The cost of their management is enormous due to the chronicity of the diseases. Indeed, the quality of life is poor, the loss of the job very high, and the long term outcome is poor, despite initial positive responses to immunomodulatory therapies. ( ref ) For this reason, new rational therapies are particularly warranted in order to stop the disease evolution and avoid the deterioration of the joints and internal organs. Autologous stem cell transplantation (ASCT)following high dose ablative chemotherapy is today a reality that has become true with an international study program. The dosage of drugs, such as cyclophosphamide (Cy), is significantly limited due to side effects and in particular to bone marrow toxicity.
For this reason, an international project was developed with the concept of exceeding that limit then rescuing the patient with an autologous ASCT. This study was developed along consensus study guidelines such that currently around 600 patients have received an ASCT mostly within the context of phase I / II studies.(ref Gerber, Gratwohl, Passegg Tyndall Best Clin Haematol 2002). Around 450 of these cases are registered in the combined European Group for Blood and Marrow Transplantation ( EBMT) and European League Against Rheumatism ( EULAR) data base. This report summarises the results of this project. It should not be forgotten that long term disease free survival in diseases such as leukaemia are today possible for many patients because of carefully performed randomised controlled trials, rather than by a full understanding of the pathophysiology . It is hoped that ASCT for RD , an intrinsically toxic and dangerous form of treatment, will become obsolete when new targeted strategies will be developed in the future.

Bone Marrow Transplantation and ASCT
One of the first published reports of attempted bone marrow transplantation (BMT) was in 1939 ( ref) in a young woman with suspected gold salt induced aplastic anaemia, the gold being given to treat pulmonary tuberculosis. Interestingly , one of the first reports of BMT coincidentally inducing long term remission of an AD was in a patient with aplastic anaemia due to gold treatment of rheumatoid arthritis.(ref). In the past decade , most transplants have been performed with peripherally harvested hematopoietic stem cells ( HSCs) , with fewer bone marrow and recently some few cord blood HCS harvesting ( table 1 – EBMT mega file).From the aspect of treating AD, there are some important differences between peripheral and bone marrow HSC source . Bone marrow contains fewer T cells , but requires a general anaesthetic and a longer reconstitution time due to fewer early progenitors. In small children ( juvenile idiopathic arthritis) , it is sometimes not possible to mobilise enough stem cells for a peripheral harvest: it is known that at least 2 X 10 6 CD34 positive cells ( stem and early progenitors) per kg body weight are needed for reliable hematological reconstitution. On the other hand a peripheral HSC source requires mobilisation of stem cells from the marrow using high dose Cy and /or growth factors , mostly G-CSF. For AD patients this raises some new aspects. In 5 patients first attempts to mobilise stem cells were unsuccessful, probably due to previous marrow toxic treatments . This was not as common as initially anticipated (ref) and was overcome by combining the graft product with a second mobilisation , or moving to a bone marrow harvest. Also, G- CSF is a potential trigger for a flare of AD , and this was observed in some patients , especially RA ( 8/72) (ref). Most of these flares were relatively easy to control, but in at least one ( multiple sclerosis) a fatal outcome ensued(ref).In some cases the Cy in doses from 2-4 gms /m2 given as mobilisation resulted in a rapid improvement of the AD, such that this was adopted as the pre-randomisation step in phase III studies for RA and SLE ( see below). Much discussion has taken place concerning the need for intense purging of the graft product of autoaggressive lymphocytes , as well as the concept that only an allograft could replace a defective immune system or “cure” an AD through a theoretical graft versus autoimmune cell reaction. Five years and 600 patients later it is reasonable to say that the more aggressive regimens such as radiation or busulphan/cyclophosphamide based were associated with more toxicity , but with only a trend toward more durable remission (ref). Concerning purging, again an assocation between severity of purging and infection risk was seen , without clear advantage. It is known that complete cellular purge either in vivo or in vitro is not possible with chemotherapy or radiation, so that at the most an “autoimmune debulking” occurs with autologous ASCT. Some groups did not manipulate the graft product , and in one study (ref) RA patients were randomised to either CD34 selection or none, and no advantage was observed in terms of relapse (ref) ; in fact a trend toward fewer relapses was seen in the non purged group (ref) , raising the issue of modulating T –cells ( previously called suppressor cells) being needed to control autoreactive processes. Overall a concept of resetting the immune auto reaction rather than ablating and inducing tolerance , as was suggested by animal model experiments , has evolved with this project.

Coincidental Autoimmune Disease and ASCT
Since the first reports of improvement and even long term remission of RA following allo ASCT (refs), many retrospective and some prospective case reports and series have been published ( refs). The original allo ASCT case reports were followed by similar short and long term benefits following auto ASCT (table 2). While of high interest, such reports have the disadvantage of publication bias and incomplete details concerning the AD status and outcome measurement. More recently negative or non response cases have been published (ref) , and it is well established that AD may be passively transferred through allo ASCT. However from these case reports some important observations have occurred. One woman with RA who received an allo ASCT from her healthy brother to treat gold induced aplastic anaemia enjoyed a 4 year clinical and serological remission of the RA , followed by a full relapse. All studied immune competent cells from the blood and joint were of donor type ( Y chromosome containing), illustrating the complexity of AD pathophysiology. In another case a man with leukaemia received an allo ASCT from his HLA identical brother with known but inactive SLE (ref) . The donor had antibodies to C1q, which later developed but then disappeared in the recipient post transplant, with no signs of renal or other manifestations of SLE. Both these cases illustrate that the host environment /modulatory cell network is as critical in the final expression of AD as the inciting clones of autoreactive cells.

Joint & Connective Tissue Diseases and ASCT
The EBMT and the EULAR combined stem cell project in autoimmune disease issued consensus guidelines (ref) before the first patient was treated and a collaboration with North America and the International Bone Marrow Transplantation Registry (IBMTR) quickly forged. Similar data sets on transplanted patients are collected world wide, the Americas in the IBMTR and the rest of the world in Basel in the EBMT/EULAR data base. The EBMT/EULAR data base contains data on 450 registrations, the most commonly transplanted diseases being systemic sclerosis (SSc) , RA , JIA and SLE (table 3). The data come from 82 transplant centres in 21 countries and the initial transplant related mortality (TRM) was 7% (ref). This was higher than the predicted 3% for autoASCT overall and reflects the general overall unwellness and multiorgan involvement of many RD patients compared with, say ,breast cancer patients undergoing high dose chemotherapy and ASCT. In fact a there was a marked difference between AD groups with a TRM of 12.5% in SSc and only one patient with RA. Also different were response rates and types. In RA, JIA and SLE more patients responded early but later relapsed than for SSc.

Systemic sclerosis
In the first 45 patients , an improvement of 25% or more was seen in 70% of the patients, with a TRM of 17%. (15). Several protocols were used, mostly either Cy based ( 4g /m2 Cy mobilisation and Cy 200 mg/kg body weight conditioning or radiation 8 Gy/Cy 120mg/kg body weight .With further patient recruitment, the TRM fell to 8.6% , considered to be related to more careful patient selection.Lung function tended to stabilise and some factors were identified as potentially hazardous for ASCT eg pulmonary hypertension > 50mmHg mean pulmonary arterial pressure, severe cardiac involvement, severe pulmonary fibrosis and uncontrolled systemic hypertension. When such patients were excluded from the analysis, the TRM was 7% , suggesting that the proposed randomised controlled trial would be ethical , given a near 50% 5 year mortality of this subgroup of patients. In the new designed trial, ASTIS (Autologous Stemcell Transplantation International Scleroderma ) Trial, only diffuse skin SSc patients are enrolled with less than 4 years of diffuse skin involvement and evidence of progressive and organ or life threatening disease. The primary end point of this trial is event free survival at 2 years. The treatment arm is mobilisation with Cy 4g/m2 and G-CSF , followed by CY 200mg/kg body weight conditioning plus ATG and a CD 34 selected graft. The control arm is monthly IVI pulse CY 750mg/m2 for 12 months.( fig 1) Each arm will have 100 patients. ASTIS is running, and so far using these selction criteria there have been no transplant related deaths. Further details are available on the website: www.astistrial.com , or E-mail astistrial-fps@unibas.ch .

Rheumatoid Arthritis
Of the 63 patients transplanted, an analysis of the first 72 showed significant improvement , with 78% achieving an ACR 50 response. This is a composite score clinical and laboratory parameters which should improve by at least 50%. Most of the patients had failed at least 3 conventional disease modifying antirheumatic drugs ( DMARDs ) such as methotrexate or sulphasalazine before the transplant. Some degree of relapse was seen in 73% of patients post transplant , but was relatively easy to control in most with drugs which had proven ineffective pretransplant. The median follow-up was 18(6-40) months , and the majority of patients received a conditioning regimen of Cy 200mg/m2 alone and received peripherally harvested stem cells after either G-CSF or Cy/ G-CSF ( equal numbers ) mobilisation. These phase I and II experiences have been integrated into a phase III randomised study, the ASTIRA ( Autologous Stemcell Transplantation International Rheumatoid Arthritis ) Trial. In this trial, will be enrolled only active RA patients who have failed at least 4 DMARDS (including methotrexate and anti TNF alpha) with a disease duration between 2-15 years. After stem celll mobilisation is achieved with Cy 4g/m2 and G-CSF, randomisation occur to either continued conventional therapy with either methotrexate or leflunamide or conditioning with Cy 200 mg/m2 and ATG. The graft is not be manipulated , and maintenance with methotrextae or leflunamide is given. The primary end point is the number of patients reaching a good or moderate EULAR response or and ACR 20 at six months. 16 patients in each arm are required, calculated on a > 50% difference in the two groups. Further details from www.EBMT.org or E-mail: 114077.1034@compuserve.com

Juvenile Idiopathic Arthritis
A total of 51 children with idiopathic juvenile arthritis, mostly the systemic form called Stills disease, have been registered . Most of these cases were treated in two Dutch centers using a bone marrow obtained stem cell source and a conditioning protocol of Cy 200mg/kg body weight, TBI 4Gy and ATG ( N Wulffraat , personal communication). In the whole group there were 15 complete remissions and 3 partial remissions reported. In those attaining remission, the corticosteroiud dose could be reduced and some patients experienced puberty and catch up growth. Three patients died from macrophage activation syndrome , thought to be related to intercurrent infection or uncontrolled systemic activity of the disease at the time of transplantation. Protocols were modified accordingly such that systemic activity is controlled before the transplant with methyl prednisolone intravenously . Since this modification , no further such deaths have occurred. Further phase I and II pilot studies will be undertaken before the optimal phase III randomised study will be proposed.

Systemic Lupus Erythematosus
Of the 55registrations , most had either renal and /or CNS involvement, and 21 had failed conventional Cy treatment. A peripheral stem cell source after mobilisation with Cy and G-CSF was used in the majority. Twenty -three patients received a conditioning with Cy and ATG , eleven with Cy and TBI and five other regimens were employed. There were 5 deaths due to treatment and one from progressive disease, resulting in an actuarially adjusted TRM of 10(2-20)%. In those patients with sufficient data for analysis , 72% achieved a “ remission” , defined as a SLEDAI ( Systemic Lupus Erythematosus Disease Activity Index) of