Hematopoietic stem cell transplantation in rheumatic diseases

Autologous Hematopoietic Stem Cell Transplantation for 3 Patients with Severe Juvenile Rheumatoid Arthritis

We performed autologous CD34+ stem cell transplantation in 3 patients with juvenile rheumatoid arthritis (JRA) refractory to conventional treatment. All patients had systemic type JRA. In case 1 (a 3-year-old boy), purified CD34+ cells from bone marrow were transplanted after a preconditioning regimen consisting of cyclophosphamide (200 mg/kg) and antithymocyte globulin (ATG) (40 mg/kg). However, the disease flared soon after transplantation. In case 2 (a 13-year-old girl) and case 3 (a 21-year-old woman), a preconditioning regimen consisting of etoposide (VP16) (2 g/m2), thiotepa (300 mg/m2), and ATG (40 mg/kg) was followed by transplantation of purified CD34+ stem cells harvested from peripheral blood mononuclear cells. The patients in cases 2 and 3 attained complete remission without any medication. Thus for patients with refractory JRA, autologous CD34+ cell transplantation appears to be a safe and feasible choice of treatment in terms of good quality of life. However, a greater number of patients and a longer observation period are needed before definitive conclusions can be drawn.

Bone marrow progenitor cell reserve and function and stromal cell function are defective in rheumatoid arthritis: evidence for a tumor necrosis factor alpha-mediated effect

Based on previous reports for impaired hematopoiesis in rheumatoid arthritis (RA), and in view of the current interest in exploring the role of autologous stem cell transplantation (ASCT) as an alternative treatment in patients with resistant disease, we have evaluated bone marrow (BM) progenitor cell reserve and function and stromal cell function in 26 patients with active RA. BM progenitor cells were assessed using flow cytometry and clonogenic assays in short-term and long-term BM cultures (LTBMCs). BM stroma function was assessed by evaluating the capacity of preformed irradiated LTBMC stromal layers to support the growth of normal CD34(+) cells. We found that RA patients exhibited low number and increased apoptosis of CD34(+) cells, defective clonogenic potential of BM mononuclear and purified CD34(+) cells, and low progenitor cell recovery in LTBMCs, compared with healthy controls (n = 37). Patient LTBMC stromal layers failed to support normal hematopoiesis and produced abnormally high amounts of tumor necrosis factor alpha (TNF alpha). TNF alpha levels in LTBMC supernatants inversely correlated with the proportion of CD34(+) cells and the number of colony-forming cells, and positively with the percentage of apoptotic CD34(+) cells. Significant restoration of the disturbed hematopoiesis was obtained following anti-TNF alpha treatment in 12 patients studied. We concluded that BM progenitor cell reserve and function and BM stromal cell function are defective in RA probably due, at least in part, to a TNF alpha-mediated effect. The role of these abnormalities on stem cell harvesting and engraftment in RA patients undergoing ASCT remains to be clarified.

Development of agents for the treatment of systemic sclerosis

Systemic sclerosis (SSc) is a multisystem connective tissue disease characterised clinically by fibrosis and ischaemic atrophy. Internal organ involvement can be life-threatening. Although there are effective treatments for some of the organ-based manifestations of SSc, for example proton-pump inhibitors for upper gastrointestinal disease, no drug has so far been proven to modify the underlying disease process. Our increased understanding of the pathogenesis of SSc, which involves a complex interplay between excessive collagen production, vascular abnormalities and immune dysfunction, is directing development of drugs which hold promise as 'disease-modifying' agents. Some of the drugs under investigation for the treatment of SSc have already been used in other conditions which 'overlap' with SSc, for example primary pulmonary hypertension. Conversely, it is to be hoped that in the future, drugs shown to be effective in SSc might prove beneficial for other fibrotic diseases.

The treatment of juvenile arthritis

Until recently, two different classification systems for juvenile arthritis (JA) were utilised, each with its own terminology and subclassification. It has been recognised that particularly within the polyarticular and pauciarticular groups, many distinct subsets exist each with a different prognosis. As a result, a new classification system for JA has been developed. It is hoped that this will allow more accurate assessment of incidence and aetiology of the various subtypes in future generations and in time will allow therapy to be targeted at those most likely to achieve benefit. Since there is a new classification system for JA, the vast majority of published clinical studies were performed using the old classification system. For the purposes of this review, unless otherwise stated, the American College of Rheumatology classification will be used. This is outlined in Table 1 with clinical features of the major subtypes described in Table 3. This review will cover current best practice and discuss future directions for research using the recent advances in the treatment of rheumatoid arthritis (RA) as a model.

New therapeutic aspects: haemopoietic stem cell transplantation

Primary systemic vasculitis responds well to intensive immunosuppression, particularly with cyclophosphomide. Use of the latter is restricted by side-effects, particularly in relapsing disease. Techniques which allow more complete immunosuppression have an obvious attraction in autoimmune disease. They are particularly suitable for vasculitis which can go into long-lasting remission even with standard therapy in many cases. The conditioning used for stem cell transplantation allows more complete deletion of auto aggressive T-cell clones, with subsequently haemopoietic rescue by previously harvested stem cell precursors. The procedure also has immune potentiating effects, perhaps by promoting peripheral suppressor mechanisms. These may be important even though immune ablation is not achieved. With rigorous patient selection, experience with this technique in vasculitis may be broadened.

New horizons in the treatment of autoimmune diseases: immunoablation and stem cell transplantation

The prevalence of autoimmune diseases (ADs) in Western countries is estimated to be from 3-7%, and the treatment of severe, relapsing/refractory cases is still not satisfactory. The concept of utilizing intense immunosuppression followed by allogeneic or even autologous hemolymphopoietic stem cells (HSCs) to treat AD is based on encouraging results in experimental animals and from serendipitous cases of patients with both ADs and malignancies who were allotransplanted for the latter. However, rare unexpected relapses despite donor immune engraftment have been reported following HSC transplantation for AD. Autologous transplantation is a more feasible procedure with lower toxicity than allogeneic transplantation. This article analyzes the experimental basis for stem cell transplantation in AD and discusses the most important clinical results of both allogeneic and autologous HSC transplants.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) but not granulocyte colony-stimulating factor (G-CSF) induces plasma membrane expression of proteinase 3 (PR3) on neutrophils in vitro

The theoretical risk of triggering vasculitis resulting from administration of G-CSF and GM-CSF to patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV), such as Wegener's granulomatosis (WG), who develop agranulocytosis due to cytotoxic therapy, is unknown. Since there is strong evidence that activation of polymorphonuclear neutrophils (PMN) induced by binding of ANCA to PR3 or myeloperoxidase (MPO) expressed on their plasma membrane is involved in the pathogenesis of systemic vasculitides (SV), we studied the surface expression of PR3 and MPO on PMN from healthy donors in response to G-CSF and GM-CSF in vitro by flow cytometric analysis. Increasing doses of G-CSF did not alter PR3 expression on either untreated or tumour necrosis factor-alpha (TNF-alpha)-primed donor PMN significantly. In contrast, GM-CSF significantly increased PR3 membrane expression on both intact PMN and neutrophils primed with TNF-alpha. MPO expression was not significantly altered by either G-CSF or GM-CSF. In summary, these data demonstrate that GM-CSF, but not G-CSF, induces plasma membrane expression of PR3 on PMN in vitro. Since in AAV accessibility of the antigen (PR3 or MPO) to the antibody (ANCA) on the plasma membrane of PMN is thought to be essential for neutrophil activation by ANCA, the results of the present study suggest that administration of GM-CSF to patients with WG with neutropenia implies a definite theoretical risk of deterioration of vasculitis via this mechanism.

Autologous stem cell transplantation in progressive multiple sclerosis--an interim analysis of efficacy

Based on the good results of experimental transplantation in animal models of multiple sclerosis and of other autoimmune diseases, we have treated 24 patients suffering from chronic progressive multiple sclerosis with high-dose chemotherapy (BEAM regimen) followed by autologous blood stem cell rescue and antithymocyte globulin. Blood stem cells were mobilised with cyclophosphamide at 4g/m2 and G- (or GM-) CSF. In 9 cases, additional CD34+ cell-selection of the graft was performed. Here we update previously published results of this novel treatment, mainly with regard to clinical efficacy, as the median follow-up time has reached 40 months (range, 21-51). Infections were the principal toxicity early after the procedure, with death of a patient from aspergillosis 65 days post stem cell infusion. No serious late events occurred apart from a case of autoimmune thyroiditis that developed 11 months after transplant in a patient who had received a CD34+ cell-depleted graft. Mild and transient neurotoxicity was observed in 10 patients (42%), most probably associated with fever and infections. Eighteen patients (18/23; 78%) responded to the treatment, i.e., they were improved or stabilized, while five patients progressed, of which 4 had primary progressive disease. Of those improved or stabilised (18), 9 patients have maintained stable condition whereas 9 developed relapses or they slowly resumed progression, although their disability scores have not gotten worse than they were before transplantation. The probability of progression-free survival (compared to entry status) at 3 years is 92% for patients with secondary progressive disease and 39% for the primary progressive type. CD34+ cell-selection did not seem to yield better results except for a delay in progression or in relapse after transplantation. These results appear better than those achieved by any other treatment of progressive multiple sclerosis, including beta-interferon, but they need to be confirmed by other open or controlled studies in view of the well-known difficulty of judging objectively the effect of a treatment in patients with this disease.

A phase I/II dose escalation study of intensified cyclophosphamide and autologous blood stem cell rescue in severe, active rheumatoid arthritis

OBJECTIVE

Based on animal studies and anecdotal case reports, high-dose therapy and autologous blood stem cell rescue have been proposed as an experimental treatment for severe, refractory rheumatoid arthritis (RA). This study aimed to establish the toxicity of this treatment and obtain preliminary efficacy data upon which to base future clinical trials.

METHODS

Two cohorts of 4 patients who fulfilled criteria for severe, active, treatment-resistant RA were recruited into a dose-escalation study of cyclophosphamide (CYC) (100 mg/kg or 200 mg/kg) followed by unmanipulated peripheral blood stem cell rescue. Patient treatment was managed according to a standard supportive care protocol. Disease-modifying drugs were discontinued before treatment, but corticosteroids were maintained and later tapered where possible. Patients' conditions were assessed using World Health Organization toxicity criteria and standard parameters for rheumatic disease.

RESULTS

Dose-dependent differences in hematologic toxicity were observed between cohorts 1 and 2, although toxicity was similar for other systems and was most significant in the gastrointestinal system. Patients in cohort 1 had only transient responses to therapy, lasting 2-3 months. Substantial improvements were sustained beyond 17-19 months in cohort 2, including steroid-independent disease remission for 1 patient, although the procedure did not completely abolish disease activity.

CONCLUSION

High-dose CYC and unmanipulated autologous blood stem cell rescue has acceptable dose-dependent toxicity in severe, treatment-resistant RA, and 200 mg/kg of CYC induces substantial clinical responses. Refinement of this intensive approach might include further intensification of the preparation regimen, graft manipulation, and posttransplant immunomodulation.