Severe autoimmune diseases: a new target for bone marrow transplantation. Sandoz-Keystone symposium, January 15-21, 1996. Abstracts

Stem Cell Therapies for Progressive Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system characterized by demyelination and axonal degeneration. MS patients typically present with a relapsing-remitting (RR) disease course, manifesting as sporadic attacks of neurological symptoms including ataxia, fatigue, and sensory impairment. While there are several effective disease-modifying therapies able to address the inflammatory relapses associated with RRMS, most patients will inevitably advance to a progressive disease course marked by a gradual and irreversible accrual of disabilities. Therapeutic intervention in progressive MS (PMS) suffers from a lack of well-characterized biological targets and, hence, a dearth of successful drugs. The few medications approved for the treatment of PMS are typically limited in their efficacy to active forms of the disease, have little impact on slowing degeneration, and fail to promote repair. In looking to address these unmet needs, the multifactorial therapeutic benefits of stem cell therapies are particularly compelling. Ostensibly providing neurotrophic support, immunomodulation and cell replacement, stem cell transplantation holds substantial promise in combatting the complex pathology of chronic neuroinflammation. Herein, we explore the current state of preclinical and clinical evidence supporting the use of stem cells in treating PMS and we discuss prospective hurdles impeding their translation into revolutionary regenerative medicines.

High-dose total body irradiation and bone marrow cells may improve efficiency of bone marrow transplantation therapy in treating type 1 diabetes

Bone marrow transplantation (BMT) has been used to treat autoimmune diseases for many years. Insulin-dependent diabetes mellitus (IDDM), also called type 1 diabetes mellitus (T1DM), is a T cell-mediated autoimmune disease resulting from a selective destruction of pancreatic islet beta cells. Recently, T1D has been a common significant cause of morbidity and mortality. However, whether BMT can be used to treat T1DM is still controversial. During BMT procedure, recipients underwent total body irradiation (TBI) and subsequent bone marrow cells (BMCs) infusion, in which TBI kills off the most T lymphocytes and BMCs stimulates hematopoiesis and immune reconstitution. We suggest that high-dose TBI and BMCs may improve efficiency of BMT therapy in T1DM treatment.

High-dose immunosuppression with autologous stem cell transplantation in severe refractory systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an immune-mediated disease that is responsive to suppression or modulation of the immune system. Patients with SLE who experience persistent multiorgan dysfunction, despite standard doses of intravenous cyclophosphamide (Cy), represent a subset of patients at high risk of early death. We investigated the efficacy and toxicity of high-dose immunosuppression and autologous hematopoietic stem cell transplantation (SCT) to treat such patients. Six patients (all female, age 15-29 years) with severe refractory SLE were enrolled in the clinic of our institution from 1998 to 2003. All patients were seriously ill, with SLE disease activity indices (SLEDAI) of 6-30, including two cases with central nervous system lupus, one case with lung vasculitis, and three cases with nephritis and nephrotic syndrome. All patients were registered in the European Group for Blood and Marrow Transplantation (EBMT)/European League Against Rheumatism (EULAR) database. Previous immunosuppression included pulse Cy intravenous, prednisolone (standard doses and pulse therapy), oral Cy and azathioprine, with little or no effect on disease progression. Autologous hemopoietic stem cells were collected from bone marrow (n = 4) or mobilized from peripheral blood with Cy and granulocyte colony-stimulating factor (G-CSF) (n = 2). Pre-transplant conditioning regimens included BEAM +/- ATG (n = 2), melphalan 140 mg/m2 + etoposid 1600 mg/m2 (n = 2) and Cy 200 mg/kg +/- ATG (n = 2). Median time to an absolute neutrophil count (ANC) greater than 0.5 x 10(9)/L and platelet count greater than 50 x 10(9)/L was 13 and 15 days, respectively. Three patients died on days 11, 22 and 63 due to transplant-related complications. The follow-up is now 60 and six months for two patients (complete remission), and 42 months for one other patient (partial response). All patients had experienced multiple and severe episodes of infections pre-SCT and long-term history of corticosteroid therapy (3-14 years). We conclude that achievement of prolonged, corticosteroid-free remissions is a reality. Judicious selection of patients earlier in disease or in remission, but with a high risk of relapse or further progression, will diminish transplantation-related mortality.

Hematopoietic stem cell transplantation in multiple sclerosis: experimental evidence to rethink the procedures

Acute immunosuppression with lymphocytic agents given at maximally tolerated doses, followed by hematopoietic stem cell rescue achieved by autologous bone marrow or peripheral blood stem cell transplantation (BMT), has proved effective in various experimental models of autoimmunity. The rationale for such an approach in autoimmune diseases is based on the concept of lymphoablation of self-reactive lymphocytes followed by de novo immune system reconstitution, which, in the presence of the autoantigens in the thymus, may reinduce self-tolerance. Our previous work shows that in experimental autoimmune encephalomyelitis (EAE), autologous/syngeneic BMT not only prevents the appearance of paralytic signs, but can also partially reverse chronic disease and induce long-term, antigen-specific tolerance. However, there are serious reservations to be considered when interpreting these data and before applying similar protocols in patients with multiple sclerosis. (1) The model of EAE is not a completely reliable model of multiple sclerosis. (2) In animals with chronic EAE, although further relapses were prevented, the established paralysis was usually not reversible. According to recent data, in chronic multiple sclerosis (MS) lesions, damage caused by axonal loss/transection and cortical/spinal cord atrophy is irreversible and probably amenable to immunotherapy. (3) Long-term, antigen-specific tolerance may be induced with BMT, but not in all cases; in passively induced CR-EAE, many of the mice relapsed upon challenge with myelin antigens, which may indicate that the presence of the immunizing, myelin antigens (on the site of immunization) during the process of immune reconstitution is critical for induction of tolerance. Finally, one should weigh the procedure-related risks (including mortality of up to 5%) of bone marrow or peripheral stem cell transplantation (SCT). A more radical solution for autoimmunity may involve the use of non-myeloablative allogeneic transplantation.

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.

Composition and function of peripheral blood stem and progenitor cell harvests from patients with severe active rheumatoid arthritis

High-dose chemotherapy with autologous stem cell rescue has been proposed as an intensive therapy for severe rheumatoid arthritis (RA). In view of previous observations of abnormal haemopoiesis in RA patients, the composition and function of peripheral blood stem cell harvests (PBSCH) was investigated. Compared with PBSCH from healthy allogeneic donors mobilized with the same dose of G-CSF (filgrastim; 10 microg/kg/d, n = 14), RA PBSCH (n = 9) contained significantly fewer mononuclear cells (375 v 569 x 10(6)/kg, P = 0.03) and CD34+ cells (2.7 v 5.8 x 10(6)/kg, P = 0.003). However, there were increased proportions of CD14+ cells (P = 0.006) and CD14+ CD15+ cells (the phenotype of previously described 'abnormal' myeloid cells, P = 0.002) in the RA PBSCH which translated into 3.5- and 7-fold increases respectively on a per CD34+ cell basis. There were no differences in T-cell activation status as judged by proportions of CD4+ and CD8+ expressing CD45RA, CD45RO, HLA-DR and CD28 (RA PBSCH, n = 7, donor PBSCH, n = 5, P = 0.2-0.7). Phytohaemagglutinin responses determined fluorocytometrically with induction of CD69 expression were reduced in CD4+ and CD8+ cells following filgrastim administration in 3/3 RA patients tested. Compared with bone marrow as a potential source of CD34+ cells, PBSCH contained 11-fold more T cells (P < 0.0005), 8-fold more B cells (P < 0.0005) and 4-fold more monocytes (P = 0.02). In short-term methylcellulose culture there were no differences in colony counts (CFU-GM, CFU-GEMM, BFU-E) per CD34+ cell from PBSCH from RA patients (n = 11) and healthy donors (n = 10). Long-term culture initiator cells were cultured successfully from cryopreserved PBSCH from RA patients (n = 9). In conclusion, PBSCH from RA patients differed significantly in composition from normal individuals, but in vitro studies support normal stem and progenitor cell function. Changes in T-cell function occur during mobilization in RA patients. This work provides reassurance for the use of PBSCH as haematological rescue and baseline data for clinical trials of graft manipulation strategies in patients with RA.

Long-term outcome of autoimmune disease following allogeneic bone marrow transplantation

OBJECTIVE

To investigate the long-term outcome of autoimmune disease following allogeneic bone marrow transplantation (BMT), and its relationship to hemopoietic chimerism.

METHODS

Three previously described patients with rheumatoid arthritis (RA) who underwent allogeneic BMT for therapy-related severe aplastic anemia and 1 new patient with psoriasis who received BMT for chronic myeloid leukemia (CML) were followed up. Molecular studies were performed to assess hemopoietic and immune reconstitution in 3 cases.

RESULTS

In 2 of the RA patients, the RA remained in remission without treatment, with nonprogressive disease, 11 and 13 years after BMT. The third patient with RA had a relapse 2 years after BMT, although the previously aggressive disease subsequently ran an attenuated course with treatment-free remission for the last 11 years. Comparison with other cases of RA suggests that graft-versus-host disease may influence the long-term outcome, perhaps through ongoing inhibition of the immune system. In the patient with psoriasis, BMT was followed by remission, but the psoriatic rash recurred and arthropathy developed 12 months later. The psoriasis and arthropathy remained active 4.5 years post-BMT, although the CML remained in remission. Molecular studies in the 2 patients whose RA remained in continued remission and in the patient with psoriasis that relapsed confirmed complete donor hemopoietic reconstitution.

CONCLUSION

Long-term followup of autoimmune disease after allogeneic transplantation confirmed cure of the autoimmune disease in some, but eventual relapse in others. The occurrence of relapse despite complete donor hemopoietic reconstitution is evidence for the development of de novo, as opposed to persistent, disease, and is possibly related to intrinsic susceptibility of the transplanted stem cells or to host factors. There may be a relationship between remission of autoimmune disease and graft-versus-host reaction. These findings have relevance for the evolving application of stem cell transplantation as a therapy for autoimmune diseases.

Outcome of rheumatoid arthritis and psoriasis following autologous stem cell transplantation for hematologic malignancy

Based on successful results in animal models, it has been proposed that high-dose myeloablative therapy followed by autologous bone marrow or stem cell transplantation (ABMT/ASCT) may cure autoimmune disease. The coexistence of autoimmune disease and hematologic malignancy provides an opportunity to examine the response of autoimmune disease to ABMT or ASCT. We describe 4 patients with autoimmune disease (3 with psoriasis and 1 with rheumatoid arthritis) and hematologic malignancy. In each patient, the autoimmune disease remitted posttransplantation, but, in 4 patients with long-term followup, it recurred at 8-24 months. The earliest relapse occurred in a patient treated with interferon-alpha. Our experience suggests that a single autograft with unpurged stem cells is unlikely to cure autoimmune disease, but that other strategies building on this approach are worthy of investigation.