Stem cell transplantation for rheumatic autoimmune diseases

Immunoablative therapy and hematopoietic stem cell transplantation (HSCT) is an intensive treatment modality aimed at 'resetting' the dysregulated immune system of a patient with immunoablative therapy and allow outgrowth of a nonautogressive immune system from reinfused hematopoietic stem cells, either from the patient (autologous HSCT) or a healthy donor (allogeneic HSCT). HSCT has been shown to induce profound alterations of the immune system affecting B and T cells, monocytes, and natural killer and dendritic cells, resulting in elimination of autoantibody-producing plasma cells and in induction of regulatory T cells. Most of the available data have been collected through retrospective cohort analyses of autologous HSCT, case series, and translational studies in patients with refractory autoimmune diseases. Long-term and marked improvements of disease activity have been observed, notably in systemic sclerosis, systemic lupus erythematosus, and juvenile idiopathic arthritis, and treatment-related morbidity and mortality have improved due to better patient selection and modifications of transplant regimens. Treatment-related mortality has decreased to approximately 7%. Prospective, randomised, controlled clinical trials are ongoing or planned in systemic sclerosis, systemic lupus erythematosus, and several nonrheumatological conditions

Allogeneic stem cell transplantation for rheumatic autoimmune diseases

Haematopoietic stem cell transplantation (HSCT) has evolved from an experimental concept to an effective treatment option for severe autoimmune diseases and has a unique ability to restore immune regulation. It is a complex multistep procedure involving the administration of high doses of immunosuppressive medication and transplantation of stem cells. Most HSCT procedures in autoimmune disease have involved autologous stem cells. In the case of allogeneic transplantation, stem cells are derived from peripheral blood or bone marrow of a healthy HLA-matched donor. Allogeneic HSCT has curative potential based on studies in experimental models of autoimmune disease, case reports, and a registry analysis but carries significant risks of rejection and graft-versus-host disease. Unless these risks become manageable, allogeneic HSCT should be offered only if all alternative treatment options have failed, if a patient has a suitable donor, and if a patient still has a chance to benefit significantly from the procedure

The role of B cells in systemic sclerosis

Systemic sclerosis (SSc) is a connective disease characterized by features of autoimmunity, vasculopathy, inflammation, and fibrosis. The disease typically starts with Raynaud’s phenomenon, followed by skin thickening in the extremities due to inflammation and fibrosis. Fibrosis results from excessive collagen production by fibroblasts, which constitutes the final common pathway of complex cellular interactions including B cells. Several studies have indicated that B cells may play a role in SSc. Lesional skin infiltrates from SSc patients consist of a variety of cells, including eosinophils, neutrophils, lymphocytes, plasma cells, and macrophages. Autoantibodies of several specificities are present in the serum of SSc patients of which antitopoisomerase 1 is the most common, and evidence has been gathered for a potential pathogenic role of some autoantibodies, eg, anti-PDGF antibodies. The blood of SSc patients contains an increased proportion of naïve B cells but a decreased proportion of memory B cells. Furthermore, serum levels of interleukin-6, an important pro-inflammatory cytokine, have been shown to correlate with skin fibrosis. Animal models of SSc have provided more in-depth information on the role of B lymphocytes, eg, through disruption of B cell function. In this review we will discuss the evidence that B cells are involved in the pathogenesis of SSc

Haematopoietic stem cell transplantation for poor-prognosis systemic sclerosis

Haematopoietic stem cell transplantation (HSCT) following intensive immune suppression has been used in >2000 patients with severe autoimmune diseases for 18 years, including 300 with SSc. The concept is to profoundly reduce the bulk of auto-aggressive immune competent cells and then rescue the patient's ablated haematopoiesis via an autologous HSCT. An early analysis of uncontrolled phase I/II data suggested that approximately one-third of these achieved a substantial improvement, with a relapse rate of 25% and a treatment-related mortality ranging from 6% to 23% across different studies. These early results led to three prospective randomized controlled trials, two of which are completed, confirming that HSCT shows clear advantages over conventional immunosuppression, but with significant toxicity. In some patients, sustained complete normalization of skin changes, reversal of positive autoantibody status and withdrawal of immunosuppressive medication were observed. These results attest to the profound effects of HSC

Cell therapy for autoimmune diseases

Cell therapy, pioneered for the treatment of malignancies in the form of bone marrow transplantation, has subsequently been tested and successfully employed in autoimmune diseases. Autologous haemopoietic stem cell transplantation (HSCT) has become a curative option for conditions with very poor prognosis such as severe forms of scleroderma, multiple sclerosis, and lupus, in which targeted therapies have little or no effect. The refinement of the conditioning regimens has virtually eliminated transplant-related mortality, thus making HSCT a relatively safe choice. Although HSCT remains a nonspecific approach, the knowledge gained in this field has led to the identification of new avenues. In fact, it has become evident that the therapeutic efficacy of HSCT cannot merely be the consequence of a high-dose immuno-suppression, but rather the result of a resetting of the abnormal immune regulation underlying autoimmune conditions. The identification of professional and nonprofessional immunosuppressive cells and their biological properties is generating a huge interest for their clinical exploitation. Regulatory T cells, found abnormal in several autoimmune diseases, have been proposed as central to achieve long-term remissions. Mesenchymal stem cells of bone marrow origin have more recently been shown not only to be able to differentiate into multiple tissues, but also to exert a potent antiproliferative effect that results in the inhibition of immune responses and prolonged survival of haemopoietic stem cells. All of these potential resources clearly need to be investigated at the preclinical level but support a great deal of enthusiasm for cell therapy of autoimmune diseases

Differentiation Potential of CD14+ Monocytes into Myofibroblasts in Patients with Systemic Sclerosis

BACKGROUND: Circulating monocytes are a highly plastic and functionally heterogeneic cell type with an activated phenotype in patients with systemic sclerosis (SSc). CD14(+) monocytes have the potential to differentiate into extra-cellular matrix (ECM) producing cells, possibly participating in fibrogenesis. AIM: To study the effect of GM-CSF, IL-4 and endothelin -1 (ET-1) alone or in combination on monocyte differentiation into myofibroblasts. METHODS: CD14(+) cells were isolated from peripheral blood from 14 SSc patients and healthy controls by positive selection and incubated with different combinations of GM-CSF, IL-4 and ET-1 for 14 days. Type-1 collagen and α-SMA were detected by Western blot, qPCR and confocal microscopy. HLA-DR, CD11c and CD14 expression was analysed by flow cytometry. A collagen gel contraction assay was performed for functional myofibroblast assessment. RESULTS: GM-CSF both induced collagen and α-SMA expression after 14 days. ET-1 further increased GM-CSF-induced collagen expression in a dose dependent manner up to 30-fold. IL-4/GM-CSF combination leads to a more DC-like phenotype of monocytes associated with reduced collagen and α-SMA expression compared to GM-CSF alone. Collagen and α-SMA expression was higher in monocytes from SSc patients and monocytes were more prone to obtain a spindle form. In contrast to controls, ET-1 and IL-4 alone were sufficient to induce α-SMA expression in monocytes from SSc patients. Despite the induction of α-SMA expression, monocyte-derived myofibroblasts only had a moderate capability of contraction in functional analyses. CONCLUSION: SSc monocytes display increased maturation towards myofibroblasts demonstrated by their phenotype and α-SMA expression when compared to monocytes from healthy controls, however only with minor functional contraction properties

Late-onset systemic sclerosis—a systematic survey of the EULAR scleroderma trials and research group database

Objective. The clinical course of SSc depends on subtype, organ involvement and age. Few data are reported on patients suffering from late-onset SSc. Methods. We analysed data from 8554 patients prospectively followed in the EULAR Scleroderma Trials and Research (EUSTAR) group database. Late-onset SSc was defined as onset of non-RP disease features at or beyond 75 years of age. Disease characteristics, clinical features, disease course and mortality were evaluated. Results. A total of 123 patients with SSc onset at or beyond 75 years of age were identified. Compared with patients <75 years they had more frequently limited than diffuse SSc and a higher prevalence of anti-centromere autoantibodies. Fewer old patients had digital ulcers. The modified Rodnan's skin score, the prevalence of lung fibrosis and renal crisis did not differ significantly between groups. Pulmonary hypertension (PH) measured by echocardiography was more prevalent in the late-onset group, as well as arterial hypertension and diastolic dysfunction. Late-onset SSc remained a positive predictor for PH in multivariate analyses. No significant difference of the two groups in skin score or diffusion capacity was observed during follow-up. Mortality due to SSc was higher in the late-onset group, but the survival time from diagnosis was longer compared with the younger patients. Conclusion. Late-onset SSc shows a distinct clinical presentation and outcome. Patients with late-onset SSc suffer more frequently from the limited subtype and PH, but fewer patients have digital ulcers. PH may in part be determined by underlying cardiovascular diseas

The c-Rel Subunit of NF-κB Regulates Epidermal Homeostasis and Promotes Skin Fibrosis in Mice

The five subunits of transcription factor NF-κB have distinct biological functions. NF-κB signaling is important for skin homeostasis and aging, but the contribution of individual subunits to normal skin biology and disease is unclear. Immunohistochemical analysis of the p50 and c-Rel subunits within lesional psoriatic and systemic sclerosis skin revealed abnormal epidermal expression patterns, compared with healthy skin, but RelA distribution was unaltered. The skin of Nfkb1−/− and c-Rel−/− mice is structurally normal, but epidermal thickness and proliferation are significantly reduced, compared with wild-type mice. We show that the primary defect in both Nfkb1−/− and c-Rel−/− mice is within keratinocytes that display reduced proliferation both in vitro and in vivo. However, both genotypes can respond to proliferative stress, with 12-O-tetradecanoylphorbol-13-acetate–induced epidermal hyperproliferation and closure rates of full-thickness skin wounds being equivalent to those of wild-type controls. In a model of bleomycin-induced skin fibrosis, Nfkb1−/− and c-Rel−/− mice displayed opposite phenotypes, with c-Rel−/− mice being protected and Nfkb1−/− developing more fibrosis than wild-type mice. Taken together, our data reveal a role for p50 and c-Rel in regulating epidermal proliferation and homeostasis and a profibrogenic role for c-Rel in the skin, and identify a link between epidermal c-Rel expression and systemic sclerosis. Modulating the actions of these subunits could be beneficial for treating hyperproliferative or fibrogenic diseases of the skin

Differential responsiveness to immunoablative therapy in refractory rheumatoid arthritis is associated with level and avidity of anti-cyclic citrullinated protein autoantibodies: a case study

In order to identify pathogenic correlates of refractory rheumatoid arthritis (RA), antibodies against anti-cyclic citrullinated protein (ACPAs) were investigated in RA patients in whom the dysregulated immune system had been ablated by high-dose chemotherapy (HDC) and autologous haematopoietic stem cell transplantation (HSCT). Six patients with refractory RA were extensively characterized in terms of levels of total immunoglobulins, RA-specific autoantibodies (ACPAs and rheumatoid factor) and antibodies against rubella, tetanus toxoid (TT) and phosphorylcholine before and after HDC plus HSCT. Additionally, the avidity of ACPAs was measured before and after treatment and compared with the avidity of TT antibodies following repeated immunizations. Synovial biopsies were obtained by arthroscopy before HDC plus HSCT, and analyzed by immunohistochemistry. In the three patients with clinically long-lasting responses to HDC plus HSCT (median 423 days), significant reductions in ACPA-IgG levels after therapy were observed (median level dropped from 215 to 34 arbitrary units/ml; P = 0.05). In contrast, stable ACPA-IgG levels were observed in three patients who relapsed shortly after HDC plus HSCT (median of 67 days). Clinical responders had ACPA-IgG of lower avidity (r = 0.75; P = 0.08) and higher degree of inflammation histologically (r = 0.73; P = 0.09). Relapse (after 38 to 530 days) in all patients was preceded by rising levels of low avidity ACPA-IgG (after 30 to 388 days), in contrast to the stable titres of high avidity TT antibodies. In conclusion, humoral autoimmune responses were differentially modulated by immunoablative therapy in patients with synovial inflammation and low avidity ACPA-IgG autoantibodies as compared with patients with high levels of high avidity ACPA-IgG. The distinct clinical disease course after immunoablative therapy based on levels and avidity of ACPA-IgG indicates that refractory RA is not a single disease entity