Immune ablation and stem-cell therapy in autoimmune disease. Experimental basis for autologous stem-cell transplantation

Role of glucose metabolism in aggressive phenotype of fibroblast-like synoviocytes: Latest evidence and therapeutic approaches in rheumatoid arthritis

Glucose metabolism is considerably increased in inflamed joints of rheumatoid arthritis (RA) patients at early stages. Fibroblast-like synoviocytes (FLSs) activation and subsequent joint damage are linked with metabolic alterations, especially glucose metabolism. It has been shown that glucose metabolism is elevated in aggressive phenotype of FLS cells. In this regard, glycolytic blockers are able to reduce aggressiveness of the FLS cells resulting in decreased joint damage in various arthritis models. Besides, metabolic changes in immune and non-immune cells such as FLS can provide important targets for therapeutic intervention. Glycolytic enzymes such as hexokinase 2 (HK2), phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB), and phosphoglycerate kinase (PGK) play essential roles in aggressive behavior of FLS cells. It has been documented that the HK2 enzyme is significantly upregulated in RA FLS cells, compared with osteoarthritis (OA) FLS cells. The HK2 is expressed in a few tissues and upregulated in the inflamed synovium of RA patients that makes it a potential target for RA treatment. Furthermore, HK2 has different roles in each cellular compartment, which offers another level of specificity and provides a specific target to reduce deleterious effects of inhibiting the enzyme in RA without affecting glycolysis in normal cells. Thus, targeting the HK2 enzyme might be an attractive potential selective target for arthritis therapy and safer than global glycolysis inhibition. Therefore, this review was aimed to summarize the current knowledge about glucose metabolism of FLS cells and suggest novel biomarkers, which are potential candidates for RA treatment.

Applications of Raman spectroscopy in the development of cell therapies: state of the art and future perspectives

This comprehensive review article discusses current and future perspectives of Raman spectroscopy-based analyses of cell therapy processes and products.

Stem cell-based therapies in inflammatory bowel disease: promises and pitfalls

Inflammatory bowel disease (IBD) is a chronic, often relapsing, condition that deeply impacts the quality of life for many patients. Although there have been significant advances in medical treatments, a large proportion of patients become refractory to available therapeutic options. Stem-cell therapy through hematopoietic stem cells (HSCs) or mesenchymal stem (stromal) cells (MSCs) is a promising therapeutic option for severe refractory cases especially when surgery is not feasible. In HSC transplantation, the objective is to destroy the 'autoreactive' immune cells responsible for disease chronicity, and to re-establish gut tolerance to gut microbes. In perianal Crohn's disease (CD), the objective is to deposit MSCs locally in fistulizing tracts to down-regulate the local immune response and induce wound healing. Results from upcoming and ongoing clinical trials will set the path of these novel therapeutic options that have the capability to successfully treat severe refractory Crohn's patients.

Autologous stem cell transplantation in children with severe progressive systemic or polyarticular juvenile idiopathic arthritis: Long-term followup of a prospective clinical trial

OBJECTIVE

To assess the safety and efficacy of intensive immunosuppression followed by T cell-depleted autologous hematopoietic stem cell transplantation (ASCT) for induction of disease remission in children with refractory progressive juvenile idiopathic arthritis (JIA).

METHODS

Twenty-two patients with progressive refractory JIA were followed up over a median period of 80 months after pretreatment with intensive immunosuppression followed by ASCT in a multicenter, prospective, phase II clinical trial. Hematopoietic stem cells were harvested from the patients' bone marrow, depleted of T cells, and kept frozen until used for ASCT. Pretreatment of patients consisted of a combination of antithymocyte globulin, cyclophosphamide, and low-dose total body irradiation. Patients were followed up for ASCT-related complications, recovery of hematologic and immune system parameters, and disease outcomes.

RESULTS

Reconstitution of hematologic values to normal range was rapid. Recovery of immune system parameters, especially normalization of CD4+, CD45RA+ naive T cells, was delayed, occurring at >/=6 months after ASCT. The prolonged period of immune deficiency resulted in a large number of viral infections and may have contributed to the development of macrophage activation syndrome (MAS), leading to death, in 2 patients. After ASCT, 8 of the 20 evaluable patients reached complete clinical remission of their JIA, 7 were partial responders, and 5 experienced a relapse of their disease (occurring 7 years after ASCT in 1 patient). Later during followup, 2 of the patients whose disease relapsed died from infections that developed after restarting immunosuppressive medication.

CONCLUSION

Intensive immunosuppression followed by ASCT resulted in sustained complete remission or marked improvement in 15 of 22 patients with progressive refractory JIA. The procedure, however, is associated with significant morbidity and risk of mortality due to prolonged and severe depression of T cell immunity. After fatal complications due to MAS were observed in some patients, the protocol was amended in 1999, to ensure less profound depletion of T cells, better control of systemic disease before transplantation, antiviral prophylaxis after transplantation, and slow tapering of corticosteroids. Following these protocol modifications, no additional ASCT-related deaths were observed among the 11 patients who received the modified treatment.

Remission of IgA nephropathy after allogeneic peripheral blood stem cell transplantation followed by immunosuppression for acute lymphocytic leukemia

We report a case with immunoglobulin A (IgA) nephropathy, showing IgA deposition which disappeared after peripheral blood stem cell transplantation (PBSCT) for acute lymphocytic leukemia (ALL). In 1996, a 28-year-old man was diagnosed with IgA nephropathy by renal biopsy. Steroid therapy improved proteinuria from 3 g/day to 1 g/day. In 2003, he received PBSCT following the initial therapy for ALL. After complete remission, urinary protein and hematuria remained at between (-) and (+/-). In 2004, the second renal biopsy specimen revealed no deposit of IgA or C3. These findings suggested that immune reconstruction with PBSCT following immunosuppression therapy was of benefit to IgA nephropathy.

Nonmyeloablative stem cell transplantation and cell therapy for malignant and non-malignant diseases

The conditioning prior to allogeneic stem cell transplantation was originally designed as a myeloablative conditioning, designed to eliminate malignant or genetically abnormal cells and then use the transplant procedure for rescue of the patients or to replace missing bone marrow products. However, allografts can induce effective graft vs. malignancy effects and can also eliminate undesirable hematopoietic stem cells in patients with genetic disorders and autoimmune diseases, thus documenting that alloreactive effects mediated by donor lymphocytes post-grafting can play a major role in eliminating hematopoietic cell of host origin, as well as provide effective immunotherapy for the treatment of disease recurrence. The efficacy of donor lymphocyte infusion (DLI) could be improved by activation with rIL-2 or by donor immunization. The cumulative experience over the years suggesting that alloreactive donor lymphocytes were most effective in eliminating tumor cells of host origin resulted in an attempt to reduce the intensity of the conditioning in preparation for the transplant procedure used for the treatment of hematological and other malignancies as well as life-threatening non-malignant disorders for which allogeneic stem cell transplantation may be indicated. Our working hypothesis proposed that the myeloablative conditioning which is hazardous and may be associated with early and late side effects, may not be required for treatment of patients with any indication for allogeneic stem cell transplantation. Instead, nonmyeloablative conditioning based on the use of reduced intensive preparatory regimen, also known as nonmyeloablative stem cell transplantation, may be sufficient for engraftment of donor stem cells while avoiding procedure-related toxicity and mortality, followed by elimination of undesirable cells of host origin by post-transplant effects mediated by alloreactive donor lymphocytes infused along with donor stem cells or administered subsequently as DLI. Improvement of the immediate outcome of stem cell transplantation using NST due to a significant decrease in transplant related mortality has broadened the spectrum of patients eligible for allogeneic stem cell transplantation, including elderly patients and other patients with less than optimal performance status. Likewise, the safer use of stem cell transplantation prompted expanding the scope of potential indications for allogeneic stem cell transplantation, such as metastatic solid tumors and autoimmune disorders, which now are slowly becoming much more acceptable. Current strategies focus on the need to improve the capacity of donor lymphocytes to eliminate undesirable malignant and non-malignant hematopoietic cells of host origin, replacing abnormal or malignant stem cells or their products with normal hematopoietic stem cells of donor origin, while minimizing procedure-related toxicity and mortality and improving the quality of life by reducing the incidence and severity of hazardous acute and chronic GVHD.

Immune ablation and stem-cell therapy in autoimmune disease. Immunological reconstitution after high-dose immunosuppression and haematopoietic stem-cell transplantation

Studies on immunological reconstitution after immune ablation and stem-cell therapy may yield important clues to our understanding of the pathogenesis of human autoimmune disease, due to the profound effects of function and organization of the immune system. Such studies are also indispensable when linking clinical sequelae such as opportunistic infections to the state of immune deficiency that ensues after the treatment. Much has been learnt on these issues from comparable studies in haemato-oncological diseases, although it remains to be proven that the data obtained from these studies can be extrapolated to rheumatological autoimmune diseases. Preliminary results from pilot studies in various rheumatological conditions not only pointed to clinical efficacy of the new treatment modality but also unveiled marked effects on T-cell receptor repertoires of circulating T lymphocytes, on titres of autoantibodies and T- and B-cell subsets.