Autologous Bone Marrow Transplantation in Multiple Sclerosis: Biomarker Relevance for Patient Recruitment and Follow up

Mobilization kinetics of CD34+ hematopoietic stem cells stimulated by G-CSF and cyclophosphamide in patients with multiple sclerosis who receive an autotransplant

BACKGROUND AIMS

Autologous hematopoietic stem cell transplantation (AHSCT) is an alternative for multiple sclerosis (MS) patients who do not respond to conventional treatment. Mobilization kinetics of CD34+ cells in MS patients has not been studied.

METHODS

Patients with MS mobilized with granulocyte colony-stimulating factor (G-CSF) and cyclophosphamide (Cy) were prospectively studied. Three counts of CD34+ cells were done in peripheral blood: at baseline before mobilization, at the start, and immediately at the end of apheresis. Complete blood counts were performed at the times of CD34+ cell counting. Standard statistical descriptive analysis of MS patients' salient features was performed, and after log 10 transformation of the data, Pearson test was performed to assess correlation between variables and CD34+ cell count. In addition, multiple linear regression of relevant data was carried out for multivariate analysis.

RESULTS

Data of 51 consecutive MS patients with median age of 48 (31-64) years were analyzed. The CD34+ cell count increased 26-fold after mobilization. During large volume leukapheresis (LVL), the number of CD34+ cells in peripheral blood increased from 51.29 CD34+/μL at the start to 62.3 CD34+/μL at the end. A negative correlation between CD34+ cell count after leukapheresis and age (r = -0.32, P = 0.02) was observed. Neither the CD34+ baseline count nor sex correlated with the CD34+ count in peripheral blood immediately at the end of apheresis.

CONCLUSIONS

Mobilization with G-CSF and Cy in MS patients resulted in effective CD34+ hematoprogenitors release from the bone marrow and in intra-apheresis recruitment.

Determine safety of outpatient chemotherapy and autotransplants using refrigerated, non-frozen grafts in persons with multiple sclerosis

BACKGROUND

Persons with multiple sclerosis are increasingly treated with intermediate- or high-dose chemotherapy and a hematopoietic cell autotransplant. This is often done in an inpatient setting using frozen blood cell grafts.

OBJECTIVE

Determine if chemotherapy and a hematopoietic cell autotransplant can be safely done in an outpatient setting using refrigerated, non-frozen grafts.

METHODS

We developed an autotransplant protocol actionable in an outpatient setting using a refrigerated, non-frozen blood graft collected after giving cyclophosphamide, 50 mg/kg/d × 2 days and filgrastim, 10 μg/kg/d. A second identical course was given 9 days later followed by infusion of blood cells stored at 4°C for 1-4 days. The co-primary outcomes were rates of granulocyte and platelet recovery and therapy-related mortality.

RESULTS

We treated 426 consecutive subjects. Median age was 47 years (range, 21-68 years). A total of 145 (34%) were male. Median graft refrigeration time was 1 day (range, 1-4 days). Median interval to granulocytes >0.5 × 10E + 9/L was 8 days (range, 2-12) and to platelets >20 × 10E + 9/L, 8 days (range, 1-12). Only 15 subjects (4%) were hospitalized, predominately for iatrogenic pneumothorax (N = 5) and neutropenic fever (N = 4). There was only 1 early death from infection.

CONCLUSION

Intermediate-dose chemotherapy and a hematopoietic cell autotransplant can be safely done in an outpatient setting using, refrigerated, non-frozen grafts.

Autologous Hematopoietic Stem Cell Transplantation in the Treatment of Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune disorder that typically affects young people during their most productive years, causing irreversible damage and accumulation of disability. Treatments over time have had modest effects at completely controlling or suppressing disease activity, but are generally aimed at controlling early dominating inflammation that, over time, accumulates damage and leads to progressive disability. Some unfortunate patients are destined to deteriorate despite even newer and more effective agents because of the inability of these drugs to fully curb the inflammatory component of the disease. These patients require something more that might be capable of halting the disease process. Using high-intensity myeloablative chemotherapeutic agents, it is now possible to completely remove the peripheral immune system and replace it anew from autologous bone marrow-derived hematopoietic stem cells, purged of disease-causing MS cells. This procedure, referred to as hematopoietic stem cell transplantation (HSCT), produces a new immune system that appears tolerant and no longer attacks the central nervous system (CNS).

Stem Cell Therapy for Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory, autoimmune, and neurodegenerative disease of the central nervous system (CNS). It is characterized by demyelination and neuronal loss that is induced by attack of autoreactive T cells to the myelin sheath and endogenous remyelination failure, eventually leading to functional neurological disability. Although recent evidence suggests that MS relapses are induced by environmental and exogenous triggers such as viral infections in a genetic background, its very complex pathogenesis is not completely understood. Therefore, the efficiency of current immunosuppression-based therapies of MS is too low, and emerging disease-modifying immunomodulatory agents such as fingolimod and dimethyl fumarate cannot stop progressive neurodegenerative process. Thus, the cell replacement therapy approach that aims to overcome neuronal cell loss and remyelination failure and to increase endogenous myelin repair capacity is considered as an alternative treatment option. A wide variety of preclinical studies, using experimental autoimmune encephalomyelitis model of MS, have recently shown that grafted cells with different origins including mesenchymal stem cells (MSCs), neural precursor and stem cells, and induced-pluripotent stem cells have the ability to repair CNS lesions and to recover functional neurological deficits. The results of ongoing autologous hematopoietic stem cell therapy studies, with the advantage of peripheral administration to the patients, have suggested that cell replacement therapy is also a feasible option for immunomodulatory treatment of MS. In this chapter, we overview cell sources and applications of the stem cell therapy for treatment of MS. We also discuss challenges including those associated with administration route, immune responses to grafted cells, integration of these cells to existing neural circuits, and risk of tumor growth. Finally, future prospects of stem cell therapy for MS are addressed.