In order to discover the ways for the remedy of diseases, studies in therapeutic approaches have been doing widely and kept increasing at accelerated pace. A lot of research areas had emerged for that purpose including one of the most fascinating and highly active areas at present, stem cells therapies. Due to self-renewal property and differentiation capability of stem cell, it becomes a new hope in modern treatment.
The first successful case of stem cell therapy in human was reported in 1959. Bone marrow restorations were observed in leukemia patients who received total body irradiation subsequent by intravenous injection of their twins’ bone marrow (Thomas et al, 1957). Nevertheless, that effect was transient and the following bone marrow transplantation attempts in non-twin patients and donors can eventually lead to patient’s death from graft-versus-host disease (Mathé et al, 1965). During that time, the safety of hematopoietic cells transplantation was not guaranteed because of the limited knowledge in human histocompatibility and immunosuppression. However, the turning point came after the discovery of human leucocyte antigen (HLA) groups (Dausset, 1958; van Rood et al, 1958), HLA typing and compatibility testing were performed prior to the transplantation. In addition, the improvement of immunosuppressive protocol also helps bringing the bone marrow transplantation to become more and more successful (Donnall and Hutchinson, 1999).
Although the success rate of hematopoietic stem cell therapy was great, patients’ mortality still happened as a result of some factors. Besides from graft-versus-host disease which have previously mentioned, infection contributes for most cases of patient death (Kernan et al, 1993). In allogeneic transplantation, patient’s immunity needs to be suppressed to avoid graft rejection. During such immunoincompetence period, there is a high risk that patient might get infected either from viral reactivation, hepatitis B (Hammond et al, 2009) and herpes simplex virus (Pillay et al, 1992) for instance, or other opportunistic infections such as Candida species (Wingard et al, 1991) and cytomegalovirus (Leung et al, 1999). However, this problem could be minimized in nonmalignant patients by using autologous transplantation.
Cell contamination is another risk factor in stem cell therapies that should be concerned. Since stem cells are human-derived products, contamination could occur at any steps in process. Start from stem cell sources or donors, they might carry viruses, parasites or diseases that can infect patients after transplantation. So, donor screening tests and assessment need to be performed (Sacchi et al, 2008). Medical and familial histories of donors are also essential and should be scrutinized in order to avoid getting stem cells from someone that might transmit congenital defect, autoimmunity or malignant disease to the patient (Niederwieser et al, 2004). Harvesting and culturing of stem cells are the...