Clinical application of stem cell transplantation

Stem cells are well known to be capable of differentiating into specialized cells performing different functions in the body. A stem cell-based, transplantation technology represents a new feasible approach to the treatment for a number of diseases which are considered as incurable by conventional measures. Actually, when transplanted, stem cells can migrate into tissue lesions and differentiate there into those cells which are required for effective tissue regeneration. As a matter of fact, stem cell-based technologies enable to replace the complicated surgery on organ transplantation by the cell grafting, an ambulatory procedure with an equivalent potential.

Fetal tissues are well known to be a source of the unique immature cells having a high growth and differentiation potential. The allogeneic stem cells have been convincingly documented to be able to survive in the major histocompatibility complex (MHC)- incompatible environment over long period of time.

This implies the possibility of effective application of fetal cell transplantation in patients without using a immunosuppression. Also of great value for medicine is the ability of fetal-derived cells not only to stimulate tissue regeneration, but also to impede and even to reverse scar connective tissue growth in the sites of tissue lesions. Such an ability of the grafted cells gives additional opportunities to compensate for the cell loss by generating new functionally active cells (Favcett J.W., 1998; Moiseev et al., 1998).

When grafted into the adult body, stem cells can be implicated in creating new blood vessels. Thus, they are able to promote the restoration of blood flow in the ischemic tissues. Not only the stem cells, but also the precursors of endothelial cells can be responsible for this effect [Murohara et al, 2000; Fuch et al, 2001].

The anticancer action of the low-differentiated, hemopoietic cells may find an important clinical implication. The ability of such cells to directly suppress the tumor growth has been shown experimentally [Seledtsov et al, 1995; 1997, 2005].There are data indicating the anti-atherosclerotic activity of the low-differentiated cells. One of the manifestations of this activity is a decrease in a level of atherogenic lipoproteins in the sera of the fetal cell-grafted persons [Runovich et al., 2000]. The transplantation of fetal-derived, immature cells may result in a substantial increase in the regenerative and adaptive abilities of the adult organism [Sukhikh G.T., 1998]. This suggests that cell-based technologies may be clinically effective in treating a diversity of age related diseases.

Of special attention now are the technologies based on transplanting patient’s own stem cells. An main advantages of these technologies are due to availability of non-nimmunogenic cellular material (acceptable source is an autological bone marrow). There are convincing experimental data suggesting potential efficacy of administering autological stem cells in the treatment for severe neurological and cardiovascular disorders [Li et al, 2001; Nakano et al 2001; Hamano et al, 2002; Edelberg et al, 2002].

Stem cell transplantation technologies are applicable in CICT for the following disease:

• Severe neurological disorders
• Hepatic diseases
• Bone and articular defects
• Vascular disorders