Stem Cell Research and Therapy

Stem Cell Therapy As A Cure For Hematological Malignancies 

- Lifecell Conference at Chennai Jan-2006 by Dr. Mammen Chandy

The first International symposium on Stem cell Research and Therapy was conducted in Chennai, on the 6th of January. The programme was organized by LifeCell, a pioneer in stem cell banking in association with Sri Ramachandra Medical College and Research Institute, one of the reputed medical institutions in the country.

Dr. Mammen Chandy, a leading hematologist, CMC, Vellore, headed the symposium. Dr. Paul. R. Sanberg, Dr. Umesh Banakar, Dr.Michael E.Trigg, Dr. Naynesh Kamani and Dr. Mammen Chandy were amongst the participants of the scientific session. The following is a summary of the lecture on the potential of Stem cell therapy in the treatment of hematological malignancies.

Recent advances in stem cell therapy have provided an optimistic approach in the treatment of hematological malignancies, which were regarded incurable previously. The advancement of stem cells as a highly potent cell graft sources had indeed resulted in accelerated research towards the search of more effective treatment strategies.

Stem cells obtained form non-embryonic sources are most welcomable as the possibility of ethical concerns regarding the use of fetal tissue is circumvented. Adult stem cells can be obtained from the brain, bone marrow, peripheral blood and cord blood. Of all the sources, bone marrow stem cells are studied more extensively compared to any other option. The main indication for allogenic bone marrow transplantation is the presence genetic or acquired disorder of hematopoietic stem cell such as severe combined immune deficiency or thalassemia. 

The donor of a bone marrow transplant can either be allogenic (performed between unrelated individuals of the same species), autologus or syngenic (transplantation between identical twins). Bone marrow transplantation is today a life saving treatment for many incurable diseases. The number of bone marrow transplantation being performed worldwide has been steadily increasing over the few years.

The problems associated with the support of post bone marrow transplant patients has resulted in the limited availability of such surgical treatment across different regions of the country. In India, only about 5% of the population can afford such a treatment. 

Allogenic stem cell transplantation is currently undertaken in 5 places across India, namely Vellore, Chennai, Mumbai, Pune and Delhi. Diseases treatable by allogenic stem cell transplantation include chronic myelogenous leukemia (CML, if resistant to imatinib therapy), acute myelogenous leukemia (AML), acute lymphoblastic leukemia (ALL), myelodysplastic syndrome (MDS), aplastic anemia, Hodgkin’s disease, large cell lymphoma and myeloma.

Allogenic stem cell transplantation can be curative in a variety of malignant and non-malignant conditions. In spite of the high probability of cure, more than 75% of potential recipients lack a matched family donor. Out of this 75%, nearly half of them may find a matched unrelated adult stem cell donor. This cannot be accomplished without the availability a 6-antigen HLA matched donor. Another half of them who do not have any viable options, cord blood transplant remain the only alternative. 

In case of allogenic stem cell transplantation, the stem cell is most commonly obtained from the bone marrow (iliac crest). The amount of aspiration is determined by the weight of the recipient. Ideally 3*10^8 cells / body weight of the recipient is obtained through a sternal needle and the contents transferred into another sterile bag, after filtration. 

The obtained sample is then processed and irradiated (to destroy lymphocytes that may precipitate an immune reaction). Some of the complications associated with this transplantation technique are regimen related toxicity, sterility, susceptibility to infections, graft Vs Host disease, rejection and relapse.

Looking at the future scope of such treatments, one can clearly understand that much progress would not be possible without increasing the availability of the donor pool and the establishment of a donor network worldwide.