Stem cells are the foundation for every organ and tissue in one's body.
Seven-time Formula 1 world champion Michael Schumacher, who went into coma after a skiing accident duringa holiday in 2013, is reportedly undergoing stem cell therapy in a Parisian hospital at the hands of renowned French surgeon Dr Philippe Menasche.
Back home, Dr Padmaja Lokireddy, Consultant Haemato Oncology and Stem Cell Transplant, Apollo Hospitals, tells us that stem cells have the potential to treat a wide range of neurological diseases such as cerebral palsy and in tissue repair and regeneration of organs. We asked the expert to explain what stem-cell therapy is all about.
Stem cells are the foundation for every organ and tissue in one's body.When talking of stem cells treating diseases,one means a stem cell transplant. In a stem cell transplant, embryonic stem cells are first specialized into the necessary adult cell type. Then, those mature cells replace tissues that are damaged by disease or injury.
“Stem cells are special human cells that have the ability to develop into many different cell types, from muscle cells to brain cells. In some cases, they also have the ability to repair damaged tissues,” explains Dr Padmaja, adding, “There are different types of stem cells. Some are so immature that they’re present only in the embryo and have the ability to grow into any type of tissue under the right bodily conditions. But as the embryo matures and as the stem cells are in the human body-in the bone marrow and fat-they are specialised to do jobs such as the production of blood cells.”
There has been a rapid growth of stem cell therapy in India; however, Dr Padmaja reminds us that research on embryonic stem cells has been banned since 2009 in many countries for ethical reasons.
“There has been tremendous research and considerable progress in the successful regeneration of organs in labs by inducing stem cells to develop into different tissues by providing them suitable environment and reprogramming them. But this has not been done in humans yet. Cartilage/ bone regeneration is done for orthopaedic conditions and has attained certain level of success in a few suitable patients,” says Dr Padmaja, who also says that cancer-specific T cell production is a new breakthrough treatment for blood cancers.
Given below are some of the approved treatments:
Msc: Other than bone marrow stem cells, there are cells called mesenchymal stem cells (MSC), which have the ability to alter immune function and have been increasingly used in clinical trials for cardiovascular repair, neurological conditions such as multiple sclerosis and osteoarthritis.
However, an article published in the Journal of Stem Cell International Volume 2019 stated that the results of MSC treatment was of temporary benefit and has not translated into long-term use for now and that it needs further studies to establish safety and efficacy. Additionally, MSC has presently been approved as treatment only in steroid refractory graft-versus-host-disease (GVHD), a complication that sets in after bone marrow transplant.
Chimeric Antigen Receptor T (CAR-T) cells therapy: This is a breakthrough treatment in cancer especially for blood cancers,in which a few millilitres of patient blood collected and T cells/immune cells are extracted and genetically engineered and grown in the lab to fight against cancer cells.
These are then injected back into the patient. CAR-T cells therapy is like a personalised treatment specific to each person.
“We hope it may not be too long before patients in India can avail cancer-specific T cell (CAR-T cells) treatment for blood disorders,” says the doctor.
Donor Lymph ocyte Infusion Therapy: Also called DLI, this is another approved treatment in which Donor T cells are given to the patient after a bone-marrow transplant. This gives a boost to the patient’s immune system and helps it to fight cancer cells. This treatment, along with bone marrow transplant, is offered routinely in many centres now.
Hematopoietic Stem Cell Transplant: Hematopoietic disorders (e.g., leukaemia, thallassemia, aplastic anemia, MDS, sickle cell anemia, storage disorders, etc.) affect the bone marrow and manifest as various systemic complications. Stem cells from a donor (either from cord blood or bone marrow) are known to reconstitute the defective bone marrow and overcome the disorder.
“Stem cells come from bone marrow are called hematopoietic stem cells, meaning blood cell producing stem cells, and they’ve been used for the treatment of many blood conditions such as thalassemia and blood cancers, including myeloma, leukemia and lymphoma, and severe immune deficiency conditions. For the above, bone marrow transplant is an approved treatment from the 1970s, and so far, over one million transplants have been done worldwide. Bone marrow transplant (or hematopoietic stem cell transplant) is the only approved stem cell therapy so far, and the rest remain under clinical trial,” she explains.
Cell therapy is therapy in which cellular material is injected, grafted or implanted into a patient; this generally means intact, living cells. For example, T cells capable of fighting cancer cells via cell-mediated immunity may be injected in the course of immunotherapy.
“We are hopeful that people with spinal cord injuries as well as Type 1 diabetes, Parkinson’s disease, amyotrophic lateral sclerosis, Alzheimer’s, heart disease, stroke, burns, cancer and osteoarthritis patients will benefit from stem cell therapies in future,” says Dr Padmaja even as she reiterates that the stem cell therapies are not approved yet.