Promising early-stage research into the use of stem cell transplants to fend off attacks by the human immunodeficiency virus (HIV) was presented at the Stem Cells & Regenerative Medicine World Congress in Palm Springs, CA, on January 20, 2009. The findings were reported by David DiGiusto, PhD, Director of Hematology and Hematopoietic Cell Transplantation at City of Hope Medical Center in Duarte, CA.
HIV attacks the body’s T-lymphocytes (a type of white blood cell), which help the immune system prevent infections. Since the virus can mutate, it can fool the body’s immune system, eventually spreading throughout the body. Once the immune system is overhelmed, the number of white blood cells diminishes. This scenario results in acquired immune deficiency syndrome (AIDS). Patients with full-blown AIDS can’t fight infections. They then become susceptible to a number of opportunistic infections, including pneumonia and several types of cancers.
The experimental therapy employs stem cells found in the bone marrow because they generate different types of blood cells, including the crucial immune-boosting white blood cells. Stem cells are nonspecific cells that can renew themselves for prolonged periods. They can also develop into different cell types, making them a potentially renewable source of replacement cells that could be used in the future to treat many conditions.
The technique involves genetically modifying a small amount of a patient’s stem cells in a laboratory with genes that target three components of HIV and enabling them to enter the immune cells, where they replicate. These anti-HIV genes are then transplanted into a patient’s bone marrow to maximize their viral-resistant properties. “When those stem cells are transplanted into patients, they create mature immune cells that circulate in the patient and protect against HIV,” explained DiGiusto.
In this first human trial, five AIDS patients already undergoing bone marrow replacement for lymphoma treatment, received transplants of the anti-HIV stem cells. The transplanted stem cells grew and manufactured new white blood cells, which helped protect against HIV. The results showed an improvement in the conditions of all of the patients.
International AIDS researchers and consumer advocates are cautiously optimistic about the results from this small study. “This is very exciting but clearly it is still in the early stages and has its complications,” said Annabel Kanabus, Director of Avert, an international HIV and AIDS charity based in the United Kingdom. “Bone marrow operations are both risky and expensive, so for it to be an effective way of treating the millions of people who have AIDS, it would need to be something that could be given more like an injection.”
DiGiusto is planning larger, more ambitious stem cell trials in the future, though it could be years before a therapy is developed. “We are trying to prevent the immunodeficiency that is a result of HIV infection,” said DiGiusto. “It is still an experimental treatment at the moment, but we hope that eventually we will be able to give AIDS patients just one transplant and that would then protect them for life.”
Source: Telegraph (online) posted January 17, 2009