stable in recent years, at about 50,000 new infection cases per year.
HIV targets the immune system and damages the function of immune cells, consequently undermining the body’s ability to fight disease. Eventually, infection leads to the development of AIDS, which increases susceptibility to opportunistic infections (OIs), such as cancers and other types of ailments that could potentially lead to death. Prevention, developing a vaccine, and finding a cure for HIV/AIDS are three necessary approaches to eradicate AIDS-related conditions. Stem cell therapy represents true hope for fighting this disease, which affects millions of people in America and abroad.
Standard HIV/AIDS Treatments
AZT, which became available in 1987, was the first FDA-approved drug for HIV treatment. Since then, about 30 drugs have been developed to treat people with HIV/AIDS, and more are under way.
Antiretroviral therapy (ART) represents the regimen of medicines currently used to manage HIV infection. For the patient, it means taking daily a combination of medicines. Although ART is recommended for everyone with HIV, it does not constitute a cure to the disease, but rather a treatment to prolong patients’ lives in the best way possible.
HIV medicines work by preventing HIV from replicating itself in the cell, therefore granting the immune system a chance to recover or fight off existing infections or potential cancers. When the amount of HIV in the body decreases, the risk of transmission to sexual partners is also reduced.
HIV/AIDS Stem Cell Clinical Trials in the United States
In 2012, Timothy Brown, also known as the “Berlin patient,” was the first person ever declared cured of HIV.
In 1995, Timothy was diagnosed with HIV. Ten years later, after being on antiretroviral drugs, it was discovered that he was suffering from an acute form of leukemia. Brown’s physicians used chemotherapy and radiation to clear his immune system, before rebuilding it with stem cells from a donor who was immune to HIV and carried a mutation in a gene involved in the transmission of the disease.
The gene in question known to the scientific world as CCR5 is not present in the cells of about 1% of Caucasians, therefore preventing HIV from entering blood cells. For Brown, this meant a second chance at life. Two stem cell transplants were performed on him, which eradicated his cancer, and transferred the genetic mutation to his immune system.
“It’s an incredible feeling—like a miracle,” Brown said. “I had two lethal diseases and was able to get rid of both of them.” His story is a testament to the way stem cell therapy could help treat HIV/AIDS as well as AIDS-related conditions.
This being said, a number of challenges still need to be met: Today, there are not enough bone marrow donors with CCR5 mutations to cover the great number of HIV patients’ needs. Additionally, such treatment has been recognized as invasive, with a strong prospect that the body might attack the donor cells, and its cost component is substantial. And finally, stem cell transplants still remain associated with significant disease and mortality risks.
In the face of such challenges and considering the amount of medication a patient needs to take to keep the virus at bay, clinical trials continue to be conducted to find new ways to handle HIV/AIDS and consequently, AIDS-related conditions.
In a trial conducted by Calimmune, California’s stem cell state agency, an innovative gene-based therapy is currently being used to protect patients with HIV from the AIDS virus and its correlated effects. In a study conducted by this agency, 12 HIV-positive individuals were infused in 2013 with their own blood stem cells that carried a gene that had been modified to block the production of CCR5. If successful in the long run, such a technique would prevent the AIDS virus from penetrating into cells, and consequently, damaging them. The therapy additionally leverages a complementary mechanism aimed at diminishing the likelihood that the virus would build resistance to such a procedure.
Other trials of the same nature and with similar objectives are being conducted by other research groups, such as the University of California–Davis Institute for Regenerative Cures, to demonstrate the efficacy and benefit of stem cell transplants.
In March 2014, the Board of the California Institute for Regenerative Medicine (CIRM) approved an additional $40 million Preclinical Development Award initiative. The objective of this award is to support projects currently under way and financed by this institution in order to develop programs aimed at manufacturing the kind of stem cells needed for therapies seeking Food and Drug Administration (FDA) approval.
The relationship between AIDS-related conditions (opportunistic infections) and HIV/AIDS infection is bidirectional. HIV is responsible for the body immunosuppression, which is in turn responsible for the fact that opportunistic pathogens trigger diseases such as bacterial pneumonia, tuberculosis, herpes zoster, malaria, septicemia, skin infections, sarcomas, and lymphomas in HIV/AIDS-infected individuals.
Prevention and treatment of opportunistic infections remain essential to help patients with HIV/AIDS to live longer. Additionally, those treatments also contribute in preventing further, transmissible infections from spreading to others.
Taking part in a clinical trial may therefore be for most patients the best treatment option, as clinical trials are conducted to find out if new treatments are effective and safe, or better than standard existing treatments.
In the case of cancer, for instance, one of the many AIDS-related conditions, standard treatments are based on previous clinical trials. So, patients who enroll in clinical trials also help improve the way the disease is treated in the future, because, even if clinical trials do not result in effective new treatments, they often provide answers to important questions, thus propelling research forward.
In AIDS-related lymphoma (an AIDS-related condition), malignant cells invade the lymph system of patients with AIDS.
High-dose chemotherapy with stem cell transplant has proven to be a way of administering chemotherapy and replacing blood-forming cells destroyed by the treatment. In this particular instance, immature blood cells (stem cells) are removed from the patient’s or donor’s bone marrow or blood to be frozen and stored. Once chemotherapy has been administered, the stored stem cells are thawed and reintroduced into the patient’s system through a process called infusion. The new stem cells restore the body’s blood cells.
Morenike Trenou
Independent Scholar
See Also: Gene Therapy: Hemoglobinopathies; Hematopoietic Transplantation: Gene Therapy; Immune Disorders.
Further Readings
Carlson, J. R., M. L. Bryant, S. H. Hinrichs, et al. “AIDS Serology Testing in Low- and High-Risk Groups.” JAMA, v.253/23 (June 21, 1985).
Eyster, M. E., M. H. Gail, J. O. Ballard, et al. “Natural History of Human Immunodeficiency Virus Infections in Hemophiliacs: Effects of T-Cell Subsets, Platelet Counts, and Age. Annals of Internal Medicine, v.107/1 (July 1987).
Walker, A. S., et al. “Daily Co-Trimoxazole Prophylaxis in Severely Immunosuppressed HIV-Infected Adults in Africa Started on Combination Antiretroviral Therapy: An Observational Analysis of the DART Cohort.” The Lancet Online (March 29, 2010).
Clinical Trials, U.S.: Amyotrophic Lateral Sclerosis
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