Stem Cell Transplant for HIV-Related Blood Cancer

May 6, 2024 
This page was reviewed under our medical and editorial policy by Leslie Popplewell, M.D., Hematologist and Medical Director of Hematology and Blood and Bone Marrow Transplant, City of Hope Atlanta

Infection with HIV (human immunodeficiency virus) doesn’t directly cause cancer, but it weakens the immune system. As a result, HIV raises the risk of developing several types of cancer, including leukemia, lymphoma and other blood cancers.

Cancer may harm stem cells in the bone marrow that normally transform into blood cells. These hematopoietic stem cells mature into:

• White blood cells, an important part of the immune system
• Red blood cells, to carry oxygen throughout the body
• Platelets, to help form clots and prevent bleeding

A stem cell or bone marrow transplant may:

• Make the body able to again create healthy blood cells to fight cancer and infection
• Help the patient maintain strength and health
• Eliminate HIV or make it undetectable in some cases (only been observed so far in a very small number of patients)

HIV/AIDS and Blood Cancers

HIV comes with a higher risk of certain cancers. Some of these so-called opportunistic cancers are considered AIDS-defining cancers because they indicate the HIV infection has progressed to AIDS (acquired immunodeficiency syndrome). One such cancer is non-Hodgkin lymphoma, the most common blood cancer diagnosed in people with HIV. According to the Center for Cancer Research, people with HIV are up to 17 times more likely to develop non-Hodgkin lymphoma than those without HIV.

Other HIV-related cancers are considered non-AIDS-defining cancers, because they don’t necessarily indicate the progression of AIDS. These cancers include Hodgkin lymphoma, another blood cancer (also called a hematologic malignancy).

According to the National Cancer Institute, in comparison to the general population, people with HIV are:

• 12 times more likely to develop non-Hodgkin lymphoma
• About eight times more likely to develop Hodgkin lymphoma

A weakened immune system makes HIV/AIDS patients less likely to fight off some viral infections linked to certain cancers, including:

• Kaposi sarcoma-associated herpesvirus, which is linked to some subtypes of lymphoma
• Epstein-Barr virus, which is linked to subtypes of both Hodgkin and non-Hodgkin lymphoma

Since the mid-1990s, antiretroviral therapy (ART) has allowed people with HIV infection or AIDS to live longer, making HIV manageable as a chronic condition instead of a likely fatal disease. As a result of a longer life expectancy, people with HIV have begun living long enough to develop cancers often associated with older patients who don’t have HIV/AIDS, such as acute myeloid leukemia.

Treatments have advanced for patients with HIV-related cancers. People with HIV typically have low blood cell levels, which would typically limit the amount of chemotherapy they could receive. The development of highly active antiretroviral therapy (HAART) and its use with drugs to boost blood cell production have helped HIV patients tolerate higher doses of chemotherapy.

Stem Cell Transplants in HIV Patients

Stem cell transplants, also referred to as bone marrow transplants, harvest stem cells from either bone marrow or blood. The iliac crest of the pelvis is the most common source for bone marrow collection. Two main forms of stem cell or bone marrow transplant procedures are autologous and allogeneic transplants.

Autologous transplant: This type of transplant uses stem cells from the HIV patient. A patient is first given medicine to increase the production of stem cells. These cells are later removed before intense chemotherapy, perhaps with radiation therapy, to destroy cancer cells. The harvested stem cells are later returned to the body intravenously. Autologous transplants have been used in HIV patients to treat types of lymphoma, including large B cell, Burkitt and Hodgkin lymphomas, and multiple myeloma.

Allogeneic transplant: This type of transplant uses stem cells from another person, called a bone marrow transplant donor. The procedure is usually performed after the patient undergoes chemotherapy, and sometimes radiation therapy, to slow down the immune system response and lessen the chance that it will attack transplanted cells. Because the stem cells in allogeneic transplants originate from a donor, proteins known as human leukocyte antigens (HLA) must first be compared to find as close of a match as possible between the donor and patient. The more HLAs the patient and donor have in common, the lower the chance of graft-versus-host disease (GVHD), which occurs when the donated cells attack the patient’s cells.

Some allogeneic transplant donors are siblings, parents or children. According to the American Society of Clinical Oncology, these donors aren’t always a 100% match, but they may be a 50% HLA match, which would necessitate a haploidentical transplant. If the donor is the patient’s identical twin, the match is called syngeneic.

Advancements in HIV and Cancer Care

Though rare, HIV patients may have a potential added transplant benefit. Scientists discovered some donors carry a genetic mutation that deters HIV from infecting a specific type of white blood cells, conveying a natural resistance. This mutation, CCR5Δ32, occurs in approximately 1% of white people, but isn’t seen in other ethnic groups, according to a September 2020 article in the Lancet HIV. Allogeneic transplants using donors with this mutation may make the recipient resistant to HIV, perhaps giving them no sign of HIV in their cells — even over long periods of time without continued use of ART. However, the odds of finding such a donor who is also HLA-compatible are low.

Newer and more appropriate combination ARTs have made it possible for patients to have undetectable levels of HIV in their blood, although a reservoir of the virus does remain in white blood cells known as CD4+T cells. If ART is stopped, the virus infection may rebound. As the effective use of both ART and allogeneic stem cell transplants has improved, cases have been reported in patients whose reservoir of HIV was dramatically reduced or undetectable after a transplant in which ART was continued throughout and after the procedure.

Bone Marrow Transplant Risks in HIV Patients

It’s important to know the potential risks of a bone marrow or stem cell transplant that may affect HIV patients. They include those detailed below.

Infection: Chemotherapy given in advance of a stem cell transplant harms the immune system, raising the risk of infection soon after the transplant. Since people with HIV/AIDS already have a weakened immune system, antibiotics are given following the procedure to reduce the chance of infection.

GVHD: The transplanted white blood cells may attack tissue in the patient’s intestines, liver, skin or other organs. This may occur within three months after the transplant, known as acute GVHD, or more than three months later, called chronic GVHD. After the transplant, medicines are given to suppress the patient’s immune system and lower the risk of GVHD or help manage the condition.

Low blood cell levels: For a week or two after the procedure, levels of red and white blood cells and platelets remain low. In addition to raising the risk of infection, low blood cell levels increase the chances of bleeding and cause fatigue. Blood and platelet transfusions may help boost blood cell levels.

Adverse drug interactions: Interactions between ART medicines that people with HIV take to control their infection and the chemotherapy given in preparation for a stem cell transplant have lessened with the use of second-generation ART drugs.

Rebound HIV infections: This may occur if ART is paused or stopped during the chemotherapy preparation for transplant or during recovery.

Reintroduction of cancer cells: Autologous transplant recipients have a low risk of cancer cells being reintroduced to their body.

Short-term side effects include:

• Mouth sores
• Skin reactions
• Hair loss
• Nausea
• Vomiting

Long-term side effects include:

• Organ damage
• Bone and muscle weakness
• Cataracts
• Infertility
• New secondary cancers
• Liver, kidney, lung or heart damage

City of Hope's Expertise in Stem Cell Transplants

Successful stem cell transplants for blood cancers in patients with HIV/AIDS result from the City of Hope expert team taking appropriate steps to:

• Reduce transplant risks, chiefly infection and GVHD
• Balance appropriate chemotherapy drugs with proper ART medications during transplant preparation
• Monitor for and treat side effects, such as nausea, fatigue and skin reactions

Home to some of the world’s leading bone marrow transplant experts and scientific researchers, City of Hope has the technological resources and expertise to treat cancer in HIV patients. The National Cancer Institute has named the Duarte hospital among the nation’s comprehensive cancer centers (its highest designation), and U.S. News & World Report’s 2023-24 list ranked the hospital the nation’s eighth best for cancer. Since 1976, when it started offering bone marrow and stem cell transplants as a cancer treatment, City of Hope has performed more than 19,000 bone marrow and stem cell transplants as part of a program accredited by the Foundation for the Accreditation of Cellular Therapy and recognized for exceptional outcomes.

One City of Hope transplant patient with HIV who received donor cells with an HIV-resistant mutation became one of five people in the world whose leukemia and HIV were no longer detectable.