Current treatments for HIV are focused on preventing the virus from replicating. Combination drug therapies are highly effective and allow the disease to be effectively managed. Rather than being a death sentence, patients diagnosed with HIV can live with the disease for decades with treatment.
Drug therapy does not cure HIV and HIV positive individuals can still transmit the virus and there is the risk that strains of HIV could evolve that are resistant to the drugs. HIV drugs are also expensive and are not available in many parts of the world. The search for a cure therefore continues.
There has been one case where a patient has been cured and now a second patient has received similar treatment that has seen the viral load fall to a level where it can no longer be detected in the blood.
While it is too early to tell if the patient has been cured, doctors report that the patient has been in remission for 18 months and has now come off HIV drugs.
In both cases, the patients had been diagnosed with Hodgkin’s lymphoma – A blood cancer that originates in white blood cells (lymphocytes). Hodgkin’s lymphoma is treatable, provided treatment starts early, ideally at Stage I or Stage II. The cancer is treated with chemotherapy or combination chemotherapy (more than one anti-cancer drug) alone, or chemotherapy followed by radiotherapy, potentially also a stem cell transplant.
Both patients received a chemotherapy followed by a stem cell transplant. In both cases the stem cells came from donors with a genetic mutation that provided resistance to HIV. While one case could be considered an anomaly, for two patients to receive similar treatments and enter long term remission, it shows that the treatment approach can be effective.
The first patient received the stem cell transplant after having his own stem cells eradicated with radiotherapy. With the second patient, radiotherapy was not necessary. Doctors used chemotherapy to wipe out the patient’s immune cells prior to the transplant. Both patients only experienced mild graft-versus-host disease following the transplant.
While it is certainly good news that HIV can be ‘cured’ in this manner, the treatment was not provided to primarily cure HIV. The treatment was provided to cure Hodgkin’s lymphoma. The treatments are aggressive and would not be suitable for widespread use.
For the treatment to be effective, it is first necessary to eliminate a person’s own blood stem cells using radiation or highly toxic chemicals and there are potential complications from this approach. The risk to patients would be considered too great, especially when there are drugs that can effectively manage HIV.
However, the case does provide further areas to research to identify different ways of treating HIV and shows that it may not be necessary to totally wipe out a patient’s immune system with radiotherapy prior to a stem cell transplant.
Details of the treatment and outcome are available in the paper – HIV-1 remission following CCR5Δ32/Δ32 haematopoietic stem-cell transplantation – which was recently published in the journal Nature. DOI: 10.1038/s41586-019-1027-4