The time at which you begin antiretroviral treatment can impact the development of tumors in HIV patients

HIV patients are at a higher risk of developing mucosal or skin cancers, even though HIV is not found in their blood. A new study by MedUni Vienna’s Department of Dermatology and the Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases (LBI-RUD), and the CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences has shown that antiretroviral therapy may affect the development of cancers. The findings were recently published in the specialist journal “Immunity”.

HIV (human immunodeficiency viruses) causes the death of immune cells that possess a specific molecule (CD4-receptor) on their surfaces. Over the course of the disease, these CD4+ T cells are significantly depleted, and this is linked to an increased risk of contracting infection. Antiretroviral treatment (ART) for people with HIV slows viral replication and decreases the viral load so that HIV is not detected in blood. This increases the amount of CD4+ T-cells present in the blood, thereby reducing the patient’s susceptibility to infection. But despite years of excellent and suppressive antiretroviral treatment, patients with HIV remain at risk of risk of developing skin and mucosal cancers. They are more likely to develop HPV-related cancers. The risk of HPV-associated anal cancer can be as high as 36 times greater for HIV-infected individuals than HIV-negative individuals.

The time of the first treatment can affect HIV patients” immune system

The research group headed by Georg Stary from the Department of Dermatology has published in the well-known journal “Immunity” an innovative mechanism for the dysregulation of tissue of the immune response in HIV patients. “We discovered that there were differences in the immune response to specific tissues based on whether antiretroviral treatment was initiated promptly following diagnosis of HIV infection or was delayed,” summarises Georg Stary who is the final author of the study. The memory T cells of the skin and mucosa of the tissue play a significant role in this process. They are part of the immunological memories and can be used to initiate a swift and effective immune response in the tissue if an organism has had contact with the pathogen.

Tissue-resident immune cells are of vital importance

In HIV patients who did not initiate antiretroviral therapy until some time after diagnosis, there was irreversible loss of tissue-resident memory T cells within the mucosa and skin despite high numbers of CD4+ T cells in blood. However, this loss of memory T cells can be avoided by initiating antiretroviral therapy promptly. It was also observed that HIV patients suffering from HPV-induced Mucosal Cancer have a lower percentage of memory cells that reside in their mucosa. This could explain the higher incidence and the more severe progress of HPV-related tumours in patients who have HIV.

“The results of the study demonstrate the importance of tissue-resident immune cells in the development of mucosal and the skin cancers in HIV patients. Georg Stary said that the findings could also have implications for those who are who are at a greater risk of developing mucosal or skin cancers. Similar issues could be a factor in patients who are immunosuppressed following organ transplantation.