Role of the Immune System in AIDS-defining Malignancies

Abstract

The Center for Disease Control and Prevention considers AIDS-defining illnesses Kaposi’s sarcoma, non-Hodgkin’s lymphoma and cervical cancer. These cancers have higher incidence in HIV-infected individuals than in the general population. Additionally, cancers’ clinical courses in HIV-positive individuals are increasingly aggressive when compared to those in HIV-negative patients. It is thus compelling to further understand the dynamics of AIDS-related cancer growth. We propose a non-integer order model to describe the role of the immune system in cancer cells’ growth in a HIV-infected individual. The model incorporates anti-retroviral therapy and chemotherapy. We simulate the model for different proliferation functions of the cytotoxic T lymphocytes (CTLs), and other parameters, namely the HIV-infection rate, the elimination rate of infected T cells by CTLs, and the elimination rate of cancer cells by the immune system and discuss the results from a physiological perspective. The order of the fractional derivative completes the discussion of the results.