Human Immunodeficiency Virus (HIV)

The first opportunistic infection from HIV was found in 1981. The causative agent was found in 1983. HIV is most commonly associated with opportunistic infection due to immunodeficiency; but this immunodeficiency is also associated with an increase risk of developing many other malignancies. The most striking are Kaposi sarcoma, Burkitt and other non-Hodgkin's lymphoma, and Hodgkin's lymphoma. Other malignancies, often due to co-infection with HPV, are also more common (cervical cancer, anal cancer).

General Features of HIV

HIV is a retrovirus that predominately infects CD4+ T lymphocytes. It is transmitted sexually (most commonly during receptive anal intercourse), parenterally (most commonly by sharing needles) or vertically (most common in Africa). Male circumcision is protective.

AIDS defining malignancies

Aquired ImmunoDeficiency Syndrome occurs with low CD4 counts, symptomatic disease, or development of an AIDS defining condition. Several of these are malignancies, including Kaposi sarcoma, Burkitt lymphoma and cervical cancer.

Pathogenesis

Kaposi Sarcoma

Kaposi sarcoma is 1000 times more common in HIV infected individuals, although the incidence is decreasing with more effective antiretroviral agents. It requires co-infection with HHV8 or Kaposi sarcoma herpes virus, which is most common in those of African descent and then in Mediterranean populations. Infection of other Caucasian populations is uncommon. Treatment depends on extent of disease; local therapy with radiation is most appropriate for local disease alone in well controlled HIV or for symptomatic lesions in patients with poor life expectancy.

Lymphoma

HIV is particularly associated with the development of CNS lymphoma (3,600 fold increase) and Burkitt lymphoma (200-600 fold increase). DLBCL represents the other common malignancy; Hodgkin's disease is also more common. Treatment depends on the control of HIV; most patients are suitable for full dose treatment. CNS lymphoma is more frequently treated with whole brain radiotherapy than in non-HIV associated cases.

Other Malignancies

Many other malignancies are more frequent with HIV infection:

  • Anal cancer is 40-80 times more common
  • Cervical intraepithelial neoplasia is more common and cervical cancer in HIV positive patients is thought to be more aggressive
  • Leiomyosarcoma of the gastrointestinal tract is more frequent, particularly in children infected vertically at birth

Summary

HIV is associated with a broad spectrum of malignancies due to its immunosuppressive properties. The most commonly seen malignancies are Kaposi sarcoma, B-cell lymphoma (particularly CNS and Burkitt lymphoma), and to a lesser extent cervical cancer and anal cancer. These malignancies are mostly associated with infection with other viruses (HHV8, EBV and HPV respectively). Treatment is similar to non-HIV positive patients due to the effectiveness of antiretroviral agents.


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