VANCOUVER, BC--Human herpesvirus-8 (HHV-8), also known as Kaposi's
sarcoma-associated herpesvirus or KSHV, appears to be linked to
the development not only of Kaposi's sarcoma (KS) but also to
a newly identified type of AIDS lymphoma, Alexandra Levine, MD,
said at an educational symposium at the 11th International Conference
Cytokine production also appears to be an important factor in
both KS and AIDS lymphomas, added Dr. Levine, head of the Department
of Hematology, University of Southern California.
New Picture of Kaposi's Sarcoma
Certain HLA types such as HLA-DQ1 are highly associated with KS
in HIV-infected persons, Dr. Levine said in her review of current
knowledge of KS pathogenesis. Hormonal factors may also have a
role, since KS is basically a disease of men. "Over the course
of HIV infection, about 40% of gay or bisexual men will be diagnosed
with KS, as opposed to 11% of heterosexual men and 2% of women,"
she said. This might reflect sexual exposure to HHV-8.
The HIV tat gene may be the initiating factor transforming a normal
mesenchymal cell, presumably of endothelial vascular origin, into
a tumor phenotype, Dr. Levine said. HIV also induces inflammatory
cytokine production by infected lymphocytes and monocytes.
"The growth of the tumor is augmented by the inflammatory
cytokines made by HIV-infected cells. Once the KS cell exists,
it is able to make its own growth factors in an autocrine fashion,"