AIDS-related Kaposi's sarcoma: principal pathogenic mechanisms.

Kaposi's sarcoma (KS) is the most common malignancy that affects patients with HIV infection. Considerable progress has recently been achieved in understanding the pathogenesis of this vascular malignancy. A novel herpesvirus has been detected in KS lesions of all types, in skin-lesions of post-transplant immunosuppressed individuals and in various lymphoproliferative disorders. Apart from this, the increased severity of this neoplasm in patients infected with HIV may be due to HIV-derived tat protein synergising with cytokines and chemokines with angiogenetic activity. Finally, the lower incidence of the malignancy in females may be related to a protective effect of human chorionic gonadotrophin (HCG), presumably mediated by its effect on microvasculature. All these advances suggest new possibilities in the management of the disease.