Kaposi's sarcoma is the most common neoplasm affecting AIDS patients, affecting almost 20% of patients with AIDS, who are not on Anti retroviral therapy (ART). KS is characterized by purple or bluish-red lesions, which are actually vascular channels, filled with blood and cancer cells. These lesions initially appear on the feet or ankles, thighs, arms, hands, face, lining of the mouth, nose and throat, and later spread on to the lungs and other vital organs. Aggressive forms of the disease are capable of spreading to the bones, whereas some other fatal forms spread through the lymph nodes to vital organs. Infection with Human Herpes Virus-8 (HHV-8) is the most important factor in the development of Kaposi's sarcoma. In fact, infection with HHV-8 increases the risk of developing KS by almost 12 times. Co-infection with HIV further, dramatically increases the risk of KS.
Studies indicate that Kaposi's sarcoma is a monoclonal neoplasm, in which multicentric tumors originate from a single clone of precursor cells. The presence of this disease in men more than women indicates a hormonal nature in its epidemiology. Various studies have revealed that HIV and HIV-encoded products interact with human cells to produce immune cytokines, the most prominent of them being IL-6.
Ahmed et al. (2001) undertook a retrospective review of 57 patients (52 males, 5 females; age range: 15 to 62 years) with Endemic Kaposi's sarcoma (EKS). In addition, 40 prospectively diagnosed patients with and without HIV infection were also studied. A total of 26 patients (24 males, 2 females) in this group were found to have EKS, while 14 (11 males, 3 females) were found to have AIDS associated Kaposi's sarcoma (AAKS).
Hale and Kelly (1998) described an 82-year old female born to Lebanese non-consanguineous parents who was diagnosed with Kaposi's sarcoma. A male and female sibling had previously been disgosed with Kaposi's sarcoma. HLA typing showed the presence of A2, A3, B35, Bx, Bw6, Cw4, DRB1*1101, DRB3, and DQB1*0301 alleles.
Mohsin et al. (2005) reported the successful treatment of the first patient in the Middle East with post transplant cutaneous and visceral Kaposi sarcoma after the conversion of cyclosporine-based to sirolimus-based immunosuppression regimen. The patient was a 48-year old Omani male who was on an immunosuppression regimen following a living-unrelated kidney transplant. Kaposi sarcoma was diagnosed 13 months after transplantation.
Sabeel et al. (2003) retrospectively assessed the prevalence of KS in 30 Sudanese renal transplant recipients followed for 16 years. Four HIV-negative patients (13.3%) developed KS within 4-36 months after transplantation. Sabeel et al. (2003) suggested that high incidence of KS in Sudanese renal transplant recipients could be linked to racial or geographic factors.