Kaposi's sarcoma in different populations in South Africa

Patients with Kaposi's sarcoma (13 black and 5 white heterosexuals and 2 homosexuals with the acquired immunodeficiency syndrome (AIDS)) were investigated clinically, histologically, serologically and immunologically. Clinically, lymph node involvement was present in 9 of the 13 black heterosexuals, but was not seen in the other two groups. Oedema, which was seen in 13 of the 14 black patients, was only present in 1 white patient. The lesions were of the nodular cutaneous type except in the AIDS patients who presented with plaque-like lesions. Whereas all non-AIDS patients were negative for HTLV-III antibodies, both AIDS patients were positive and showed a marked cell-mediated immune (CMI) deficiency. Only 1 heterosexual white and 4 heterosexual black patients had some degree of CMI deficiency. South Africans with Kaposi's sarcoma do not have significant underlying immunodeficiency or associated opportunistic infections. No serological or electron microscopic evidence was found to support the aetiological role of cytomegalovirus in Kaposi's sarcoma. The findings suggest that the cell of origin of this tumour is the vascular endothelial cell.