Background: Herpesvirus-like DNA sequences have been found in lesions from patients with Kaposi's sarcoma in its several forms, suggesting that this tumor may be caused by a new herpesvirus, referred to as Kaposi's sarcoma-associated herpesvirus or human herpesvirus 8.
Methods: We analyzed DNA from skin and lung lesions, healthy skin, and peripheral blood mononuclear cells of three heart transplant recipients with Kaposi's sarcoma. We also studied DNA from normal skin and from peripheral blood of Kaposi's sarcoma-free heart transplant recipients. Samples were analyzed by polymerase chain reaction with specific primers to amplify the KS 330 sequence.
Results: The KS 330 fragment was found in Kaposi's sarcoma tissue of all three patients, in normal skin of one of them, and in peripheral blood of two. It was not detected in any of the samples from skin or peripheral blood of heart transplant recipients not affected by Kaposi's sarcoma. DNA extracted from a peripheral blood sample of one patient before transplantation showed that the KS 330 sequence was already detectable at that time.
Conclusions: These findings suggest that Kaposi's sarcoma-associated herpesvirus may play a significant role in the pathogenesis of all forms of Kaposi's sarcoma. The development of the tumor in transplant recipients may be related, at least in some cases, to transplantation-associated immunosuppression, rather than to the acquisition of the virus from the donor.