Kaposi's sarcoma in renal transplant patients: experience at the Cruces Hospital in Bilbao

BACKGROUND: Kaposi's sarcoma (KS) in renal transplant recipients (RTRs) probably arises from a complex interplay of multiple factors. OBJECTIVE: In order to analyze the prevalence of KS in patients transplanted at the Cruces Hospital in Bilbao, together with their clinical features, treatment, and etiologic factors, we performed a study using the registry of RTRs in our center. METHODS: The records of 1,230 kidney transplant patients at the Cruces Hospital between 1979 and 1998 were reviewed. Immunosuppressive therapy was reduced once a diagnosis of KS was made. A nested polymerase chain reaction was used to detect human herpesvirus 8 (HHV-8) DNA in the biopsy tissue. The DNA was extracted from fresh tissue (n = 2) or from formalin-fixed, paraffin-embedded specimens (n = 5). RESULTS: Six cases of KS were diagnosed. All patients with cutaneous KS improved with a reduction in immunosuppressive drugs. HHV-8 was detected in 100% (2/2) of the frozen biopsies and 20% (1/5) of the formalin-fixed samples investigated. CONCLUSIONS: Our experience indicates that a continuous state of immunodeficiency is important for the development of KS in RTRs. The association, previously described between HHV-8 and transplant-associated KS, also exists in the studied population.