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 1230 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.