Kaposi's sarcoma following living donor kidney transplantation: review of 7,939 recipients

Kaposi's sarcoma (KS) is one of the most common tumors to occur in kidney recipients, especially in the Middle East countries. Limited data with adequate sample size exist about the development of KS in living kidney recipients.Therefore, we made a plan for a multicenter study, accounting for up to 36% (n = 7,939) of all kidney transplantation in Iran, to determine the incidence of KS after kidney transplantation between 1984 and 2007.Fifty-five (0.69%) recipients who developed KS after kidney transplantation were retrospectively evaluated with a median follow-up of 24 (1-180) months. KS occurred more often in older age when compared to patients without KS (49 +/- 12 vs. 38 +/- 15 years, P = 0.000). KS was frequently found during the first 2 years after transplantation (72.7%). Skin involvement was universal. Furthermore, overall mortality rate was 18%, and it was higher in patients with visceral involvement compared to those with mucocutaneous lesions (P = 0.01). However, KS had no adverse affect on patient and graft survival rates compared to those without KS. Forty-four patients with limited mucocutaneous disease and four with visceral disease responded to withdrawal or reduction of immunosuppression with or without other treatment modalities. Renal function was preserved when immunosuppression was reduced instead of withdrawn in patients with and without visceral involvement (P = 0.001 and 0.008, respectively).The high incidence of KS in this large population studied, as compared to that reported in other transplant patient groups, suggests that genetic predisposition may play a pathogenetic role.