Incidence and clinical predictors of Kaposi's sarcoma among 1721 Italian solid organ transplant recipients: a multicenter study

Kaposi's sarcoma (KS) can be a complication of solid organ transplantation but with an important incidence rate variability in different geographical areas. Here we analyzed the incidence rate, timing and clinical correlates of KS, in a cohort of Italian solid organ transplant recipients from four distinct transplantation centers. A total of 1721 renal, heart and liver transplant recipients were recruited between 1997 and 2004. KS was diagnosed in 40 patients, after a median follow up of 1 year (range 0.8-5.1). Visceral involvement was detected in 7/40 patients. Incidence rate of KS in the whole population was 2.3 cases per 1000 individuals per year. The standardized incidence rate (SIR) for KS, in renal transplant recipients was 149.9 (95% Cl 103.0-212.0), with the excess risk greater among women (SIR 316.0) than among men (SIR 133.6). In a Cox proportional hazard regression model, age at transplantation equal or older than 30 years and only combined immunosuppressive therapy with mycophenolate mofetil + cyclosporine + prednisolone were independently associated with KS. Italian organ transplant recipients have an increased risk (about 100 times greater) for KS compared to the general population, especially during the first two years after transplantation. Age older than 30 years at transplantation and a more aggressive immunosuppressive regimen were both independent risk factors the disease.