Evaluating Kaposi Sarcoma in Kidney Transplant Patients: A Systematic Review and Meta-Analysis.

Kaposi's sarcoma (KS) is a malignancy that commonly appears as lesions on the skin or mucosal surfaces but can also develop in other organs. This cancer is usually caused by the human herpesvirus 8 (HHV-8), recently known as Kaposi's sarcoma-associated herpesvirus (KSHV). KS is rare in the general population but can develop in kidney transplant recipients with varying incidence due to immunocompromised status from immunosuppression. The main aim of the present systematic review was to identify the prevalence and treatment of KS in kidney transplant patients. PubMed, Cochrane Library, and Google Scholar databases were searched for studies until October 2023. Full-text studies with similar research objectives were included, while non-English articles, reviews, case reports, ongoing clinical trials, and studies evaluating KS in HIV patients or after other solid organ transplants were excluded. All studies were observational; therefore, methodological quality was assessed using the Newcastle-Ottawa Scale. The statistical analyses were performed with the Comprehensive Meta-Analysis (CMA) software (Biostat, Inc. Englewood, NJ). The pooled analysis from the 15 studies included showed that KS develops in 1.5% of kidney transplant recipients and is more prevalent in African (1.7%) and Middle Eastern (1.7%) recipients than in Western recipients (0.07%). KS was also significantly more prevalent among male recipients than female recipients (OR: 2.36; p < 0.0001). Additionally, cyclosporine-based immunosuppression accounts for most KS incidences (79.6%) compared to azathioprine-based immunosuppression (28.2%). Furthermore, reduction or withdrawal of immunosuppression alone resulted in 47.8% KS complete remissions. Post-kidney transplantation KS is more frequent among males and patients of Middle Eastern and African origin. However, the gender difference may be attributed to most patients undergoing kidney transplants being male. Therefore, if gender balance is considered in future studies, then the difference might be insignificant. Based on our results, we can concur that the mainstay treatment for post-transplant KS is reduction or withdrawal of immunosuppression. However, the patients should be closely monitored to avoid KS recurrence and kidney rejection. Furthermore, there is an increased risk for KS with the use of cyclosporine-based immunosuppression. However, this does not mean that the withdrawal of this immunosuppression agent might result in improved KS outcomes because the withdrawal of azathioprine with or without cyclosporine reduction has also led to improved outcomes.