Supplementary Material for: Kaposi’s Sarcoma in a kidney transplant recipient: A case report on Paclitaxel response

Introduction In immunocompromised individuals, particularly organ transplant recipients, the risk of developing Kaposi sarcoma (KS) increases significantly due to prolonged immunosuppressive therapy. The onset of post-transplant KS is highly variable, though most cases occur within the first two years following transplantation. The effectiveness and safety of systemic therapies in the management of post-transplant KS are not well established. In this report, we describe a rare case of early-onset KS in a Tunisian kidney transplant recipient, revealed by deep vein thrombosis just six months after transplantation, and successfully managed with paclitaxel as first-line therapy. Case Presentation We present the case of a 52-year-old Tunisian male who underwent a living-donor kidney transplant in June 2022. Six months after transplantation, the patient presented with deep vein thrombosis, and large purplish plaques were observed on the anterior left thigh. A skin biopsy confirmed the diagnosis of KS. Further investigations revealed systemic involvement. The patient was treated with paclitaxel-based chemotherapy in combination with sirolimus and a reduction in immunosuppressive therapy. As of November 2024, the patient had demonstrated marked clinical improvement, with resolution of KS lesions and stable renal function. Conclusion This case of early-onset Kaposi sarcoma highlights the potential effectiveness of paclitaxel-based chemotherapy combined with sirolimus and a carefully adjusted reduction in immunosuppressive therapy as a promising first-line treatment option.