Kaposi Sarcoma Inflammatory Cytokine Syndrome in an HIV-Positive Kidney Transplant Patient

Introduction: Kaposi sarcoma (KS) is a malignancy that typically appears as skin or mucosal lesions but can develop in other organs. HHV-8 is an oncogenic herpes virus that causes KS. KS is rare but can develop in HIV+ and kidney transplant (KT) patients. A highly fatal presentation is Kaposi Sarcoma Inflammatory Cytokine Syndrome (KICS), which causes multisystem organ failure. Case Description: A 39 year old male with HIV on ART (CD4 <50 cells/mm3, viral load undetectable) and ESKD status post living donor kidney transplant one year prior (CMV +/+, EBV +/+) presented with febrile illness, acute kidney injury (AKI) and pancytopenia. Prior induction was thymoglobulin and maintenance immunosuppression (IS) was belatacept (due to CNI toxicity), mycophenolate and prednisone; tacrolimus was recently discontinued. Extensive infectious evaluation revealed CMV and EBV viremia, treated with valganciclovir. His condition deteriorated and he developed shock and acute hypoxic respiratory failure requiring mechanical ventilation. Due to persistent cytopenias, bone marrow biopsy was done which showed metastatic KS. HHV-8 returned at 505,000 copies/mL and IL-6 at 183 pg/mL. He was treated with rituximab and liposomal doxorubicin; HHV-8 and IL-6 levels rose, so Tocilizumab was added. IS was changed to sirolimus. AKI required continuous renal replacement therapy. He developed ARDS and died after two months. Discussion: There is an increased incidence of KS in HIV+ patients as well as KT recipients. There is no consensus guidance regarding HHV-8 screening in the pre or post transplant period in HIV+ KT recipients. Reduction in IS and transition to sirolimus have been associated with KS regression, while the role for antiviral therapy is uncertain. KICS should be considered in at-risk patients with shock, respiratory failure, cytopenias and elevated inflammatory markers. In our patient, this catastrophic syndrome manifested prior to diagnosis of KS becoming evident, as he had no cutaneous lesions and KS was only identified on bone marrow biopsy. Optimal treatment for KICS is uncertain and may include chemotherapeutic and immunomodulatory drugs. It is associated with a high mortality rate, underscoring the importance of consideration of an HHV-8 screening strategy, as well as awareness of this condition among transplant nephrologists.