A Fatal Case of Kaposi Sarcoma Immune Reconstitution Syndrome (KS-IRIS) Complicated by Kaposi Sarcoma Inflammatory Cytokine Syndrome (KICS) or Multicentric Castleman Disease (MCD): A Case Report and Review.

BACKGROUND Kaposi Sarcoma Inflammatory Cytokine Syndrome (KICS) is a relatively new syndrome described in patients co-infected with Human Immunodeficiency Virus (HIV) and Kaposi Sarcoma (KS) Herpes Virus (KSHV). KICS clinically resembles Multicentric Castleman disease (MCD) and both present with various degrees of lymphadenopathy, pancytopenia, HIV and KSHV viremia, and signs of systemic inflammatory syndrome (SIRS). KICS has higher mortality than MCD and is rarely recognized. Lymph node, bone marrow, or splenic biopsy can help differentiate between the 2 entities. CASE REPORT We present a case of a 28-year-old African American man with advanced acquired immunodeficiency syndrome (AIDS) who was diagnosed with disseminated pulmonary and cutaneous KS. Following initiation of combined antiretroviral therapy (cART), rapid immunologic recovery occurred followed by rapid clinical deterioration (IRIS) with multiorgan failure, overwhelming SIRS, and ultimately death. The patient's symptoms, signs, and laboratory findings during this episode could not be solely explained by KS-IRIS, and MCD versus KICS was diagnosed. CONCLUSIONS SIRS in patients with uncontrolled HIV viremia and CD4 lymphopenia has a broad differential diagnosis, including infectious and noninfectious causes. It encompasses sepsis due to common bacterial pathogens, various HIV-specific opportunistic infections, immunological conditions such as hemophagocytic lymphohistiocytosis (HLH), and IRIS, malignancies such as primary effusion lymphoma (PEL) and MCD, and finally KCIS. Clinicians involved in treatment of these patients should have a high index of suspicion for less-known and recently described syndromes such as KICS to recognize it early and initiate timely treatment, which might improve the high mortality associated with KICS.