Elevated IL-13 in effusions of patients with HIV and primary effusion lymphoma as compared with other Kaposi sarcoma herpesvirus-associated disorders

OBJECTIVE To assess the cytokine and viral profiles of effusions and peripheral blood among patients diagnosed with HIV and Kaposi sarcoma herpesvirus [KSHV, also known as human herpesvirus 8 (HHV-8)]-associated conditions. DESIGN Retrospective comparative study evaluating clinicopathologic findings in patients with HIV and KSHV-associated conditions presenting with an effusion between 2010 and 2018. METHODS Paired peripheral blood and effusion samples collected at the time of pathological diagnosis of KSHV-associated conditions [Kaposi sarcoma, KSHV-associated multicentric Castleman disease (KSHV-MCD), primary effusion lymphoma (PEL), or KSHV-associated inflammatory cytokine syndrome (KICS)] were evaluated for disease-specific and compartment-specific (effusion vs. blood) characteristics. We assessed 12 cytokines, KSHV viral DNA (KSHV-VL), and Epstein--Barr virus (EBV) viral DNA (EBV-VL). RESULTS Nine patients had PEL, five patients had KSHV-MCD, and eight patients met criteria for KICS; all but one patient had concurrent Kaposi sarcoma in addition to these conditions. PEL effusions had substantially higher levels of IL-13 (median 16.9 pg/ml; interquartile range 9.7--26.9 pg/ml) compared with KSHV-MCD (median