330. Survival of HIV-Positive Patients with Hemophagocytic Lymphohistiocytosis

Background Hemophagocytic lymphohistiocytosis (HLH) is a rare but life-threatening disorder resulting from dysregulated cytokine production. The diagnosis of HLH requires five of eight abnormalities: fever, splenomegaly, bicytopenia, hypertriglyceridemia and/or hypofibrinogenemia, hyperferritinemia, hemophagocytosis on biopsy, low or absent NK cell activity, or elevated soluble CD25. The link between Human Immunodeficiency Virus (HIV) and HLH is incompletely understood; we sought to further define the characteristics and outcomes of this patient population. Methods We performed a retrospective study on HLH patients with and without concurrent HIV infection treated at our institution from January 2008 to July 2018. At the time of HLH diagnosis, we extracted data on the HIV status and associated malignancies. The primary outcome was overall survival from time of diagnosis of HLH in patients with HIV vs. those without HIV. Secondary analysis was performed with survival by HIV and malignancy status. Survival was analyzed by Kaplan–Meier curves with hazard ratios calculated using the log-rank test with significance set at P ≤ 0.05. Results Forty-three patients were included; 11 had HIV at the time of diagnosis of HLH and all met criteria for AIDS at time of inclusion. Patients with HIV who were diagnosed with HLH had similar survival compared with patients without HIV (Hazard ratio for death (HR) 0.87 [95% confidence interval (CI) 0.37–2.904]). All patients with malignancy had a worse survival (HR for death 3.648 [95% CI 1.804–9.169] P = 0.0009), regardless of HIV status. HLH in HIV patients with malignancy resulted in a trend toward worse survival (HR = 3.86 95% CI 1.09–22.60, P = 0.0578) compared with those without malignancy, although the limited number of patients prohibits a definitive conclusion. In HIV-negative patients, the presence of malignancy is associated with worse survival (HR 3.56 [95% CI 1.475–10.11] P = 0.0063). Conclusion In this retrospective, single-institution review of HLH patients, HIV was not associated with worse overall survival compared with patients without HIV. The presence of malignancy resulted in worse survival in the overall population. Further investigation is needed to optimize the care of these patients. Disclosures All authors: No reported disclosures.