Histoplasmosis-Associated Hemophagocytic Lymphohistiocytosis: A Review of the Literature

Background. Histoplasmosis is an endemic fungal disease with diverse clinical presentations. Histoplasmosis-associated hemophagocytic lymphohistiocytosis (HLH) is a rare disorder with limited data regarding treatment and outcome. We described the clinical features, treatment, and outcomes of five patients in our institution with histoplasmosis-associated HLH. This review also summarizes the current literature about presentation, treatment, and outcome of this infection-related HLH entity. Methods. We searched the electronic medical records for patients with histoplasmosis-associated HLH at our institution from 1/1/2006 to 9/30/2017. Diagnosis of HLH was confirmed by chart review using the HLH-04 criteria. We also searched the current literature for case reports and case series. Results. Five cases of histoplasmosis-associated HLH were included from our institution. All five patients were diagnosed after 2010. The literature review yielded 60 additional cases of histoplasmosis-associated HLH. The most common underlying condition was HIV in 61% of cases. The majority of histoplasmosis patients (81%) were treated with amphotericin B formulations. Documented specific treatments for HLH were as follows: nine patients received steroids only, six patients received intravenous immunoglobulin (IVIG) only, three patients received dexamethasone and etoposide, two patients received etoposide, dexamethasone, and cyclosporine, two patients received steroids and IVIG, and one patient received Anakinra and IVIG. The inpatient case fatality rate was 31% with most of the deaths occurring within two weeks of hospital admission. Conclusions. Histoplasmosis-associated HLH among adults is an uncommon but serious complication with high associated mortality. Early antifungal therapy with a lipid formulation amphotericin B is critical. The initiation of immunosuppressive therapy with regimens like HLH-04 in this disease entity should be individualized.