Hemophagocytic lymphohistiocytosis associated with Leishmania: A hidden passenger in endemic areas.

Abstract Introduction Hemophagocytic lymphohistiocytosis (HLH) is an aggressive and life-threatening syndrome characterized by excessive immune activation. We analyzed the presentation, diagnosis and prognosis of our cohort of HLH-Leishmania cases. Methods We studied HLH cases in patients over 14 years of age in the province of Granada (Spain), from January 2008 to November 2019. Results In this study, Leishmania was the predominant trigger of adult HLH in our region. There were no differences in the clinical-analytical presentation between HLH triggered by Leishmania and those initiated by a different cause. RT-PCR was the best tool to identify Leishmania as the trigger of HLH, given that the other microbiological tests showed low sensitivity to detect the parasite in our HLH-Leishmania cases. Conclusion A comprehensive search for Leishmania is mandatory in HLH cases. Based on our findings, we propose that RT-PCR for Leishmania in bone marrow samples must be included in HLH differential diagnostic protocols.