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

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.