Hemophagocytic lymphohistiocytosis and visceral leishmaniasis in children: a series of cases and literature review.

Objective: Hemophagocytic lymphohistiocytosis syndrome (HLHS) is characterized by an immunological hyperactivation of cytotoxic T cells, natural killer cells, and macrophages, leading to the secretion of proinflammatory cytokines. HLHS associated with Visceral Leishmaniasis might be difficult to diagnose once symptoms are similar, resulting in the death of untreated patients. Our aim is to describe a series of cases of Visceral Leishmaniasis with HLHS admitted to a referral hospital for infectious diseases.
Case Description: All 115 cases of Visceral Leishmaniasis referred to a referral center for pediatric infectious diseases were reviewed to identify the cases of HLHS. Five cases (4.5%) were confirmed with HLHS and they presented fever, splenomegaly, cytopenia, hypertriglyceridemia or hypofibrinogenemia, increased ferritin and hemophagocytosis in the bone marrow.
Comments: It important to rule out HLHS in children with infectious diseases that do not respond adequately to treatment or in patients with severe symptoms, especially in leishmaniasis endemic areas.