Case of hemophagocytic lymphohistiocytosis with leishmaniasis.

Sir,

Hemophagocytosis is although a common phenomenon observed in bone marrow but at times it is overlooked. It is essential to distinguish whether the hemophagocytosis present in the marrow is only an isolated finding or is associated with hemophagocytic lymphohistiocytosis (HLH) syndrome. HLH requires certain clinical, biochemical and genetic criteria, which are to be fulfilled for its diagnosis.[12] The differentiation of hemophagocytosis triggered due to infection or secondary HLH associated with infection is important as HLH is life threatening condition and only the pathogen directed therapy is usually not sufficient to control severe hyper-inflammation in HLH.[3] The association of HLH with leishmaniasis has been rarely described in the literature, and present report describes it.

A 25-year-old male presented with fever and abdominal distension for last 6 weeks. Ultrasonography of the upper abdomen showed gross spleenomegaly and hepatomegaly. Laboratory investigations revealed pancytopenia with total leukocyte count of 0.84 × 109/L, hemoglobin of 69.6 g/L, total red blood cell count of 2.3 × 1012/L and platelet count of 67 × 109/L. Peripheral blood smear examination revealed predominantly normocytic normochromic erythrocytes with leucopenia and marked neutropenia. The serum aspartate aminotransferase level (50 IU/L) and serum alkaline phosphatase was elevated (234 IU/L) with hyponatremia (131.7 mmol/L). Serum ferritin (750 μg/L) and triglycerides levels (350 mg/dl) were also increased with hypoalbuminemia (1.4 g/dl). The patient was nonreactive for hepatitis B surface antigen and hepatitis C virus antibody. In view of pancytopenia, the patient was subjected to bone marrow examination. Jenner Giemsa stain of bone marrow aspirate smears showed predominantly normoblastic maturation with adequate and functional megakaryocytes. The smears also revealed Leishmania donovani (LD) amastigote forms (LD bodies) along with the phenomenon of hemophagocytosis demonstrating reactive histiocytes containing phagocytosed LD bodies along with phagocytosed leukocytes [Figure 1]. Based on these findings the case was diagnosed as leishmaniasis with HLH syndrome. The patient responded adequately to amphotericin and was later discharged.

Figure 1

Bone marrow aspirate showing phenomenon of hemophagocytosis demonstrating reactive histiocytes containing phagocytosed leukocyte and bodies (Jenner Giemsa; ×1000)

Hemophagocytic lymphohistiocytosis is described as highly stimulated and ineffective immune response that may be familial or acquired and is considered as life-threatening condition.[3] Hypersecretion of pro-inflammatory cytokines such as interferon gamma, tumor necrosis factor alpha, and CD8 T-cells are said to play a crucial role in the pathogenesis of HLH.[34] HLH associated with leishmaniasis is rarely reported in the literature and at times the diagnosis of this association may be challenging.[5] It is necessary to distinguish between leishmaniasis showing hemophagocytosis on bone marrow and a case of secondary HLH with leishmaniasis. Bone marrow examination, which may be at times repeated along with relevant biochemical and laboratory examination, is essential for a definite diagnosis. The early recognition of HLH with leishmaniasis followed by prompt treatment is necessary to avoid poor prognosis of such cases.