Paediatric Hemophagocytic Lymphohistiocytosis: A Case Series With a Diverse Spectrum From a Resource-Limited Setting

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome characterized by cytokine storms leading to multi-organ dysfunction and is a highly fatal disease. Infectious diseases are the most common cause of secondary HLH. A wide variety of infections can lead to secondary HLH. In this case series, we report five cases of HLH which had different therapeutic approaches and varied clinical courses, with one of them diagnosed as a rare entity of coronavirus disease 2019 (COVID-19)-associated HLH of multisystem inflammatory syndrome in children (MISC) spectrum, one case each of idiopathic HLH, staphylococcal infection-associated secondary HLH, leptospirosis with secondary HLH and dengue-associated HLH. The case of idiopathic HLH required initiation of immunosuppressive therapy but had a fatal outcome while others were treated successfully with antibiotics, steroids, intravenous immunoglobulin and supportive therapy. Our case series highlights the importance of evaluating for all possible infective causes thoroughly in HLH. Most patients can be managed without chemotherapy by treating the secondary causes of HLH, including common tropical infections and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Keywords: dengue associated hlh; hemophagocytic lymphohistiocytosis; idiopathic hlh; infection associated hlh; leptospirosis associated hlh; pediatric; sars-cov-2 associated hlh; secondary hlh.

Figure 1. Bone marrow aspiration of case 1 showing histiocytes with engulfed cells inside (black arrow)

Figure 2. Bone marrow aspirate smear showing histiocyte with phagocytic activity in a hemorrhagic background in case 2 (black arrow)

Giemsa stain, 40X

Figure 3. Bone marrow aspirate smear of case 5 showing histiocyte with active phagocytosis (black arrow)

Giemsa stain, 40X