Hemophagocytic lymphohistiocytosis (HLH) is an aggressive and life-threating immune dysregulation syndrome characterized by persistent activation of the mononuclear phagocytic system leading to uncontrolled systemic hyperinflammatory response. The proliferation and activation of histiocytes and lymphocytes lead to production of large amounts of cytokines, also called cytokine storm. Hematopoiet...

The authors describe a rare case of a 27- year old previously healthy male presenting with high grade fever, pancytopenia, hepatosplenomegaly, high levels of ferritin and triglyceride, suggesting a diagnosis of hemophagocytic lymphohistiocytosis (HLH) syndrome. Other investigations showed a positive Leishmania infantum serology and high Epstein-Barr virus (EBV) viremia. The diagnosis of a visce...

EDITORIAL Hemophagocytic lymphohistiocytosis as a possible cause of prolonged fever, splenomegaly, and cytopenia Linfohistiocitosis hemofagocítica como posible cause de fiebre prolongada, espelomegalia y citopenia Hyperinflammatory response may be one of the causes for a long-lasting unexplained fever in children and adults. 1 Clinical syndrome of the exaggerated inflammatory reaction is called...

STUDY PURPOSE Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease of severe hyperinflammation caused by uncontrolled proliferation of activated lymphocytes and macrophages. In this study, we aimed to explore the genetic factors involved in the pathogenesis of both acquired and familial type HLH. METHOD The ION TORRENT semi-conductor sequencing method was used to sequence sa...

introduction hemophagocytic lymphohistiocytosis (hlh) is a heterogeneous group of clinical syndromes characterized by activation and subsequent uncontrolled non-malignant proliferation of t-lymphocytes, histiocytes and macrophages leading to a cytokine storm and manifesting as prolonged fever, organomegaly, cytopenia, hyperferritinemia and demonstrable hemophagocytosis in the bone marrow. concl...

Patients with hemophagocytic lymphohistiocytosis (HLH) exhibit immune hyper-activation as a consequence of genetic defects in secretory granule proteins of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. Murine models of HLH demonstrate significant activation of CTL as central to the disease pathogenesis, but evaluation of CTL and NK activation in children with HLH or inflammatory ...

Dengue, transmitted by the mosquito Aedes aegypti affects millions of people worldwide every year. Dengue induced hemophagocytic lymphohistiocytosis (HLH) is a serious condition and may prove fatal if not detected early and treated appropriately. Diagnosis of HLH is challenging and usually missed as clinical and laboratory findings are nonspecific. Moreover, the pathophysiology of the systemic ...

The impairment of cytotoxic activity of lymphocytes disturbs immune surveillance and leads to the development of hemophagocytic lymphohistiocytic syndrome (HLH). Although cytotoxic T lymphocyte (CTL) control of HLH development is well documented, the role for natural killer (NK)-cell effector functions in the pathogenesis of this immune disorder remains unclear. In this study, we specifically t...

TFE3 is a DNA-binding protein that activates transcription through the muE3 site of the immunoglobulin heavy-chain enhancer. Its amino acid sequence reveals two putative protein dimerization motifs: a helix-loop-helix (HLH) and an adjacent leucine zipper. We show here that both of these motifs are necessary for TFE3 to homodimerize and to bind DNA in vitro. Using a dominant negative TFE3 mutant...

Cell differentiation in the nervous system is dictated by specific patterns of gene expression. We have investigated the role of helix-loop-helix (HLH) proteins during differentiation of PC12 pheochromocytoma cells in response to nerve growth factor. Gel mobility shift assays using PC12 cell nuclear extracts demonstrated that active basic HLH complexes exist throughout differentiation. Addition...