Perforin gene (PRF1) mutations cause the primary form of hemophagocytic lymphohistiocytosis (HLH). We report a genetic defect of PRF1 in a 62-year-old Japanese man with recurrent episodes of HLH. Sequencing of PRF1 from both peripheral blood mononuclear cells and nail clippings showed compound heterozygous mutation, including deletion of two base pairs at codons 1090 and 1091 (1090-1091delCT) a...

Hemophagocytic lymphohistiocytosis (HLH) is a rare but life-threatening syndrome resulting from excessive immune activation. Secondarily, HLH is often associated with autoimmune disease, infection, and malignancy. The most common infectious trigger is Epstein-Barr virus (EBV) infection. HLH is rarely triggered by parvovirus B19. We discuss a case of a 62-year-old male who presented with multi-o...

Hemophagocytic lymphohistiocytosis (HLH) in immunocompromised hosts is a fulminant syndrome of immune activation with high rates of mortality that may be triggered by infections or immunodeficiency. Rapid diagnosis and treatment of the underlying disorder is necessary to prevent progression to multiorgan failure and death. We report a case of HLH in a patient with human immunodeficiency virus, ...

Hemophagocytic lymphohistiocytosis (HLH) is an aggressive inflammatory syndrome that results from inappropriate activation of the immune system. HLH has a high mortality if not treated. We describe a case of a fulminant HLH, associated with a reactivation of an EBV infection. The patient responded well to steroid treatment.

The Caenorhabditis elegans pharynx (or foregut) functions as a pump that draws in food (bacteria) from the environment. While the "organ identity factor" PHA-4 is critical for formation of the C. elegans pharynx as a whole, little is known about the specification of distinct cell types within the pharynx. Here, we use a combination of bioinformatics, molecular biology, and genetics to identify ...

Background: Scrub typhus is a mite-borne bacterial infection caused by Orientia tsutsugamushi. Hemophagocytic lymphohistiocytosis (HLH) is a potential severe complication. Most reported cases of HLH associated with scrub typhus were single cases or case series with a small sample sizes. Thus, no clear consensus exists on clinical manifestations and differences between pediatric and adult cases ...

BACKGROUND Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome that is often fatal despite treatment. It is caused by a dysregulation in natural killer T-cell function, resulting in activation and proliferation of histiocytes with uncontrolled hemophagocytosis and cytokines overproduction. The syndrome is characterized by fever, hepatosplenomegaly, cytopenias, liver dysfunction, and hyp...

There is a paucity of literature addressing infection-related morbidity and mortality in children with primary hemophagocytic lymphohistiocytosis (HLH), a rare condition characterized by abnormal proliferation of macrophages, hypercytokinemia, and T cell immunosuppression. Therefore, a retrospective chart review was done of patients diagnosed with primary HLH over a 15-year period. Significant ...

Introduction Haemophagocytic lymphohistiocytosis (HLH) is a severe condition in which there is extreme uncontrolled inflammation, and may progress rapidly to multi-organ failure and death. HLH may be genetic (primary HLH), or secondary to infection or autoimmune/ autoinflammatory conditions; if the latter, it is also referred to as macrophage activation syndrome (MAS). Distinguishing between pr...

RATIONALE Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease entity primarily described in children, but not less relevant in adults. It is characterized by a misdirected activation of the immune system, resulting in an uncontrolled cytokine release from macrophages and cytotoxic T-cells (CTLs). Primary HLH relies on a genetic predisposition, whereas secondary HLH develops i...