title: Hemophagocytic lymphohistiocytosis in a patient with x-linked lymphoproliferative disease.
abstract: X-linked lymphoproliferative disease (XLP) is a primary immunodeficiency affecting approximately 1 to 3 per million live male births. Patients are generally healthy until facing a viral infection such as Epstein-Barr Virus and then may develop fulminant infectious mononucleosis and die. XLP patients are also at increased risk of hemophagocytic lymphohistiocytosis (HLH), which may be triggered by assorted viruses. Here we report a novel case of HLH in a patient with XLP. Significant to his presentation is a paradoxical increase in natural killer (NK) cell activity. We hypothesize that this indicates that Parvovirus B19 activates NK cells via a signaling lymphocytic activation molecule-associated protein (SAP)-independent mechanism. Our case demonstrates an important etiology to consider in the differential diagnosis of XLP patients with nonfocal findings and febrile illnesses.
authors.affiliation: Allergy and Immunology Section, Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas 77030, USA.
authors.forename: J Andrew
authors.initials: JA
authors.lastname: Bird
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: McClain
authors.forename: Howard M
authors.initials: HM
authors.lastname: Rosenblatt
authors.forename: Stuart L
authors.initials: SL
authors.lastname: Abramson
authors.forename: Imelda C
authors.initials: IC
authors.lastname: Hanson
mesh_terms: D001424:Bacterial Infections / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005334:Fever; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D051359:Lymphohistiocytosis, Hemophagocytic / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D008232:Lymphoproliferative Disorders / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D008297:Male; D009102:Multiple Organ Failure / Q000209:etiology; D010322:Parvoviridae Infections / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D016732:Parvovirus B19, Human / Q000276:immunology* / Q000472:pathogenicity; D010375:Pedigree; D018805:Sepsis / Q000150:complications; D000071179:Signaling Lymphocytic Activation Molecule Associated Protein
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C114953:SH2D1A protein, human; D000071179:Signaling Lymphocytic Activation Molecule Associated Protein