title: Atypical Clinical Course in Pediatric Hodgkin Lymphoma: Association With Germline Mutations in Interleukin-2-inducible T-Cell Kinase.
abstract: BACKGROUND
  Inherited or acquired immune dysregulation is associated with increased risk of lymphoproliferative disorders (LPDs), including classic Hodgkin lymphoma (cHL). A germline mutation in interleukin-2-inducible T-cell kinase (ITK) is described in individuals manifesting B-cell LPDs, cHL, and hemophagocytic syndromes following Epstein-Barr virus (EBV) infection.
  
  
  METHODS
  We report a novel ITK mutation in a child with EBV-associated cHL and multiple-site reactive polyclonal B-cell hyperplasia followed by relapsed cHL at another site. Following relapse, the child was successfully treated with allogeneic hematopoietic stem cell transplantation and EBV cytotoxic T cells.
  
  
  CONCLUSIONS
  ITK-mutated T cells cause a defective antiviral immune response and the resulting immune dysregulation can lead to EBV-associated polyclonal hyperplasia with subsequent outgrowth of neoplastic B-cell clones, which in some instances may progress to LPDs, including cHL.
authors.affiliation: *Division of Pediatric Hematology/Oncology/Stem Cell Transplantation †Department of Pathology and Cell Biology, Columbia University Medical Center, NY Presbyterian Hospital, New York, NY.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Alme
authors.forename: Prakash
authors.initials: P
authors.lastname: Satwani
authors.forename: Bachir
authors.initials: B
authors.lastname: Alobeid
authors.forename: Govind
authors.initials: G
authors.lastname: Bhagat
authors.forename: Kara M
authors.initials: KM
authors.lastname: Kelly
mesh_terms: D002675:Child, Preschool; D020031:Epstein-Barr Virus Infections / Q000150:complications; D005260:Female; D018095:Germ-Line Mutation; D018380:Hematopoietic Stem Cell Transplantation; D006689:Hodgkin Disease / Q000235:genetics* / Q000628:therapy; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000628:therapy; D011505:Protein-Tyrosine Kinases / Q000235:genetics*
chemical_list: D011505:Protein-Tyrosine Kinases; C080813:emt protein-tyrosine kinase