title: Epstein-Barr virus (EBV) positive classical Hodgkin lymphoma of Iraqi children: an immunophenotypic and molecular characterization of Hodgkin/Reed-Sternberg cells.
abstract: BACKGROUND
  Classical Hodgkin lymphoma (cHL) in children is often associated with EBV infection, more commonly in developing countries.
  
  
  METHODS
  Here we describe the histological, immunohistochemical, and molecular features of 57 cases of HL affecting Iraqi children under 14 years of age.
  
  
  RESULTS
  Histologically, 51 cases were classified as cHL of Mixed Cellularity and Nodular Sclerosis subtypes (MC = 69%; NS = 31%), and 6 cases as Nodular Lymphocyte Predominant HL (NLP-HL). EBV infection of H/RS cells was demonstrated in 44 of 51 cases of cHL (86%), and was more common in MC than in NS (97% vs. 63%; P = 0.0025). The immunophenotypic profile of H/RS cells was similar in MC and NS, and was not influenced by EBV infection; H/RS cells were consistently positive for PAX-5 and to a lesser degree for other B cell markers including CD20/CD79a, OCT-2, and BOB-1. Clonal IGH rearrangements were detected in 14 of 38 cHL (37%), with no significant difference between MC and NS cases, and with no association with the EBV status. Oligoclonal/monoclonal TCRγ rearrangements were present in 28 of 38 cases (74%), suggestive of restricted T cell responses.
  
  
  CONCLUSIONS
  Our findings indicate that cHL occurring in Iraqi children is characterized by immunohistochemical and molecular features undistinguishable from those present in cHL occurring elsewhere in the world. Moreover, the high incidence of EBV-infected H/RS cells and frequent occurrence of restricted T cell responses might be indicative of a defective local immune response perhaps related to the very young age of the children.
authors.affiliation: Department of Clinical and Molecular Medicine, Pathology Unit, Sant'Andrea Hospital, Sapienza University, Roma, Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Di Napoli
authors.forename: Mazin F
authors.initials: MF
authors.lastname: Al-Jadiri
authors.forename: Caterina
authors.initials: C
authors.lastname: Talerico
authors.forename: Enrico
authors.initials: E
authors.lastname: Duranti
authors.forename: Emanuela
authors.initials: E
authors.lastname: Pilozzi
authors.forename: Pankaj
authors.initials: P
authors.lastname: Trivedi
authors.forename: Eleni
authors.initials: E
authors.lastname: Anastasiadou
authors.forename: Adel R
authors.initials: AR
authors.lastname: Alsaadawi
authors.forename: Amir F
authors.initials: AF
authors.lastname: Al-Darraji
authors.forename: Salma A
authors.initials: SA
authors.lastname: Al-Hadad
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Testi
authors.forename: Stefania
authors.initials: S
authors.lastname: Uccini
authors.forename: Luigi
authors.initials: L
authors.lastname: Ruco
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D020031:Epstein-Barr Virus Infections / Q000150:complications* / Q000276:immunology; D005260:Female; D006689:Hodgkin Disease / Q000276:immunology / Q000473:pathology / Q000821:virology*; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D017403:In Situ Hybridization; D007493:Iraq; D008297:Male; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D016539:Reed-Sternberg Cells / Q000276:immunology / Q000473:pathology* / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta
keywords: Epstein-Barr virus (EBV); Hodgkin lymphoma; IGH gene rearrangement; Iraqi children; TCRγ gene rearrangement; restricted T cell response