title: Detection of Epstein-Barr virus and subsets of lymphoid cells in adenoid tissue of children under 2 years of age.
abstract: Epstein-Barr virus (EBV) has been closely associated with undifferentiated nasopharyngeal carcinoma (NPC) and T/NK nasal non Hodgkin lymphoma. Nevertheless, the presence of EBV in non neoplastic lymphoid tissue of the nasopharynx has been rarely investigated. In a previous study by our group, using in situ hybridization to detect EBV in adenoids of children (2-13 years old) resected because of nasal obstruction due to hypertrophy, we found EBV genome in 72% of the cases. It was now intended to study the frequency of EBV expression in adenoids from children that underwent surgical removal, belonging to a lower age group (1-2 years old). It was also intended to establish which lymphoid subsets are involved in this infection. Adenoidal paraffin sections from 21 patients aged 1-2 years old (mean 1.6 years), 15 males and six females were submitted to double labeling: in situ hybridization with EBER 1/2 probes to detect EBV and immunohistochemistry to determine the lymphocyte typing of EBV-positive cells (CD20 for B-lymphocytes, CD3 for T-lymphocytes and CD56 and CD57 for NK-cells). Among 21 patients, seven showed positive lymphoid cells for EBV (33%). In almost all cases, EBV-positive cells were also CD20-positive. Some EBV-positive cells showed no labeling with any of the lymphoid markers, but in no instance they were positive for CD3, CD56 or CD57. This study confirms the preferential infection of B-lymphocytes by EBV, which in some instances can down regulate the expression of CD20.
authors.affiliation: Department of Otorrhinolaryngology, State University of Campinas, Rua Guilherme da Silva 281, apto 111 Cambuí, Campinas 13025-070, São Paulo, Brazil. luiza_endo@hotmail.com
authors.forename: Luiza H
authors.initials: LH
authors.lastname: Endo
authors.forename: José
authors.initials: J
authors.lastname: Vassallo
authors.forename: Eulália
authors.initials: E
authors.lastname: Sakano
authors.forename: Pierre
authors.initials: P
authors.lastname: Brousset
mesh_terms: D000234:Adenoids / Q000473:pathology / Q000821:virology*; D000367:Age Factors; D018951:Antigens, CD20 / Q000276:immunology; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D019002:CD56 Antigen / Q000276:immunology; D018959:CD57 Antigens / Q000276:immunology; D002675:Child, Preschool; D046508:Culture Techniques; D005260:Female; D004854:Herpesvirus 4, Human / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D018951:Antigens, CD20; D019002:CD56 Antigen; D018959:CD57 Antigens