title: Epstein-Barr virus and regulatory T cells in Egyptian paediatric patients with acute B lymphoblastic leukaemia.
abstract: OBJECTIVE
  Acute B lymphoblastic leukaemia (B-ALL) is the most common type of childhood malignancy worldwide but little is known of its origin. Recently, many studies showed both a high incidence of Epstein-Barr virus (EBV) infection and high levels of CD4+CD25+Foxp3+(Treg cells) in children with B-ALL. In our study, we investigated the possible relationship between EBV infection and the onset of B-ALL, and its relation to expression of CD4+, CD25high+Foxp3+ T regulatory cells.
  
  
  METHODS
  We analysed expression and mean fluorescence intensity (MFI) of Treg cells in peripheral blood of 45 children with B-ALL and in 40 apparently healthy children as a control, using flow cytometry. Serum anti-EBV viral capsid antigen (VCA) IgG, anti-EBV nuclear antigen (EBNA) IgG (for latent infection) and anti-EBV VCA IgM (for acute infection) were investigated using ELISA.
  
  
  RESULTS
  Analysis of the Treg cells population in patients and controls revealed that expression of CD4+CD25high+T lymphocytes was higher in patients than in controls (mean±SD 15.7±4.1 and 10.61±2.6 in patients and controls, respectively, and MFI of Foxp3 was 30.1±7.1 and 16.7±3.7 in patients and controls, respectively (p<0.001)). There was a high incidence of latent EBV infection in patients (31%) compared with controls (10%) while the incidence of acute infection was 12% in patients and 0% in the control group. To study the role of latent EBV infection in the pathogenesis of acute B-ALL, OR was calculated (OR=4.06, coefficient index 1.2-13.6).
  
  
  CONCLUSIONS
  These findings suggest a possible role for Treg cells and EBV in the pathogenesis of B-ALL. Further studies are needed on the possible mechanisms of tumour genesis related to Treg cells and EBV in children with B-ALL.
authors.affiliation: Department of Clinical Pathology, Faculty of Medicine, Zagazig University, Zagazig, Sharkia, Egypt.
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: Ateyah
authors.affiliation: Department of Clinical Pathology, Faculty of Medicine, Zagazig University, Zagazig, Sharkia, Egypt.
authors.forename: Mona E
authors.initials: ME
authors.lastname: Hashem
authors.affiliation: Department of Paediatrics, Faculty of Medicine, Zagazig University, Zagazig, Sharkia, Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdelsalam
mesh_terms: D002648:Child; D002675:Child, Preschool; D004534:Egypt; D020031:Epstein-Barr Virus Infections / Q000276:immunology* / Q000473:pathology / Q000821:virology; D019309:Epstein-Barr Virus Nuclear Antigens / Q000276:immunology; D005260:Female; D004854:Herpesvirus 4, Human; D006801:Humans; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology* / Q000473:pathology / Q000821:virology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000473:pathology / Q000821:virology
chemical_list: D019309:Epstein-Barr Virus Nuclear Antigens
keywords: ALL; EBV; LEUKAEMIA