title: Detection of Epstein-Barr Virus DNA in Langerhans Cell Histiocytosis.
abstract: BACKGROUND
  Langerhans cell histiocytosis (LCH) is a rare histiocytic proliferation of unknown etiology. It is characterized by granuloma-like proliferation of Langerhans-type dendritic cells and mainly affects young children. Although multiple investigators have suggested the possible role of viruses, such as Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6), Herpes simplex virus (HSV) types 1 and 2, and Cytomegalovirus (CMV) in the pathogenesis of LCH, it remains, however, debated.
  
  
  OBJECTIVE
  The EBV infection is reported to be associated with LCH. Nevertheless, no report could be found about involved Iranian children in English medical literature. In this study, we investigated the presence of EBV in Iranian children with LCH.
  
  
  METHODS
  In this retrospective study, in which we investigated the prevalence of presence of EBV DNA in LCH, using paraffin-embedded tissue samples of 30 patients with LCH and 30 age and tissue-matched controls, who were operated for reasons other than infectious diseases (between the years 2002 and 2012), by real-time polymerase chain reaction (RT-PCR) method, in the department of pediatric pathology. No ethical issues arose in the study, because only the pathology reports were reviewed, retrospectively, and the patients were anonymous.
  
  
  RESULTS
  There was a significant difference in prevalence of EBV presence between patients and controls. The EBV was found by RT-PCR in 19 (63.33%) out of 30 patients and only in eight (26.7%) of 30 control samples. The P = 0.004, was calculated using chi-square test (OR: 4.75; 95% CI: 1.58 ‒ 14.25).
  
  
  CONCLUSIONS
  Our study is the first investigation performed on patients with LCH and its possible association with EBV in Iran. Considering the P = 0.004, which is statistically significant, the findings do support the hypothesis of a possible role for EBV in the pathogenesis of LCH. These results are in accordance with several previous investigations, with positive findings.
authors: Department of Pathology, Pediatric Pathology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors: Maliheh
authors: M
authors: Khoddami
authors: Virology Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors: Seyed Alireza
authors: SA
authors: Nadji
authors: Department of Pathology, Pediatric Infectious Disease Research Center, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors: Paria
authors: P
authors: Dehghanian
authors: Department of Pathology, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors: Mahsa
authors: M
authors: Vahdatinia
authors: Department of Community Oral Health, Dental Research Center, Dentistry Research Institute, School of Dentistry, Tehran University of Medical Sciences, Tehran, IR Iran.
authors: Ahmad Reza
authors: AR
authors: Shamshiri
keywords: Cell Proliferation; Dendritic Cells; Epstein-Barr Virus Infections; Histiocytosis; Langerhans-Cell; Polymerase Chain Reaction