title: A Comparative Immunohistochemical Analysis of Langerhans Cells in Oral Mucosa, Oral Lichen Planus and Oral Squamous Cell Carcinoma.
abstract: BACKGROUND
  Langerhans cells (LCs) are immunocompetent cells resident within oral mucosa which, together with intraepithelial lymphocytes, play a role in mucosal defence. LCs play a role in the pathogenesis of Oral lichen planus (OLP), a chronic mucocutaneous disorder thought to result from cell-mediated immune damage. In oral squamous cell carcinoma (OSCC), LCs are thought to present tumour antigens to the lymphocytes.
  
  
  OBJECTIVE
  To assess and compare LCs immuno-histochemically in normal mucosa, oral lichen planus and oral squamous cell carcinoma using anti S100 antibody and to know whether LCs play any role in local immune response to these diseases.
  
  
  METHODS
  The study was carried out in 65 cases (study group), 30 oral lichen planus and 35 oral squamous cell carcinoma (15 well differentiated, 14 moderately differentiated and 6 poorly differentiated), that were randomly selected from the archives of department of oral pathology and along with control group consisting of 30 normal healthy mucosa. The tissue sections were stained immunohisto-chemically by using anti S100 antibody in each group for detection of LCs.
  
  
  RESULTS
  There was significant change in mean value of number of LCs in the study groups i.e. OLP and OSCC when compared to that of control group. The results of our study also revealed that there was decrease in the mean value of langerhans cells as the tumour progressed from well differentiated squamous cell carcinoma to poorly differentiated LCs carcinoma.
  
  
  CONCLUSIONS
  A better understanding and clarity of LCs is pivotal for designing novel or improved therapeutic approaches that will allow proper functioning of LC's in patients with OLP and OSCC, thus significantly reducing the morbidity of OLP and OSCC patients.
authors.affiliation: Senior Lecturer, Department of Oral Pathology, Kamineni Institute of Dental Sciences , Nalgonda,Telangana, India .
authors.forename: Aruna Kumari
authors.initials: AK
authors.lastname: Maloth
authors.affiliation: Senior Lecturer, Department of Oral Pathology, Kamineni Institute of Dental Sciences , Nalgonda,Telangana, India .
authors.forename: Shyam Prasad Reddy
authors.initials: SP
authors.lastname: Dorankula
authors.affiliation: Professor and Head, Mallareddy Dental college for Women's, Suraram Main Road , Jeedimatla, Hyderabad, India .
authors.forename: Ajay Prakash
authors.initials: AP
authors.lastname: Pasupula
authors.affiliation: Reader, Department of Oral Pathology, Lenora Institute of Dental Sciences , NH-16 Rajanagaram, Rajahmundry, East Godavari, Andhra Pradesh, India .
authors.forename: Madhusudan Rao
authors.initials: MR
authors.lastname: Thokala
authors.affiliation: Senior Lecturer, Department of Oral Pathology, Kamineni Institute of Dental Sciences , Nalgonda,Telangana, India .
authors.forename: Keerthi
authors.initials: K
authors.lastname: Muddana
authors.affiliation: IIIyr Post Graduate, Department of Anaesthesia, Kamineni Institute of Dental Sciences , Nalgonda,Telangana, India .
authors.forename: Ravinder
authors.initials: R
authors.lastname: Ramavath
keywords: Antigen presenting cell; Cell mediated immunity; S100