title: Immunoglobulin-like transcripts 6 (ILT6) polymorphism influences the anti-Ro60/52 autoantibody status in South Indian SLE patients.
abstract: BACKGROUND
  Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder with complex etiology. Loss of immune tolerance against self-antigens results in activation of the immune system to produce autoantibodies, which in turn contribute to the clinical manifestations of the disease. Immune cells harbor a plethora of regulatory receptors. Immunoglobulin-like transcripts (ILTs) exhibit both immune activation and inhibitory properties. Genetic defects in genes encoding these receptors may predispose to development of autoimmune diseases secondary to loss of their function. The aim of our study was to analyze the presence or absence of the 6.7 kb segment in the ILT6 gene and its association with susceptibility to SLE and its different manifestations.
  
  
  METHODS
  A total of 188 SLE patients and 192 age-, sex similar-, ethnicity-matched controls were recruited. They were genotyped to test the presence or absence of the 6.7 kb segment of the ILT6 gene by polymerase chain reaction.
  
  
  RESULTS
  The mutant allele lacking the 6.7 kb gene segment had an equal frequency in patients as well as controls (20% and 18%, respectively). The mutant allele was not associated with SLE or its clinical manifestations. However, the mutant allele was associated with the presence of anti-Ro60 (p = 0.0005, OR 3.5, 95% CI 1.8-7.1) and anti-Ro52 (p = 0.0027, OR 2.99, 95% CI 1.5-6.06) autoantibodies.
  
  
  CONCLUSIONS
  ILT6 deletion polymorphism does not appear to be a lupus susceptibility gene in South Indian Tamils, but may behave as a genetic modifier of autoantibody phenotype by influencing the production of anti-Ro60 and anti-Ro52 autoantibodies and thus indirectly contribute to autoimmune responses in SLE.
authors.affiliation: Department of Clinical Immunology.
authors.forename: P
authors.initials: P
authors.lastname: Devaraju
authors.affiliation: Zentrum Innere Medizin, Klinik fur Immunologie und Rheumatologie, Medizinische Hochschule Hannover (MHH), Germany.
authors.forename: T
authors.initials: T
authors.lastname: Witte
authors.affiliation: Zentrum Innere Medizin, Klinik fur Immunologie und Rheumatologie, Medizinische Hochschule Hannover (MHH), Germany.
authors.forename: R E
authors.initials: RE
authors.lastname: Schmidt
authors.affiliation: Genetic Services Unit, Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, India.
authors.forename: R
authors.initials: R
authors.lastname: Gulati
authors.affiliation: Department of Clinical Immunology vsnegi22@yahoo.co.in.
authors.forename: V S
authors.initials: VS
authors.lastname: Negi
mesh_terms: D000328:Adult; D000483:Alleles; D001323:Autoantibodies / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007194:India; D008180:Lupus Erythematosus, Systemic / Q000235:genetics / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011971:Receptors, Immunologic / Q000235:genetics*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; C530062:LILRA3 protein, human; D011971:Receptors, Immunologic
keywords: ILT; ITAM; ITIM; SLE; autoantibodies