title: Associations of killer cell immunoglobulin like receptors with rheumatoid arthritis among North Indian population.
abstract: BACKGROUND
  Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory disease of unknown etiology. Killer cell immunoglobulin-like receptors (KIR) expressed on surface of natural killer cells and CD28 null T-cells which are present in synovial membrane of RA. The present study has evaluated associations of KIR genes with RA among North Indian population from Uttar Pradesh.
  
  
  METHODS
  KIR genotypes were determined in 100 RA cases and 100 healthy controls using sequence specific primer polymerase chain reaction (PCR-SSP) method.
  
  
  RESULTS
  RA cases positive for KIR3DS1 (OR = 1.17, p-value = 0.0498) and KIR2DS2 (OR = 2.21, p-value = 0.0120) showed risk associations. While, KIR2DL2 (OR = 0.40, p-value = 0.0026), KIR2DL3 (OR = 0.44, p-value = 0.0283) and KIR3DL1 (OR=0.32, p-value = 0.0012) showed protective associations. Increased incidence of BB genotype (45%) was revealed among cases. Risk association was noted against telomeric region (OR = 2.12, p = 0.0120) genes for RA. Pair-wise linkage disequilibrium (LD) analysis among RA cases revealed KIR2DS1-2DL1 (D' = 0.83, r(2) = 0.36), KIR3DL1-3DS1 (D' = 1, r(2) = 0.58) and KIR2DL1-2DL2 (D' = 1, r(2)=0.61) to be in significant LD. KIR3DS1 and KIR2DS3 genes showed significant risk associations among RA patients with extra-articular manifestations (OR = 5.14, p-value = 0.0018; OR = 3.79, p-value = 0.0106) and in limited range of motion in affected joints (OR = 14.91, p-value = 0.0001; OR = 2.95, p-value=0.0126).
  
  
  CONCLUSIONS
  The KIR activating genes have risk association with RA in the present study.
authors.affiliation: Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raibareily Road, Lucknow, Uttar Pradesh, India.
authors.forename: Swayam
authors.initials: S
authors.lastname: Prakash
authors.affiliation: Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raibareily Road, Lucknow, Uttar Pradesh, India.
authors.forename: Shahnawaz
authors.initials: S
authors.lastname: Alam
authors.affiliation: Margaret M. and Albert B. Alkek Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, United States.
authors.forename: Uddalak
authors.initials: U
authors.lastname: Bharadwaj
authors.affiliation: Department of Immunology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raibareily Road, Lucknow, Uttar Pradesh, India.
authors.forename: Amita
authors.initials: A
authors.lastname: Aggarwal
authors.affiliation: Department of Immunology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raibareily Road, Lucknow, Uttar Pradesh, India.
authors.forename: Ram Nath
authors.initials: RN
authors.lastname: Mishra
authors.affiliation: Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raibareily Road, Lucknow, Uttar Pradesh, India. Electronic address: sur_ksha_agrawal@yahoo.co.in.
authors.forename: Suraksha
authors.initials: S
authors.lastname: Agrawal
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D015870:Gene Expression; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007194:India; D007694:Killer Cells, Natural / Q000276:immunology* / Q000473:pathology; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D020033:Protein Isoforms / Q000235:genetics / Q000276:immunology; D054340:Receptors, KIR / Q000235:genetics* / Q000276:immunology; D013583:Synovial Membrane / Q000276:immunology* / Q000473:pathology
chemical_list: D020033:Protein Isoforms; D054340:Receptors, KIR
keywords: Autoimmune disease; Genetic association; Killer immunoglobulin like receptor (KIR); Polymerase chain reaction-sequence specific primer (PCR-SSP); Rheumatoid arthritis (RA)