title: HLA-G and HLA-E in patients with juvenile idiopathic arthritis.
abstract: OBJECTIVE
  To investigate the expression and release of HLA-G and HLA-E in JIA.
  
  
  METHODS
  Soluble (s)HLA-G and HLA-E were measured in sera from 58 JIA patients and 54 healthy donors. Surface expression of HLA-G, HLA-E and immunoglobulin-like transcript (ILT)2 and ILT4, two receptors for HLA-G, was assessed on T, B cells and monocytes from peripheral blood (PB) and SF of 12 JIA patients and from PB of 12 controls.
  
  
  RESULTS
  Serum sHLA-G concentration was significantly lower in patients than in controls. Both sHLA-G and sHLA-E were detected in SF and sHLA-E concentration in SF was higher in extended oligoarticular/polyarticular than in limited oligoarticular JIA. Patients compared with controls showed: (i) down-regulation of HLA-E and ILT2 expression on T cells; (ii) up-regulation of HLA-E expression on B cells and monocytes; and (iii) down-regulation of ILT4 expression on monocytes. Comparing JIA patients' SF and PB we found: (i) up-regulation of HLA-E and ILT2 expression in T and B cells and monocytes; and (ii) down-regulation of ILT4 expression in monocytes. ILT4 was up-regulated in monocytes from oligoarticular extended/polyarticular compared with oligoarticular limited JIA.
  
  
  CONCLUSIONS
  A lower concentration of sHLA-G in sera may predispose to JIA, as observed for other autoimmune diseases. sHLA-E concentration in SF correlate with the number of affected joints. Higher ILT2 expression on SF cell populations compared with PB may be related to high sHLA-G concentration in SF. Higher HLA-E expression in SF than in PB cell populations may protect them from NK cytolysis.
authors.affiliation: Laboratory of Oncology, G. Gaslini Scientific Institute, Largo G. Gaslini 5, 16148 Genova, Italy.
authors.forename: Ignazia
authors.initials: I
authors.lastname: Prigione
authors.forename: Federica
authors.initials: F
authors.lastname: Penco
authors.forename: Alberto
authors.initials: A
authors.lastname: Martini
authors.forename: Marco
authors.initials: M
authors.lastname: Gattorno
authors.forename: Vito
authors.initials: V
authors.lastname: Pistoia
authors.forename: Fabio
authors.initials: F
authors.lastname: Morandi
mesh_terms: D000293:Adolescent; D015703:Antigens, CD / Q000378:metabolism; D001171:Arthritis, Juvenile / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015536:Down-Regulation; D005260:Female; D059951:HLA-G Antigens / Q000378:metabolism*; D015395:Histocompatibility Antigens Class I / Q000378:metabolism*; D006801:Humans; D007223:Infant; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D007963:Leukocytes, Mononuclear / Q000378:metabolism / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D055815:Young Adult; D000097625:HLA-E Antigens
chemical_list: D015703:Antigens, CD; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D000097625:HLA-E Antigens; C105299:LILRB1 protein, human; C491341:LILRB2 protein, human