title: Innate immunity alterations in idiopathic interstitial pneumonias and rheumatoid arthritis-associated interstitial lung diseases.
abstract: BACKGROUND
  This is a prospective cohort study elucidating innate immunity in idiopathic pulmonary fibrosis (IPF), cryptogenic organizing pneumonia (COP), rheumatoid arthritis-associated usual interstitial pneumonia (RA-UIP) and RA-associated non specific interstitial pneumonia (RA-NSIP).
  
  
  METHODS
  23 IPF subjects, 9 COP subjects, 5 RA-UIP subjects, 8 RA-NSIP subjects were enrolled. 10 subjects were excluded. 19 healthy subjects served as controls. Blood and bronchoalveolar lavage (BAL) were obtained. Natural killer (NK) and NKT cells, NK cells apoptosis and the expression of triggering receptor expressed on myeloid cells type 1 (TREM-1) were assessed. Tumor necrosis factor-α (TNF-α) production was measured in cell cultures after stimulation with lipopolysaccharide endotoxin (LPS) and Pam3CysSK3, and in BAL. Surface expression of Toll-like receptors (TLR) 2 and 4 on peripheral blood monocytes (PBMC's) and circulating NK cells was also assessed.
  
  
  RESULTS
  RA-NSIP had low blood NKs, marginally insignificant (p=0.07). These NKs poorly produced TNF-α after LPS stimulation. TLR's expression on NK cells was similar throughout disease groups and controls. PBMC's mainly from IPF patients exhibited low TNF-α production after LPS stimulation but not after Pam3CysSK3 stimulation, while TLR4 expression on PBMC's was found normal in all study groups. TLR2 expression on PBMC's was increased in IPF, but mainly in COP, RA-UIP and RA-NSIP (p=0.015). TREM-1 expression was significant on COP monocytes and on COP neutrophils versus controls. RA-NSIP monocytes also exhibited TREM-1 expression (p=0.07). Decreased TNF-α concentration in BAL was finally observed in IPF and RA-UIP.
  
  
  CONCLUSIONS
  Innate immunity in the lungs and the peripheral circulation in IPF and RA-UIP are similar and more fibrotic than in RA-NSIP which is characterized by NK cell depletion and dysfunction. TREM-1 and TLR's likely affect patterns of inflammation in various interstitial lung diseases.
authors.affiliation: 3rd Pulmonary Department, Sismanoglion General Hospital, Sismanogliou 1, 15126 Attica, Greece. Electronic address: ipapanikolaou76@hotmail.com.
authors.forename: Ilias C
authors.initials: IC
authors.lastname: Papanikolaou
authors.affiliation: Rheumatology Department, Sismanoglion General Hospital, Sismanogliou 1, 15126 Attica, Greece. Electronic address: kboki@otenet.gr.
authors.forename: Kyriaki A
authors.initials: KA
authors.lastname: Boki
authors.affiliation: 4th Department of Internal Medicine, ATTIKON University General Hospital, Rimini 1, 12462 Attica, Greece. Electronic address: egiamarel@med.uoa.gr.
authors.forename: Evangelos J
authors.initials: EJ
authors.lastname: Giamarellos-Bourboulis
authors.affiliation: 4th Department of Internal Medicine, ATTIKON University General Hospital, Rimini 1, 12462 Attica, Greece. Electronic address: antigonebut@yahoo.com.
authors.forename: Antigoni
authors.initials: A
authors.lastname: Kotsaki
authors.affiliation: 3rd Pulmonary Department, Sismanoglion General Hospital, Sismanogliou 1, 15126 Attica, Greece. Electronic address: konstantinos.kagouridis@gmail.com.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kagouridis
authors.affiliation: 3rd Pulmonary Department, Sismanoglion General Hospital, Sismanogliou 1, 15126 Attica, Greece. Electronic address: nap@karagianidis.gr.
authors.forename: Napoleon
authors.initials: N
authors.lastname: Karagiannidis
authors.affiliation: 3rd Pulmonary Department, Sismanoglion General Hospital, Sismanogliou 1, 15126 Attica, Greece. Electronic address: vlasispo@hotmail.com.
authors.forename: Vlasis S
authors.initials: VS
authors.lastname: Polychronopoulos
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000276:immunology* / Q000378:metabolism; D007113:Immunity, Innate / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008168:Lung / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D017563:Lung Diseases, Interstitial / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism; D008875:Middle Aged; D055611:Natural Killer T-Cells / Q000276:immunology / Q000378:metabolism; D011446:Prospective Studies; D011658:Pulmonary Fibrosis / Q000276:immunology / Q000378:metabolism; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000276:immunology / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000276:immunology / Q000378:metabolism; D000073871:Triggering Receptor Expressed on Myeloid Cells-1; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000378:metabolism
chemical_list: D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D000073871:Triggering Receptor Expressed on Myeloid Cells-1; D014409:Tumor Necrosis Factor-alpha
keywords: Innate immunity; Interstitial lung diseases; Natural killer cells; Rheumatoid arthritis; Toll-like receptors; Triggering receptor expressed on myeloid cells 1