title: TNF-alpha Production by Peripheral Blood Monocytes in Multiple Sclerosis Patients and Healthy Controls.
abstract: BACKGROUND
  Aberrant immune responses are evident in the pathogenesis of multiple sclerosis (MS) and it has been proposed that the spectrum of cytokines influence disease outcomes. Leptin and lipopolysaccharide (LPS) of Gram-negative bacteria are both potent cellular stimulators for production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α). The aim of this study was to compare the TNF-α production by peripheral blood monocytes from MS patients with healthy controls.
  
  
  METHODS
  Peripheral blood samples were stimulated with LPS or leptin. After blocking the Golgi apparatus, intracellular cytokine production was assessed using a monoclonal antibody against human TNF-α by the flow cytometry technique. Moreover, plasma level measurement of cytokines was performed using enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  Intracellular levels of TNF-α were 16.80 ± 8.21 and 16.52 ± 8.23in MS patients and healthy controls which showed no statistically significant difference between them (p = 0.850). Leptin-stimulated and LPS-stimulated TNF-α production showed no significant difference between MS patients and the control group (p = 0.263 and p = 0.191, respectively). However, after treatment with leptin, a weak significant difference was shown between cases and control group (p = 0.049). There were significant differences between cases and controls regarding serum levels of IL-6 and Toll-like receptor-4 (TLR-4) before and after stimulation with leptin and LPS, separately (p < 0.05).
  
  
  CONCLUSIONS
  Taken together, we cannot definitely conclude that TNF-α does not play an important role in pathogenesis of MS. However, other characteristics of monocyte activation such as IL-6 or TLRs can elucidate implication of peripheral blood monocytes in MS pathogenesis.
authors.affiliation: Department of Neurology, School of Medicine, Isfahan University of Medical Sciences , Isfahan , Iran .
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Farrokhi
authors.forename: Masoud
authors.initials: M
authors.lastname: Etemadifar
authors.forename: Maryam Sadat
authors.initials: MS
authors.lastname: Jafary Alavi
authors.forename: Sayyed Hamid
authors.initials: SH
authors.lastname: Zarkesh-Esfahani
authors.forename: Mohaddeseh
authors.initials: M
authors.lastname: Behjati
authors.forename: Ali
authors.initials: A
authors.lastname: Rezaei
authors.forename: Ali
authors.initials: A
authors.lastname: Amani-Beni
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D009000:Monocytes / Q000276:immunology*; D009103:Multiple Sclerosis / Q000276:immunology*; D051197:Toll-Like Receptor 4 / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000276:immunology*; D055815:Young Adult
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha
keywords: Flow cytometry; leptin; multiple sclerosis; tumor necrosis factor-alpha