title: Hydrogen sulfide acts as a pro-inflammatory mediator in rheumatic disease.
abstract: OBJECTIVE
  Hydrogen sulfide (H2S) is a gaseous mediator produced in the body. In experimental models, endogenously produced H2S has been shown to have pro-inflammatory effects. The aim of this study was to investigate whether H2S is present in three common rheumatic diseases, rheumatoid arthritis (RA), gout and osteoarthritis (OA) and to determine if H2S levels correlate with disease activity.
  
  
  METHODS
  Patients with RA, gout, OA, and healthy controls (n = 30 each) were recruited. Plasma and where possible, synovial fluid (SF), were obtained. Levels of H2S and interleukin-6 (IL-6) (a known inflammatory marker as a positive control) were determined and assessed for their relationship with disease activity.
  
  
  RESULTS
  SF-H2S levels were significantly elevated in both RA and gout when compared to respective plasma levels. Plasma levels of H2S were not different from those in healthy controls in patients with either RA or gout. In OA, plasma levels of H2S were significantly elevated compared to healthy controls. In RA, SF-H2S levels correlated with Disease Activity Score (DAS)-28 and tender joint count.
  
  
  CONCLUSIONS
  H2S is present in the joint and acts as a pro-inflammatory mediator in rheumatic diseases. H2S may be a novel therapeutic target for these conditions.
authors.affiliation: Department of Pathology, University of Otago, Christchurch, New Zealand.
authors.forename: Nethaji
authors.initials: N
authors.lastname: Muniraj
authors.affiliation: Department of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Stamp
authors.affiliation: Department of Pathology, University of Otago, Christchurch, New Zealand.
authors.forename: Alireza
authors.initials: A
authors.lastname: Badiei
authors.affiliation: Department of Pathology, University of Otago, Christchurch, New Zealand.
authors.forename: Akhil
authors.initials: A
authors.lastname: Hegde
authors.affiliation: Department of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Vicky
authors.initials: V
authors.lastname: Cameron
authors.affiliation: Department of Pathology, University of Otago, Christchurch, New Zealand.
authors.forename: Madhav
authors.initials: M
authors.lastname: Bhatia
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D006073:Gout / Q000097:blood* / Q000175:diagnosis; D006801:Humans; D006862:Hydrogen Sulfide / Q000097:blood*; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000097:blood* / Q000175:diagnosis; D012720:Severity of Illness Index; D013582:Synovial Fluid / Q000737:chemistry*
chemical_list: D015415:Biomarkers; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D006862:Hydrogen Sulfide
keywords: disease activity; gout; hydrogen sulfide; inflammation; interleukin-6; rheumatoid arthritis