title: Multiplex serum protein analysis reveals potential mechanisms and markers of response to hyperimmune caprine serum in systemic sclerosis.
abstract: Hyperimmune caprine serum (HICS) is a novel biological therapy with potential benefit for skin in established diffuse cutaneous systemic sclerosis. Here we report multiplex protein analysis of blood samples from a placebo-controlled phase II clinical trial and explore mechanisms of action and markers of response.
  
  
  
  Patients were treated with HICS (n = 10) or placebo (n = 10) over 26 weeks, with follow-up open-label treatment to 52 weeks in 14 patients. Serum or plasma samples at baseline, 26 and 52 weeks were analysed using multiplex or individual immunoassays for 41 proteins. Patterns of change were analysed by clustering using Netwalker 1.0, Pearson coefficient and significance analysis of microarrays (SAM) correction.
  
  
  
  Cluster analysis, SAM multiplex testing and paired comparison of individual analytes identified proteins that were upregulated or downregulated during treatment with HICS. There was upregulation of the hypothalamo-pituitary-adrenal axis after HICS treatment evidenced by increases in α-MSH and ACTH in cases treated with HICS. Interestingly, significant increase in PIIINP was associated with HICS treatment and improved MRSS suggesting that this may be a marker of extracellular matrix turnover. Other relevant factors reduced in HICS-treated patients compared with controls, although not reaching statistical significance included COMP, CCL2, IL6, TIMP2, Fractalkine and TGFβ1 levels.
  
  
  
  Our results suggest mechanisms of action for HICS, including upregulation of α-MSH, that has been shown to be anti-fibrotic in preclinical models, and possible markers to be included in future trials targeting skin in diffuse cutaneous systemic sclerosis.
  
  
  
  Eudract, No. 2007-003122-24. ClinTrials.gov, No. NCT00769028 . Registered 7 October 2008.
authors.affiliation: Centre for Rheumatology, UCL Division of Medicine, Royal Free Campus, Rowland Hill Street, London, NW3 2PF, UK.
authors.forename: Niamh
authors.initials: N
authors.lastname: Quillinan
authors.affiliation: Centre for Rheumatology, UCL Division of Medicine, Royal Free Campus, Rowland Hill Street, London, NW3 2PF, UK.
authors.forename: Kristina E N
authors.initials: KE
authors.lastname: Clark
authors.affiliation: Department of Neurophysiology, Royal Free London NHS Foundation Trust, London, UK.
authors.forename: Bryan
authors.initials: B
authors.lastname: Youl
authors.affiliation: Daval International, London, UK.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Vernes
authors.affiliation: Daval International, London, UK.
authors.forename: Deirdre
authors.initials: D
authors.lastname: McIntosh
authors.affiliation: Daval International, London, UK.
authors.forename: Syed
authors.initials: S
authors.lastname: Haq
authors.affiliation: Centre for Rheumatology, UCL Division of Medicine, Royal Free Campus, Rowland Hill Street, London, NW3 2PF, UK. c.denton@uc.ac.uk.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Denton
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D015415:Biomarkers / Q000097:blood*; D001798:Blood Proteins / Q000627:therapeutic use*; D005260:Female; D006041:Goats; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D045743:Scleroderma, Diffuse / Q000097:blood* / Q000188:drug therapy*; D012867:Skin
chemical_list: D015415:Biomarkers; D001798:Blood Proteins; D007155:Immunologic Factors
keywords: Biomarker; Clinical trial; Goat serum; Melanocortin; Scleroderma