title: Vitamin D status does not predict sustained virologic response or fibrosis stage in chronic hepatitis C genotype 1 infection.
abstract: OBJECTIVE
  The relationship between vitamin D status and response to antiviral therapy and liver histology in hepatitis C virus genotype 1 (HCV-1) infection remains unclear, with studies to date yielding inconsistent results and failing to use reference assay methodology. We therefore analyzed pre-treatment 25-hydroxyvitamin D [25(OH)D] level, using reference liquid chromatography-tandem mass spectrometry methodology, in a cohort of treatment-naïve patients with HCV-1 to evaluate the association between vitamin D status, virologic response, and liver histology.
  
  
  METHODS
  274 patients, with pre-treatment liver biopsy and up to 48 weeks of pegylated interferon alfa-2a plus ribavirin therapy, were tested for serum 25(OH)D level. Predictors of sustained virologic response (SVR), and variables associated with fibrosis stage, activity grade and 25(OH)D status were identified using multivariate analysis.
  
  
  RESULTS
  Mean 25(OH)D level was 79.6 nmol/L, with a prevalence of 25(OH)D <75 nmol/L and <50 nmol/L of 48% and 16%, respectively. Season, race and geographic latitude were independent predictors of 25(OH)D status, while vitamin D deficiency was more prevalent in those with high activity grade (21% vs. 11%; p=0.03). Mean 25(OH)D level was lower (76.6 vs. 84.7 nmol/L; p=0.03) and 25(OH)D <75 nmol/L more prevalent (53% vs. 40%; p=0.03) in patients with an SVR, but no association between 25(OH)D status and SVR was found in multivariate analysis. Mean 25(OH)D level did not vary between fibrosis stage or activity grade.
  
  
  CONCLUSIONS
  Baseline 25(OH)D level is not independently associated with SVR or fibrosis stage in HCV-1, but vitamin D deficiency is associated with high activity grade.
authors.affiliation: Alfred Hospital, Melbourne, Australia.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Kitson
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Dore
authors.forename: Jacob
authors.initials: J
authors.lastname: George
authors.forename: Peter
authors.initials: P
authors.lastname: Button
authors.forename: Geoffrey W
authors.initials: GW
authors.lastname: McCaughan
authors.forename: Darrell H G
authors.initials: DH
authors.lastname: Crawford
authors.forename: William
authors.initials: W
authors.lastname: Sievert
authors.forename: Martin D
authors.initials: MD
authors.lastname: Weltman
authors.forename: Wendy S
authors.initials: WS
authors.lastname: Cheng
authors.forename: Stuart K
authors.initials: SK
authors.lastname: Roberts
mesh_terms: D000328:Adult; D004359:Drug Therapy, Combination; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000145:classification*; D019698:Hepatitis C, Chronic / Q000097:blood / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D016898:Interferon-alpha / Q000008:administration & dosage; D008099:Liver / Q000473:pathology; D008103:Liver Cirrhosis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000008:administration & dosage; D011994:Recombinant Proteins / Q000008:administration & dosage; D012254:Ribavirin / Q000008:administration & dosage; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D016898:Interferon-alpha; D011994:Recombinant Proteins; D014807:Vitamin D; D011092:Polyethylene Glycols; D012254:Ribavirin; C104450:25-hydroxyvitamin D; C100416:peginterferon alfa-2a