title: Assessment of total hepatitis C virus (HCV) core protein in HCV-related mixed cryoglobulinemia.
abstract: BACKGROUND
  In hepatitis C virus (HCV)-related mixed cryoglobulinemia (MCG), the nonenveloped HCV core protein (HCV-Cp) is a constituent of the characteristic cold-precipitating immune complexes (ICs). A possible correlation between HCV-Cp, virologic, laboratory, and clinical parameters in both untreated MCG patients and those undergoing specific treatment was explored.
  
  
  METHODS
  HCV-Cp was quantified by a fully automated immune assay. Correlations between HCV-Cp and HCV RNA, cryocrit, and virus genotype (gt) were investigated in 102 chronically HCV-infected MCG patients.
  
  
  RESULTS
  HCV-Cp concentrations strongly correlated with HCV RNA levels in baseline samples. An average ratio of 1,425 IU and 12,850 IU HCV RNA per picogram HCV-Cp was estimated in HCV gt-1 and gt-2 patients, respectively. This equation allowed us to estimate that, on average, HCV-Cp was associated with the viral genome in only 3.4% of the former and in 35% of the latter group of patients. The direct relation between HCV-Cp and the cryocrit level suggests that the protein directly influences the amount of cryoprecipitate. Although the therapy with rituximab (RTX) as a single agent resulted in the enhancement of HCV-Cp levels, in patients treated with RTX in combination with a specific antiviral therapy (pegylated interferon-α plus ribavirin), the prompt and effective clearance of HCV-Cp was documented.
  
  
  CONCLUSIONS
  Our data provide evidence that HCV-Cp has a direct effect on the cold-precipitation process in a virus genotype-dependence in HCV-related MCG patients.
authors.forename: Sabino
authors.initials: S
authors.lastname: Russi
authors.forename: Domenico
authors.initials: D
authors.lastname: Sansonno
authors.forename: Maria Addolorata
authors.initials: MA
authors.lastname: Mariggiò
authors.forename: Angela
authors.initials: A
authors.lastname: Vinella
authors.forename: Fabio
authors.initials: F
authors.lastname: Pavone
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Lauletta
authors.forename: Silvia
authors.initials: S
authors.lastname: Sansonno
authors.forename: Franco
authors.initials: F
authors.lastname: Dammacco
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003449:Cryoglobulinemia / Q000821:virology*; D005260:Female; D016174:Hepacivirus / Q000737:chemistry*; D006526:Hepatitis C / Q000150:complications*; D006801:Humans; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D014758:Viral Core Proteins / Q000032:analysis*
chemical_list: D014758:Viral Core Proteins