Assessment of total hepatitis C virus (HCV) core protein in HCV-related mixed cryoglobulinemia
1 Liver Unit, Division of Internal Medicine and Clinical Oncology, University of Bari “Aldo Moro”, Bari, Italy
2 Laboratory of General Pathology and Experimental Oncology, University of Bari “Aldo Moro”, Bari, Italy
3 Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro”, Bari, Italy
4 C.U.R.E. Centre for Liver Diseases Research and Treatment, Institute of Internal Medicine, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy
Arthritis Research & Therapy 2014, 16:R73 doi:10.1186/ar4513Published: 18 March 2014
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.
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.
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.
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.