Essential cryoglobulinemia is closely associated with hepatitis C virus (HCV). The mechanism responsible for occurrence of the disease is unclear however.
A study by members of the Sapporo City General Hospital Department of Gastroenterology, Sapporo, Japan, has therefore investigated potential pathogenic roles of HCV in cryoglobulinemia.
A total of 167 consecutive patients with HCV were studied clinically by HCV grouping, HCV RNA levels, GBV-C/HGV, HCV quasispecies and HLA polyporphism.
In the case of HCV quasispecies, the target region was hypervariable region-1, with quasispecies in cryoprecipitate being compared to those in supernatant.
The results of HLA polymorphisms of patients with cryoglobulinemia were compared with patients without the disease and with healthy controls.
The research team found that HCV-related cryoglobulinemia was present in 71 of 167 patients (43%) within the study population.
Patients with cirrhosis (36 of 63, 57%) suffered from cryoglobulinemia more frequently, compared to those with chronic hepatitis (35 of 104, 34%, with and without cryoglobulinemia).
| Liver disease is a pathogenic factor associated with cryoglobulinemia.|
|Journal of Medical Virology|
No significant differences were found between the two groups (patients with and without cryoglobulinemia) when evaluated by age, gender, HCV grouping, HCV RNA level, or frequency of GBV-C/HGV.
However, HCV was found quantitatively and clonally more frequently in the cryoprecipitate, than in the supernatant.
The researchers also found that HLA polymorphism presented no significant differences among three groups.
A. Nagasaka, speaking of behalf of his fellow authors, said the study suggested that the stage of liver disease is one of the pathogenetic factors associated with cryoglobulinemia.
He added, "The greater presence of HCV quasispecies in cryoprecipitate, rather than in the supernatant, indicates that various antigen presentations play an important role in the formation of cryoglobulin.
"However, HLA typing does not seem to contribute to the development of cryoglobulinemia."