Antibody to GBV‐C second envelope glycoprotein (anti‐GBV‐C E2): Is it a marker for immunity?

Abstract

The clinical significance of GB virus C (GBV-C E2) antibody is under investigation. The prevalence rates of GBV-C RNA and antibody to GBV-C E2 glycoprotein were determined in a population of 123 Egyptian anti-hepatitis C virus (HCV)-positive patients with chronic liver disease (CLD) who had not been treated previously with interferon. Sera were tested for GBV-C RNA by the LCx assay (Abbott Laboratories, North Chicago, IL), and for GBV-C E2 antibody by enzyme immunoassay. GBV-C RNA was present in 11.4% of patients. GBV-C E2 antibody was detected in 55.9% of GBV-C RNA-negative patients and in 2.2% of GBV-C RNA-positive patients (P = 0.006). GBV-C RNA was associated significantly with a history of schistosomiasis (relative risk [RR] = 5.83, 95% confidence interval [CI] 1.99-17.14, P < 0.005) but not with parenteral risk factors. The presence of GBV-C E2 antibody was not associated with age, gender, parenteral risk factors, schistosomal infection, or HCV viremia. The HCV genotype and level of viremia were similar in GBV-C anti-E2-positive and negative patients. There was a trend toward more severe histological disease with anti-E2 seropositivity (RR = 1.45, 95% CI 0.89-2.45, P = 0.11), an association which was independent of the evidence of schistosomiasis. It is concluded that GBV-C infection is common among HCV-infected Egyptian patients with CLD due to HCV infection. A significant negative correlation between the GBV-C viremia and GBV-C E2 antibody suggests that an antibody response is associated with viral clearance. This antibody response presumably occurs spontaneously, as none of the patients had received antiviral therapy. The unexpected association between GBV-C RNA and schistosomiasis suggests that nonparenteral or occult parenteral routes of GBV-C infection are likely to be important.

GB Virus C/Hepatitis G Virus

“…Blood recipients who received GBV-C:HGV by transfusion from GBV:HGV RNA-positive donors often seroconverted and became anti-GBV-C:HGV E 2-positive after clearing the GBV-C:HGV viremia (35). Thus, the presence of antibodies against the GBV-C:HGV E 2 glycoprotein indicates a past infection (32,(36)(37)(38). However, it has to be considered that the available GBV-C:HGV antibody assays are rst-generation tests and their sensitivity and speci city have not been fully evaluated.…”

GB virus C/hepatitis G virus—is it a novel human ‘hepatitis’ virus?

“…However, unlike in hepatitis C virus, a typical core nucleoprotein seems to be either absent or defective in GBV‐C/HGV [1,6,11,12]. The manner in which this absent or defective core protein influences the pathogenesis of any associated disease is unknown [13].…”

“…Recently, an enzyme‐linked immunosorbent assay (ELISA) for detecting antibodies to a putative GBV‐C/HGV envelope protein (anti‐GBV‐C/HGV E2) has been developed [20,21]. Whether this immunoassay will be useful in diagnosing infection with GBV‐C/HGV, and what the clinical significance is of anti‐GBV‐C/HGV E2 antibody, have still to be determined [13,21,22].…”

Seroprevalence of GB virus C/hepatitis G virus–RNA and anti‐envelope antibody in high‐risk populations in Taiwan

“…Recently, an ELISA assay detecting the antibodies to the E2 protein (anti‐envelope) of GBV‐C/HGV has been developed 21,22 . Although the natural course of GBV‐C/HGV infection is largely unknown, it has been shown that the occurrence of the anti‐envelope antibody is usually associated with the clearance of serum GBV‐C/HGV and indicates recovery from the clinical situation 23–25 . The purpose of the present study was to test the presence of both GBV‐C/HGV‐RNA and anti‐envelope antibody in high‐risk populations in Taiwan and to evaluate the true level of its exposure.…”