Zein, Nizar N.

ABSTRACTBackground:The cause of fulminant hepatic failure in children remains unknown, but a viral origin has been suspected in most cases. The recently discovered blood‐borne virus, hepatitis G, has been suggested as a possible causative agent.Method:Six consecutive children who underwent liver transplantation for fulminant hepatic failure were studied. The children were tested for hepatitis G virus antibodies and hepatitis G virus RNA by polymerase chain reaction after excluding other causes of fulminant hepatic failure.Results:No evidence of hepatitis G virus infection was found in these patients.Conclusion:Hepatitis G virus is unlikely to be a common cause of fulminant hepatic failure in pediatric patients from the upper midwestern United States.

A second-generation recombinant immunoblot assay (RIBA 2.0) is used in the United States to confirm infection with hepatitis C virus (HCV) in samples that are anti-HCV (enzyme immunoassay) positive. In some cases, indeterminate results of RIBA 2.0, which are defined as reactivity to a single antigen species or reactivity limited to two proteins derived from the same coding region of the HCV genome, are encountered. This study was performed to establish the significance of indeterminate RIBA 2.0 results in relation to HCV RNA detection, high positivity for the c22-3 band, and the HCV genotype as determined by direct DNA sequencing. Ninety-six samples with indeterminate RIBA 2.0 results were studied. HCV RNA was detected in 21 of 34 (62%) samples with high reactivity to c22-3 and in 8 of 62 (13%) samples with low reactivity to c22-3. The HCV genotype distribution in samples that were RIBA 2.0 indeterminate and HCV RNA positive was significantly different from that in samples of a control group with positive results for both the RIBA 2.0 and HCV PCR. These results suggest that highly positive c22-3 samples are likely to be associated with HCV viremia and that infection with less common HCV genotypes is more commonly associated with indeterminate RIBA 2.0 results.

SUMMARYOn the basis of phylogenetic analysis of nucleotide sequences, multiple genotypes and subtypes of hepatitis C virus (HCV) have been identified. Characterization of these genetic groups is likely to facilitate and contribute to the development of an effective vaccine against infection with HCV. Differences among HCV genotypes in geographic distributions have provided investigators with an epidemiologic marker that can be used to trace the source of HCV infection in a given population. HCV genotype 1 may represent a more aggressive strain and one that is less likely to respond to interferon treatment than HCV genotype 2 or 3. However, these observations require confirmation before HCV genotyping can be used in clinical settings.

Ethnic differences in the outcome of hepatitis C have been described. Our aim was to investigate ethnic differences in the distribution of genotypes associated with polymorphisms of the tumor necrosis factor-α promoter, interleukin-10 promoter, and transforming growth factor-β1 leader sequence in patients with hepatitis C. Genomic DNA was obtained from 71 Egyptians and 67 Caucasians (hepatitis C and control patients). Amplification of appropriate gene segments was followed by direct sequencing. Infrequently occurring polymorphisms were identified at positions −244 and −77 of the tumor necrosis factor-α promoter and at positions −851 and −657 of the interlukin-10 promoter. The G/A genotype associated with tumor necrosis factor-α promoter positions −376 and −244 was more frequent in Egyptians (P =0.001 and P =0.004, respectively). The −244 G/A genotype occurred only in healthy Egyptians (P =0.024). Thus, ethnic differences in the distribution of genotypes of the tumor necrosis factor-α promoter exist, which may have clinical implications on the outcome of hepatitis C.