Prevalence of hepatitis-C virus RNA in serum and throat washings of children with chronic hepatitis

Serum samples from 46 children with chronic and probably transfusion acquired hepatitis were tested for the presence of hepatitis C virus (HCV) RNA by a “nested” polymerase chain reaction (PCR) assay, to judge a possible risk of HCV transmission from these patients. In 73% of the samples, viral RNA was detected, indicating a high virus prevalence in this patient group. High titers of HCV-RNA were observed in some sera as shown by the detection of virus in some samples even at dilutions of 10^?3. Comparison of simultaneously obtained PCR results and ALT values revealed no significant correlation between virus presence in serum and higher ALT levels. It was, however, shown that unusually high ALT values may reflect a high titer of viral RNA in serum. To investigate the prevalence of viral RNA in saliva, which could be a vehicle of virus transmission, 35 throat washing samples from the HCV-infected children were screened by PCR. Using three different sample preparation procedures, 20% of the throat washings were found to be positive for HCV-RNA. This indicates a prevalence of virus in this fluid lower than that reported previously. © 1994 Wiley-Liss, Inc.     

Study of CYP2D6 gene in children with autoimmune hepatitis and P450 IID6 autoantibodies.

Cytochrome P450 IID6 is an autoantigen recognized by the sera of children affected with a subtype of autoimmune hepatitis. It was hypothesized that a mutation in the CYP2D6 gene could explain the autoimmune response in these patients. To examine this question, genomic DNA from peripheral lymphocytes (n = 9) and liver (n = 1) of 10 patients with anti-LKM-1 antibody was analysed by Southern blot for genetic association studies between a particular CYP2D6 haplotype and autoimmune hepatitis. In addition, a region of CYP2D6, from the same genomic DNA, was amplified by polymerase chain reaction (PCR) and digested by BstNI, in a search for the most prevalent 29B mutation, described in subjects who do not express the P450 IID6. Total RNA and proteins, prepared from the liver of an anti-LKM-1+ patient, were analysed by Northern and Western (immunoblot) blots respectively. Our results do not reveal any major structural change in the DNA of this patient at the CYP2D6 locus that could explain their autoimmune response. Corroborating this observation, no changes were noted either in P450 IID6 mRNA size or in the corresponding protein. However, these data do not exclude the possibility of subtle changes in the protein due to point mutations in critical regions that might trigger an autoimmune response.     

Hepatitis B virus-DNA in the serum of patients followed-up longitudinally with acute and chronic hepatitis B

Sera from 79 patients with acute self-limiting hepatitis, 17 patients with acute hepatitis B evolving into chronic HBsAg carriership, and 43 chronic HBsAg carriers without a history of acute hepatitis were analyzed for presence of hepatitis B virus (HBV)-DNA by a molecular hybridization technique. In acute self-limiting hepatitis, HBV-DNA was cleared within a few weeks after the onset of clinical symptoms. The longest period of DNA positivity observed in this group was 42 days. In 29 of 52 patients HBV-DNA was cleared before HBeAg disappeared. Among 17 patients who became chronic HBsAg carriers, HBV-DNA was present for more than 6 months in all but one. Most of the HBsAg carriers eventually cleared HBV-DNA. The DNA clearance frequently preceeded the conversion of HBeAg to anti-HBe. Thus, in many patients there was a transitional period with HBeAg but without HBV-DNA. HBV-DNA was found to be a better index of impending chronicity than HBeAg since persistence of HBeAg for more than 42 days was noted in 10% of the patients who nevertheless cleared HBsAg within 6 months. By that time all those patients had turned negative for HBV-DNA. On the other hand, in 16 of the 17 patients who became chronic carriers of HBsAg, HBV-DNA as well as HBeAg persisted for more than 6 months. The present results also suggest that infectivity in acute hepatitis B is a feature mainly of the presymptomatic and early symptomatic period.     

DNA cloned from the ayw subtype of hepatitis B virus

DNA from the ayw subtype of hepatitis B virus (HBV) was ligated into the EcorI site of DNA from plasmid pBR322 and propagated in E coli chi 776. A plasmid with a 3200 base pair insert (pHBV-1) was isolated and the cloned HBV DNA was mapped with restriction endonucleases. Differences were found in restriction endonuclease cleavage sites for DNAs from HBV of subtype ayw and adr.     

Hepatitis C viraemia in adults with type 2 autoimmune hepatitis.

Sera from 14 patients with type 2 autoimmune hepatitis (anti-LKM1 positive) were investigated for evidence of hepatitis C virus (HCV) infection. Antibodies to HCV were detected in 13 patients by both commercial and "in-house" ELISAs and also by a second generation recombinant immunoblot assay. Nine of the 13 (69%) anti-HCV positive patients were shown to be viraemic by a polymerase chain reaction-based assay for serum HCV RNA. Neither anti-HCV nor serum HCV RNA were detected in any of 6 controls with primary biliary cirrhosis or in 39 healthy blood donors. These findings strongly suggest a role for HCV in the pathogenesis of type 2 autoimmune hepatitis.     

慢性乙型肝炎肝内HBV DNA和HBsAg的双标记定位研究

应用原位杂交和免疫组化PAP法双标记技术,结合病人乙型肝炎(乙肝)病毒血清学标志物检测结果,研究了31例慢性乙肝病人肝穿刺组织中乙型肝炎病毒DNA(HBV DNA)和HBsAg的分布及意义。结果显示,肝组织内检出HBV DNA 23例,HBsAg 26例,二者同时检出者21例。从同组病人肝组织内HBV DNA和HBsAg双标检测结果与其乙肝病毒血清学标志物检测结果的比较来看,肝组织内HBV DNA和HBsAg同时阳性很可能表明HBV正处于复制及表达的活动状态。     

慢性乙型肝炎患者外周血T细胞KIR表达研究

目的：检测慢性乙型肝炎患者外周血T细胞表面KIR的表达情况。方法：采用三色流式细胞术检测慢性乙型肝炎患者外周血CD4^＋T细胞和CD8^high T细胞表面KIR分子表达，并与正常外周血比较。结果：慢性乙型肝炎患者外周血中CD8^high T细胞KIR表达明显高于对照组CD8^high T细胞。正常外周血CD4^＋T细胞几乎不表达KIR，慢性乙型肝炎患者外周血中CD4^＋T细胞表达KIR。结论：慢性乙型肝炎患者T细胞表面KIR表达明显增加。     

A replicon-based bioassay for the measurement of interferons in patients with chronic hepatitis C

Overall treatment results of chronic hepatitis C have improved markedly with the introduction of pegylated interferon-alpha (PEG–IFN-) and ribavirin combination therapy. However, cure rates in the most common genotype 1 infection are still unsatisfactory. IFN- dose–response studies on viral kinetics suggest that inadequate dosing might be a key factor but drug levels have hardly been tested, which is in part due to difficulties in measuring this cytokine in patient samples. We have shown recently that hepatitis C virus (HCV) replicons are highly sensitive to IFN-. In this report we tested whether the replicon system could be used as a sensitive bioassay to determine the amount of biologically active IFN- in serum or heparinized plasma of patients under therapy. To facilitate the measurements, a stably replicating subgenomic HCV RNA was developed that carries the gene encoding the firefly luciferase. Dose response studies with IFN- demonstrate that the amount of expressed luciferase directly correlates with the level of HCV replication. By using this cell-based assay, serum samples of HCV patients treated with different types and doses of IFN- were analyzed in parallel to IFN- standards made by serial dilutions of the same type of IFN- the patient was treated with. Based on nonlinear logistic models serum concentrations corresponding to 1.3–19 U/ml were determined in patients under standard or high dose IFN- therapy, and from 3.8 to 4.1 ng/ml in patients treated with PEG IFN-. In conclusion, the HCV-replicon based bioassay allows determining the levels of biologically active IFN- in serum and heparinized plasma of patients under treatment.