Detection of hepatitis C virus (HCV) RNA by PCR related to HCV antibodies in serum and liver histology in Swedish blood donors

Prevalence and associated factors of Treponema pallidum infection in a rural area of southwestern China

Background

Epidemiological data on Treponema pallidum infection are scarce from the southwestern region of China. The purpose of this study was to determine the distribution and determinants of T. pallidum infection in the region.

Methods

A community-based cross-sectional study of 2608 participants aged ≥14 years was conducted in a rural area of southwestern China in 2014–15. A pretested questionnaire was used to collect sociodemographic characteristics and other factors associated with T. pallidum infection. The diagnoses of T. pallidum, human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were determined by commercial test kits. Logistic regression analysis was used to determine the correlates for T. pallidum infection, and adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated.

Results

The prevalence of T. pallidum infection was 1.2% (95% CI 0.8 to 1.7%). Risk factors varied by gender. In the male group, T. pallidum infection was significantly associated with ever injection drug use (aOR = 9.42, 95% CI 2.47 to 35.87) and HCV infection (aOR = 13.28, 95% CI 3.20 to 51.70). In the female group, correlates for T. pallidum infection included spouse having syphilis (aOR = 126.66, 95% CI 7.58 to 2122.94), ever having blood transfusion (aOR = 10.51, 95% CI 1.58 to 41.21) and HBV infection (aOR = 4.19, 95% CI 1.35 to 10.93).

Conclusions

The prevalence of T. pallidum infection was high in the rural area of southwestern China. Correlates for T. pallidum infection varied with sex specific. Intervention should be developed for the prevention and control of T. pallidum infection.

Allogeneic hematopoietic cell transplant in HCV-infected patients

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. After allogeneic Hematopoietic Cell Transplant (HCT), HCV is known to be associated with transient hepatitis in the immediate post-transplant period, and a potential risk factor of veno-occlusive disease (SOS). Very recently, HCV-infected HCT recipients have been shown to be at higher risk of earlier cirrhosis, leading to greater morbidity and mortality. Long-term survivors after HCT are thus at a high risk for HCV-related complications and, as a consequence, the treatment of HCV infection becomes critical. We describe here the potential clinical complications in HCV-infected recipients, in the short, but also the long-term follow-up after HCT. The pathophysiology of liver fibrosis is discussed as well as the present recommended therapy in this particular population.

Detection of parvovirus B19, cytomegalovirus and enterovirus infections in cases of intrauterine fetal death

AIMS

Maternal infections with parvovirus B19, cytomegalovirus (CMV) and enterovirus have been associated with intrauterine fetal death (IUFD), but the incidence of these infections is not clear. This prospective study was conducted to estimate this incidence.

METHODS

A prospective study of 38 months was conducted on cases of IUFD referred to Huddinge University Hospital, Stockholm, Sweden. Placental biopsies, fetal blood and amniotic fluid were collected from cases of IUFD (n=52). Placental biopsies from normal pregnancies at term (n=53) were used as controls. These tissues were examined for parvovirus B19 DNA, CMV DNA and enterovirus RNA using polymerase chain reaction (PCR). Maternal viral serology was measured in 46 cases and virus isolation for enterovirus in maternal stool samples was performed in 31 cases.

RESULTS

Viral nucleic acid was recovered in at least one tissue sample from six cases of fetal death (parvovirus B19 in two cases, CMV in three and enterovirus in one), while all placental biopsies from controls were found negative. Serological signs of primary maternal infection were found in two of the cases, and virus isolation for enterovirus was negative in all samples examined.

CONCLUSION

Parvovirus B19, CMV and enterovirus may be considered as etiologic agents in cases of fetal death. PCR on placental and/or fetal tissue improves diagnostic accuracy for these infections.

High rate of chronicity in HCV infection determined by antibody confirmatory assay and PCR in 4110 patients during long-term follow-up

BACKGROUND

It is still unclear how many patients with hepatitis C virus (HCV) antibodies have viremia and hence are infectious.

OBJECTIVES

To determine the chronicity of HCV infection by correlation of HCV antibodies with presence of viremia in long-term follow-up.

STUDY DESIGN

In a longitudinal study sera of 4110 patients were analyzed with second generation HCV-enzyme immunoassay (EIA) and polymerase chain reaction (PCR). Only those patients were included in this study in whom sequential serum samples over a period of 2 years were available. To avoid preanalytical and analytical failures, we used a transport solution to prevent RNA degradation and a four-antigen recombinant immunoblot assay, established in our laboratory, for confirmation of antibody reactivity.

RESULTS

Of 2815 patients with confirmed HCV antibodies 2784 (98.9%) were also positive in HCV-PCR assay. False reactive EIA results were detected in 177 (13.7%) individuals as shown by confirmatory assay and PCR. Only one patient (0.04%) spontaneously lost detectable HCV viremia and subsequently HCV-specific antibodies.

CONCLUSIONS

Our study clearly demonstrates that presence of confirmed HCV-specific antibodies correlates significantly (98.9%; P < 0.001) with HCV viremia, and that spontaneous loss of viremia is a very rare event in HCV infection. We also found that elimination of HCV infection is not sufficiently predicted by the loss of detectable viremia in PCR, but can be concluded from the disappearance of virus-specific antibodies.

Histological and virological long-term outcome in patients treated with interferon-alpha2b and ribavirin for chronic hepatitis C

Long-term virological and histological outcome following interferon-alpha2b (IFN-alpha2b) and ribavirin treatment for 24 weeks was studied in 20 patients with chronic hepatitis C who were without a lasting response to IFN as monotherapy. Following combination therapy, sustained virological response (SR) was achieved in 12 patients (i.e. hepatitis C virus (HCV) RNA negative in serum 6 months post-treatment). Eleven of these patients remained HCV RNA negative in serum 2 years post-treatment. A virological long-term response (LTR) was more frequent in patients with a previous end-of-treatment response to IFN monotherapy than in non-responders. Liver histology at follow-up, >/=24 months post-treatment, showed substantial improvement in patients with a virological LTR to the combination treatment. In all nine patients biopsied at the 2-year follow-up, liver inflammation had disappeared totally (grade=0), and the stage (fibrosis) had improved. In contrast, no significant changes in grade or stage were noted in patients with a virological non-LTR to combination treatment. A significant improvement in inflammation was noted, in patients with a virological LTR, from 3.6 to 0.2 (P<0.01) and in fibrosis from 2.0 to 1.4 (P<0.05) whereas the corresponding scores for patients with a virological non-LTR did not change significantly, from 3.1 to 1.5 for inflammation and for fibrosis from 1.3 to 1.3. We conclude that patients with chronic hepatitis C who achieve a virological sustained response 6 months post-treatment with IFN-alpha2b and ribavirin will remain virological responders for a follow-up period of least 24 months, concomitant with a disappearance of inflammatory activity and a marked improvement of fibrosis in the liver.

Long-term follow-up of chronic hepatitis C patients with sustained virological response to alpha-interferon

BACKGROUND/AIMS

This study aimed to determine the long-term outcome of hepatitis C virus (HCV)-infected patients who respond to interferon treatment with clearance of serum HCV RNA.

METHODS

We performed a long-term biochemical, virological, and histological follow-up of all sustained virological responders, defined as those who became HCV RNA negative at follow-up 6 months after the end of treatment, from 3 controlled interferon trials performed in Sweden between 1988 and 1994.

RESULTS

At biochemical and virological long-term follow-up performed in 26 sustained virological responders 3.5-8.8 years (mean +/- SD, 5.4+/-1.6 years) after the end of IFN therapy, 22 patients (85%) had normal serum ALT levels, and 24 patients (92%) were HCV RNA negative in serum. Liver biopsies performed in 23 patients 2.1-8.7 years (mean +/- SD, 5.0+/-1.8 years) after end of treatment showed no or minimal inflammation, whereas mild and probably irreversible fibrosis was seen in a few patients.

CONCLUSION

In this well-defined material of sustained responders to IFN therapy, the long-term prognosis was excellent. Nearly all had a durable response, not only biochemically and virologically, but more importantly also histologically with normalisation or near normalisation of previous histological lesions.

Cooperative oligonucleotides mediating direct capture of hepatitis C virus RNA from serum

A novel method for direct capture of hepatitis C virus (HCV) RNA from clinical samples has been developed. This approach takes advantage of the cooperative interactions between adjacently hybridized oligonucleotides. Here, this cooperative effect was combined with solid-phase technology, whereby a capture probe was covalently coupled to magnetic beads and a second probe, which anneals adjacent to the capture probe site, was prehybridized in solution to the target. When these contiguously hybridized probes were used for the extraction of HCV RNA from clinical samples, the capture efficiency was increased up to 25-fold in comparison to capture with a single probe. The applicability of this sample preparation assay was further investigated by performing a comparative study with both a conventional guanidinium extraction method and a commercial quantitative assay.

Long-term lymphoblastoid interferon-alpha therapy for non-cirrhotic chronic hepatitis C: an Italian multicentre study on dose and duration of IFN alpha treatment

The aims of the study were to evaluate the long-term efficacy and tolerability of different doses of interferon-alpha (IFN alpha) and different durations of treatment in chronic hepatitis C by comparing 3 or 6 mega units (MUs) three times weekly given for either 12 or 24 months, and the possibility of obtaining a response in non-responder patients by increasing the dose or by administering IFN daily. A total of 504 patients with non-cirrhotic chronic hepatitis C enrolled in a multicentre study were consecutively assigned to receive either 3 (255 patients) or 6 MU (249 patients) of lymphoblastoid IFN alpha 3 times a week (tiw). At the 12th month of therapy, patients with normal aminotransferase (AMT) in both groups were either given IFN for an additional 12 months with an unmodified or halved dose, or else discontinued therapy. For patients with unmodified AMT levels after 6 months of therapy, the IFN dose was doubled in the 3-MU group, while it was administered at 3 MU daily in the 6-MU group. When no improvement was achieved, therapy was discontinued; otherwise it was prolonged until the 18th month. Patients were followed up for 12 months after discontinuing IFN. Of the 255 patients enrolled at 3 MU, therapy was stopped during the first 6 months in 36 patients (14.1%) because of side effects, and in 24 (9.4%) because of lack of cooperation. Of the remaining 195 patients at the 6th month of therapy, 119 (61%) had normal and 76 (39%) unmodified AMT levels; 14 of the 76 normalized AMT after doubling the dose of IFN, but only 5 (6.6%) had a sustained response. Of the 119 patients with normal AMT, 40 discontinued IFN at the 12th month (schedule A), 39 remained at 3 MU tiw (schedule B) and 40 were given a dose of 1.5 MU tiw (schedule C) for an additional 12 months. At the end of follow-up, 23/40 (57.5%) patients in schedule A, 31/39 (79.5%) on schedule B and 29/40 (72.5%) on schedule C still had normal AMT (A vs. B p = 0.04). In an intention-to-treat analysis, the sustained response rate for patients enrolled at 3 MUs, including the 5 initial non-responders, was 34.5%. Of the 249 patients enrolled at 6 MU, therapy was discontinued during the first 6 months for 39 (15.7%) because of side effects, and for 27 (10.8%) because of lack of cooperation. Of the remaining 183 patients at the 6th month of therapy, 110 (60%) had normal and 73 (40%) unmodified AMT levels. Of the 73 patients, 55 accepted the daily regimen and 8 of them (14.5%) showed a sustained response. Of the 110 patients with normal AMT, 32 (29.1%), despite normalization of AMT, spontaneously discontinued IFN or reduced the dose because of a poor quality of life, while 78 continued with 6 MU until the 12th month, when therapy was discontinued for 28 (schedule A1); 24 patients were given an unmodified dose (schedule B1) and 26 a halved dose (schedule C1) for an additional 12 months. At the end of follow-up, 18/28 (64.3%) patients on schedule A1, 19/24 (79.2%) on schedule B1 and 19/26 (73.1%) on C1 still had normal AMT (p = NS). In an intention-to-treat evaluation, the sustained response rate for patients enrolled at 6 MU, including the 8 from the daily treatment, was 25.7% (64/249). HCV viraemia was undetectable 1 year after discontinuation of IFN in 72.6% of patients with a sustained response. Sustained response was observed in 36.4% of patients with minimal, 46.6% of those with mild, and 33.3% with moderate or severe histological activity (p = NS). The rate of sustained response was lower in patients with genotype 1b (23.6%) than in those with genotype 2a (67.8%, p = 0.002) or genotype 3 (50%, p = 0.03), irrespective of the histological activity. In conclusion, 6 MU IFN alpha are no more effective than 3 MU in inducing a sustained response in treatments of both 12 and 24 months. A 24-month treatment is more effective than a 12-month treatment in maintaining a biochemical response after discontinuation of IFN. In terms of efficacy, compliance and cost, 3 MU for 24 months app

Variation in the hepatitis C virus NS5a region in relation to hypervariable region 1 heterogeneity during interferon treatment

The putative interferon sensitivity determining region (ISDR) in the NS5a region of the hepatitis C virus (HCV) was analyzed in 13 interferon alpha (IFN-alpha) treated patients representing genotypes 1a, 1b, and 2b. These patients had previously been followed longitudinally during treatment with respect to viral load and to virus heterogeneity using the hypervariable region 1 (HVR1) sequence as a marker. In the present study, the NS5a region was analyzed for nonresponders and sustained responders using direct DNA sequencing. While the previous results of analyzing viral composition and load showed evidence of selection, no corresponding selection of specific NS5a ISDR sequences was observed in the nonresponders, and identical ISDR sequences were observed among both sustained responders and nonresponders. Thus, we cannot verify a correlation between ISDR sequence and the observed selection of IFN-alpha-resistant quasispecies demonstrated as a restriction of HVR1 heterogeneity. This indicates that the potential for using ISDR as a diagnostic or prognostic marker during IFN-alpha treatment is limited.

Failure to find an association between hepatitis C virus and thyroid autoimmunity

A high frequency of hepatitis C antibodies has been reported from France in patients with autoimmune thyroiditis. Two cases of Hashimoto's thyroiditis in association with chronic active hepatitis and hepatitis C infection have also been reported. We have examined this potential association in 46 patients with autoimmune hypothyroidism and found that 16 apparently had hepatitis C antibodies in one of the two commercially available enzyme-linked immunosorbent assays (ELISA), but all patients were negative in a confirmatory commercially available recombinant immunoblot assay (RIBA-3) indicating that none of the patients were truly positive for hepatitis C antibodies. We also tested sera from 111 patients with proven hepatitis C infection and found no increased prevalence of thyroid autoantibodies. These results suggest that hepatitis C infection is not a risk factor for the development of thyroid autoimmunity in the United Kingdom.

Effective detection of active HCV infection: HCV RNA carrier state in a context free of hepatitis symptoms

HCV immunological assays have limited specificity due to considerable variability of genomic coding sequences. Accordingly, PCR RNA detection also shows variable incidence of HCV in a non-A, non-B (NANB) hepatitis context. We used in-house designed nested PCR applying primers from the 5' untranslated region in 150 thalassemic patients classified in four groups according to anti-HCV screening and glutamic-pyruvate transaminase (GPT) levels. Group A: anti-HCV+/high GPT levels; group B: anti-HCV+/normal GPT levels; group C: anti-HCV(-)+high GPT levels; group D: anti-HCV(-)+normal GPT levels. Viral incidence and concentration, both high in group A, decreased towards group D. Group C RNA incidence was unexpectedly high and, moreover, one control case proved HCV-RNA+. Compared with the Amplicor kit or primers were considerably more sensitive.

Antibody production against hepatitis C virus core and nonstructural 3 proteins is highly sensitive to deficits in T-cell function

The influence of suppression of CD4+ and CD8+ T cells on the humoral responses to hepatitis C virus (HCV) core and nonstructural 3 proteins was studied. An increasing viral burden cannot substitute for the lack of functional T cells in maintaining humoral HCV-specific responses.

Detection of hepatitis B virus DNA and RNA in kidneys of HBV related glomerulonephritis

Glomerular deposition of hepatitis B virus (HBV) antigens are observed in chronic HBsAg carriers with different glomerulonephritides yet the etiologic role of HBV remains uncertain. We examined the paraffin section of kidney biopsies from 40 chronic HBsAg carriers with membranous nephropathy (MGN), mesangiocapillary glomerulonephritis (MCGN) or IgA nephropathy (IgAN) for HBV DNA and HBV RNA using in situ hybridization (ISH). Glomerular HBV antigens were present in all biopsies by immunofluorescence. HBsAg or HBcAg mRNA was also studied in RNA extracted from frozen renal tissue using a two-step polymerase chain reaction (PCR) following reverse transcription (RT). HBcAg DNA was not easily detected with ISH alone, but was readily found in 31 biopsies (78%) following PCR. HBV DNA was detected mainly in the cytoplasm of proximal tubular epithelia but not in glomerular cells. HBsAg and/or HBcAg mRNA were detected by RT-PCR in extracted RNA from 13 biopsies (33%). The PCR findings were further confirmed by (a) Southern blot hybridization using a cloned HBV probe and (b) absence of PCR product following treating RNA with RNase or omitting the RT. It is plausible that HBV DNA in renal tubules represents endocytosis of HBV DNA in the urinary filtrate and the HBV RNA extracted from kidney biopsies could derive from infiltrating cells bearing HBV RNA. Hence, ISH with specific HBV core gene RNA probe was performed subsequently. HBcAg RNA, localized in the nuclei and cytoplasm of glomerular and tubular cells, was detected in 56%, 20%, and 36% of renal biopsies in chronic HBsAg carriers with MGN, MCGN, and IgAN, respectively. Our findings indicate the presence of viral transcription in glomerular cells and renal tubular epithelia, supporting an etiological role of HBV in some chronic HBsAg carriers who develop coexisting glomerulonephritides.

HCV-Infection in blood donors: association between anti-HCV core IgM antibodies and serum HCV RNA

Among 47 blood donors tested positive with HCV EIA 2.0 Abbott, 27 (57.4%) also reacted with four ¿third-generation' EIAs. The presence of anti-HCV antibodies was confirmed with 3 different immunoblot assays in 16 of 27 sera (34.0%) while 10 samples (21.3%) had indeterminate profile with antibodies usually directed against structural core antigen. Anti-HCV core IgM response was found in 12 of 47 sera (25.5%) and HCV viremia detected by the polymerase chain reaction (PCR) procedure was observed in 15 samples (31.9%). A comparative study of the different markers confirmed a good correlation between a strong antibody response in EIAs and immunoblot assays and the presence of HCV RNA in the serum; only 2 immunoblot indeterminate samples were PCR positive. An association was observed between IgM antibodies against "core' epitopes and HCV RNA carriage: all IgM-positive sera were found positive by PCR. However, the direct detection of viral genome remains the best method for identifying HCV carriers in the blood donor population.

Vertical transmission of hepatitis C virus infection

Vertical transmission of hepatitis C virus (HCV) was studied in 58 infants of 55 mothers (3 sets of twins). HCV RNA analyses by the polymerase chain reaction (PCR) and alanine aminotransferase (ALT) were performed on consecutive blood samples from birth to 18 months of age (0, 3, 9 and 18 months). Data on factors possibly influencing mother-to-infant transmission of HCV, such as concomitant human immunodeficiency virus (HIV) and hepatitis B virus infection during pregnancy, maternal HCV RNA status at delivery, mode of delivery, prematurity and breastfeeding habits were collected. In addition, 6 older siblings (age 4-10 years) of the infants were tested once for anti-HCV. Of the 55 mothers 52 (95%) had a history of intravenous drug use (IVDU). Two mothers were HIV positive. 40/54 (75%) tested mothers were HCV RNA positive. 16 (27%) infants were delivered by Caesarean section, and 50 (86%) infants were breastfed. All infants were HCV RNA negative on all occasions and anti-HCV negative at the age of 18 months. Maternally acquired anti-HCV antibodies disappeared and were not detected by 9 months in 78%. One of the 6 older siblings was anti-HCV and HCV RNA positive. We conclude that the risk of vertical HCV transmission is low in infants of HCV-positive/HIV-negative mothers, and that breastfeeding seems to be safe in this group.

Dynamic analysis of heterogeneous hepatitis C virus populations by direct solid-phase sequencing

In the present study, we used a semiautomated solid-phase direct sequencing method to analyze sequence diversity and variation of the hypervariable E2/NS1 region in the hepatitis C virus (HCV) genome in isolates from patients seropositive for HCV. A total of 24 isolates of various origins were sequenced. Six of the patients, not subject to any antiviral therapy, were monitored longitudinally, and rapid sequence variations were observed over a period of 14 months. The nucleotide change rate was found to be 0.1 to 0.2 nucleotide substitution per genome site per year. Furthermore, isolates from five of the patients were used for a comparative study of the direct solid-phase sequencing approach versus the frequently used approach of sequencing individual reverse transcriptase PCR clones. The advantage of direct solid-phase sequencing for studying dynamic changes in heterogeneous populations of HCV is discussed.

Combined treatment with interferon alpha-2b and ribavirin for chronic hepatitis C in patients with a previous non-response or non-sustained response to interferon alone

Ten patients with chronic hepatitis C, six of whom had not responded and four of whom had responded in a non-sustained fashion to interferon-alpha treatment alone, were given interferon alpha-2b and ribavirin in combination during 24 weeks. Interferon alpha-2b was given subcutaneously, at a dose of 3 MU thrice weekly, together with ribavirin orally, at a dose of 1,000-1,200 mg/day. All four patients with a prior non-sustained response to interferon alone had normal alanine aminotransferase (ALT) levels at the end of treatment as well as during follow-up (> or = 24 weeks post treatment). Furthermore, all four lost serum HCV-RNA at the end of treatment and three continued to be negative during follow-up. Among patients with a prior non-response to interferon alone three of six had normal ALT levels at the end of treatment and one at follow-up. Two of six became HCV-RNA negative at cessation of treatment, one of whom was negative also at follow-up. All former non-sustained responders and one of six non-responder patients thus showed a sustained biochemical response with eradication of HCV-RNA from serum in all cases but one. It is concluded that combination therapy with interferon alpha-2b and ribavirin offers a chance of sustained biochemical response with eradication of the viremia in patients who have not shown a persistent response to interferon-alpha alone.

Transmission of hepatitis C virus by transfusion in Orebro County, Sweden, 1990-1992

A retrospective study of hepatitis C virus (HCV) transmission by transfusion was conducted in Orebro county. Out of the 7,900 active, registered blood donors, 21 repeatedly anti-HCV reactive (RIVA 2 positive or indeterminate) donors were diagnosed. Their 84 recipients from January 1990 through June 1992 were identified and 41 (49%) were alive in December 1992. A total of 13 anti-HCV reactive (RIBA 2 positive or indeterminate) were diagnosed in 39 investigated recipients. Of these 11 were previously undiagnosed, and seven were HCV RNA-positive. In the donor population 1.03% were anti-HCV-positive by ELISA, but only 0.09% were RIBA and HCV RNA-positive. In 1990, 0.06% of the blood components came from the HCV RNA-positive donors, and none during the first 6 months of 1992. In order to identify transfusion-transmitted HCV infections that took place before the introduction of tests for anti-HCV antibodies, patients with a history of transfusion and symptoms and signs of liver dysfunction or damage should be thoroughly tested.

Hepatitis C infection in patients with primary hypogammaglobulinemia after treatment with contaminated immune globulin

BACKGROUND

In Scandinavia many patients with primary hypogammaglobulinemia contracted non-A, non-B hepatitis after intravenous treatment with an immune globulin product that was later found to contain a non-A, non-B hepatitis virus.

METHODS

We studied the prevalence and clinical course of hepatitis C virus (HCV) infection in a group of 55 Norwegian patients with primary hypogammaglobulinemia and investigated its association with the use of contaminated immune globulin. We used the polymerase chain reaction to detect HCV RNA and performed HCV genotyping. We also analyzed the responses to treatment with interferon.

RESULTS

Of 20 patients who received the contaminated immune globulin, 17 were seropositive for HCV RNA: In addition, 1 of 35 patients not exposed to the contaminated immune globulin was HCV RNA--positive. HCV genotype V was found in all 12 patients for whom genotyping was performed, but 8 patients also had genotype II or III, or both. All HCV RNA--positive patients had abnormal results on biochemical liver tests. All liver-biopsy specimens (from 15 patients) were abnormal, with portal inflammation, bile-duct damage, and focal necrosis. In six patients there was cirrhosis. Two patients died of liver failure. In 4 of the 10 patients treated with interferon there were complete, though transient, biochemical responses, but the follow-up biopsy specimens showed evidence of histologic progression. The poorest responses to interferon were among the patients with multiple HCV genotypes. All but one patient remained positive for HCV RNA:

CONCLUSIONS

In patients with primary hypogammaglobulinemia there was a high rate of HCV infection after treatment with contaminated immune globulin. In these immunocompromised patients HCV infection has a severe and rapidly progressive course, and responses to interferon are poor.

Viral hepatitis. Current concepts for dental practice

The transmission of blood-borne viruses in the dental office is a potential hazard to patients and dental staff, particularly to oral and maxillofacial surgeons. Hepatitis B virus has been a recognized hazard for several years, and in the past oral surgeons and other dental health care staff have been infected as a result of occupational exposure. Hepatitis C virus in contrast does not appear to be a major occupational hazard to dental staff, nevertheless, infection with this virus can lead to significant morbidity and may have oral manifestations. Hepatitis D virus can be nosocomally transmitted, but vaccination against the hepatitis B virus minimizes this problem. Hepatitis E virus is not of clinical relevance to dentistry, although dental staff who are in areas of endemic infection can become infected as a result of enteric transmission. A number of other putative viral agents may also cause hepatitis, but additional data is awaited, and their significance to dental practice is unknown. This article summarizes current data on hepatitis viruses A, B, C, D, and E.

Third-generation hepatitis C virus tests in asymptomatic anti-HCV-positive blood donors

This study evaluated the performance of third-generation anti-HCV assays in blood donors who were positive by second-generation anti-HCV, and assessed any possible relationship between antibody patterns, HCV replication and liver damage. Fifty-two second-generation enzyme immunoassay-positive asymptomatic Italian blood donors were retested for anti-HCV by third-generation enzyme immunoassay and recombinant immunoblot assay (Ortho third-generation enzyme immunoassay, third-generation recombinant immunoblot assay), utilising recombinant C33c and NS5 and synthetic peptide C100 and C22 antigens, and for HCV-RNA by "nested" polymerase chain reaction with 5' region primers. Alanine aminotransferases were tested monthly for 6 months. Two out of 52 second-generation enzyme immunoassay-positive donors were third-generation enzyme immunoassay, third-generation recombinant immunoblot assay and HCV-RNA negative. Among 50 third-generation enzyme immunoassay-positive cases, two had a third-generation enzyme immunoassay optical density < or = 1: one was third-generation recombinant immunoblot assay and HCV-RNA negative, and the other was third-generation recombinant immunoblot assay "indeterminate" and HCV-RNA-positive. The remaining 48 cases had third-generation enzyme immunoassay optical density > 1: six were third-generation recombinant immunoblot assay negative (one HCV-RNA+ve), eight "indeterminate" (two HCV-RNA+ve) and 34 positive (22 HCV-RNA+ve). All "indeterminate" subjects reacted only to C22. HCV-RNA was positive in 22/34 cases with positive third-generation recombinant immunoblot assay (two or more Ags), 3/9 "indeterminate" and 1/11 negative. Alanine amino-transferases were abnormal in 13 cases with positive third-generation recombinant immunoblot assay, one was "indeterminate" and three were negative.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-HCV related to HCV PCR and risk factors analysis in a blood donor population of central Brazil

Data concerning HCV infection in Central Brazil are rare. Upon testing 2,350 voluntary blood donors from this region, we found anti-HCV prevalence rates of 2.2% by a second generation ELISA and 1.4% after confirmation by a line immunoassay. Antibodies against core, NS4, and NS5 antigens of HCV were detected in 81.8%, 72.7%, and 57.5%, respectively, of the positive samples in the line immunoassay. HCV viremia was present in 76.6% of the anti-HCV-positive blood donors. A relation was observed between PCR positivity and serum reactivity in recognizing different HCV antigens in the line immunoassay. The majority of the positive donors had history of previous parenteral exposure. While the combination of ALT > 50 IU/l and anti-HBc positivity do not appear to be good surrogate markers for HCV infection, the use of both ALT anti-HCV tests is indicated in the screening of Brazilian blood donors.

Hepatitis C: progress and problems

The hepatitis C virus (HCV), a single-stranded RNA virus, is the major cause of posttransfusion hepatitis. HCV isolates differ in nucleotide and amino acid sequences. Nucleotide changes are concentrated in hypervariable regions and may be related to immune selection. In most immunocompetent persons, HCV infection is diagnosed serologically, using antigens from conserved regions. Amplification of RNA may be necessary to detect infection in immunosuppressed patients. Transmission by known parenteral routes is frequent; other means of spread are less common and may represent inapparent, percutaneous dissemination. Infection can lead to classical acute hepatitis, but most infected persons have no history of acute disease. Once infected, most individuals apparently remain carriers of the virus, with varying degrees of hepatocyte damage and fibrosis ensuing. Chronic hepatitis may lead to cirrhosis and hepatocellular carcinoma. However, disease progression varies widely, from less than 2 years to cirrhosis in some patients to more than 30 years with only chronic hepatitis in others. Determinants important in deciding outcome are unknown. Alpha interferon, which results in sustained remission in selected patients, is the only available therapy. Long-term benefits from such therapy have not been demonstrated. Prevention of HCV infection by vaccination is likely to be challenging if ongoing viral mutation results in escape from neutralization and clearance.

Isotype-specific immune response to a single hepatitis C virus core epitope defined by a human monoclonal antibody: diagnostic value and correlation to PCR

In this study we tested the seroreactivity of 223 selected anti-HCV-reactive blood donors to the human B-cell epitope N-VYLLPR-C (C34-39) of the hepatitis C virus core antigen. The epitope was recently identified and characterized by the human monoclonal IgG antibody Ul/F10 and is located within the amino acid residues 34-39 of the aminoterminal core region. The blood donor sera were selected from anti-HCV ELISA (Ortho, 2nd generation)-reactive samples. Sixty-seven of these sera were further reactive in RIBA (Ortho, 2nd generation). According to their RIBA pattern, these samples were divided into four groups. Samples in the first group (n = 18) reacted to all four recombinant HCV antigens. The samples of the second (n = 9) and third group (n = 8) reacted to c22-3/c33c and c22-3/c100-3, respectively. Sera from group 4 (n = 32) showed a RIBA indeterminate pattern with reactivity only to c22-3. All 223 samples were analyzed for anti-C34-39 antibodies by ELISA, and the 67 RIBA-reactive samples were additionally tested for the presence of HCV RNA by RT/PCR. In groups 1 and 2, over 80% of the samples showed anti-C34-39 reactivity which was restricted to the IgG1 isotype. In contrast, in groups 3 and 4, antibodies to the epitope C34-39 were detected in less than 10% of the samples. Interestingly, the anti-C34-39 response correlates with the presence of HCV RNA; 95.5% of the samples had coincident results in all subgroups. None of the RIBA-negative sera showed a specific seroreaction to the C34-39 peptide.

Hepatitis C virus-polymerase chain reaction of routinely processed liver biopsies

The aim of the study was to evaluate the specificity and sensitivity of detection of hepatitis C virus (HCV)-RNA in formalin-fixed paraffin-embedded (FFPE) liver biopsies by polymerase chain reaction (PCR). Routinely processed FFPE diagnostic needle liver biopsies as well as stored serum samples from 43 patients with liver disease were tested for HCV-RNA by reverse transcription-nested PCR using the same sets of primers and following strict anticontamination measures. Twenty-nine cases were positive and 14 were negative for serum HCV-RNA. Tissue HCV-RNA was detected in 17 out of the 29 serum HCV-RNA-positive cases but not in any of the 14 serum HCV-RNA-negative cases. Compared to serum-PCR, tissue-PCR was 100% specific, 58.6% sensitive, and 72% efficient. HCV-RNA was detected more frequently in biopsies stored for less than 1 year, than in those stored for more than 1 year (P = 0.046). In biopsies stored for up to 1 year detection of HCV-RNA by PCR was 81.8% sensitive and 90.9% efficient. Short (< 0.5 cm) liver biopsies were as sufficient for nucleic acid extraction and amplification as long (> 0.5 cm) ones. It is concluded that following strict anticontamination measures, HCV-RNA detection by PCR in routinely fixed, processed, and stored diagnostic liver biopsies provides a valuable adjunct to diagnosis of HCV infection. In this study, this option was free from contamination problems, even though routine batch histological processing schedules were used.

Histological outcome in patients with chronic hepatitis C given a 60-week interferon alfa-2b treatment course

Forty patients with chronic hepatitis C virus (HCV) infection were treated with 3 MU interferon alfa-2b given subcutaneously for 60 weeks. A biochemical response with normalization of serum alanine aminotransferase (s-ALT) levels was seen in 24 patients (60%) at treatment cessation. A sustained response with continuously normal s-ALT levels during 24 weeks of follow up was seen in 15 of these 24 patients (62%), all of whom also became HCV RNA negative in serum. Histological changes in the pre- and posttreatment liver biopsies were assessed using a numerical scoring system. Biochemical responders had a significant decrease in all four scored categories: portal inflammation, piecemeal necrosis, spotty necrosis and fibrosis. Non-responders had a significant decrease in piecemeal necrosis and spotty necrosis, whereas the scores for portal inflammation and fibrosis remained unchanged. There was no significant difference in any of the scored categories in the pretreatment biopsy between responders and non-responders. We conclude that patients suffering from chronic HCV infection who responded biochemically and virologically to interferon treatment also improved their liver histology. Necroinflammatory activity decreased to some extent in biochemical non-responders, possibly giving them some benefit from the treatment, but not to the same extent as responders. No specific histological pretreatment findings were predictive of biochemical response to interferon treatment.

Interferon therapy in chronic hepatitis C virus infection

Antiviral treatment of chronic hepatitis C with interferon is reviewed. Alpha-interferon, both recombinant alpha-2a, -2b and human lymphoblastoid interferon given at a dose of > or = 3MU t.i.w. for 6-12 months will result in normalisation of ALT levels (complete response) in some 50-60% of treated patients with chronic hepatitis C virus (HCV) infection. Approximately half of the complete responders to interferon will relapse within 6 months once treatment is withdrawn (non-sustained response). Longer treatment schedules (6 vs. 12 months) seem to diminish the relapse rate and increase the percentage of sustained response. In patients with sustained response to interferon treatment with continuously normal ALT levels > or = 6 months after treatment stop a concomitant eradication of the viraemia is usually seen, whereas a non-sustained or non-response to interferon usually will indicate a continuous viraemia. Factors predictive of a favourable response are low pretreatment HCV RNA levels in serum, genotypes other than type II according to Okamoto, short disease duration, female gender and less pronounced liver damage, whereas high serum HCV RNA levels, having genotype II and cirrhosis, are predictive of a less favourable response. Patients with a sustained response and eradication of the viraemia will also improve their liver inflammation with diminishing scores for portal inflammation, piecemeal necrosis, lobular inflammation and also fibrosis after treatment. For non-responders and non-sustained responders to interferon, ribavirin especially in combination with interferon will offer some hope for the future.

Clinical significance of hepatitis C antibodies in blood donors

The clinical significance of hepatitis C antibodies (anti-HCV) in a healthy population was studied by liver function tests and liver biopsies. The patient population consisted of 195 (96.1%) of the 203 blood donors found to be either anti-HCV positive or indeterminate by a recombinant immunoblot assay (RIBA) during the first year of anti-HCV screening of 307,606 donors in Finland using a first generation enzyme-linked immunosorbent assay. Alanine aminotransferase (ALT) levels in 67 donors reacting positively and in 128 reacting indeterminately by a second generation RIBA (RIBA-4) were monitored to evaluate the prevalence of liver damage. Serum N-terminal type III procollagen (PIIINP) concentrations were measured in all donors who fulfilled our criterion for possible hepatitis C (ALT values over two times the normal upper limit on two occasions or over five times the normal upper limit on one occasion) and in 23 randomly selected RIBA-4 positive donors without ALT abnormalities (control group). Two (1.6%) of the RIBA-4 indeterminate donors had ALT values compatible with possible hepatitis C (negative by polymerase chain reaction) whereas there were 25 (37.3%) such individuals among the RIBA-4 positive donors (P < 0.0005). Twenty (80%) of the latter 25 RIBA-4 positive donors with possible hepatitis C consented to liver biopsy. Of these 20 donors, 11 (55.0%) were found to have chronic persistent hepatitis, four (20.0%) mild, three (15.0%) moderate, and two (10.0%) severe chronic active hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS)

A sensitive PCR method for detecting HCV RNA in plasma pools, blood products, and single donations

Although current manufacturing processes appear to efficiently inactivate hepatitis C virus (HCV), it is possible that contaminated blood products may result from failure of some stage during manufacture or from virus overload of plasma pools used for preparation of products. While antibody screening probably removes the majority of HCV positive donations, some donations which are antibody-negative but HCV positive may be included in pools. The HCV RNA content of plasma pools from paid and voluntary donors was investigated by polymerase chain reaction (PCR). A sensitive PCR method using a single pair of primers from the 5' non-coding region of the HCV genome and a "hot-start" was established and shown to be as sensitive as the more conventional nested PCR (which uses two pairs of primers). The majority of pools from paid donors (prescreening) were HCV RNA positive, while all pools from voluntary donors were both antibody and RNA negative. Intravenous immunoglobulins prepared from contaminated pools were RNA negative despite having high antibody levels, indicating satisfactory clearance of the virus during manufacture. The virus load of the pools was at least a thousand-fold lower than that of single donations, possibly as a result of treatment during the production of the pools or the presence of factors in pools which reduce the sensitivity of some part of the PCR assay. The HCV content of a plasma donation was determined as 3.6 x 10(6) genomes/ml by an end point dilution method. Thus a simple and sensitive PCR assay was established for detecting HCV RNA in plasma pools and blood products.

Colorimetric detection of competitive PCR products for quantification of hepatitis C viremia

A method based on competitive polymerase chain reaction (PCR) and colorimetric detection of the amplified products was developed to quantify hepatitis C virus (HCV) genomes. Serum samples were obtained from patients who were treated with interferon alpha (IFN-alpha). After reverse transcription of the HCV RNA, the cDNA was coamplified with a serially diluted cloned HCV competitor DNA using nested PCR. The competitor DNA consisted of the amplified region of the wild type HCV cDNA with an internal region substituted with the lac operator (lacO) sequence. The PCR products were quantitated specifically by a colorimetric solid-phase assay. The results suggest that the method is well suited for analysing the kinetics of the anti-HCV effects during IFN-alpha treatment. The quantification assay is simple, reliable and suitable for quantitating HCV genomes in a large number of clinical samples.

Hepatitis C virus serological and polymerase chain reactions in human immunodeficiency virus-positive and -negative patients

BACKGROUND

Polytransfused patients may be dually infected with hepatitis C virus (HCV) and human immunodeficiency virus (HIV).

OBJECTIVES

To assess the correlation of antibodies to HCV with viral RNA in serum as determined by polymerase chain reaction (PCR) in anti HIV-positive and -negative haemophiliacs.

STUDY DESIGN

Serum from 150 Patients with or without HIV infection were examined for anti-HCV by second generation enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblotting assay (RIBA). A sample was also tested in a nested-reverse transcription PCR for a conserved sequence of the 5' untranslated region of HCV. PCR-positive specimens were titrated and a type-specific PCR using viral core gene sequences was used to determine distribution of HCV viral types.

RESULTS

Eighty-seven percent of the patients were positive in ELISA. All the positives but 2 were either positive of indeterminate in RIBA. The frequency of indeterminate RIBA results was 33% among HIV-positive subjects and less than 1% among HIV-negative ones. PCR was positive in 68% of 73 RIBA-positive or -indeterminate individuals and negative in all HCV-seronegative individuals examined. No significant differences were observed in HCV viral type, prevalence or titers of viraemia between HIV-positive or -negative patients.

CONCLUSIONS

The majority (68%) of anti-HCV-positive haemophiliacs examined in this study had HCV RNA in their sera and anti-HCV profile determined by RIBA had no apparent influence on viraemia. The presence of HIV infection in these patients had no significant impact on HCV RNA prevalence, titer or HCV type distribution.

Liver disease in anti-hepatitis C virus-positive Norwegian blood donors

In a prospective study of 16,756 consecutive blood donors, we found 54 donors (0.3%) to be anti-hepatitis C virus (HCV)-positive by a first-generation enzyme-linked immunosorbent assay. After retesting, 18 donors were confirmed positive or indeterminate by a second-generation recombinant immunoblot assay. Sixteen of these donors were found positive by a second-generation enzyme-linked immunosorbent assay, and 15 of these were positive by HCV polymerase chain reaction with two primer sets. Nine donors (50%) had a history of drug abuse. In 15 donors found positive by a second-generation enzyme-linked immunoblot assay liver biopsy specimens were taken after at least 6 months' follow-up. In all except one hepatitis C RNA-negative donor, histologic abnormalities were observed, even when alanine aminotransferase (ALAT) levels were continuously normal or only moderately elevated. The abnormalities were less pronounced in these donors (n = 5) than in donors with ALAT levels increased more than twice the upper normal limit (p < 0.05). In conclusion, we found the proportion of previous drug abusers in anti-HCV-positive blood donors to be high. We confirm that the presence of anti-HCV (second generation) usually, and HCV-RNA always, seems to indicate ongoing infection--also when ALAT levels are normal. Our study further suggests that low-activity hepatitis, evaluated by ALAT levels, may indicate a milder disease.

Variability of the E2/NS1 region of Swedish hepatitis C virus strains and its correlation to genotypes

Serum RNA was extracted from 5 Swedish patients infected with hepatitis C virus (HCV). The N-terminal part of the genomic region coding for the gp70 (E2/NS1), including the hypervariable domain of the E2 protein, was reverse transcribed and amplified by the polymerase chain reaction (PCR) using biotinylated primers. The amplicon was immobilized on magnetic polystyrene beads coated with streptavidine. Solid-state sequencing was carried out on the bound single-stranded DNA, after denaturation. The results of phylogenetic sequence analysis and calculated ratios of transition and transversion mutations showed that 4 of the strains clustered together with the USA prototype strains HCV-1 and HCV-H (genotype I), while 1 strain was close to the Japanese isolate HCV-J, and particularly to isolate HCV-BK (genotype II). Possible antigenic epitopes in the Swedish strains were mapped in the HVR region.

Long-term histological outcome in patients with chronic hepatitis C treated repeatedly with interferon alpha-2b without sustained response

Nine patients with chronic hepatitis C who responded with normal or near-normal serum alanine aminotransferase (s-ALT) levels during an initial interferon alpha-2b treatment course, but who had subsequent relapses with elevated s-ALT levels after treatment cessation, were retreated once (3 patients) or twice (6 patients). The liver histological findings before the first and after the last treatment course were compared. The mean follow-up time between the initial and the follow-up assessment was 44 months (range 34-53). The histological findings were classified as chronic persistent hepatitis (CPH), chronic active hepatitis (CAH) or cirrhosis (Ci) by using a numerical scoring system assessing each portal zone separately. In the initial biopsy, 2 patients were classified as having CPH and 7 as having CAH, 2 of whom with signs of cirrhosis. According to the conventional classification, 4/9 (44%) patients improved after treatment, 3/9 (33%) remained unchanged, and 2/9 (22%) deteriorated. The mean histological scores for the necro-inflammatory parameters: portal inflammation, piecemeal necrosis, spotty necrosis and fibrosis improved, but the changes did not reach statistical significance. We conclude that repeated interferon alpha-2b treatment courses are probably beneficial in patients with chronic hepatitis C who show a non-sustained response to interferon, since studies on the natural course of chronic hepatitis C have indicated a progressive deterioration of the histological picture in many untreated patients, most marked among those with CAH.

Serum hepatitis C virus RNA levels in chronic hepatitis C--importance for outcome of interferon alfa-2b treatment

Sera from 39 out of 40 patients with chronic hepatitis C virus (HCV) infection who had been treated for 60 weeks with interferon alfa-2b proved initially HCV RNA positive by reversed transcriptase polymerase chain reaction (PCR). These patients were analysed for genotype and quantitatively for HCV RNA levels prior to treatment by using a competitive PCR method with colorimetric detection of the amplified products. HCV RNA levels were correlated to outcome of treatment, mode of acquisition, histology and HCV genotype. The median pretreatment HCV RNA level in sustained responders (n = 15) with eradication of the viremia and normalization of serum ALT levels lasting 24 weeks post treatment was significantly lower than that in the combined group of non-sustained responders (n = 9) and non-responders (n = 15), 2.52 x 10(5) vs 8.90 x 10(5) genome equivalents per ml serum, p < 0.0125, respectively. 10 out of 17 patients with HCV RNA levels lower than the median level (5.64 x 10(5) genome equivalents per ml serum) had a sustained response to interferon treatment versus only 5/22 with levels equal to or higher than the median level, p = 0.04. No significant pretreatment differences in median HCV RNA levels according to mode of acquisition, genotype, or liver histology prior to treatment were seen. It is concluded that a low pretreatment HCV RNA level seems to be indicative of a sustained response to interferon alfa-2b treatment, whereas a high level seems to be indicative of a non-sustained or non-response. In the individual patient, however, the levels varied widely irrespective of response category.

Laboratory diagnosis of human hepatitis viruses

Conventional serologic methods of antigen or antibody detection are now widely applied for diagnosis of hepatitis viruses A, B, C, and D. Nucleic acid quantitation has become very useful for monitoring response to antiviral therapy in cases of hepatitis B and C. Special confirmatory testing of HCV serologies can be quite specific, but overall serologies for HCV lack sensitivity for early diagnosis. Thus HCV RNA detection may ultimately be the preferred method for HCV diagnosis and for screening blood donors. Unfortunately, HEV diagnosis may rest on the efforts of research laboratories for electron microscopy, Western blot, or nucleic acid detection.

Analysis of discordant test results among five second-generation assays for anti-hepatitis C virus antibodies also tested by polymerase chain reaction-RNA assay and other laboratory and clinical tests for hepatitis

The diagnostic performances of five commercially available second-generation assays for anti-hepatitis C virus antibody, two enzyme-linked immunosorbent assays, one enzyme immunoassay, and two particle agglutination assays (passive hemagglutination assay and particle agglutination assay), were evaluated. Among 104 samples from healthy subjects and 300 consecutive samples from patient ordered for routine determinations of anti-hepatitis C virus antibody in serum, assay results showed variable degrees of discordance for 17 samples (4.2%). These 17 samples were further tested by an immunoblot assay, the polymerase chain reaction-RNA assay, and the hemagglutination inhibition assay. Four of the 17 samples were regarded as true positive, since all supplementary assays and clinical data indicated active hepatitis C virus infection. Another five samples were considered false positive because no confirmatory evidence was obtained from the laboratory analysis or clinical data. The remaining eight samples were negative for hepatitis C virus RNA, but the results of the other supplementary tests were indeterminate. Some of these samples with indeterminate results may have been from patients with subclinical cases of disease who spontaneously recovered from hepatitis with persistent anti-hepatitis C virus antibody in their sera.

Hepatitis C viral RNA titers in serum prior to, during, and after oral treatment with ribavirin for chronic hepatitis C

Ten patients with biopsy verified chronic hepatitis C virus (HCV) infection were treated with oral ribavirin at a dose of 1,000-1,200 mg per day in two divided doses for 12 weeks. Serum alanine aminotransferase (ALT) levels and hepatitis C viral ribonucleic acid (RNA) levels in serum were followed prior to, during, and 12 weeks posttreatment. ALT levels decreased significantly in all patients during therapy from a mean level of 3.21 mukat/l (range 1.22 to 7.79) before, to 1.25 mukat/l (range 0.78 to 2.04) at the end of treatment (P < 0.005). Hereafter, relapse to pretreatment levels was seen within 12 weeks after treatment stop. The hepatitis C viral RNA levels decreased from a mean 10 log titer of 4.1 (range 1-6) before treatment to 3.4 (range 1-5) at treatment stop. Five patients did not change their HCV RNA titers during treatment. Twelve weeks posttreatment only 3 patients had lower titers than prior to treatment. We conclude that oral ribavirin seems to reduce the viral load, at least temporarily, in some patients with chronic viremic HCV infection. Further studies are needed to evaluate fully the effect of oral ribavirin on chronic HCV infection.