Factors influencing the response to interferon therapy in chronic hepatitis C. Studies on viral genotype and induction of 2',5'-oligoadenylate synthetase in the liver and peripheral blood cells

BACKGROUND

The mechanism behind the antiviral action of interferon (IFN) therapy in chronic hepatitis C virus (HCV) infection is not well understood, and, furthermore, few factors have been shown to be good predictors of a favourable response to IFN treatment in chronic HCV infection.

METHODS

Freshly explanted liver cells and peripheral blood mononuclear cells (PBMC) from 80 patients with chronic HCV infection were used to study the capacity of IFN to induce the enzyme 2',5'-oligoadenylate synthetase (2'5'-AS) in vitro. The HCV genotype was determined in 53 patients. The induction of 2'5'-AS was correlated to the results of IFN-alpha treatment in 36 patients.

RESULTS

Normalization of transaminases during IFN treatment was significantly associated with 2'5'-AS levels in liver cells cultured in the absence of IFN. A similar tendency, although not statistically significant, was found for IFN-induced levels of 2'5'-AS in liver cells. No such associations were found when PBMC were analysed. Six patients showed a sustained biochemical response. These six did not deviate significantly from the remaining patients with regard to base-line or IFN-induced levels of 2'5'-AS in liver cells or PBMC. Eradication of HCV RNA during IFN treatment did not correlate with 2'5'-AS levels in liver cells. Comparison of HCV genotype and clinical response showed that patients with genotype 3a had the most favourable outcome. No association was found between liver histology and treatment outcome.

CONCLUSION

These data imply that direct effects of IFN on liver cells are of importance for the response to IFN treatment.

Utility of an anonymous questionnaire for the identification of a primary transmission route and possible secondary transmission in adults with acute hepatitis B virus infection

By letting adults with acute hepatitis B virus (HBV) infection answer an anonymous questionnaire covering risks associated with the acquisition and further transmission of HBV infection, we found that a likely relevant transmission route could be identified in most patients. Despite being informed of the diagnosis, 50% of the patients exposed others via sexual contact during their contagious period.

Restriction of hepatitis C virus heterogeneity during prolonged interferon-alpha therapy in relation to changes in virus load

To determine how interferon-alpha (IFN-alpha) treatment changes the heterogeneity of the hepatitis C virus (HCV) population, the hypervariable region 1 (HVR1) was directly sequenced, and the virus load was quantified in 15 patients who had received IFN-alpha for 15 months. Before treatment, 13 patients exhibited heterogeneous HVR1 sequences. In 7 subjects who did not respond or did not sustain a response to treatment, significantly decreased heterogeneity of the HVR1 was found at the end of treatment (P=.01). In 6 of these patients, the virus load decreased in parallel with the changes in HVR1 heterogeneity. At follow-up, both the virus load and the heterogeneity increased in 4 patients, and the virus load, but not the heterogeneity, increased in 2. In the seventh patient, the virus load steadily increased during treatment and follow-up. These results suggest that a selection of HVC strains may occur during prolonged IFN-alpha treatment, concomitant with general suppression of the viral replication.

Activated Cellular Immunity in Chronic Hepatitis C

The importance of local immune mechanisms in the development of chronic hepatitis C and its relation with systemic immune disorders is becoming clear and suggests a more generalized involvement of the immune response in this disease. For this reason, we have investigated the serum concentrations of the soluble immune activation markers neopterin, β2-microglobulin and interferon-γ in 28 patients with hepatitis C virus related chronic active hepatitis (n=20) or chronic persistent hepatitis (n=8). Increased levels of neopterin, β2-microglobulin and interferon-γ were found in a subgroup of the patients. Serum β2-microglobulin and neopterin concentrations were strongly related. Patients with chronic active hepatitis had higher β2-microglobulin levels than those with chronic persistent hepatitis. There were no significant differences in neopterin and interferon-γ levels between chronic active hepatitis and chronic persistent hepatitis. A strong association was found between older age and higher β2-microglobulin levels. Because patients with chronic active hepatitis were older than patients with chronic persistent hepatitis, older age may have at least partly contributed to the difference in β2-microglobulin. Because of the known association between cell-mediated immune activation and the production of interferon-γ, neopterin and β32-microglobulin, our results imply that a Th1-type immune response is stimulated in chronic hepatitis C.

Risk factors for hepatitis A, B and C virus infection among Swedish expatriates

The influence of different risk factors for viral hepatitis A, B and C, particularly if sexual contact with the indigenous population was related to an increased risk of having hepatitis B virus (HBV) markers, was assessed by multivariate analysis in a logistic regression model in a prospectively enrolled series of 563 adult Swedish expatriates. The most frequently reported recognised risk factors for the acquisition of viral hepatitis (as reported in a self-administered questionnaire) were having received an inoculation during medical or dental treatment, reported by 45% of all subjects, and having had sexual contact with the indigenous population, reported by 35%. Whilst the prevalences of hepatitis A virus (HAV) and hepatitis C virus (HCV) markers in these expatriates were of the same magnitude as previously reported in the general Swedish population, 8% and 0.3%, respectively, the prevalence of markers for a past or present HBV infection was about twice as high (5%). The presence of HBV markers was associated with being a health care professional or having received inoculations during medical or dental treatment in Africa. No significant association was found between having HBV markers and having had sexual contact with the indigenous population.

HCV genotypes in Swedish blood donors as correlated to epidemiology, liver disease and hepatitis C virus antibody profile

Sixty-two anti-HCV and HCV-RNA positive Swedish blood donors (44 men, 18 women; median age 34 years) were studied. HCV genotypes were correlated to parenteral risk factors, liver morphology, serum alanine aminotransferase (ALAT) levels and HCV antibody profile. Forty percent of the donors were infected with HCV genotype 1a, 10% with 1b, 21% with 2b, and 29% with 3a. Intravenous drug use (IVDU) was more common in donors with genotype 3a than in those with genotype 1a (p = 0.024), and prior blood transfusion more common in genotype 2b than in 3a (p = 0.012). Chronic active hepatitis with and without cirrhosis was found in 38% of donors infected with genotype 2b as compared to 8% of donors infected with 1a (p = 0.034). Forty percent of donors with genotype 1a had normal ALAT at the time of liver biopsy versus 11% with genotype 3a (p = 0.046). Antibodies to C33c and C22-3 were present in nearly all donors whereas reactivity to C100-3 and 5-1-1 was detected more often in donors with genotypes 1a and 1b as compared to donors with genotypes 2b and 3a. In conclusion, genotype 3a was correlated to IVDU or tattooing as parenteral risk factors for the acquisition of HCV infection, and genotype 2b to prior blood transfusion. Donors with genotypes 1a seemed to have less severe liver disease than those infected with genotypes 2b and 3a.

Distinguishing acute from symptomatic chronic hepatitis C virus (HCV) infection by site-directed serology of the HCV structural proteins

To distinguish acute from symptomatic chronic hepatitis C virus (HCV) infection, site-directed serology was done on the complete core, envelope 1, and envelope 2 proteins using multiple peptide assays. Serum samples were obtained from 7 patients with clinically confirmed acute HCV infections and from 36 patients with symptomatic chronic HCV infections. At onset of symptoms, all patients with acute infection had HCV RNA in serum, 1 had > 2 strong core peptide reactivities (A405 > 1.0), and the number of core reactivities increased with time in 6 patients. In contrast, 35 of 36 chronic-phase patients with HCV RNA in serum had 3-12 strong core reactivities (P < .001). Envelope 2 antibodies were found in 2 acute-phase and in 32 chronic-phase HCV patients (P < .01). Thus, a serum sample with HCV RNA from a patient with hepatitis can be classified as acute or chronic using site-directed serology of the HCV structural proteins.

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.

Two-year biochemical, virological, and histological follow-up in patients with chronic hepatitis C responding in a sustained fashion to interferon alfa-2b treatment

Fourteen patients with chronic hepatitis C who had a sustained response to a 60-week interferon alfa-2b treatment course were followed, biochemically and virologically, 2 years after treatment cessation. Biopsies were repeated in 12 of 14 for histological and virological evaluation at 2-year follow-up. All 14 patients had normal serum alanine transaminase (s-ALT) levels and were negative for hepatitis C virus (HCV) RNA in serum during treatment and at short-term follow-up 6 months post-treatment. At 2-year follow-up, 13 patients still had normal ALT levels (< 0.6 mukat/L for women; < 0.8 mukat/L for men), 1 a near normal level (0.76 mukat/L); all were HCV RNA negative in serum, and 11 of 12 also in the liver. Liver histology improved during treatment and remained stable during the 2-year follow-up. The authors conclude that most sustained responders, who have normal ALT levels and are nonviremic at short-term follow-up 6 months after interferon treatment, will continue to have a durable long-term response without relapse of the viremia.

Combination treatment with interferon alfa-2b and ribavirin for chronic hepatitis C in patients who have failed to achieve sustained response to interferon alone: Swedish experience

BACKGROUND

Only 10-20% of patients treated with interferon alfa alone attain long-term benefits. More effective regimens are needed.

METHODS

Twenty Swedish patients with chronic hepatitis C virus infection, ten with a prior non-response and ten with a non-sustained response to interferon alfa treatment alone, were treated with interferon alfa-2b and ribavirin in combination for 24 weeks, then followed up for another 24 weeks. Patients received interferon alfa-2b subcutaneously 3 MU thrice weekly and oral ribavirin 1000-1200 mg/day.

RESULTS

All ten patients with a prior non-sustained response to interferon alone had a sustained biochemical response with normal aminotransferase levels at follow-up; nine also had a sustained viral response with a negative HCV-RNA test in serum. Among the ten patients with a prior biochemical non-response to interferon alone, five had normal aminotransferase levels at the end of therapy; four were negative for HCV RNA in serum. At follow-up, three had normal aminotransferase levels and a negative HCV-RNA test in serum. No major adverse effect was seen, apart from fatigue and an expected fall in hemoglobin levels from a mean of 155 g/l to 124 g/l at the end of therapy. All patients completed the treatment schedule, but the ribavirin dose was reduced in one patient because of a fall in hemoglobin to 99 g/l.

CONCLUSIONS

These results indicate that combination treatment with interferon alfa-2b and ribavirin offers a chance of sustained biochemical response and virus eradication in a subset of patients who fail to achieve sustained response with interferon alfa alone.

Hepatitis E virus infections in patients with acute hepatitis non-A-D in Sweden

A total of 12 patients previously treated for acute hepatitis of unknown aetiology were retrospectively found to be anti-hepatitis E virus (HEV) IgG-positive. Four patients were anti-HEV IgM- and IgG-positive consistent with an acute HEV infection. All 4 had travelled to or were immigrants from HEV-endemic countries. One anti-HEV IgM-negative patient seroconverted from anti-HEV IgG-negative to positive and 3 from anti-HEV IgG-positive to negative in 2 consecutive serum samples. Of the remaining 4 patients without anti-HEV IgM, 3 had a history of recent travel to an HEV-endemic country. Most patients were young adults and all but 1 recovered from the hepatitis. One patient with a fulminant hepatitis was anti-HEV IgG-positive when tested 4 months after a journey to Turkey. She died from her fulminant hepatitis shortly after admission. All the other patients but 1 normalized their serum liver enzymes within 1-2 months after the onset of disease.

Response to a booster dose 18 months after a low anti-HBs response (10-99 IU/l) to three doses of intradermally or intramuscularly administered recombinant hepatitis B vaccine

The response to a booster dose, given by the same route 18 months after the completion of the primary vaccination scheme, was studied in hospital staff members who responded with anti-HBs levels in the range of 10-99 IU/l after three intradermal (i.d., n = 51) or intramuscular (i.m., n = 11) doses of recombinant hepatitis B virus (HBV) vaccine administered at 0, 1 and 6 months. At the time of boostering the anti-HBs levels had declined to < 10 IU/l in 44/51 (86%) of the i.d. and 10/11 of the i.m. vaccines. All i.m. and 90% of i.d. vaccinees responded to the booster dose with anti-HBs level > or = 10 IU/l, and with geonmetric mean titres 1,074 IU/l and 121 IU/l, respectively. It was concluded that all i.m. and 90% of i.d. vaccinees with an initial anti-HBs response of 10-99 IU/l after three doses of HBV vaccine (among whom the anti-HBs levels in the majority had declined < 10 IU/l) mounted an anti-HBs level > or = 10 IU/l after a booster dose. The anti-HBs concentrations were generally higher after i.m. than i.d. booster doses in accordance with the response to primary vaccination.

Genotyping of hepatitis C virus isolates by a modified polymerase chain reaction assay using type specific primers: epidemiological applications

A polymerase chain reaction (PCR)-based assay using primers against the hepatitis C core gene has been described [Okamoto et al. (1992a): Journal of General Virology 73:673-679]. Within the two major HCV genotypes 1 and 2, the Okamoto system identifies two subtypes each (1a, 1b and 2a, 2b, respectively). Typing is achieved by a primary PCR with consensus primers followed by a nested PCR with type specific primers. The original assay was modified by addition of a parallel second PCR identifying the recently described major genotype 3. The assay also identifies in duplicate subtype 1b (type II by Okamoto), suggested to respond poorly to interferon. Reaction conditions were reviewed and melting temperatures of all typing primers equalised to increase strigency. The modified system functioned well and typing results were supported by partial core sequencing. The following distribution of genotypes was found in 53 hepatitis C virus (HCV) infected Swedish blood donors: genotype 1a (57%), 3 (19%), 1b (13%), and 2b (11%). In six recipients of HCV infected blood identified in a retrospective study, the recipient HCV genotype was identical to donor HCV genotype. Furthermore, in HCV positive couples identical genotype was observed when only one partner had an external risk factor; whereas genotypes were often diverse if both sex partners had parenteral risk factors. Finally, a cluster of hepatitis C cases in a haemodialysis unit was evaluated retrospectively. Eight patients had genotype 1b, two had mixed 1a and 1b, and one had type 1a. The modified HCV genotyping assay was of value in examining different epidemiological situations and can be expanded presumably to include future genotypes.

Treatment of chronic replicative hepatitis B virus infection with short-term continuous infusion of foscarnet

Three patients with chronic replicative hepatitis B virus infection were treated for 7 days with a continuous intravenous infusion of foscarnet (trisodium phosphonoformate) after an initial bolus dose of 20 mg/kg body weight. Although the dose was calculated from a nomogram, approximately only half the intended plasma concentration (500 microM/l = 150 micrograms/l) was achieved. The levels of s-ALAT, HBV-DNA and DNA-polymerase changed only marginally during the treatment and 24-week follow-up period. All three patients remained HBsAg and HBeAg positive during treatment and follow-up. There were no severe side-effects. We conclude that foscarnet treatment with the dose regimen given in this study had no or only a minor antiviral effect in patients with chronic replicative HBV infection. It remains to be explored if higher doses, longer treatment periods or the use of foscarnet in combination regimen are more effective.

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.

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.

Prevalence of antibodies against hepatitis C virus infection among health care workers in Stockholm

The prevalence of hepatitis C virus (HCV) markers was investigated among health care staff with a high rate of exposure to blood or needle-stick injuries. After screening sera in pools of 10 at a time and individual testing of all reactive pools, totally 6 of 880 (0.7%; 95% confidence interval, 0.25-14.8%) were positive for anti-HCV, a figure of the same order as that found among Swedish first-time blood donors. Among the seropositives, all of five evaluable had been exposed to blood and four of five to needle-stick injuries. Our data suggest that HCV, in addition to hepatitis B virus, may constitute an occupational hazard for health care workers in Stockholm, even though the risk appears to be low, and personal risk factors such as intravenous drug abuse or blood transfusion could not be ruled out as sources of the infection.

High sustained response rate and clearance of viremia in chronic hepatitis C after treatment with interferon-alpha 2b for 60 weeks

To evaluate the effect of prolonged interferon-alpha treatment on serum aminotransferase levels and hepatitis C virus RNA in serum, 40 patients with chronic hepatitis C virus infection were treated with 3 MU interferon-alpha 2b thrice weekly for 60 wk. Before treatment all patients had elevated serum ALT levels for at least 1 yr, antibodies to HCV by second-generation tests and liver histological findings consistent with chronic hepatitis C. Before treatment hepatitis C virus RNA was found in serum in 39 of 40 (97.5%) patients. Normalization of ALT levels at treatment cessation was seen in 24 of 40 (60%) patients, of whom 15 of 24 (62.5%) had sustained ALT responses up to 24 wk after treatment. At follow-up, 24 wk after treatment, hepatitis C virus RNA was cleared from serum in 17 of 40 (42.5%) patients, including all sustained responders, one nonsustained responder and one nonresponder. We conclude that 60 wk of treatment with interferon-alpha 2b seems to induce a high percentage of sustained response, which coincides with cessation of viral replication.

Seroconversion after additional vaccine doses to non-responders to three doses of intradermally or intramuscularly administered recombinant hepatitis B vaccine

Hospital staff members who failed to respond (anti-HBs < 10 IU/l) after 3 doses of a recombinant hepatitis B (HBV) vaccine (given either as 20 micrograms intramuscularly (n = 8) or 2 micrograms intradermally (n = 15)) received 1 or 2 additional doses by the same route as the initial vaccination. After the first additional dose, 12/23 responded with anti-HBs levels > or = 10 IU/l and after the second, another 2/5 responded, corresponding to a total response rate of 61%. No significant difference was seen in the response rate according to vaccination route, gender, age, or whether the vaccinee was a smoker or not. In this limited study some 50% of non-responders to 3 intradermal or intramuscular doses of recombinant HBV vaccine seroconverted after an additional 1-2 doses given by the same route as the initial vaccination, suggesting that additional doses can be administered by the same route as the initial one.

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.

Hepatitis C virus replication in liver and peripheral blood mononuclear cells of interferon-alpha-treated and untreated patients with chronic hepatitis C

Serum, liver tissue, and peripheral blood mononuclear cells (PBMC) were obtained from 72 patients with chronic hepatitis C, 19 of whom had received interferon-alpha (IFN-alpha) treatment. Hepatitis C virus (HCV) RNA was detected by polymerase chain reaction in the serum and liver of all patients with relapse after treatment and in 51 of 53 (96%) sera, 28 of 29 (97%) livers, and all of 13 (100%) PBMC from untreated patients but not in 3 patients with completely sustained responses. Minus-stranded HCV RNA was found in 5 of 14 (35%) sera, 16 of 17 (94%) livers, and 7 of 13 (53%) PBMC from untreated patients. The results indicate that HCV RNA is present not only in serum and liver but also in PBMC from the vast majority of untreated anti-HCV-seropositive patients and also in patients who respond to IFN-alpha treatment but then relapse. HCV replicates in the liver of almost all patients, but replication may possibly also occur in PBMC. By contrast, HCV RNA seems to be eradicated in patients with completely sustained responses.

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.