Detection of hepatitis C virus by polymerase chain reaction and response to interferon-alpha therapy: relationship to genotypes of hepatitis C virus

To investigate the relationship between genotypes of hepatitis C virus and response to interferon-alpha therapy, hepatitis C virus RNA was assayed by polymerase chain reaction with three sets of primers and probes in 70 patients with non-A, non-B chronic hepatitis who received interferon-alpha. Twenty-four patients sustained long-term remissions (complete responders). Polymerase chain reaction for 5'-terminal noncoding region detected hepatitis C virus RNA in 94.3% (66 of 70) of the patients. Polymerase chain reaction for nonstructural region 3, in which primers and a probe were synthesized to be identical to hepatitis C virus-J, detected hepatitis C virus RNA in 40 patients. Polymerase chain reaction for nonstructural region 5-in which sequences of primers and a probe were derived from hepatitis C virus-K2, a genotype different from hepatitis C virus-J--detected hepatitis C virus RNA in 17 patients. Only one patient was positive on both nonstructural region 3 and nonstructural region 5 polymerase chain reaction. Nucleotide sequence of clones obtained from 5' terminal noncoding region polymerase chain reaction products of two patients positive on polymerase chain reaction for nonstructural region 3 and negative on polymerase chain reaction for nonstructural region 5 (group 1) corresponded to that of the hepatitis C virus-J group, and those of clones from two patients negative on polymerase chain reaction for nonstructural region 3 and positive on polymerase chain reaction for nonstructural region 5 (group 2) corresponded to that of hepatitis C virus-K2.(ABSTRACT TRUNCATED AT 250 WORDS)

Tumor necrosis factor alpha production by peripheral blood mononuclear cells of patients with chronic liver disease

We investigated the production of tumor necrosis factor alpha by peripheral blood mononuclear cells of patients with chronic liver disease and its association with hepatitis activity. Tumor necrosis factor alpha production was measured with an enzyme-linked immunosorbent assay. Tumor necrosis factor alpha production by peripheral blood mononuclear cells stimulated with recombinant gamma-interferon of patients with chronic active hepatitis (5.8 +/- 4.0 units per ml, p less than 0.05) and patients with cirrhosis (4.1 +/- 2.1 units per ml, p less than 0.05) was significantly increased when compared with controls (2.5 +/- 1.6 units per ml). Tumor necrosis factor alpha production by peripheral blood mononuclear cells stimulated with a combination of recombinant gamma-interferon and recombinant interleukin 2 of patients with chronic persistent hepatitis (5.8 +/- 3.8 units per ml, p less than 0.05), patients with chronic active hepatitis (8.9 +/- 3.0 units per ml, p less than 0.001) and patients with cirrhosis (6.7 +/- 3.2 units per ml, p less than 0.05) was significantly increased in comparison with controls (3.3 +/- 1.8 units per ml). Tumor necrosis factor alpha production of patients with chronic active hepatitis was significantly higher than that of patients with chronic persistent hepatitis (p less than 0.05). There was a significant correlation (r = 0.5699, p less than 0.005) between tumor necrosis factor alpha production and histologic activity index in patients with chronic persistent hepatitis or chronic active hepatitis. These findings show that tumor necrosis factor alpha production is increased in chronic liver disease and that the increased tumor necrosis factor alpha production is related to hepatitis activity.

Transient elastography: Applications and limitations

Transient elastgraphy with use of FibroScan is one of most accurate methods for assessment of liver fibrosis. FibroScan can be readily used with an operator with a short training. In many different studies, liver stiffness measured by transient elastgraphy correlates well with fibrosis stages, and cutoff values of liver stiffness for fibrosis staging are similar even among different diseases. However there is wide variation of stiffness values in the same fibrosis stage, and some overlap between the adjacent stages. In addition, inflammatory activity and size of nodule of cirrhosis affect the liver stiffness values. The reproducibility may be reduced by age, obesity, steatosis, narrow intercostal space and lower degrees of hepatic fibrosis in patients. Thus the estimation of fibrosis stages from liver stiffness should be cautiously done. To improve the accuracy of liver fibrosis staging, the combination of transient elastography with other noninvasive methods such as FibroTest should be required.

Measurement of liver stiffness as a non-invasive method for diagnosis of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of liver disease worldwide. To detect early stages of NAFLD and start treatment or to monitor the changes in trials of new drugs, non-invasive diagnostic methods are needed, such as biochemical markers or liver stiffness measurement (LSM). LSM with transient elastography (TE) and acoustic radiation force impulse (ARFI) has been shown to be useful in NAFLD, although the cut-off values have varied among reports. Magnetic resonance elastography and real-time tissue elastography also can be useful for the diagnosis of NAFLD, although the number of studies is limited. Fibrosis is absent in 8-40% of patients with non-alcoholic steatohepatitis (NASH), making it difficult to diagnose NASH by LSM because LSM is usually associated with fibrotic stage. The presence of inflammation or hepatocyte ballooning may affect LSM and aid the diagnosis of NASH without fibrosis. However, obesity significantly increases the failure of LSM and its interference is more conspicuous in TE than in ARFI. The newly implemented XL probe of TE has overcome the difficulty to some degree. Nonetheless, the effects of obesity, hepatocyte ballooning, steatosis and inflammation on LSM values have not yet been adequately investigated, although they are likely to affect LSM values. Further studies are needed to establish the clinical utility of LSM in NAFLD.

Humoral immune response to the hypervariable region of hepatitis C virus differs between genotypes 1b and 2a

Antibody to the hypervariable region (HVR) of HCV is thought to have neutralizing activity. The HCV genotype is known to affect the clinical course of infection. The antibody response to HVR and its relationship to the virologic and clinical characteristics were investigated in 21 patients with chronic hepatitis C. HVRs amplified by polymerase chain reaction from serum HCV were expressed as glutathione S-transferase fusion proteins. From 8 to 34 clones per serum sample were obtained (375 clones total), and the anti-HVR antibody in serum was assessed by Western blot. Both the incidence of fusion proteins positive for anti-HVR antibody and the activity of antibody were significantly higher in 6 patients with genotype 2a than in 15 patients with genotype 1b. This result suggests that the quantity of humoral response to HVR affects the clinical outcome of infection with these two HCV genotypes.

Immunohistochemical studies of intrahepatic tumour necrosis factor alpha in chronic liver disease

To determine the intrahepatic production of tumour necrosis factor alpha (TNF alpha) in chronic liver disease three monoclonal antibodies were used against TNF alpha in immunohistochemical studies of liver tissue sections from patients with chronic liver disease. All three monoclonal antibodies stained infiltrating mononuclear cells. Monoclonal antibody II 7C2 also stained the cytoplasm or nucleus, or both, of a varied number of hepatocytes from nine patients with chronic hepatitis B virus infection, suggesting that the antigenic epitope related to hepatitis B core antigen (HBcAg) crossreacted with II7C2. The other two monoclonal antibodies, III2F3 and IV3E5, stained significantly larger numbers of mononuclear cells in cases of chronic active hepatitis B than in chronic persistent hepatitis B, or hepatitis B related liver cirrhosis. III2F3 stained significantly larger numbers of mononuclear cells in non-A, non-B chronic active hepatitis than in chronic persistent hepatitis B or hepatitis B related liver cirrhosis. These results indicate that TNF alpha is produced and secreted by infiltrating mononuclear cells in focal inflammatory areas of the liver, and suggest that TNF alpha may have a role in the inflammatory activity of chronic liver disease.

Predictive factors in the response to interferon therapy in chronic hepatitis C

Factors predicting the efficacy of interferon therapy were statistically analyzed on 111 patients with chronic hepatitis C. Of the treated patients (total doses of interferon; 96-468 MU), 35 (31.5%) had a long-term remission. On multivariate analysis, hepatitis C virus genotype (p < 0.0001), histological diagnosis (p < 0.05), fibrosis score of histological activity index (p < 0.01) and source of infection (p < 0.05) were found useful for predicting the response to interferon therapy. Our findings suggest that the outcome of interferon therapy can be predicted to some degree from pretreatment data, and that a new therapeutic strategy is necessary for the group of patients who are predicted to be nonresponders.

Can non-invasive assessment of liver fibrosis replace liver biopsy?

Transient elastgraphy, acoustic radiation force impulse and real-time elastography are the methods with very good or excellent diagnostic accuracy for the assessment of liver fibrosis stage. They do not provide the information on inflammatory activity, steatosis, iron deposition or other findings derived from liver biopsy. Even on account of fibrosis stage, these non-invasive methods do not give us the estimation completely corresponding to that of liver biopsy. However they provide us useful clinical information that liver biopsy has been providing us, such as appropriate time to start antiviral therapy, prediction of response to antiviral therapy, evaluation of effects of antiviral therapy, assessment of natural course of hepatitis and estimation of prognosis of hepatitis. Recently non-invasive methods for assessment of inflammatory activity, steatosis and iron deposition in the liver have been developed. Thus in the near future, non-invasive methods will replace liver biopsy.

Deficiency of antibody response to hypervariable region of hepatitis C virus in patients with chronic hepatitis C

BACKGROUND/AIMS

Frequent mutations in the hypervariable region of hepatitis C virus have been suggested to be a cause of persistent infection by providing a way for the virus to escape host immunity. However, the variation rate in the hypervariable region is often low in patients with chronic hepatitis. The aim of this study was to elucidate the mechanism of persistent infection in patients with chronic hepatitis by investigating the relationship between the antibody response to and the variation in hypervariable region.

METHODS

The hypervariable regions of 26 clones of six patients with chronic hepatitis C were expressed as proteins fused with glutathione S-transferase, and sera of the patients were serially tested for antibody to these proteins.

RESULTS

The extent of antibody response to the hypervariable region differed considerably among the patients. Three patients showed no or only scanty antibody response. These had a lower variation rate in the hypervariable region (0-1.3/year) than in the others with frequent or persistent antibody response (2.1-14.6/year). In two patients, serum samples were found to be reactive with the clones even before the appearance of the clones. In three patients, coexistence of the antibodies and corresponding clones were noted. An augmentation of antibody response always followed rises in serum alanine aminotransferase levels.

CONCLUSION

Deficiency of antibody response to the hypervariable region may be one of the causes of persistency in hepatitis C virus infection.

Biochemical response to interferon therapy correlates with interferon sensitivity-determining region in hepatitis C virus genotype 1b infection

Biochemical responders maintain normal alanine aminotransferase levels after interferon (IFN) therapy despite persistent presence of hepatitis C virus (HCV) RNA in their sera. There have been few reports on predictive factors for biochemical response. A region associated with sensitivity to IFN was identified in the nonstructural protein 5 A of genotype 1b [aa 2209-2248; IFN sensitivity-determining region (ISDR)]. The substitutions in ISDR correlate with sustained response to IFN. In this report, we assessed the association of ISDR with biochemical response. The sequences of ISDR were determined in 62 patients with HCV genotype 1b treated by IFN in two randomized controlled trials. 30 patients had wild ISDR (identical to HCV-J), 20 intermediate ISDR (1-3 amino acid substitutions compared with HCV-J), and 12 mutant ISDR (four or more amino acid substitutions). All 12 patients with mutant ISDR had a sustained response, while only one of those with wild or intermediate ISDR had a sustained response (P < 0.0001). In the 49 patients other than sustained responders, the patients with intermediate ISDR obtained biochemical response significantly more frequently (52.6%, 10/19) than those with wild-type ISDR (20.0%, 6/30) (P < 0.05). Multivariate analysis indicated the number of substitutions in ISDR as the most important predictor for biochemical response (discriminant coefficient=1.08, P < 0.05) and sustained response (discriminant coefficient=6.13, P < 0.0001). In phylogenetic analysis, clustering of sustained responders and biochemical responders was observed. These results demonstrate that the substitutions in ISDR are the most important predictor for biochemical response to IFN in patients infected with genotype 1b as well as for sustained response.

Effect of interferon alpha, gamma, and tumor necrosis factor alpha on the HLA-A, B, C expression of cell lines derived from human liver

Our study was undertaken to determine whether human recombinant interferon alpha(rIFN alpha), gamma(rIFN gamma), and tumor necrosis factor alpha(rTNF alpha) exert an effect on the HLA-A, B, C expression of human liver cell lines. The HLA-A, B, C expression was assayed by immunoperoxidase staining and enzyme-linked immunosorbent assay. rIFN alpha and gamma enhanced the HLA-A, B, C expression of the three cell lines tested, Chang cells, SK-Hep-1, and PLC/PRF/5. The activity of rIFN gamma proved more than 8000 times more potent than that of rIFN alpha in Chang cells, 30 times in SK-Hep-1, and 20 times in PLC/PRF/5, respectively. rTNF alpha also enhanced the HLA-A, B, C expression of the three cell lines. The enhancement of HLA-A, B, C expression by rIFN alpha and gamma reached a peak on day 3, and that by rTNF alpha on day 5. These findings suggest that IFN alpha, IFN gamma, and TNF alpha may play similar roles in enhancement of HLA-A, B, C expression of hepatocytes in hepatitis and hepatoma cells.

Randomized controlled trial of twice-a-day administration of natural interferon beta for chronic hepatitis C

We conducted a randomized controlled trial to assess the efficacy of twice-a-day administration of natural interferon beta (IFNbeta) as an induction of IFN therapy for chronic hepatitis C. Seventy-one patients with chronic hepatitis C were enrolled into the trial and randomly assigned into three treatment groups. Six million units (MU) of IFNbeta were administered once-a-day for the first 4 weeks, and then thrice weekly for 12 weeks in 20 patients (once-a-day group). Three milion units of IFNbeta were administered twice-a-day for the first 2 weeks, 6 MU once-a-day for the next 2 weeks, and then thrice weekly for 12 weeks in 23 patients (twice-a-day+beta group), or 6 MU of lymphoblastoid IFNalpha were administered thrice weekly for the last 12 weeks instead of IFNbeta in 28 patients (twice-a-day+alpha group). Four patients in once-a-day group (20%), 9 in twice-a-day+beta group (39%), and 12 in twice-a-day+alpha group (43%) obtained sustained response. Sustained response rate in twice-a-day groups was higher than in once-a-day group, although there was no statistical significance. The present study suggested the possible superiority of twice-a-day administration of IFNbeta as an induction therapy to once-a-day administration, but further studies are needed to confirm this regimen.

Interferon sensitivity-determining region of nonstructural region 5A of hepatitis C virus genotype 1b correlates with serum alanine aminotransferase levels in chronic infection

The mutations in the interferon (IFN) sensitivity-determining region (ISDR) of nonstructural region 5A (NS5A) of hepatitis C virus (HCV) have been correlated with response to IFN therapy. NS5A appears to disrupt a host antiviral pathway that plays a role in suppressing virus replication and protects hepatocytes from apoptosis. We assessed whether ISDR correlates with viral load and serum alanine aminotransferase (ALT) levels. Serum viral load and ALT levels were prospectively measured bimonthly by HCV core protein assay and monthly, respectively, for 22 months in 87 patients chronically infected with HCV genotype 1b. ISDR of HCV was directly sequenced from the products of reverse transcription and polymerase chain reaction of HCV RNA. Five patients had four or more substitutions (mutant type), 33 had 1-3 (intermediate type), and 49 had no substitutions (wild type) in ISDR. The numbers of substitutions in ISDR were inversely correlated with mean viral load over a 22-month period (r = 0.292, P = 0.0060) and directly with mean serum ALT levels (r = 0.360, P = 0.0006). The numbers of substitutions in ISDR was significantly larger in the patients with changes of viral load more than fivefold during the 22 months (1.4 +/- 2.4) than in those without changes (0.6 +/- 0.8) (P = 0.0188). The present study demonstrates that the patients with more substitutions in ISDR had significantly higher serum ALT levels and smaller viral load. These results suggest that NS5A with more substitutions in ISDR may lose the ability to block host antiviral pathways and to protect hepatocytes from apoptosis.

Randomized controlled trial of lymphoblastoid interferon alpha for chronic hepatitis C (comparison of 9-MU and 6-MU doses). IFN Treatment Group of Affiliated Hospitals of the Third Department of Internal Medicine at Nagoya University School of Medicine

OBJECTIVE

We conducted a randomized controlled trial to compare the efficacy of two different dosages of lymphoblastoid interferon alpha (IFN) for the treatment of chronic hepatitis C.

METHODS

Eighty-four patients with chronic hepatitis C were enrolled and randomly assigned into the two groups; group A was treated with 6 million units (MU) and group B with 9 MU daily for the first 2 wk, and then thrice weekly for an additional 14 or 22 wk.

RESULTS

Eighty patients were evaluated (39 patients in group A and 41 in group B); 14 patients in group A (35.9%) and 15 in group B (36.6%) obtained sustained response. The percentages of patients who became negative for HCV RNA at the end of the second wk differed slightly between the groups, without statistical significance (56.4% and 68.3%). When assessed in detail, patients with genotype 1 and < 1 Meq/ml of viral load became negative for HCV RNA significantly more frequently in group B (eight of eight) than in group A (three of seven) (p < 0.05) at the end of the second week, whereas the sustained response rate was similar between the groups (five of eight and four of seven). Predictors of sustained response by multivariate analysis were low viral load (< 1.0 Meq/ml) and negativity of HCV RNA at the end of the second wk of IFN.

CONCLUSIONS

The results indicated that there was no difference in sustained response rate between the 6-MU and 9-MU doses. The earlier disappearance of HCV RNA, at the end of the second wk or at least by the end of the fourth week, is an essential condition for sustained response.

Recombinant human interleukin 1 alpha is cytotoxic for and increases surface expression of HLA-A,B,C antigens of a human hepatoma cell line, PLC/PRF/5

Our study was undertaken to determine whether human recombinant interleukin 1 alpha (rIL 1 alpha) has any effect on the proliferation and expression of HLA-A,B,C antigens of human liver cell lines. The addition of rIL 1 alpha reduced the cell number of the human hepatoma cell line, PLC/PRF/5. This effect was determined to be cytotoxic, but not growth inhibitory, rIL 1 alpha did not change the number of Chang cell or SK-Hep-1 at a concentration as, high as 25,000 U/ml. rIL 1 alpha enhanced the expression of HLA-A,B,C antigens on PLC/PRF/5, but had no effect on Change cell or SK-Hep-1. Receptor binding studies showed that 125I-rIL 1 alpha bound to PLC/PRF/5 in a specific and saturable manner, but did not bind to Chang cell or SK-Hep-1. Scatchard plot analysis of the binding to PLC/PRF/5 revealed a single type of high affinity binding site with an apparent dissociation constant of approximately 5 x 10(-5) M and the presence of approximately 150 binding sites per cell. These findings suggest that IL 1 alpha may play a role in host defense against some hepatomas as cytotoxic factor and may be an enhancer of expression of HLA-A,B,C antigens on tumor cells.

Activity of antibodies to hepatitis C virus of patients with chronic non-A, non-B hepatitis decreases during interferon alpha therapy

The activity of antibodies to hepatitis C virus (anti-HCV) was investigated in 80 patients with chronic non-A, non-B liver diseases. Anti-HCV antibodies were positive in 82.5% (66/80), and the titers were 1 for 18 patients, 2 for 40 and 3 for 8, respectively. The frequency of anti-HCV was significantly lower in patients with chronic persistent hepatitis (8/13, 61.5%) than in those with chronic active hepatitis (42/49, 85.7%) (P less than 0.05). There was no significant difference in the distribution of anti-HCV titers among the different stages of hepatitis. There was no correlation between anti-HCV titer and histology activity index score in chronic hepatitis. Activity of anti-HCV decreased more frequently in the patients who responded to interferon alpha (IFN alpha) therapy (8/22, 36.4%) than in those who did not (0/9, 0%) (P less than 0.05). These results indicate that anti-HCV activity does not correlate with the activity or disease stage of chronic hepatitis, but that anti-HCV activity decrease more frequently during IFN alpha treatment in patients who responded to IFN alpha therapy.

Occurrence of immunohistochemically detected small Mallory bodies in liver disease

To determine the diagnostic significance of immunohistochemically detected small Mallory bodies (MBs) which are invisible by conventional stainings, we investigated the occurrence of MBs in liver tissue with alcoholic and nonalcoholic liver disease by immunoperoxidase staining with monoclonal anti-MB antibody, anti-NMB-3. In conventional stainings, MBs were detected in only six of 26 (23%) patients with alcoholic liver disease, and nine of 63 (14%) patients with nonalcoholic liver disease. On the other hand, MBs were detected in 20 of 26 (77%) patients with alcoholic liver disease, and 25 of 63 (40%) patients with nonalcoholic liver disease by immunoperoxidase staining. Immunohistochemically detected MBs were shown to possess the ultrastructural characteristics of MBs by immunoelectronmicroscopy in the four specimens. Our result indicates that the small MBs are not rare in nonalcoholic liver disease, and the presence of immunohistochemically detected small MBs is not a good marker of an alcoholic etiology.

Anti-hepatitis C antibodies in patients with chronic non-A, non-B hepatitis: relation to disease progression and effect of interferon alpha

The activity of antibodies to hepatitis C virus (anti-HCV) was investigated in 80 patients with chronic non-A, non-B liver diseases. Serum anti-HCV titer was determined by the "Ortho-HCV" enzyme-linked immunosorbent assay with some modifications to quantify the activity. Anti-HCV was positive in 82.5% of cases (66/80). Anti-HCV occurred significantly less often in the patients with chronic persistent hepatitis (8/13, 61.5%) than in those with chronic active hepatitis (42/49, 85.7%) (p less than 0.05). Anti-HCV titer of the patients with chronic persistent hepatitis and that with chronic active hepatitis was significantly higher than that with liver cirrhosis (p less than 0.01 and p less than 0.05). There was no correlation between anti-HCV titer and histology activity index in chronic hepatitis. Serial study demonstrated that anti-HCV titer decreased more frequently in the patients who responded to IFN alpha therapy (11/22, 50.0%) than in those who did not respond to IFN alpha therapy (0/10, 0%) (p less than 0.01). These results indicate that anti-HCV level does not correlate with the activity of hepatitis, but that it decreases in accordance with the disease progression to liver cirrhosis or with the response to IFN alpha therapy.

[Predicting factors for the response to interferon therapy against hepatitis C virus infection: HCV genotyping]

The predictive factors in the efficacy of interferon therapy were analyzed on the patients with chronic hepatitis C by multivariate analysis, and HCV genotype and histological diagnosis were found useful for predicting the response to interferon therapy. Of the patients, 57% were found to be infected with HCV II, 27% were with HCV III, and 3% were with HCV IV. HCV I was not found in our patients. The complete response rate of the patients with HCV II (21%) was significantly lower than that of HCV III (63%). The concentration of HCV RNA was significantly larger in the patients with HCV II than in those with HCV III. When the patients with equal concentrations of HCV RNA were compared, the complete response rate was also significantly lower in the patients with HCV II than in those with HCV III. On histological diagnosis, the patients with mild disease were significantly more responsive than those with severe disease. The complete response rate of the patients with HCV II who have severe histological lesions (severe CAH) was 7%. On the other hand, the complete response rate of the patients with HCV III and a histological diagnosis of mild disease (CPH or mild CAH) was 80%. Our findings suggest that the outcome of interferon therapy can be predicted to some degree from the pretreatment data.

Interleukin-2 activity in chronic active liver diseases: response by T cells and in the autologous mixed lymphocyte reaction

The T cell growth factor, interleukin-2 (IL-2), is a lymphokine which supports the immunoregulatory function of T cells. We measured the production of and response to IL-2 of peripheral blood T cell subsets from patients with chronic active liver diseases (CALD) and other liver diseases (Others) by the proliferative response of the cells activated with phytohaemogglutin P. Both production of and response to IL-2 of T cells from 24 patients with CALD were markedly decreased (P less than 0.001) in comparison with 13 controls. T cells from 10 patients with Others yielded low IL-2 titre (P less than 0.05) and responded to IL-2 in a depressed manner (P less than 0.05). OKT4+ and OKT8+ cells from five CALD patients as well as five controls equally produced IL-2 and responded to it. However, IL-2 production (P less than 0.05) and response to IL-2 (P less than 0.01) of OKT4+ cells from CALD patients were decreased in contrast to those of OKT8+ cells. We also examined the effect of IL-2 on the autologous mixed lymphocyte reaction. A highly significant increase (P less than 0.001) in the proliferative response of OKT8+ cells and unseparated T cells from 15 patients with CALD occurred with the addition of IL-2 although the values were still lower (P less than 0.01) than those of OKT8+ and unseparated T cells from 12 controls. Addition of IL-2 did not result in a significant increase of the reactivity of OKT4+ cells from patients with CALD. These results further delineate the nature of the immunoregulatory aberration in CALD.

Serial quantitation of serum core protein and viral RNA of hepatitis C virus after interferon therapy: increase in viral loads in biochemical responders

OBJECTIVES

Interferon (IFN) therapy is often ineffective in eradicating hepatitis C virus (HCV). Some patients show normal serum ALT levels for a long time after IFN therapy despite the presence of HCV. These patients are considered not virological responders but biochemical responders. We investigated the changes in the amount of HCV after IFN therapy in biochemical responders.

METHODS

Nine biochemical responders and 11 nonresponders were studied. Serum HCV amount was measured by fluorescence enzyme immunoassay for HCV core (pg/ml) and Amplicor HCV Monitor test for HCV RNA (logarithms of copy numbers per milliliter).

RESULTS

In biochemical responders, core protein and HCV RNA were increased significantly at 1 month after IFN therapy (291 +/- 191 pg/ml and 5.4 +/- 0.9, respectively; p < 0.05 for both) and at 1 yr (324 +/- 189 pg/ml and 5.6 +/- 0.7, respectively; p < 0.01 for both) compared with pretreatment values (122 +/- 114 pg/ml and 4.8 +/- 0.9, respectively). The change ratios of core protein at 1 month and 6 months after therapy to the pretreatment values were significantly higher in biochemical responders (3.2 +/- 2.4 and 2.9 +/- 2.3, respectively) than in nonresponders (0.9 +/- 0.7 and 1.1 +/- 0.8, respectively) (p < 0.05 for both). Similarly, the change ratios of HCV RNA at 1 month and 1 yr after IFN therapy were significantly higher in biochemical responders (9.9 +/- 14.6 and 12.8 +/- 15.1) than in nonresponders (0.6 +/- 0.5 and 1.2 +/- 1.2) (p < 0.05 for both).

CONCLUSIONS

HCV amount increased significantly after IFN therapy in biochemical responders, whereas it did not change notably in nonresponders.