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.

Enhancement of antibody production to hepatitis B surface antigen by interleukin 2

Studies were undertaken to determine whether induction of antibody to hepatitis B surface antigen (anti-HBs) production by cultured lymphocytes which had been conducted with pokeweed mitogen (PWM) could be replaced by interleukin 2 (IL 2). In cultures stimulated with purified HBsAg and IL 2, the comparable levels of anti-HBs production to those obtained in cultures stimulated with PWM alone occurred when peripheral blood mononuclear cells (PBMC) from patients positive for serum anti-HBs and recipients of HBsAg vaccine were used as effector cells. Detectable amounts of anti-HBs were produced only when IL 2 was added to the second-set cultures again. IL 2 or HBsAg alone, however, did not induce anti-HBs production. Anti-HBs production was not observed by the additions of these additives when PBMC from chronic HBsAg carriers and control individuals were used. These findings indicate that IL 2 could modulate the immune response to HBsAg.

Mutations in interferon sensitivity-determining region of hepatitis C virus: its relation to change in viral load

OBJECTIVE

Interferon sensitivity-determining region (ISDR) in nonstructural region 5A of hepatitis C virus (HCV) genotype-1b has been reported to be associated with viral load. Viral load is usually small in the patients with mutant type (four or more amino acid substitutions, compared with HCV-J) and large in those with wild (identical to HCV-J) or intermediate type (from one to three amino acid substitutions). A possible correlation was investigated between mutations in ISDR and alterations of viral load during the course of disease.

METHODS

The sequences of ISDR were determined in eight patients with significant changes of viral load and in 11 patients without changes.

RESULTS

In two of the eight patients with significant alterations of viral load, ISDR sequences changed significantly. In one patient whose viral load increased after a course of interferon therapy, the number of substitutions, compared with HCV-J, decreased from five to zero or one; the type of ISDR converted from mutant type to wild or intermediate type. In one patient whose viral load decreased significantly after two courses of interferon therapy, the number of substitutions increased from one to six; ISDR changed from intermediate type to mutant type. In the remaining six patients with changes of viral load and in the other 11 patients without changes, the sequences of ISDR did not change significantly.

CONCLUSIONS

The mutations in ISDR are one of the viral factors involved in the changes in viral load during the course of disease, although the majority of other factors involved are still unknown.

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.

Additional effect of low iron diet on iron reduction therapy by phlebotomy for chronic hepatitis C

BACKGROUND/AIMS

Iron-induced oxidative stress plays an important role in the pathogenesis of chronic hepatitis C. Both phlebotomy for removing body iron stores and low iron diet for minimizing portal iron supply to the liver have been shown to improve serum transaminase levels in patients with the disease. However, the cooperative effects of phlebotomy and low iron diet have not yet been elucidated in detail.

METHODOLOGY

A pilot study was undertaken to investigate whether a low iron diet could improve the efficacy of phlebotomy in iron reduction therapy. Of 21 patients diagnosed with chronic hepatitis C, 10 patients were treated with phlebotomy alone (group A) while 11 patients were treated with a low iron plus phlebotomy (group B). Phlebotomy was repeated biweekly until serum ferritin levels reached 10 ng/mL in both A and B groups. In addition, a low iron diet (iron intake of 8 mg/day or less) was recommended for group B, followed by estimation of iron intake from daily diet records.

RESULTS

Serum alanine aminotransferase levels were significantly improved from 106+/-30 to 68+/-22 IU/L (p<0.005, paired t-test) in group A and from 100+/-33 to 46+/-10 IU/L (p<0.002, paired t-test) in group B. The enzyme levels after treatment were significantly higher in group A (p<0.02, non-paired t-test), which showed a higher upward distribution of the enzyme activity. The estimated dietary iron intake in group B was reduced from 17.6+/-6.1 to 8.2+/-3.7 mg/day.

CONCLUSIONS

These findings suggest that phlebotomy alone does not completely remove iron-induced oxidative stress and a low iron diet induces an additional effect in iron reduction therapy for chronic hepatitis C.

[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.

In vitro production of antibody to hepatitis B core and E antigens by peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection

To evaluate the relative immunogenicity of and the mechanism for production of antibody to hepatitis B core (HBc) and hepatitis B e (HBe) Ag, we investigated the in vitro anti-HBc and anti-HBe production by PBMC from 25 patients with chronic active hepatitis (CAH) (15 with HBeAg and 10 with anti-HBe) and 12 ASC (5 with HBeAg and 7 with anti-HBe) in the presence of PWM, rHBcAg, or purified HBeAg. PWM-stimulated culture produced higher titer anti-HBc (mean % inhibition +/- SD = 73 +/- 23%, p less than 0.001) than anti-HBe (34 +/- 17%). HBcAg stimulation elicited greater anti-HBc response (43 +/- 26%, p less than 0.001) than did HBeAg for anti-HBe (26 +/- 12%). Both HBcAg and HBeAg induced equivalent anti-HBe response. Anti-HBc production in response to HBcAg was higher in CAH patients (51 to 55%) than in asymptomatic carriers of hepatitis B surface Ag (22 to 28%) irrespective of their HBeAg/anti-HBe status, but reflecting serum anti-HBc value. Similar findings were noted in HBeAg-stimulated anti-HBe production for the two patient groups. In HBeAg- and anti-HBe-positive CAH, HBcAG-stimulated anti-HBc production was similar in T (1.4 x 10(6)) and B (0.6 x 10(6)) cells coculture, and B cells (2 x 10(6)) alone culture. However, in the HBeAg-stimulated culture, T plus B cells produced significantly higher titer anti-HBe than B cells alone did. These results indicate that HBcAg has a relatively higher immunogenicity in terms of antibody production as compared to HBeAg. Furthermore, HBcAg was shown to function as a T cell-dependent and -independent Ag, whereas HBeAg is T cell-dependent during chronic hepatitis virus B infection in man.

Hepatitis B core antigen-specific IFN-gamma production of peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection

To evaluate the specificity of cellular immune response to hepatitis B virus (HBV) Ag in patients with chronic HBV infection, we have measured IFN-gamma production and proliferation of PBMC of 16 patients with chronic active hepatitis (CAH), 17 asymptomatic carriers of HBV (ASC), 6 anti-hepatitis B surface (HBs)-positive subjects, and 6 control individuals with ELISA procedure and [3H]thymidine incorporation. There was no significant increase in the mean proliferative response to recombinant HB surface and core Ag (rHBsAg and rHBcAg), nor was IFN-gamma production elicited with rHBsAg in any group. In contrast, PBMC of HBeAg-positive and anti-HBe-positive CAH patients, and anti-hepatitis B "e" Ag (HBe)-positive ASC showed significantly enhanced IFN-gamma production in response to HBcAg, whereas those of HBeAg-positive ASC and anti-HBs-positive subjects did not respond to HBcAg. The maximal response was observed in a 5-day culture with 500 ng/ml of rHBcAg when assessed by stimulation index value. Monocytes did not demonstrate an increased suppressor or helper activity for IFN-gamma production in these patients. T cell subset fractionation revealed that CD4+ cells were main population of IFN-gamma production specific for HBcAg and CD8+ cells did not suppress IFN-gamma production of CD4+ cells. Furthermore, CD4+ cells of HBeAg-positive ASC generated lesser amounts of IFN-gamma than HBeAg-positive CAH patients did. These results show that the measurement of IFN-gamma production is useful to determine cellular immune response to HBV Ag and suggest that IFN-gamma production depends on the helper activity of CD4+ T cells sensitized to HBcAg.

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.

Serum levels of alpha-interferon and gamma-interferon in patients with acute and chronic viral hepatitis

We measured activities of alpha- and gamma-interferon simultaneously in 198 sera of 70 patients with acute and chronic viral hepatitis using specific and sensitive enzyme immunoassay and immunoradiometric assay. The results were compared with those in patients with influenza and in healthy controls. Twelve out of 28 patients with acute viral hepatitis showed positive alpha-IFN and/or gamma-IFN activities. alpha-IFN was detectable throughout the clinical course while gamma-IFN levels rose in the convalescent phase regardless of etiology. Conversely, in patients with influenza, both alpha-IFN and gamma-IFN levels of initial samples tended to be higher than those of late samples. Six out of 12 patients with chronic active type B hepatitis showed increased alpha-IFN and/or gamma-IFN values during acute deterioration with marked elevation of serum alanine aminotransferase. However, the two interferons did not always appear simultaneously, although either was detectable in both acute and chronic hepatitis. Enhanced alpha-IFN or gamma-IFN activity was not found in asymptomatic chronic hepatitis B carriers or in patients with chronic persistent hepatitis and liver cirrhosis with chronic hepatitis B virus infection, with the exception of 2 cases. Our results indicated that circulating multiple IFN species were present during the clinical course in some patients with acute and chronic viral hepatitis.

Interferon-gamma receptors on T cells in patients with chronic liver disease

Interferon-gamma (IFN-gamma) appears to be important for the activation of T cells, and its binding to IFN-gamma receptors on T cells is an essential step for its actions. We investigated the expression of IFN-gamma receptors on T cells in chronic liver disease using radioiodinated recombinant interferon-gamma binding assay, and by Scatchard analysis. The mean numbers of IFN-gamma receptors on T cells from controls, asymptomatic hepatitis B virus carriers (ASC), patients with chronic active hepatitis (CAH), and patients with liver cirrhosis (LC) were 2,205 +/- 497, 2,494 +/- 1,074, 1,925 +/- 735, and 1,666 +/- 653, respectively. The numbers of IFN-gamma receptors on T cells from the patients with LC were significantly smaller than those of controls (P less than 0.05). Kids of IFN-gamma receptor on T cells from control and patient groups were 2.3 4.8 x 10(-9) M, and there was no significant difference among the groups. The percentage of T cells reactive with OKT3, OKT4, or OKT8 was similar in control and patient groups. These findings suggest that the decrease in IFN-gamma receptors in LC is not related to the activity of the liver damage, but is associated with the severity of the underlying disease. The normal expression of IFN-gamma receptors on T cells from CAH may provide a reasonable basis for IFN-gamma therapy to type B CAH.

Comparisons of peripheral blood and hepatic lymphocyte subpopulations and interferon production in chronic viral hepatitis

Studies were undertaken to clarify the immunological mechanism in patients with chronic hepatitis C compared with chronic hepatitis B. Phenotypic study by flow cytometry showed that CD8+ T cells and HLA-DR+ cells isolated from liver biopsy specimen were significantly increased in their proportions as compared with those in peripheral blood, while intrahepatic CD4+ T cells were significantly lower than peripheral blood CD4+ T cells in both types of patients with chronic active hepatitis (CAH). Furthermore two-color analysis revealed that CD8+ CD11- and CD3+ HLA-DR+ cells were significantly elevated in liver tissue than in peripheral blood in both patients groups. In in vitro tests, mononuclear cells obtained from the liver of type B and type C CAH had a reduced capacity to produce IFN-gamma in response to pokeweed mitogen, while they produced equal amounts of IFN-alpha under stimulation with Newcastle disease virus as compared with control peripheral blood mononuclear cells. In contrast, spontaneous productions of both IFNs were greater in liver infiltrates of the two patients groups. These results indicate that functionally activated T cells are distributed in a similar manner in the liver of both chronic hepatitis B and C, suggesting that cytotoxic T cell plays a major role in the hepatocellular injury of both groups of patients.