A phase I/II study of recombinant human interleukin-12 in patients with chronic hepatitis B

BACKGROUND/AIMS

Interleukin-12 (IL-12) may be active against hepatitis B virus (HBV). The objective of the study was to assess the tolerability, activity, pharmacokinetics, and pharmacodynamics of three dose levels (0.03 microg/kg b.w., n=15; 0.25 microg/kg b.w., n=15; 0.50 microg/kg b.w., n=16) of recombinant human (rHu) IL-12 given s.c. once a week for 12 consecutive weeks.

METHODS

Forty-six patients with chronic hepatitis B, HBV DNA positivity and aminotransferase elevation were included in a multicenter prospective randomized phase I/II study.

RESULTS

Compared with the baseline, HBV DNA levels had decreased significantly at the end of rHuIL-12 treatment and after the 12-week follow-up period (p<0.001). The response to rHuIL-12 treatment was dose-dependent: at the end of the study HBV DNA clearance was greater in patients treated with 0.50 microg/kg b.w. (25%) or with 0.25 microg/kg b.w. (13%) compared with those given 0.03 microg/kg b.w. (7%). Moreover, HBeAg became undetectable at the end of follow-up in five of the patients given the 0.25microg/kg (2/15) or the 0.50 microg/kg (3/16) dose. The drug pharmacology showed that IL-12 had an estimated half-life of 30 h with levels remaining detectable for more than 48 h after rHuIL-12 administration. The serum levels of IL-12, interferon-gamma, IL-10, neopterin and beta2-microglobulin as well as the area under the curve (AUC) were rHuIL-12 dose-related. Side effects were observed more frequently with higher doses, including moderate decreases in lymphocyte and neutrophil counts; three patients withdrew prematurely from treatment. The local reaction observed at the injection site was unrelated to the drug dose. Only one patient showed detectable antibody levels to rHuIL-12 without clinical impact.

CONCLUSIONS

Treatment with rHuIL-12 at the doses investigated is safe and tolerable, and appears to be active against HBV in patients with chronic hepatitis B.

Overlapping but distinct specificities of anti-liver-kidney microsome antibodies in autoimmune hepatitis type II and hepatitis C revealed by recombinant native CYP2D6 and novel peptide epitopes

Anti-liver-kidney microsome antibodies (anti-LKM) occur in autoimmune hepatitis (AIH) type II and in a subset of patients with hepatitis C. Anti-LKM1 in AIH are directed against cytochrome P4502D6 (CYP2D6), but conflicting data exist concerning the specificity of anti-LKM in hepatitis C. The aim of this study was to evaluate binding specificities of anti-LKM antibodies in both diseases using novel test antigens as well as their inhibitory capacity on CYP2D6 enzyme activity. Sera from 22 patients with AIH type II and 17 patients with hepatitis C being anti-LKM-positive in the immunofluorescence test were investigated for binding to native recombinant CYP2D6 and liver microsomes by ELISA and immunoblotting, and to synthetic peptides covering the region 254-339 (254-273, 257-269, 270-294, 291-310, 307-324, 321-339, 373-389) as well as the novel peptide 196-218 by ELISA. Furthermore, all sera were tested for inhibition of CYP2D6-dependent bufuralol 1'-hydroxylase activity. Twenty of the 22 AIH type II sera (91%) and nine of the 17 hepatitis C sera (53%) were positive for CYP2D6 by ELISA and/or immunoblotting. The previously described major peptide epitope comprising CYP2D6 amino acids 257-269 was recognized by 16 of the 22 AIH sera but by only one hepatitis C serum. A further epitope, 196-218, could be defined for the first time as another immunodominant epitope for AIH because it was recognized by 15 of the 22 AIH (68%) but only three of the 17 hepatitis C sera (18%). With the exception of the peptide 254-273, the other peptides showed no significant reactivity. Analysing the inhibitory properties of anti-LKM antibodies it emerged that 95% of AIH sera and 88% of hepatitis C sera inhibited enzyme function. These data indicate that anti-LKM antibodies in AIH and hepatitis C react with CYP2D6, as shown by their inhibitory activity, and that besides the known epitope 257-269 a further immunodominant epitope exists on CYP2D6 which is recognized by sera from patients with AIH II but hardly by sera from patients with hepatitis C.

Occurrence of a novel DNA virus (TTV) infection in patients with liver diseases and its frequency in blood donors

A novel DNA virus (TTV) was identified recently in Japanese patients with posttransfusion hepatitis non-A-E and has been implicated as a cause of acute and chronic liver diseases of unknown etiology in some patients. The frequency of TTV infections was investigated in 284 blood donors, 105 patients with different liver disorders before and after liver transplantation (OLT), as well as in 64 patients with chronic hepatitis C who received antiviral therapy. TTV infections were found more frequently by nested-PCR in patients with liver disorders (15%) as compared to blood donors (7%). TTV occurred independently of the aetiology of the liver disease (e.g., cryptogenic cirrhosis [12.5%], alcoholic cirrhosis [16%], fulminant hepatic failure non-A-E [35%], and chronic hepatitis C [12.5%]; p=n.s.). After OLT, a high rate of TTV de novo infections (44%) was observed. However, TTV viremia after OLT (in 56 out of the 105 patients) was not associated with graft hepatitis. Analysis of patients with chronic hepatitis C coinfected with TTV who have been treated with interferon alpha alone or in combination with ribavirin revealed that TTV is an interferon-sensitive virus. Phylogenetic analysis of TTV sequences suggest that at least four different genotypes and several subtypes exist in Germany. In conclusion, the high prevalence of TTV infections observed in patients with parenteral risk factors is an argument in favour of transmission of the virus via blood and blood products. A relevant hepatitis-inducing capacity of TTV, however, seems unlikely, considering the observation that in the majority of patients, TTV infection after OLT was not accompanied by graft hepatitis.

Occurrence of a novel DNA virus (TTV) infection in patients with liver diseases and its frequency in blood donors

A novel DNA virus (TTV) was identified recently in Japanese patients with posttransfusion hepatitis non-A-E and has been implicated as a cause of acute and chronic liver diseases of unknown etiology in some patients. The frequency of TTV infections was investigated in 284 blood donors, 105 patients with different liver disorders before and after liver transplantation (OLT), as well as in 64 patients with chronic hepatitis C who received antiviral therapy. TTV infections were found more frequently by nested-PCR in patients with liver disorders (15%) as compared to blood donors (7%). TTV occurred independently of the aetiology of the liver disease (e.g., cryptogenic cirrhosis [12.5%], alcoholic cirrhosis [16%], fulminant hepatic failure non-A-E [35%], and chronic hepatitis C [12.5%]; p=n.s.). After OLT, a high rate of TTV de novo infections (44%) was observed. However, TTV viremia after OLT (in 56 out of the 105 patients) was not associated with graft hepatitis. Analysis of patients with chronic hepatitis C coinfected with TTV who have been treated with interferon alpha alone or in combination with ribavirin revealed that TTV is an interferon-sensitive virus. Phylogenetic analysis of TTV sequences suggest that at least four different genotypes and several subtypes exist in Germany. In conclusion, the high prevalence of TTV infections observed in patients with parenteral risk factors is an argument in favour of transmission of the virus via blood and blood products. A relevant hepatitis-inducing capacity of TTV, however, seems unlikely, considering the observation that in the majority of patients, TTV infection after OLT was not accompanied by graft hepatitis.

Interferon-antibodies and the breakthrough phenomenon during ribavirin/interferon-alpha combination therapy and interferon-alpha monotherapy of patients with chronic hepatitis C

BACKGROUND/AIMS

The significance of interferon antibodies with respect to response to treatment in patients with chronic hepatitis C treated with interferon-alpha (INF-alpha) remains a matter of debate. The influence of ribavirin on IFN-antibody formation in combination therapy with IFN-alpha has not yet been studied. Therefore we evaluated the relationship between IFN-antibodies and response to ribavirin/IFN-alpha combination therapy and IFN-alpha monotherapy.

METHODS

We studied 169 patients with chronic hepatitis C who were treated either with IFN alpha 2a (6 MU, thrice weekly) alone or in combination with ribavirin (14 mg/kg per day) for twelve weeks. Thereafter, patients who achieved a virological response (HCV-RNA-negative) were treated with 3 MU IFN-alpha thrice weekly for another 40 weeks. IFN antibodies were analyzed and quantified by a double-antigen sandwich enzyme immunoassay (EIA). In 86 patients two neutralization assays--an antiviral neutralization assay as well as an antiproliferative neutralization assay--were performed in addition. The relationship of the development of IFN-antibodies with the virologically defined response to treatment was analyzed.

RESULTS

Ribavirin did neither influence the prevalence nor the level of IFN-antibodies. The frequencies of IFN-antibody formation did not differ in the response groups. However, patients with breakthrough showed significantly higher IFN-antibody titers as compared to responder at end of treatment (median 1,336 BU/ml vs. 148 BU/ml; p = 0.018). Among the breakthrough patients those with IFN-antibodies showed the reappearance of HCV-RNA during therapy significantly earlier (median week 24) than those without IFN-antibodies (median week 32; p = 0.03).

CONCLUSION

The addition of ribavirin to IFN-alpha does not influence the formation of IFN-antibodies. The development of high-titer IFN-antibodies during IFN-alpha or ribavirin/IFN-alpha therapy of patients with chronic hepatitis C may account for the early occurrence of breakthrough in some patients, while other mechanisms seem to be responsible for this phenomenon in the majority of the afflicted patients.

A phase I/II study of recombinant human interleukin-12 in patients with chronic hepatitis C

Interleukin-12 (IL-12) plays a central role in mounting an effective cellular immune response directed towards elimination of intracellular pathogens. The present open-label, multicenter, dose-escalation phase I/II study was designed to assess tolerability, pharmacokinetics, pharmacodynamics, and efficacy of subcutaneously administered recombinant human interleukin-12 (rHuIL-12) in the treatment of chronic hepatitis C. Sixty patients (42 men, 18 women, aged 24-60) were treated with 0.03 microgram/kg (n = 16), 0.1 microgram/kg (n = 14), 0.25 microgram/kg (n = 15), or 0.5 microgram/kg rHuIL-12 (n = 15) for 10 consecutive weeks. rHuIL-12 was generally well tolerated, with 2 patients (3.3%) being withdrawn from treatment for adverse events. Treatment was associated with temporary decreases in neutrophils and lymphocyte counts and with elevations in serum transaminases and bilirubin. Serum IL-12 levels observed were higher at 0.5 microgram/kg compared with 0.25 microgram/kg doses, suggesting a dose-related increase in systemic exposure of IL-12. Measurable levels of interferon gamma (IFN-gamma) were also observed at the highest dose of 0.5 microgram/kg. At the end of treatment hepatitis C virus (HCV) RNA was detectable in all patients. A more than 50% decrease in pretreatment HCV RNA levels was observed in 3 of 16 patients of the 0.03-microgram/kg dose group, in 3 of 14 of the 0.10-microgram/kg dose group, in 6 of 15 of the 0.25-microgram/kg dose group, and in 8 of 15 patients of the 0.5-microgram/kg dose group. Although in several cases serum alanine transaminase (ALT) levels decreased either during or after treatment, ALT normalization was observed in only 4 patients at the end of treatment and in 5 patients at the end of follow-up. Significant anti-rHuIL-12 antibody titers were not detectable in any patient. In conclusion, antiviral activity of rHuIL-12 in patients with chronic hepatitis C does not appear advantageous in comparison with other currently available treatments.

[Increased occurrence of oral lichen planus in hepatitis C infection]

The present study evaluated the risk of hepatitis C virus-infected (HCV) patients in Germany to develop oral lichen planus (OLP). We screened 127 patients with chronic HCV-infection for OLP. In three of 127 patients (2.4%) OLP was found. Twenty-four patients with OLP were examined for hepatitis C. Only one patient (4.2%) was positive for HCV-RNA. Our data show no increased prevalence for OLP in German patients infected with HCV. Also no increased rate of HCV infection in OLP patients was found in this study. Further studies of HCV-infected patients from different geographical areas and ethnic groups are necessary to determine the rate of OLP in HCV-infection and to clarify whether HCV acts locally to develop OLP, or whether host immune response to HCV is of importance.

Dynamics of GB virus C viremia early after orthotopic liver transplantation indicates extrahepatic tissues as the predominant site of GB virus C replication

The principal site of GB virus C (GBV-C) replication is unknown. To determine whether hepatic GBV-C replication is important for the maintenance of a measurable viremia level in GBV-C infection, the influence of hepatectomy followed by liver transplantation on GBV-C viremia was investigated. GBV-C RNA levels were determined by a quantitative TaqMan polymerase chain reaction (PCR) in 12 patients with pretransplantation GBV-C infection before and daily after orthotopic liver transplantation (OLT) for 25 to 28 days. Compared with the pretransplantation values (mean, 12.4 +/- 3.9 x 10(7) copies/mL), mean GBV-C RNA levels declined significantly by 1 log by day 1 after OLT (mean, 3.5 +/- 1.6 x 10(7) copies/mL), but subsequently remained relatively stable on this high level for the entire observation period, indicating ongoing high-level virus replication (mean GBV-C RNA levels on days 7 and 28 were: 1.7 +/- 0. 5 x 10(7) and 2.8 +/- 0.7 x 10(7) copies/mL; P = ns). Thus, at the end of the follow-up, mean GBV-C RNA levels were not significantly different from that of the 1st and 7th postoperative day and remained significantly lower compared with the pretransplantation values. However, in 2 of the 12 patients, different kinetics were observed. Both already had low-level viremia pre-OLT (0.02 and 0.002 x 10(7) copies/mL) and became persistently GBV-C RNA-negative 2 days after OLT. In 5 patients, liver tissues were collected 6 to 9 days after OLT and investigated for GBV-C RNA. All but 1 were GBV-C RNA-negative in the liver, although 2 of them had rather high serum GBV-C RNA levels at this time. The kinetics of GBV-C viremia observed in our study were neither influenced by the immunosuppressive therapy nor by the number of blood and blood product transfusions given after OLT. In addition, they were quite different from those observed in patients with chronic hepatitis C in whom early reinfection of the graft could be demonstrated by a steady increase in HCV RNA levels starting 3 days after OLT and exceeding preoperative levels by day 8. From our data, one can conclude that the liver is certainly not the major site of GBV-C replication in most patients. However, one cannot exclude that host or viral factors exist that predispose GBV-C replication predominantly in the liver.

A clinical and virological study of hepatitis C virus-related cryoglobulinemia in Germany

BACKGROUND/AIMS

Several reports, especially from Southern Europe, have demonstrated a close association between hepatitis C virus (HCV) infection and mixed cryoglobulinemia. In this study we have analyzed the significance of HCV-related cryoglobulinemia in Germany.

METHODS

Sera from 79 patients with cryoglobulinemia of type I (n=21), II (n=28) or III (n=30) were investigated for HCV markers. Furthermore, 132 consecutive patients with chronic hepatitis C were studied for the presence of cryoglobulins. Genotypes of HCV were determined according to Simmonds, and HCV-RNA concentrations were measured in patients with and without cryoglobulinemia.

RESULTS

In 79 patients with cryoglobulinemia we found anti-HCV antibodies in 17 (22%) and HCV-RNA in 11 patients (14%). HCV antibodies were more frequent in essential (44%) compared to secondary mixed cryoglobulinemia (15%). In 132 patients with chronic HCV infection cryoglobulins were detected in 37 patients (28%), in 21 of them at low levels. Clinical symptoms due to cryoglobulinemia were observed in eight of the 37 patients, severe vasculitis in three patients with high cryocrit-levels and cryoprecipitation at room temperature. HCV genotype 1 and subtype 1b were most prevalent, both in patients with and without cryoglobulinemia, and mean HCV-RNA levels were not different between the two groups. Comparison of HCV-RNA levels in cryoprecipitates, supernatant and native serum suggests binding of HCV-RNA to the cryoprecipitate with different affinity in individual patients.

CONCLUSIONS

The lower prevalence of HCV-related cryoglobulinemia in our study compared with data from Italy and France suggests a south-north gradient in the prevalence of HCV-associated cryoglobulinemia in Europe.

Pretransplant virological markers hepatitis C virus genotype and viremia level are not helpful in predicting individual outcome after orthotopic liver transplantation

BACKGROUND

Recurrence of hepatitis C viremia after orthotopic liver transplantation (OLT) is nearly universal, leading to variable outcome from no to severe recurrent disease. In the present study, the prognostic relevance of hepatitis C virus (HCV) genotypes and viremia for the development and severity of graft hepatitis was investigated.

METHODS

A total of 79 patients with chronic hepatitis C who could be followed for 1 to 78 months (mean: 30 months) after OLT were included in this study. HCV RNA concentrations were measured before OLT, 1 month after OLT, as well as in the long-term follow-up after OLT in 54 of the 79 patients.

RESULTS

Graft hepatitis could be documented in 40 of the 79 patients (51%), and 7 of them (9%) progressed to liver cirrhosis. More severe forms of graft hepatitis predominated in patients with subtype 1b infection, and all seven patients with progression to liver cirrhosis had subtype 1b (P=NS). Neither the pretransplant nor the posttransplant HCV RNA levels were significantly associated with the occurrence of graft hepatitis. However, there was a trend of more severe recurrent disease in subtype 1b-infected patients with high level viremia in the early course after OLT.

CONCLUSIONS

Pretransplant HCV virological markers are not helpful to predict the outcome after OLT. However, it should be further investigated whether estimation of HCV genotype and viremia levels very early after OLT, i.e., within the first weeks, may be a better approach to recognize high-risk patients.

Searching for the optimal management of hepatitis C patients after liver transplantation

The optimal immunosuppressive regimen in patients transplanted for hepatitis C (HCV) is still under discussion. High immunosuppression may promote viral replication and recurrent graft hepatitis. But acute and chronic rejection frequently seen in conjunction with HCV recurrence may require some rescue therapy. One hundred and thirty-seven patients transplanted for HCV cirrhosis, who were HCV-RNA positive prior to transplantation, were analyzed. Seventy-nine patients received CSA-based immunosuppression and 58 patients FK506-based immunosuppression. One-month patient survival was 100% in both groups. Three month and 1-year survival rates and the cumulative 1-5-year patient survival was similar in CsA-treated [67/79 (84.8%)] and FK506-treated patients [50/58 (86.2%)]. Retransplantations for HCV recurrence were performed in 5.1% of CsA-treated patients and 6.9% of FK506-treated patients; it was successful in 50% and 75% of patients, respectively. Conversion from CsA to FK506 and vice versa was high with 25 out of 79 patients (31.6%) converting in the CsA group and 8 out of 58 patients (13.8%) converting in the FK506 group. Conversion to FK506 was performed due to acute and chronic rejection and to CsA because of toxicity and HCV recurrence. In both groups, 25% of converted patients died. Five patients of the CsA group and 9 of the FK506 group received OKT3; more than one-third of each group died. Five patients in the CsA group and 6 in the FK506 group received mycophenolate mofetil (MMF) for HCV recurrence or acute and chronic rejection in conjunction with HCV recurrence. All patients of this critical group are alive with good graft function. In conclusion, survival rates of HCV patients were similar to those seen for other indications. Conversion from CsA to FK506 and vice versa was high and reflects a critical group concerning patient survival. OKT3 treatment should be avoided. A promising therapeutic option for critical patients experiencing acute or chronic rejection in conjunction with HCV recurrence may be treatment with MMF.

Quality control study on the performance of GB virus C/hepatitis G virus PCR

BACKGROUND/AIMS

A novel virus, GBV-C/HGV, with a genome RNA organization similar to that of the Flaviviridae family was identified in sera of patients with hepatitis. The presence of GBV-C/HGV RNA can only be determined by the amplification of genomic regions using the reverse transcriptase-polymerase chain reaction (RT-PCR).

METHODS

To assess the quality of the RT-PCR, 14 laboratories investigated a coded serum panel that comprised three GBV-C/HGV RNA-positive sera from three different patients, dilutions of these sera, and three GBV-C/HGV RNA-negative serum samples, two of which were collected from patients with hepatitis C but without GBV-C/HGV infection. In-house RT-PCR as well as commercially available GBV-C/HGV test kits were used in this study.

RESULTS

Only four laboratories (29%) reported the expected results, and four laboratories (29%) false-positive results; nine laboratories (64%) reported at least one false-negative result. Eleven laboratories (79%) detected the undiluted samples. The majority of false results were obtained with the dilutions of GBV-C/HGV RNA-positive samples. Negative results in the 10(-4) dilution were not considered to be false-negative, since during pre-screening GBV-C/HGV RNA had been detected in this dilution in only 50% of assays by the three laboratories involved in organizing the evaluation. Results obtained by commercial kits and by in-house assays were indiscriminate in quality of performance in this study.

CONCLUSION

To facilitate further quality assessment studies on the performance of GBV-C/HGV RNA detection, an international GBV-C/HGV RNA standard should be made available. Further efforts are required to optimize GBV-C/HGV RT-PCR.

Hepatitis B virus with antigenically altered hepatitis B surface antigen is selected by high-dose hepatitis B immune globulin after liver transplantation

"Escape" variants of hepatitis B virus (HBV) can cause infection despite previous immunization. These viruses show alterations of the immunogenic major hydrophilic loop of the HBV small surface protein (s-protein). We studied whether HBV "escape" variants were selected in patients with graft infection after liver transplantation for HBV-related diseases who received passive immunoprophylaxis with high-dose polyclonal hepatitis B hyperimmune globulin (HBIG). For that, pre- and posttransplantation sera of 34 patients were analyzed for the occurence of HBV S-gene variants. In addition, binding of in vitro-translated variant s-proteins to HBIG was studied. Variants with exchanges of amino acid (aa) 144 (s144) in HBV genotype A and 145 in genotype D (s145) were found to emerge, persist, and predominate during HBIG, and thus fulfilled criteria of "escape" variants selected. In addition to already-known variants sG145R/K/E, we could demonstrate that newly described variants sX144G and sG145A were antigenically altered and showed impaired recognition by polyclonal HBIG in vitro. Diminished recognition of variant s-proteins correlated with the failure of HBIG to prevent infection of the liver graft with antigenically altered variant HBV Patients infected with "escape" variants s144 or s145 showed a worse clinical outcome compared with the other patients on high-dose, long-term HBIG prophylaxis (44% vs. 23% graft failure caused by HBV infection). Our results suggest that antigenically altered HBV variants s144 and s145 can be selected by HBIG and can influence clinical outcome after liver transplantation.