Hemolytic anemia induced by ribavirin therapy in patients with chronic hepatitis C virus infection: role of membrane oxidative damage

Band 3/complement-mediated recognition and removal of normally senescent and pathological human erythrocytes

Band 3 modifications that normally occur during physiological red blood cell (RBC) senescence in humans, and occasionally in pathological conditions are described in the context of their role in enhancing RBC recognition and phagocytic removal. Band 3 modifications are mostly due to oxidative insults that gradually accumulate during the RBC lifespan or impact massively in a shorter time period in pathological conditions. The oxidative insults that impact on the RBC, the protective mechanisms that counteract those damages and the phenotypic modifications that accumulate during the RBC lifespan are described. It is shown how specific oxidative as well as non-oxidative band 3 modifications enhance RBC membrane affinity for normally circulating anti-band 3 antibodies, and how membrane-bound anti-band 3 antibodies bring about a limited complement activation and membrane deposition of complement C3 fragments. The partially covalent complexes between anti-band 3 antibodies and complement C3 fragments are very powerful opsonins readily recognized by the CR1 complement receptor on the phagocyte. Band 3 modifications typically encountered in old RBCs have crystallized to a number of band 3-centered models of RBC senescence. One of those band 3-centered models, the so-called 'band 3/complement RBC removal model' first put up by Lutz et al. is discussed in more detail. Finally, it is shown how the genetic deficiency of glucose-6-phosphate dehydrogenase (G6PD) plus fava bean consumption, and a widespread RBC parasitic disease, P. falciparum malaria, may lead to massive and rapid destruction of RBCs by a mechanism comparable to a dramatic, time-compressed enhancement of normal RBC senescence.

Management of chronic Hepatitis C virus in patients with HIV

The life expectancy of HIV seropositive persons is approaching the life expectancy of those who are uninfected with HIV. Hepatitis C virus (HCV) infection has emerged as a worldwide epidemic. Given the similar transmission route between HCV and HIV, there has been an explosion in the number of individuals infected with both viruses. Because of the successful introduction of antiretroviral therapy, patients are more susceptible to new opportunistic infections such as HCV. HCV leads to a more rapid progression to end-stage liver disease in patients with HIV, and the morbidity and mortality related to HCV in co-infected patients is on the rise. Therefore, it has become imperative to treat both HIV and HCV in co-infected patients. The primary goal of HCV therapy is permanent eradication of the virus. Secondary goals include reduction in hepatic fibrosis progression, development of decompensated cirrhosis, and hepatocellular carcinoma. Early studies using standard interferon-alfa for the treatment of HCV in co-infected individuals were discouraging, as poor outcomes, high discontinuation rates, and severe adverse events were observed. The current standard of care for treatment of HCV is pegylated-interferon and ribavirin. New studies have recently demonstrated a higher sustained virologic response rate and a better adverse event profile than previously reported in co-infected patients. As a result, we recommend considering all co-infected patients for HCV therapy while watching closely for unique treatment-related toxicities. The treatment of HCV in co-infected patients should be a high priority for all providers.

Treating HCV with ribavirin analogues and ribavirin-like molecules

Nucleos(t)ide analogues have proven useful in the treatment of viral infections. Ribavirin is a nucleoside, guanosine analogue, whose mechanisms of action include inhibition of inosine monophosphate dehydrogenase (IMPDH), which is the key step in de novo guanine synthesis, a requirement for viral replication. In combination with pegylated interferon alfa, ribavirin is the standard of care for the treatment of chronic hepatitis C today. However, the medication is associated with significant haemolytic anaemia, which may require dose reduction, discontinuation or treatment with recombinant human erythropoietin. Dose reduction also appears to decrease sustained viral clearance rates. Newer IMPDH inhibitors are in various stages of development. Viramidine, a liver-targeting prodrug of ribavirin, has demonstrated significant antiviral activity and erythrocyte-sparing properties. It is currently in Phase 3 trials. Clinical trials of merimepodib, another investigational IMPDH inhibitor, have completed enrolment for a Phase 2b study as a third medication for administration with pegylated interferon plus ribavirin. Although other IMDPH inhibitors also have antiviral activity, these medications appear best suited as immunosuppressive medications at this time.

Management of the hematologic complications of hepatitis C therapy

Consensus guidelines are in place for treating chronic hepatitis C virus infection. This article highlights some of the hematologic complications of hepatitis C therapy. Management options are presented.

Ribavirin monotherapy for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. The disease progresses without symptoms for several decades. Ribavirin monotherapy may represent a treatment for some patients.

OBJECTIVES

To assess the beneficial and harmful effect of ribavirin monotherapy for patients with chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, authors of trials, and pharmaceutical companies until May 2005.

SELECTION CRITERIA

We included all randomised trials irrespective of blinding, language, or publication status comparing ribavirin versus no intervention, placebo, or interferon for chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were the six months sustained loss of hepatitis C virus RNA in blood after end of treatment and liver-related morbidity plus all-cause mortality. Secondary outcome measures were end of treatment virological response, biochemical response, histological response, and adverse events. Random- and fixed-effects meta-analyses with 95% confidence intervals (CI) were performed for all outcomes. We used Peto odds ratios (OR) for analysis of morbidity plus mortality and relative risks (RR) for the remaining outcomes.

MAIN RESULTS

We identified 13 randomised trials including 594 patients with chronic hepatitis C. Most trials had low methodological quality. Compared with placebo/no intervention, ribavirin had no significant effect on sustained (RR 1.01, 95% CI 0.96 to 1.07, five trials) or end of treatment virological response (RR 1.00, 95% CI 0.94 to 1.07, ten trials). Ribavirin had no significant effect on liver-related morbidity plus mortality (Peto OR 1.96, 95% CI 0.20 to 19.0, eleven trials). Ribavirin significantly improved end of treatment biochemical and histological response but not sustained biochemical response. Further, ribavirin significantly increased the risk of anaemia. Ribavirin was significantly inferior to interferon regarding virological and biochemical response (four trials).

AUTHORS' CONCLUSIONS

We found that ribavirin versus placebo/no intervention had no significant beneficial effect on virological response and liver morbidity, but may improve biochemical and histological response transiently. Ribavirin increased the risk of anaemia. Therefore, we cannot recommend ribavirin monotherapy for patients with chronic hepatitis C outside randomised trials.

Baseline Factors associated with Haematological Toxicity that Leads to a Dosage Reduction of Pegylated Interferon-α2a and Ribavirin in HIV- and HCV-Coinfected Patients on HCV Antiviral Therapy

Objective

To assess the baseline factors associated with haematological toxicity that lead to ribavirin or pegylated interferon (peginterferon) dosage reductions in hepatitis C and human immunodeficiency virus (HCV/HIV)-coinfected patients.

Design

Multicentre, prospective, observational study.

Setting

Eleven hospitals in Spain during the period 2002–2003.

Subjects and methods

One-hundred and forty-two HIV/HCV-coinfected patients received peginterferon-α2a plus ribavirin. Baseline characteristics and haematological parameters were recorded at baseline, week 4, 8, 12, 24 and 48. Cox's regression model was used to study the factors associated with the appearance of a haemoglobin level below 10g/dl (haemoglobin-endpoint), a neutrophil count below 750/mm3 (neutrophil-endpoint) and a platelet count below 50,000/mm3 (platelet-endpoint).

Results

Nineteen patients (13.4%) reached the haemoglobin-endpoint, 22.5% the neutrophil-endpoint and 7% the platelet-endpoint. Mean time of follow-up was 8 months (±3.5). A baseline haemoglobin level below 14g/dl [hazard ratio (HR): 3.65; 95% confidence interval (CI): 1.46–9.06] and treatment with zidovudine (HR: 3.25; 95% CI: 1.31–8.11) were the independent factors associated with the appearance of the haemoglobin-endpoint. A baseline neutrophil below 2050/mm3 (HR: 3.59; 95% CI: 1.77–7.28) and baseline weight <60 kg (HR: 2.21; 95% CI: 1.04–4.56) were independently associated with the appearance of the neutrophil-endpoint. Baseline platelet count (x1000/mm3 decrease) (HR: 1.074; 95% CI: 1.04-1.11) was independently associated with the appearance of the platelet-endpoint.

Conclusions

Baseline factors allow the identification of a subset of HIV/HCV-coinfected patients who are prone to experience haematological toxicity during HCV antiviral therapy.

Pharmacokinetic/pharmacodynamic and time-to-event models of ribavirin-induced anaemia in chronic hepatitis C

BACKGROUND

Interferon (IFN)-alpha and ribavirin combination therapy is the standard treatment for patients with chronic hepatitis C. However, ribavirin induces anaemia, especially by haemolysis, an adverse effect that is dose-limiting.

OBJECTIVES

The aim of this study was to determine the relationships between ribavirin exposure and haemoglobin time-course, the time-to-anaemia and the covariates influencing these relationships in a population of patients treated for chronic hepatitis C. In addition, we also intended to establish a simple rule defining the need for dosage adjustment, using data obtained during the first month of treatment.

METHODS

A retrospective analysis of 99 patients treated with IFNalpha plus ribavirin, with known dosage administration history, liver biopsy, demographic data, red blood cell counts, haemoglobin level (1037 measurements, median 10 per patient, range 2-31) and serum creatinine during the entire treatment period (178 days, range 53-382 days) was conducted. The data were analysed by a pharmacokinetic/pharmacodynamic population model and Weibull time-to-anaemia model. The rule defining the need for dosage adjustment was as follows: adjustment was needed if haemoglobin at steady state (H(ss)), estimated by the Bayesian method based on data obtained during the first month of treatment, was <12 g/dL for men or <11 g/dL for women.

RESULTS

In both models, anaemia was related to the exposure of erythrocytes to ribavirin at time t (RT in mg/kg/day) by a maximum effect model, with RT(50) (dosage administration rate at which half the maximal effect is reached) approximately 12 mg/kg/day, and the significant covariates were initial haemoglobin level and bodyweight. Performances of a Bayesian prediction of H(ss) based on two early haemoglobin level measurements were encouraging (mean prediction error 0.12 g/dL, precision 0.85 g/dL). The proposed rule for the need of dosage adjustment was able to predict the actual evolution of the dosage regimen in 76% of non-adapted patients and 69% of adapted patients.

CONCLUSION

The current guidelines for ribavirin dosage administration, based on bodyweight, are adequate, at least in the 45-105 kg range. Results indicate that Bayesian therapeutic monitoring could be helpful in controlling ribavirin-induced anaemia.

Successful treatment of hepatitis C reinfection with interferon-alpha2b and ribavirin after liver transplantation

INTRODUCTION

Recurrence of hepatitis C virus (HCV) infection after orthotopic liver transplantation (OLT) is a virtually universal occurrence, and a significant proportion of patients develop chronic hepatitis and cirrhosis. The aim of this study was to evaluate the safety and efficacy of interferon (IFN)-alpha2b plus ribavirin (RIBA) in the treatment of recurrent HCV after OLT over the long term.

MATERIAL AND METHODS

Fifteen patients with recurrent HCV infection (positive serum HCV RNA, elevated serum aminotransferases, histological activity) were started on IFN-alpha2b (3-6 million units administered subcutaneously three times a week) plus RIBA (800-1200 mg/day) 18+/-5 months after OLT. HCV RNA was determined 1, 3, 6, 9, 12 and 18 months after initiation of treatment. Liver biopsy was performed before and after therapy. The patients were followed up for a mean of 33+/-5 months.

RESULTS

Thirteen patients (87%) were treated for at least 6 months and nine patients (60%) for 12 months. After 3 months, 11 patients (73%) were free from HCV RNA (<50 copies/ml); the virological end-of-treatment response was 67%. Five patients (33%) remained HCV RNA-negative 6 months posttreatment (sustained response (SR)). During the follow-up period, four patients (27%) died of liver failure, recurrent HCV after virological response, or HCC. The histological activity index improved significantly for both inflammatory activity and fibrosis, from 8.8 to 4.7 and from 7.3 to 4.8, respectively. In none of the patients were signs of rejection observed.

CONCLUSION

Combination therapy with IFN and RIBA in transplanted patients with chronic hepatitis C is an effective treatment that results in a high virological SR rate. It is well tolerated and leads to an improvement in histological outcome.

Approach to the management of patients with chronic hepatitis C who failed to achieve sustained virologic response

The combination of peginterferon and ribavirin is the most effective therapy for patients with chronic hepatitis C virus (HCV) infection. Although more than half of all patients are able to achieve a sustained virologic response (SVR), a significant proportion of patients, particularly those with genotype 1, fail to have undetectable HCV RNA during treatment or relapse after completing therapy with return of detectable HCV RNA. The management of these patients creates a formidable challenge. This article outlines various strategies for patients who have failed to achieve SVR and discusses the merits of different approaches to management.

Phosphorylation of ribavirin and viramidine by adenosine kinase and cytosolic 5'-nucleotidase II: Implications for ribavirin metabolism in erythrocytes

Many nucleoside analog drugs, such as ribavirin and viramidine, are activated or metabolized in vivo through 5'-phosphorylation. In this report, we determined the steady-state kinetic parameters for 5'-monophosphorylation of ribavirin and viramidine by adenosine kinase. The apparent Km for ribavirin is 540 microM, and k(cat) is 1.8 min-1. Its catalytic efficiency of 3.3 x 10(-3) min-1 . microM-1 is 1,200-fold lower than that of adenosine. In contrast to the common belief that ribavirin is exclusively phosphorylated by adenosine kinase, cytosolic 5'-nucleotidase II was found to catalyze ribavirin phosphorylation in vitro. The reaction is optimally stimulated by the physiological concentration of ATP or 2,3-bisphosphoglycerate. In phosphate-buffered saline plus ATP and 2,3-bisphosphoglycerate, the apparent Km for ribavirin is 88 microM, and k(cat) is 4.0 min-1. These findings suggest that cytosolic 5'-nucleotidase II may be involved in ribavirin phosphorylation in vivo. Like ribavirin, viramidine was found to be phosphorylated by either adenosine kinase or cytosolic 5'-nucleotidase II, albeit with a much lower activity. The catalytic efficiency for viramidine phosphorylation is 10- to 330-fold lower than that of ribavirin, suggesting that other nucleoside kinase(s) may be involved in viramidine phosphorylation in vivo. Both ribavirin and viramidine are not phosphorylated by deoxycytidine kinase and uridine-cytidine kinase. The coincidence of presence of high concentrated 2,3-bisphosphoglycerate in erythrocytes suggests that cytosolic 5'-nucleotidase II could play an important role in phosphorylating ribavirin and contribute to anabolism of ribavirin triphosphate in erythrocytes. Elucidation of ribavirin and viramidine phosphorylation mechanism should shed light on their in vivo metabolism, especially the ribavirin-induced hemolytic anemia in erythrocytes.

Ribavirin plus interferon versus interferon for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. The disease progresses without symptoms for several decades and most patients are diagnosed based on the presence of hepatitis C virus ribonucleic acid and elevated transaminases.

OBJECTIVES

To assess the beneficial and harmful effects of ribavirin and interferon combination therapy versus interferon monotherapy for chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, approaching authors of trials and pharmaceutical companies, until May 2004.

SELECTION CRITERIA

We included randomised trials, irrespective of blinding, language, or publication status, comparing ribavirin plus interferon versus interferon alone for treatment of chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were the sustained loss of hepatitis C virus and liver-related morbidity plus all-cause mortality. We separately analysed patients who were naive, relapsers, or non-responders to previous antiviral treatment. Random-effects and fixed-effect model meta-analyses were performed for all outcomes. We used Peto odds ratios (OR) with 95% confidence intervals (CI) for analysis of morbidity plus mortality. The remaining outcomes were presented as relative risks (RR).

MAIN RESULTS

We included 72 randomised trials with 9991 patients. Most trials had low methodological quality but we did not find any significant influence of quality on our results. Compared with interferon, combination therapy had a significant beneficial effect on sustained virological response (RR 0.73, 95% CI 0.71 to 0.75) and in subgroups of naive patients (RR 0.72, 95% CI 0.68 to 0.76), relapsers (RR 0.63, 95% CI 0.54 to 0.73), and non-responders (RR 0.89, 95% CI 0.84 to 0.94) individually. Combination therapy significantly reduced morbidity plus mortality (Peto OR 0.46, 95% CI 0.22 to 0.96), but not in naive, relapsers, or non-responders individually. Combination therapy also had a significant beneficial effect on the histological response. Combination therapy significantly increased the risk of anaemia (RR 10.48, 95% CI 5.34 to 20.55), which occurred in 22% of patients on combination therapy. Combination therapy also significantly increased the risk of dermatological, gastrointestinal, infectious, and miscellaneous (cough, dyspnea, fatigue) adverse events. Accordingly, combination therapy significantly increased the risk of treatment discontinuation (RR 1.19, 95% CI 1.01 to 1.39).

AUTHORS' CONCLUSIONS

Compared with interferon alone, ribavirin plus interferon is more effective in clearing hepatitis C virus and improving liver histology. This may lead to reduced morbidity and mortality. However, combination therapy significantly increased the risk of several adverse events.

Herbal medicine Ninjinyoeito ameliorates ribavirin-induced anemia in chronic hepatitis C: A randomized controlled trial

AIM: Ribavirin (RBV) shows a strong antiviral effect on hepatitis C virus when used in combination with interferon. However, RBV-induced anemia is a major problem in this therapy. It would be of great clinical importance to ameliorate the anemia without reducing the RBV dose. We report here that, Ninjinyoeito (NYT), a herbal medicine can reduce the RBV-induced anemia.

METHODS: Twenty-three patients with chronic hepatitis C were treated with interferon alpha 2b plus RBV with (NYT group) or without (control group) NYT by a randomized selection. Eighteen patients completed the treatment schedule, and hemato-biochemical and virological effects were evaluated.

RESULTS: There was no significant difference in biochemical and virological responses between the two groups. However, anemia was significantly reduced in the NYT group compared with the control group. The maximal decrease of Hb in the NYT group (2.59 ± 1.10 g/dL) was significantly (P = 0.026) smaller than that in the control group (3.71 ± 0.97 g/dL). There was no significant difference in serum glutathione peroxidase activity, serum RBV concentration, and Th1/Th2 balance between the two groups. There was no specific adverse effect in NYT administration.

CONCLUSION: These results suggest that NYT could be used as a supportive remedy to reduce the RBV-induced anemia in the treatment of chronic hepatitis C.

Adverse effects of ribavirin and outcome in severe acute respiratory syndrome: experience in two medical centers

STUDY OBJECTIVES

To assess the effect of ribavirin-induced anemia on the outcome of severe acute respiratory syndrome (SARS).

DESIGN

A retrospective observational study.

SETTING

Two medical centers in Taiwan.

PATIENTS

Forty-four patients with SARS who received ribavirin and 7 patients with SARS who did not receive ribavirin.

MEASUREMENTS AND RESULTS

The mean peak C-reactive protein and lactate dehydrogenase levels were higher in SARS patients who were receiving ribavirin therapy than in SARS patients who were not receiving ribavirin therapy. The mortality was also higher, but the difference was not statistically significant. On multivariate analysis, hemoglobin level was an independent prognostic correlate of hypoxemia or mortality (odds ratio, 2.0; 95% confidence interval, 1.1 to 3.8; p = 0.03). The hemoglobin began decreasing in two thirds of SARS patients (32 of 44 patients; 73%) who were receiving ribavirin 3 days after therapy with the antiviral drug was started. Patients with a drop in hemoglobin level of > 2 g/dL had a significantly higher mortality rate than the other patients. Hypoxemia developed in one third of SARS patients (17 of 44 patients; 39%) who were receiving ribavirin, all of whom were anemic. Of the 17 hypoxemic patients, 11 (65%) had a drop in hemoglobin of > 2 g/dL, and 4 patients (24%) required a blood transfusion. The mean slope of the hemoglobin decrease was significantly steeper (p = 0.001) in hypoxemic patients with SARS who were receiving ribavirin than in the nonhypoxemic patients with SARS who were receiving ribavirin. Only one of seven SARS patients (14%) who was not receiving ribavirin became anemic, but this individual was not hypoxemic. Eventually, 5 of 17 hypoxemic and anemic SARS patients (29%) who were receiving ribavirin died. The combination of hypoxia with anemia was thus significantly associated with a higher mortality (p < 0.001).

CONCLUSIONS

Hypoxia combined with anemia increased the risk for death in SARS patients. Unless ribavirin can be shown to be effective against SARS-coronavirus, the risk of anemia posed by this drug argues against its use in SARS patients.

Suppression of haematopoiesis during therapy of chronic hepatitis C with different interferon alpha mono and combination therapy regimens

BACKGROUND

Treatment of chronic hepatitis C with interferon (IFN)-alpha and ribavirin has haematotoxic effects. We evaluated the effects of four different IFN/IFN-ribavirin treatment regimens on haematopoiesis.

METHODS

Haematopoiesis was studied in 133 patients with chronic hepatitis C receiving IFN-alpha2b alone (group A) or in combination with ribavirin (group B), pegylated IFN-alpha2a (group C), or pegylated IFN-alpha2b (group D) in combination with ribavirin.

RESULTS

At week 4, haemoglobin levels were diminished in all groups receiving combination therapy. In the monotherapy group, haemoglobin decreased slightly after eight weeks. In all groups, haemoglobin remained diminished throughout therapy. In all patients, leucocytes (while blood cells) decreased after four weeks and remained low during treatment. Platelets (peripheral platelet count (PPC)) were decreased in all groups after four weeks and remained below baseline levels during therapy in group A, C, and D whereas in group B PPC recovered early and reached baseline levels at week 16 of therapy. Concomitantly with the decreases in haemoglobin and PPC, erythropoietin increased in all groups receiving combination therapy and thrombopoietin in all groups. Patients treated with pegylated IFN-alpha2a and those who received pegylated IFN-alpha2b combination therapy differed only in leucopoiesis, whereas erythropoiesis and thrombopoiesis were comparable.

CONCLUSION

IFN-alpha based therapies are associated with a decrease in all three haematopoietic lineages, irrespective of the type of therapy used. The stronger suppressive effect of pegylated IFN-alpha2a on leucopoiesis could be due to a dose effect. Overall, concentrations of endogenous haematopoietic growth factors are increased but can only partially alleviate haematotoxicity. Potential uses of exogenous haematopoietic growth factors and their impact on the virological response need to be explored.

Epoetin alfa for the treatment of combination therapy-induced hemolytic anemia in patients infected with hepatitis C virus

In the United States, about 2.7 million people are chronically infected with the hepatitis C virus, accounting for nearly 1.8% of the population. The current standard of therapy is a combination of pegylated interferon products and ribavirin. A common adverse effect associated with this therapy is anemia, which is frequently referred to as mixed anemia because of the synergistic contribution of the interferons and ribavirin. The effect of ribavirin on the development of anemia is considered greater than that of interferon. The current standard of practice for treating this adverse effect is reduction of the dosages of both drugs, at prespecified hemoglobin levels. However, recent findings underscore the importance of maintaining adequate dosages of interferon and ribavirin, which may be crucial in achieving an early virologic response and a sustained virologic response in treating patients with hepatitis C infection. Treatment with epoetin alfa for this mixed anemia significantly improved hemoglobin levels and quality of life, and enabled adequate dosages of ribavirin to be maintained. Future studies should address several issues: when to start epoetin alfa treatment, the duration of treatment, the drug's optimal dosage, its effects on end-of-treatment and sustained virologic response rates, and a cost analyses.

Antibody-mediated pure red cell aplasia due to epoetin alfa during antiviral therapy of chronic hepatitis C

Anemia frequently complicates the treatment of chronic hepatitis C with interferon and ribavirin (RVN), requiring dose reduction and jeopardizing sustained virologic response. Increasingly, epoetin alfa is used to prevent anemia in this setting. Below, we report the first case of pure red cell aplasia (PRCA) in a patient with chronic hepatitis C who received epoetin alfa (Procrit) to manage anti-viral treatment-induced anemia. Red blood cell transfusion-dependence developed 16 wk after the patient was started on peginterferon alfa-2b and RVN for chronic hepatitis C despite the simultaneous administration of epoetin alfa and subsequent discontinuation of the antiviral medications. Bone marrow biopsy was consistent with PRCA. High-titer erythropoietin antibodies, assayed by two methods, appeared shortly after epoetin alfa was administered, and were associated with a decline in serum erythropoietin to undetectable levels. Erythropoietin antibodies directed toward epoetin alfa were shown to cross react with darbepoetin alfa (Aranesp), and a neutralization assay confirmed that they inhibited cell growth in the presence of erythropoietin. Transfusion-dependence resolved approximately 16 wk after discontinuing epoetin alfa, and 6 wk after starting danazol. PRCA caused by the development of erythropoietin antibodies is a potentially life-threatening complication of administering epoetin alfa to prevent the anemia associated with antiviral therapy in patients with chronic hepatitis C.

Treatment with peg-interferon alfa-2b and ribavirin of hepatitis C virus-associated mixed cryoglobulinemia: a pilot study

BACKGROUND/AIMS

The aim of this study is to verify the efficacy and safety of peg-interferon alfa-2b in combination with ribavirin for initial treatment of HCV-associated mixed cryoglobulinemia.

METHODS

Eighteen patients (7 women and 11 men) affected by mixed cryoglobulinemia were included in the study and treated with peg-interferon alfa-2b 1.0 microg/kg once a week plus ribavirin (1000 mg daily) for 48 weeks, regardless of the HCV genotype.

RESULTS

At the end of the treatment HCV-RNA became undetectable in 15 patients (83%) and most patients improved clinically. One subject suspended treatment at 13th week due to depression. A large fraction of the patients (8 cases: 44%) relapsed both virologically and clinically a few weeks after the end of therapy. At the end of follow-up, only eight patients (44%) obtained a sustained virological response.

CONCLUSIONS

Peg-interferon alfa-2b in combination with ribavirin seems safe and useful for patients affected by mixed cryoglobulinemia, but not as effective as in patients with HCV-positive chronic hepatitis without cryoglobulinemia.

Milk thistle for alcoholic and/or hepatitis B or C virus liver diseases

BACKGROUND

Alcohol and hepatotoxic viruses cause the majority of liver diseases. Randomised clinical trials have assessed whether extracts of milk thistle, Silybum marianum (L) Gaertneri, have any effect in patients with alcoholic and/or hepatitis B or C virus liver diseases.

OBJECTIVES

To assess the beneficial and harmful effects of milk thistle or milk thistle constituents versus placebo or no intervention in patients with alcoholic liver disease and/or viral liver diseases (hepatitis B and hepatitis C).

SEARCH STRATEGY

The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and full text searches were combined (December 2003). Manufacturers and researchers in the field were contacted.

SELECTION CRITERIA

Only randomised clinical trials in patients with alcoholic and/or hepatitis B or C virus liver diseases (acute and chronic) were included. Interventions encompassed milk thistle at any dose or duration versus placebo or no intervention. The trials could be double blind, single blind, or unblinded. The trials could be unpublished or published and no language limitations were applied.

DATA COLLECTION AND ANALYSIS

The primary outcome measure was mortality. Binary outcomes are reported as relative risks (RR) with 95% confidence interval (CI). Subgroup analyses were performed with regard to methodological quality.

MAIN RESULTS

Thirteen randomised clinical trials assessed milk thistle in 915 patients with alcoholic and/or hepatitis B or C virus liver diseases. The methodological quality was low: only 23% of the trials reported adequate allocation concealment and only 46% were considered adequately double-blinded. Milk thistle versus placebo or no intervention had no significant effect on mortality (RR 0.78, 95% CI 0.53 to 1.15), complications of liver disease (RR 0.95, 95% CI 0.83 to 1.09), or liver histology. Liver-related mortality was significantly reduced by milk thistle in all trials (RR 0.50, 95% CI 0.29 to 0.88), but not in high-quality trials (RR 0.57, 95% CI 0.28 to 1.19). Milk thistle was not associated with a significantly increased risk of adverse events (RR 0.83, 95% CI 0.46 to 1.50).

AUTHORS' CONCLUSIONS

Our results question the beneficial effects of milk thistle for patients with alcoholic and/or hepatitis B or C virus liver diseases and highlight the lack of high-quality evidence to support this intervention. Adequately conducted and reported randomised clinical trials on milk thistle versus placebo are needed.

Regulation of K-Cl cotransport: from function to genes

This review intends to summarize the vast literature on K-Cl cotransport (COT) regulation from a functional and genetic viewpoint. Special attention has been given to the signaling pathways involved in the transporter's regulation found in several tissues and cell types, and more specifically, in vascular smooth muscle cells (VSMCs). The number of publications on K-Cl COT has been steadily increasing since its discovery at the beginning of the 1980s, with red blood cells (RBCs) from different species (human, sheep, dog, rabbit, guinea pig, turkey, duck, frog, rat, mouse, fish, and lamprey) being the most studied model. Other tissues/cell types under study are brain, kidney, epithelia, muscle/smooth muscle, tumor cells, heart, liver, insect cells, endothelial cells, bone, platelets, thymocytes and Leishmania donovani. One of the salient properties of K-Cl-COT is its activation by cell swelling and its participation in the recovery of cell volume, a process known as regulatory volume decrease (RVD). Activation by thiol modification with N-ethylmaleimide (NEM) has spawned investigations on the redox dependence of K-Cl COT, and is used as a positive control for the operation of the system in many tissues and cells. The most accepted model of K-Cl COT regulation proposes protein kinases and phosphatases linked in a chain of phosphorylation/dephosphorylation events. More recent studies include regulatory pathways involving the phosphatidyl inositol/protein kinase C (PKC)-mediated pathway for regulation by lithium (Li) in low-K sheep red blood cells (LK SRBCs), and the nitric oxide (NO)/cGMP/protein kinase G (PKG) pathway as well as the platelet-derived growth factor (PDGF)-mediated mechanism in VSMCs. Studies on VSM transfected cells containing the PKG catalytic domain demonstrated the participation of this enzyme in K-Cl COT regulation. Commonly used vasodilators activate K-Cl COT in a dose-dependent manner through the NO/cGMP/PKG pathway. Interaction between the cotransporter and the cytoskeleton appears to depend on the cellular origin and experimental conditions. Pathophysiologically, K-Cl COT is altered in sickle cell anemia and neuropathies, and it has also been proposed to play a role in blood pressure control. Four closely related human genes code for KCCs (KCC1-4). Although considerable information is accumulating on tissue distribution, function and pathologies associated with the different isoforms, little is known about the genetic regulation of the KCC genes in terms of transcriptional and post-transcriptional regulation. A few reports indicate that the NO/cGMP/PKG signaling pathway regulates KCC1 and KCC3 mRNA expression in VSMCs at the post-transcriptional level. However, the detailed mechanisms of post-transcriptional regulation of KCC genes and of regulation of KCC2 and KCC4 mRNA expression are unknown. The K-Cl COT field is expected to expand further over the next decades, as new isoforms and/or regulatory pathways are discovered and its implication in health and disease is revealed.

Hematologic side effects of interferon and ribavirin therapy

Pegylated (PEG)-interferon and ribavirin combination therapy are the standard of care for the treatment of chronic hepatitis C and are associated with a high rate of sustained virologic response. However, there is a high incidence of hematologic side effects with this therapeutic regimen. Hematologic side effects are particularly common; bone marrow suppression caused by interferon may result in neutropenia and thrombocytopenia. Ribavirin is directly toxic to red blood cells and is associated with hemolysis, which is usually dose-related but self-limited. Historically, the traditional management of hematologic side effects of interferon therapy has been dose reduction. However, recent studies have shown that response to therapy is strongly influenced by adherence to optimal doses of interferon and particularly ribavirin. Therefore, there is increasing emphasis on the use of growth factors such as filgrastim and erythropoietin to stimulate bone marrow production of erythrocytes and leukocytes to allow patients to receive the optimal doses of interferon and ribavirin. The incidence, magnitude, and possible mechanisms of hematologic complications associated with interferon and ribavirin are described in this review.

Assessment of lipid peroxidation and serum vitamin E concentration in dogs with immune-mediated hemolytic anemia

OBJECTIVE

To determine plasma malondialdehyde (MDA) and serum vitamin E concentrations in dogs with immune-mediated hemolytic anemia (IMHA) and healthy control dogs.

SAMPLE POPULATION

Serum and plasma samples from 36 dogs with IMHA and 40 healthy control dogs.

PROCEDURE

Blood samples were collected from all study dogs. Plasma MDA concentrations were measured by use of a commercial colorimetric assay, and serum vitamin E concentrations (alpha-, gamma, and delta-tocopherol concentrations) were measured via high-performance liquid chromatography.

RESULTS

Plasma MDA concentrations were significantly higher in the dogs with IMHA than in the control dogs. Compared with control dogs, serum alpha-, gamma-, and &tocopherol concentrations were significantly lower in the IMHA-affected dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated a state of oxidative stress and reduced antioxidant reserve in dogs with IMHA; this finding provides support for further investigation of the potential benefits of antioxidant treatment in dogs with this disease.

Liquid chromatography assay for routine monitoring of cellular ribavirin levels in blood

Ribavirin-induced hemolytic anemia is one cause for cessation of combination therapy with alpha interferon 2b and ribavirin for hepatitis C infection. Determining cellular ribavirin levels in blood, including the levels of its phosphorylated metabolites, might be useful for predicting ribavirin-induced anemia, because the metabolites accumulate in erythrocytes. We simplified an assay method developed previously to make it suitable for routine monitoring of cellular ribavirin. Whole blood diluted with a sixfold volume of ice-cold distilled water was subjected to acid phosphatase digestion to convert phosphorylated ribavirin metabolites to free ribavirin. The resulting mixture, spiked with an internal standard, was treated by phenyl boronic acid column extraction, followed by reverse-phase high-performance liquid chromatography analysis. The calibration curve for ribavirin levels in whole blood was linear at concentrations of 5.3 to 1,024 microM (r(2) = 0.9999). Validation coefficients of variation for intra- and interday assays were 2.9 to 5.8% and 4.3 to 8.3%, respectively. We tested this method by monitoring blood ribavirin concentrations in two hepatitis C patients receiving alpha interferon 2b-plus-ribavirin combination therapy.

Oxidative status in chronic hepatitis C: the influence of antiviral therapy and prognostic value of serum hydroperoxide assay

The effect of alpha-interferon (alpha-IFN) and ribavirin (RBV) treatment on oxidative status in chronic hepatitis C (CHC) is unknown.

AIM

To study the time course of oxidative status in patients with CHC during alpha-IFN and RBV administration, and to evaluate the role of oxidative status in order to predict the therapeutic response.

PATIENTS AND METHODS

Fifty one patients with CHC were studied. All received a combination of alpha-IFN and RBV for 6 or 12 months in relation to the type of response. The hydroperoxides concentration in serum test samples by D-ROM test was measured in all of the patients before therapy. In 27 patients, hydroperoxides were also measured during the treatment and during the 12 subsequent months.

RESULTS

Cross-sectional analysis demonstrates that patients with a successive long-term response had a lower basal serum hydroperoxide concentration than non-responders (280 +/- 40.8 vs 337 +/- 83 CARR Units, p < 0.05). This resulted to be an independent factor predictive of long-term response in the multi-varied analysis. Longitudinal observation on 27 patients showed that the mean hydroperoxide concentration decreased significantly during treatment (T0 329 +/- 79.2 vs T12 272 +/- 34.5 CARR Units) and that the decrease in the mean values was mainly due to variations in the relapsers group.

CONCLUSIONS

Normal basal hydroperoxide concentration helps to predict long-term response to combination therapy. The D-ROM test may be used for screening patients before treatment.

The management of side-effects during therapy for hepatitis C

The results of interferon and ribavirin combination therapy for chronic hepatitis C infection have substantially improved in recent years, such that the majority of patients in randomized-controlled trials now achieve a sustained virological response. However, adverse effects are commonplace, often disabling and may lead to interruption or cessation of therapy with subsequent loss of efficacy. Constitutional, neuropsychiatric and haematological reactions have proved particularly troublesome. In this review, we discuss these adverse effects in more detail and highlight recent advances in their management.

Subnormal rise of erythropoietin in patients receiving interferon and ribavirin combination therapy for hepatitis C

OBJECTIVES

Anemia is a common complication during interferon-ribavirin therapy for hepatitis C. While normally a fall in hematocrit in results in an exponential compensatory rise in erythropoietin, such that the correlation between hematocrit and erythropoietin is sharply negative, the erythropoietin response during interferon-ribavirin combination therapy is not known.

METHODS

We measured the hematocrit and erythropoietin levels before and after about 4 weeks of interferon-ribavirin therapy for hepatitis C (n = 43), and compared their relation to the normal human response to anemia.

RESULTS

The hematocrit fell from an average pre-treatment level of 43.7 +/- 3.7% to 36.9 +/- 5 (P < 0.0001). The erythropoietin level rose from 14.5 +/- 15.1 to 58.5 +/- 94.1 units/L (P < 0.0001), indicating there was an adequate stimulus for erythropoietin release. The rise of erythropoietin was severely impaired in relation to the normal human response to a fall in hematocrit. Using the normal human response to anemia as the population line, for our population there was a significant difference in the slope of hematocrit (x) versus log10 erythropoietin (y) (-8.7 vs. -3.098 respectively, P < 0.001) and y-intercept (4.609 vs. 2.753 respectively, P < 0.001). The Bonferroni adjusted "p" value was derived to be <0.002. There was an approximate 2 log10 reduction in maximal achievable erythropoietin level in subjects exposed to interferon-ribavirin combination.

CONCLUSION

There is a subnormal rise of erythropoietin after interferon-ribavirin combination therapy for hepatitis C.

Determination of glycated hemoglobin in patients with advanced liver disease

AIM: To evaluate the glycated hemoglobin (HbA 1c) determination methods and to determine fructosamine in patients with chronic hepatitis, compensated cirrhosis and in patients with chronic hepatitis treated with ribavirin.

METHODS: HbA_1c values were determined in 15 patients with compensated liver cirrhosis and in 20 patients with chronic hepatitis using the ion-exchange high performance liquid chromatography and the immunoassay methods. Fructosamine was determined using nitroblue tetrazolium.

RESULTS: Forty percent of patients with liver cirrhosis had HbA1c results below the non-diabetic reference range by at least one HbA_1c method, while fructosamine results were either within the reference range or elevated. Twenty percent of patients with chronic hepatitis (hepatic fibrosis) had HbA_1c results below the non -diabetic reference range by at least one HbA_1c method. In patients with chronic hepatitis treated with ribavirin, 50% of HbA1c results were below the non-diabetic reference using at least one of the HbA_1c methods.

CONCLUSION: Only evaluated in context with all liver function parameters as well as a red blood count including reticulocytes, HbA 1c results should be used in patients with advanced liver disease. HbA _1c and fructosamine measurements should be used with caution when evaluating long-term glucose control in patients with hepatic cirrhosis or in patients with chronic hepatitis and ribavirin treatment.

Tomato-based functional food as interferon adjuvant in HCV eradication therapy

GOALS

The authors conducted a study to verify whether supplementation with an antioxidant-rich tomato-based functional food reduces anemia during pegylated interferon and ribavirin therapy for chronic hepatitis C.

BACKGROUND

Oxidative stress plays a major role in the physiopathology of hemolytic anemia during ribavirin therapy. The efficacy of antioxidant supplementation with vitamins C and E as pure compounds, is still controversial.

METHODS

A functional food with a high content of natural antioxidants and with high carotenoid bioavailability was developed. The authors enrolled 92 patients with chronic hepatitis C, treated with standard combination therapy. Forty-six of them received a daily dose (100 g) of functional food (group 1), and 46 did not (group 2). The effect of antioxidant activity was assessed comparing compliance with the full dose of ribavirin and hemoglobin levels during the first 3 months of treatment.

RESULTS

Only 8.7% of patients in group 1 had to reduce their daily ribavirin dose, whereas ribavirin reduction was necessary for 30.4% of patients in group 2 (P = 0.09). Hemoglobin levels showed significant differences at 15, 30, and 90 days during the observation time.

CONCLUSION

Results demonstrated that the authors' functional food reduces the severity of ribavirin-related anemia and improves the tolerance to the full dose of ribavirin in patients with chronic hepatitis C.

Induced oxidative stress and activated expression of manganese superoxide dismutase during hepatitis C virus replication: role of JNK, p38 MAPK and AP-1

Activation of cellular kinases and transcription factors mediates the early phase of the cellular response to chemically or biologically induced stress. In the present study we investigated the oxidant/antioxidant balance in Huh-7 cells expressing the HCV (hepatitis C virus) subgenomic replicon, and observed a 5-fold increase in oxidative stress during HCV replication. We used MnSOD (manganese-superoxide dismutase) as an indicator of the cellular antioxidant response, and found that its activity, protein levels and promoter activity were significantly increased, whereas Cu/ZnSOD was not affected. The oxidative stress-induced protein kinases p38 MAPK (mitogen-activated protein kinase) and JNK (c-Jun N-terminal kinase) were activated in the HCV repliconcontaining cells and in Huh-7 cells transduced with Ad-NS5A [a recombinant adenovirus encoding NS5A (non-structural protein 5A)], coupled with a 4-5-fold increase in AP-1 (activator protein-1) DNA binding. Ava.1 cells, which encode a replication-defective HCV replicon, showed no significant changes in MnSOD, p38 MAPK or JNK activity. The AP-1 inhibitors dithiothreitol and N -acetylcysteine, as well as a dominant negative AP-1 mutant, significantly reduced AP-1 activation, demonstrating that this activation is oxidative stress-related. Exogenous NS5A had no effect on AP-1 activation in vitro, suggesting that NS5A acts at the upstream targets of AP-1 involving p38 MAPK and JNK signalling cascades. AP-1-dependent gene expression was increased in HCV subgenomic replicon-expressing Huh-7 cells. MnSOD activation was blocked by inhibitors of JNK (JNKI1) and p38 MAPK (SB203580), but not by an ERK (extracellular-signal-regulated kinase) inhibitor (U0126), in HCV-replicating and Ad-NS5A-transduced cells. Our results demonstrate that cellular responses to oxidative stress in HCV subgenomic replicon-expressing and Ad-NS5A-transduced cells are regulated by two distinct signalling pathways involving p38 MAPK and JNK via AP-1 that is linked to increased oxidative stress and therefore to an increased antioxidant MnSOD response.

SOD2-deficiency anemia: protein oxidation and altered protein expression reveal targets of damage, stress response, and antioxidant responsiveness

SOD2 is an antioxidant protein that protects cells against mitochondrial superoxide. Hematopoietic stem cells (HSCs) lacking SOD2 are capable of rescuing lethally irradiated hosts, but reconstituted animals display a persistent hemolytic anemia characterized by increased oxidative damage to red cells, with morphologic similarity to human "sideroblastic" anemia. We report further characterization of this novel SOD2-deficiency anemia. Electron micrographs of SOD2-deficient reticulocytes reveal striking mitochondrial proliferation and mitochondrial membrane thickening. Peripheral blood smears show abundant iron-stainable granules in mature red cells (siderocytes). Fluorescence-activated cell sorting (FACS) analysis of cells labeled with oxidation-sensitive dyes demonstrates enhanced production of superoxide and hydrogen peroxide by SOD2-deficient cells. Oxidative damage to proteins is increased in SOD2-deficient cells, with much of the damage affecting membrane/insoluble proteins. Red cell proteome analysis demonstrates that several proteins involved in folding/chaperone function, redox regulation, adenosine triphosphate (ATP) synthesis, and red cell metabolism show altered expression in SOD2-deficient cells. This data, combined with information on how protein expression levels change upon antioxidant therapy, will aid in identification of proteins that are sensitive to oxidative damage in this model, and by extension, may have a role in the regulation of red cell lifespan in other hemolytic disorders.

Use of alveolar carbon monoxide to measure the effect of ribavirin on red blood cell survival

A major side effect of ribavirin (RBV) treatment is anemia. While this anemia is thought to result from increased RBC turnover, RBC survival has not been determined in subjects receiving RBV due to the complexity of the techniques commonly used to quantitate RBC life span. We recently described a simple, rapid, non-invasive technique that utilizes measurements of alveolar carbon monoxide (CO) concentration to determine RBC survival. In the present report, this method was employed to assess RBC survival in patients receiving RBV for hepatitis C. Each of the 31 measurements of RBC survival in 12 subjects with RBV-associated anemia was below the lower limit of normal (77 days), and the average survival (46 +/- 14 days) in these subjects was only about 38% of that of healthy controls (122 +/- 23 days). Five hepatitis C patients not undergoing RBV treatment had normal RBC survivals (112 +/- 17 days). While the mean reticulocyte percentage was significantly elevated in subjects treated with RBV, 59% of these measurements fell within the limits of normal. We conclude that RBV-associated anemia consistently is associated with reduced RBC survival as determined from breath CO measurements and that this reduced survival frequently is not associated with an elevated reticulocyte count.

Amantadine therapy for chronic hepatitis C

OBJECTIVE

Although treatment of hepatitis C has improved, up to 50% do not respond to standard therapy with interferon regimes or cannot tolerate the treatment due to side effects. The purpose of the present investigation was to evaluate the safety and effectiveness of the antiviral drug amantadine for the treatment of hepatitis C in those who had either previously failed interferon therapy or were not candidates for interferon.

DESIGN

A prospective double-blind randomized placebo-controlled trial.

SETTING

Outpatient research clinic of a teaching hospital.

PATIENTS/PARTICIPANTS

One hundred fifty-two patients with confirmed hepatitis C with abnormal liver enzymes, detectable hepatitis C RNA in the blood, and abnormal liver histology by biopsy were randomized to receive treatment or placebo.

MEASUREMENTS AND MAIN RESULTS

Patients received either amantadine 100 mg twice daily by mouth or placebo for 6 months. After 6 months, placebo-treated patients were crossed over and treated with amantadine for 6 months and amantadine-treated subjects received 6 additional months of therapy. Amantadine therapy resulted in a significant decline in serum alanine aminotransferase compared to placebo (P =.03). Nine percent cleared the virus at the end of therapy and 6.8% had a sustained virologic response 6 months after discontinuation of amantadine, but this was not statistically significant. Side effects were minimal, and the social quality of life survey improved with 12 months of amantadine (P =.02).

CONCLUSIONS

Oral amantadine may provide a safe alternative treatment for those patients who are intolerant or unresponsive to interferon.

Low membrane protein sulfhydrils but not G6PD deficiency predict ribavirin-induced hemolysis in hepatitis C

Hemolysis is a frequent adverse effect of ribavirin (RBV). It has been suggested that oxidative stress plays a role, but mechanisms and predictive risk factors for severe forms remain unknown. Markers of redox status were determined in erythrocytes of 34 patients with hepatitis C-four of them with glucose-6-phosphate-dehydrogenase (G6PD) deficiency-before and during treatment with RBV and interferon (IFN) and were compared with 10 healthy control subjects. In addition, erythrocytes were incubated with RBV, and the effects of dipyridamole (DPD), diethylmaleate (DEM), and glutathione ester (GSHE) were studied in vitro. Of the 30 patients without G6PD deficiency who were treated with RBV and IFN-alpha, five developed major hemolysis (Delta hemoglobin > 6 g/dL) and 25 developed minor hemolysis (Delta hemoglobin < 2.5 g/dL). Patients with major hemolysis had lower median pretreatment values of membrane protein sulfhydrils than patients with minor hemolysis (28.4 vs. 36.7 nmol/mg, P <.001). Erythrocytes of G6PD-deficient patients were not more susceptible to RBV-induced hemolysis. In in vitro incubations of erythrocytes, DEM enhanced the RBV-induced decrease of glutathione, protein sulfhydrils, and osmotic resistance. Supplementation of GSHE and DPD prevented the RBV-induced decrease in osmotic resistance, adenosyl triphosphate (ATP), and 2,3-diphosphoglycerate (DPG), the loss of glutathione and protein sulfhydrils, and the formation of thiobarbituric acid reactive substances (TBARs). In conclusion, the data indicate that low membrane protein sulfhydrils prior to therapy but not G6PD deficiency are predictive of RBV-induced major hemolysis. In vitro, GSHE and DPD reduce the RBV-associated oxidative stress in erythrocytes and prevent the increase in osmotic fragility, suggesting that these compounds might decrease the risk of hemolysis in patients.

Changes in haemoglobin during interferon alpha-2b plus ribavirin combination therapy for chronic hepatitis C virus infection

Interferon alpha and ribavirin (RBV) combination therapy is associated with decreases in haemoglobin (Hb) concentrations and anaemia. The aim of this analysis was to better characterize the magnitude and frequency of Hb changes and risk factors. This retrospective analysis evaluated treatment-related changes in Hb in 677 patients who participated in either of two interferon alpha-2b plus RBV studies for chronic hepatitis C virus (HCV) infection. Study 1 included 192 interferon alpha-naïve patients randomized to receive RBV 1000-1200 mg/day plus interferon alpha-2b 3 million IU daily or three times weekly for 48 weeks. Study 2 included 485 interferon alpha-experienced patients randomized to receive RBV 1000-1200 mg daily plus interferon alpha-2b 3 million IU daily or three times weekly for 4 weeks, followed by three times weekly dosing for 44 weeks. More than 50% of all patients experienced a decrease in Hb > or =30 g/L. Women were 4.4 times as likely as men to experience a Hb level of <100 g/L; however, men were at a 40% higher risk to experience a Hb decline of >30 g/L from baseline. Daily use of interferon alpha-2b did not impact the magnitude of Hb decrease. In this pooled analysis, RBV dose reduction resulted in increases in Hb concentration of approximately 10 g/L. Lower baseline creatinine clearance, higher baseline Hb levels and increased age were independently associated with increased risk of Hb decreases of >27.7%. Lower baseline weight was not associated with increased risk of Hb decrease. Substantial Hb decreases occur frequently with interferon alpha/RBV combination therapy. Sex, the magnitude of the Hb decline and renal function are potentially important factors to consider in patients receiving RBV. Further research is needed to determine the impact on virological response and to develop strategies to manage the medical consequences.

Epoetin alfa treatment for acute anaemia during interferon plus ribavirin combination therapy for chronic hepatitis C

Infection with the hepatitis C virus (HCV) remains chronic in 75% of infected individuals, in whom it can cause liver inflammation and progressive fibrosis leading to cirrhosis in 20% of patients. A sustained viral response (SVR) to HCV therapy, i.e. undetectable plasma HCV RNA 6 months after the end of treatment, leads to permanent eradication of the virus in 98.3% of patients. The current treatment of choice is combination therapy with pegylated interferon alfa (PEG-IFN alfa), 2a or 2b, and ribavirin (RBV), which achieves an SVR in 54-56% of patients. In patients with HCV genotype 1, RBV doses of 1000-1200 mg/day are associated with a higher SVR than 800 mg/day (51 vs 40%). However, RBV also causes dose-dependent reversible haemolytic anaemia that, in combination with the myelosuppressive effects of PEG-IFN, results in a mean drop in haemoglobin (Hb) level of 3.7 g/dL within 4 weeks. Conventionally, this acute anaemia has been managed with RBV dose reductions. However, this may result in a decreased SVR rate. Alternatively, this anaemia can be managed with administration of epoetin alfa at 40 000 IU once weekly. In a randomized placebo-controlled trial, treatment with epoetin alfa has been shown to raise Hb levels and maintain RBV doses. Furthermore, the increase in Hb level was associated with improved quality of life. Anaemia in patients treated with interferon plus RBV combination therapy can be managed effectively and safely with once weekly epoetin alfa without sacrificing optimal dosing of RBV.

Serum LD1 isoenzyme and blood lymphocyte subsets as prognostic indicators for severe acute respiratory syndrome

BACKGROUND

The pathophysiology of severe acute respiratory syndrome (SARS) is at present poorly understood, but advanced age and serum total lactate dehydrogenase (LD) activity >300 U L(-1) have been associated with adverse clinical outcomes. Blood leucocytes and lymphocyte subsets were reported to decrease, respectively, in 47% and up to 100% of 38 patients in Beijing. However, their prognostic implications have not been thoroughly investigated.

OBJECTIVE

To investigate serum total LD, LD isoenzymes, and other parameters including blood lymphocyte subsets as prognostic indicators in SARS patients for adverse clinical outcomes in terms of admission to intensive care unit (ICU) and death.

DESIGN

Retrospective analysis.

SUBJECTS AND METHODS

A total of 109 patients with a clinical diagnosis of SARS according to the modified World Health Organization case definition of SARS were recruited from two major acute hospitals in Hong Kong. They were either involved in the initial outbreak of SARS, or cases from the community outbreak of Amoy Gardens between 10 March and 5 May 2003. The clinical diagnosis was subsequently confirmed by serological test and/or molecular analysis. Serum total LD and LD isoenzyme activities, complete blood picture with total leucocyte count and differential counts, absolute counts of CD3+, CD4+, CD8+, natural killer cells and B lymphocytes were measured daily upon admission. Receiver operating characteristic curve analysis was used to determine and compare different cut-offs for various biochemical and immunological parameters at peak serum total LD concentration in predicting adverse clinical outcomes.

RESULTS

Of a total of 109 patients, 41 were admitted to ICU and 42 died. Of 42 fatal patients, 24 died in ICU and 18 died in general medical wards. Age was found to be an independent prognostic indicator for death with an area under curve (AUC) of 0.96 [95% confidence interval (CI) = 0.90-0.99] but not for admission to ICU [AUC = 0.61 (CI = 0.51-0.70)]. Whilst serum total LD could only achieve AUC of 0.68 (CI = 0.59-0.77) for predicting death, LD1 isoenzyme was found to be the best biochemical prognostic indicator with AUC of 0.84 (CI = 0.75-0.90), sensitivity of 62% (CI = 46-76%), specificity of 93% (CI = 83-98%) at cut-off activity of > or =80 U L(-1). CD3+, CD4+, CD8+ and natural killer cell counts were promising immunological prognostic indicators for predicting admission to ICU with AUC of 0.94 (CI = 0.86-0.98), 0.91 (CI = 0.81-0.96), 0.93 (CI = 0.85-0.98), and 0.87 (CI = 0.76-0.94), respectively.

CONCLUSIONS

Apart from age, serum LD1 activity was the best prognostic indicator for predicting death in patients with SARS compared with serum total LD activity, haemoglobin concentration, leucocyte and lymphocyte counts. Its release could possibly be from blood erythrocytes and body tissues other than the myocardium. Blood CD3+, CD4+, CD8+ and natural killer cell counts were found to be good prognostic indicators for predicting admission to ICU in patients with SARS compared with age, leucocyte count and LD isoenzymes. The suppressed CD3+, CD4+, CD8+, and natural killer cell counts were also implicated in the pathophysiology of SARS. Patients with increased serum LD1 should be closely monitored to ensure prompt management, and preparation for admission to ICU could be planned ahead for patients with suppressed lymphocyte subsets.

Marked elevation of erythrocyte ribavirin levels in interferon and ribavirin-induced anemia

BACKGROUND & AIMS

To elucidate the effects of blood ribavirin disposition on ribavirin-induced anemia, the relationship between erythrocyte ribavirin concentration and change in hematologic parameters was examined in interferon and ribavirin combination therapy for HCV eradication.

METHODS

Nine HCV RNA-positive patients were treated with combination therapy including 11.3 +/- 1.2 mg.kg(-1).day(-1) of ribavirin. Blood concentrations of ribavirin and its phosphorylated metabolites were measured in plasma as well as erythrocyte.

RESULTS

Blood ribavirin concentrations gradually increased to steady-state levels of 8.8 +/- 1.4 micromol/L and 1389 +/- 371 micromol/L in plasma and erythrocytes, respectively, within 3-4 weeks of initiating therapy. Erythrocyte phosphorylated metabolite levels (1215 +/- 302 micromol/L) were found to be exceedingly high, i.e., 87% of the measured erythrocyte ribavirin concentration. In contrast, plasma phosphorylated metabolite levels were undetectable. Positive correlation was found to exist between erythrocyte ribavirin concentrations and a decrease in hemoglobin (r = 0.620, P < 0.001).

CONCLUSIONS

We concluded that marked elevation of erythrocyte ribavirin including its phosphorylated metabolites was associated with hemoglobin reduction, leading to interferon and ribavirin-induced anemia.

Adherence to combination therapy: influence on sustained virologic response and economic impact

The health care burden of hepatitis C virus (HCV) infection is projected to continue to increase over the next two decades, so improving the efficacy of anti-HCV therapy has the potential to significantly affect health care utilization associated with the disease. Adherence to standard combination therapy and maintaining the doses of interferon (IFN) or peginterferon (PEG-IFN) and ribavirin (RBV) are now recognized as critical to maximizing a sustained virologic response (SVR) rate, particularly in patients infected with genotype 1 and patients who demonstrate an early virologic response. Early identification and management of the treatment-related side effects that are most likely to result in dose reductions or discontinuation might also play a role in successful adherence to therapy and achieving an SVR, as side effects are the primary reason for nonadherance. Educating patients, their family members, and their caregivers about the expectations of treatment, side effects, and the importance of maintaining doses and completing therapy is essential to optimizing adherence. Although patient quality of life (QOL) may decrease during treatment, patients achieving an SVR experience an improved QOL. Cohort economic modeling studies and available data from recent controlled trials suggest that PEG-IFN/RBV therapy increases life expectancy and is cost effective compared with standard IFN/RBV, and that the use of treatment management algorithms based on early virologic testing can substantially reduce antiviral drug costs and further improve the cost effectiveness of therapy, as can increased adherence to PEG-IFN/RBV therapy. Further research will be needed to develop optimum and cost-effective treatment strategies for the general HCV-infected population, particularly patients with comorbidities.

Role of epoetin alfa in maintaining ribavirin dose

Current therapy for the treatment of hepatitis C virus (HCV) infection is standard interferon (IFN) or pegylated interferon (PEG-IFN) in combination with ribavirin (RBV). Hematologic side effects (neutropenia, thrombocytopenia, anemia) are a major reason for dose reduction of anti-HCV therapy. Because treatment adherence and maintenance of IFN or PEG-IFN and RBV doses have been shown to be important in achieving a sustained virologic response, appropriate management of hematologic side effects might play a substantial role in optimizing treatment outcomes. Neutropenia and thrombocytopenia are usually managed by IFN or PEG-IFN dose reduction; the role of hematopoietic growth factors to ameliorate these side effects needs further evaluation, but some studies suggest granulocyte colony-stimulating factor (G-CSF) may be useful in the management of IFN/PEG-IFN-associated neutropenia. Anemia is primarily due to RBV-induced hemolytic anemia, but IFN/PEG-IFN also suppresses bone marrow erythroid precursors. Treatment-induced anemia has usually been managed by RBV dose reduction or discontinuation. However, recent studies suggest that epoetin alfa can increase hemoglobin levels and facilitate maintenance of RBV dosage in patients with chronic hepatitis C who became anemic during standard combination therapy. Results of a randomized, randomized, double-blind, placebo-controlled trial suggest that epoetin alfa therapy can maintain RBV dosage, increase hemoglobin levels, and improve quality of life in this population. In patients who have chronic hepatitis C who experience hematologic toxicities during standard therapy, the use of hematopoietic growth factors such as epoetin alfa might have the potential to improve treatment adherence rates and allow optimal doses of IFN or PEG-IFN and RBV to be maintained, thereby leading to improved treatment outcomes.

Treating hepatitis C: the state of the art

Treatment of chronic hepatitis C has improved significantly, but more effective and well-tolerated therapies are needed. While new therapies are being developed, it is important to optimize the use of currently available treatments. Current treatment regimens are associated with substantial side effects, especially hematologic and neuropsychiatric side effects, that can lead to nonadherence, dose reduction, and treatment discontinuation. Because treatment adherence is critical to achieving a sustained virologic response, especially in patients who have genotype 1, early recognition and appropriate management of these side effects should lead to improved patient outcomes. Pending the availability of new therapies, further progress can be made mainly by maximizing benefits for individuals infected with HCV through appropriate selection of patients for antiviral treatment and increasing treatment adherence through better patient and caregiver education, closer patient follow-up, and more aggressive management of the side effects that lead to dose reduction or discontinuation. Further clinical and research efforts are needed to expand treatment to subgroups of patients previously considered ineligible because of comorbidities such as psychiatric and substance-use disorders. Optimum management of patients with hepatitis C will involve a larger cooperative team effort that includes physician specialists from various disciplines, including mental health care providers and physician extenders. Continued efforts are needed to develop novel therapies and treatment approaches to benefit patients who do not respond to current therapies, to increase our understanding of the natural history and pathology of HCV infection, and to promote public education to better identify infected individuals and improve hepatitis C prevention.

[Use of erythropoietin in the treatment of anemia induced by ribavirin/interferon in patients with hepatitis C]

We are presenting 20 patients with hepatitis C, who developed anemia on interferon alpha-2b/ribavirin treatment and were treated with recombinant human c alpha. Median age was 43 years (range 25-72). Four patients received previous treatment. Interferon-alpha-2b was given at six million units three times a week to 10 patients and at three million units three times a week to five patients. PEG-interferon-alpha-2b (80-120 mug/week) was given to five patients. The dose of ribavirin was 800-1200 mg/day (19 patients) and 200 mg/day (one patient with renal failure). Duration of an interferon/ribavirin treatment was 6-12 months. Baseline median hemoglobin was 13.3 g/dl (range 12.2-15.8); median hemoglobin nadir: 9.8 g/dl (range 8.4-11.2). On erythropoietin, the hemoglobin increased to median 11.7 g/dl (range 9.6-12.8). The ribavirin dose had been decreased to 800 mg in four patients, to 600 mg in four patients, to 400 mg in one patient. Thirteen patients responded to interferon/ribavirin treatment, six patients (all genotype 1) did not. Of the 13 initial responders 11 had sustained response, one still under treatment and two patients relapsed. In conclusion, in our patients with chronic hepatitis C treated with interferon/ribavirin combination therapy, erythropoietin was beneficial in the treatment of ribavirin-induced anemia.

Evidence that plasma concentration rather than dose per kilogram body weight predicts ribavirin-induced anaemia

Ribavirin in combination with interferon alpha-2 or pegylated interferon is the standard treatment for chronic hepatitis C. The current dosage recommendations for ribavirin are based on body weight (bw). Ribavirin is mainly eliminated by the kidneys and we have recently shown that ribavirin plasma concentrations are determined primarily by renal function. It is therefore reasonable to hypothesize that side-effects of ribavirin, i.e. anaemia, should be more closely related to plasma concentrations of ribavirin than to the dose per kg bw. A total of 108 consecutive patients eligible for treatment of chronic hepatitis C were studied. Ribavirin concentrations in plasma were measured by high-performance liquid chromatography (HPLC)-UV after solid-phase extraction in trough samples taken 4, 8 and 12 weeks after the treatment commenced. A total of 213 samples were obtained and the change in the haemoglobin level and the creatinine concentration was measured in addition to ribavirin. The dose of ribavirin per kg bw did not correlate with the drop in haemoglobin level induced by ribavirin. The concentration of ribavirin was non-linearly related to the drop in the haemoglobin level as revealed by fitting a standard Hill equation type dose-response curve. The half maximal drop in haemoglobin was obtained at 4.4 microm. The results from this study suggest that the anaemia induced by ribavirin depends primarily on the concentration of ribavirin, and not on the dose per kg bw. This lends further support to the idea that ribavirin should be dosed according to renal function.

Sickle cell disease: from membrane pathophysiology to novel therapies for prevention of erythrocyte dehydration

Sickle cell anemia is characterized by the presence of dense dehydrated erythrocytes that have lost most of their K content. Due to the unique dependence of Hb S polymerization on intracellular Hb S concentration, preventing this dehydration should markedly reduce polymerization. The erythrocyte intermediate conductance Ca-activated K channel (hSK4 or KCNN4), first described by Gardos, has been shown to be a major pathway for sickle cell dehydration. Studies with the imidazole antimycotic clotrimazole have shown reduction of sickle cell dehydration in vivo in a small number of patients with sickle cell disease; dose-limiting gastrointestinal and liver toxicities were observed. Based on the chemical structure of clotrimazole metabolites, a novel Gardos channel inhibitor, ICA-17043, has been developed. It has shown substantial activity both in vitro and in vivo in transgenic sickle mice. ICA-17043 is currently in phase 2 human trials. Another potential therapeutic target is the K-Cl cotransport. When sickle erythrocytes are exposed to relatively acidic conditions, they undergo cell shrinkage via activation of this pathway. K-Cl cotransport can be blocked by increasing the abnormally low erythrocyte Mg content of sickle erythrocytes. Oral Mg supplementation has been shown to reduce sickle cell dehydration in vivo in transgenic sickle mice and in patients in two separate clinical trials. Oral Mg pidolate is being tested in clinical trials in homozygous sickle cell disease and in Hb S/HbC (SC) disease, either as a single agent or in combination with hydroxyurea. The ongoing trials will determine the clinical effectiveness of therapies aimed at preventing sickle erythrocyte dehydration.

Once-weekly epoetin alfa improves anemia and facilitates maintenance of ribavirin dosing in hepatitis C virus-infected patients receiving ribavirin plus interferon alfa

OBJECTIVE

The aim of this study was to determine the efficacy of epoetin alfa in alleviating anemia and minimizing ribavirin (RBV) dose reductions in patients with chronic hepatitis C virus (HCV) infection receiving combination RBV/interferon alfa (IFN) therapy.

METHODS

HCV-infected patients who had Hb levels of 12 g/dl or less during the first 24 wk of combination RBV/IFN therapy (n=64) were randomized to treatment with epoetin alfa (40,000 units) s.c. q.w. or to standard of care (SOC) for anemia management (RBV dose reduction or discontinuation, transfusions). Primary and secondary efficacy endpoints were changes in Hb level and RBV dosage, respectively, from baseline to week 16 of epoetin alfa therapy. Based on intent-to-treat analysis, the mean changes from baseline Hb levels at week 16 were +2.8 g/dl for epoetin alfa versus +0.4 g/dl for SOC (p<0.0001), and the mean changes in RBV dosage were -34 mg/day for epoetin alfa versus -146 mg/day (p=0.060) for SOC. The mean Hb level at week 16 in the epoetin alfa group (13.8 g/dl) was significantly (p<0.0001) higher than that of the SOC group (11.4 g/dl). At week 4 and subsequently, significantly more patients in the epoetin alfa group did not have RBV dosage reductions (p<0.011). At study end, 83% of epoetin alfa-treated patients maintained RBV dosages of at least 800 mg/day, compared with 54% of patients receiving SOC (p=0.022). Epoetin alfa was well tolerated.

CONCLUSIONS

In anemic HCV-infected patients treated with RBV/IFN, epoetin alfa increases Hb levels and maintains RBV dosing. Based on these results, epoetin alfa seems to be promising in the treatment of HCV treatment-related anemia. Further research is warranted to determine the potential impact on outcomes, including quality of life and sustained viral response rate.

Controversies in the management of hepatitis C virus infection after liver transplantation

Recurrence of hepatitis C virus infection after liver transplantation is universal. A significant percentage of these patients develop progressive graft injury and cirrhosis. Those factors that modulate disease progression in liver transplant recipients with recurrent hepatitis C virus infection remain controversial and are poorly understood. Treatment of recurrent hepatitis C virus after liver transplantation with either interferon or interferon and ribavirin has yielded only limited success. Regardless of this, treatment is instituted. Peginterferon is more effective than standard interferon for treatment of chronic hepatitis C virus infection in the nontransplantation setting when used either alone or with ribavirin. The effectiveness of peginterferon, both with and without ribavirin in the posttransplantation setting, is currently being explored. In this review those factors thought to affect disease progression in patients with recurrent hepatitis C virus will be discussed, strategies that have been used to treat recurrent hepatitis C virus will be reviewed, and the impact that peginterferon may have on hepatitis C virus infection in the pretransplantation and posttransplantation setting will be explored.

Autoimmune hemolytic anemia occurred prior to evident nephropathy in a patient with chronic hepatitis C virus infection: case report

BACKGROUND

Renal involvement in patients with chronic hepatitis C virus infection has been suggested to be due to a variety of immunological processes. However, the precise mechanism by which the kidneys are damaged in these patients is still unclear.

CASE PRESENTATION

A 66 year old man presented with the sudden onset of autoimmune hemolytic anemia. Concomitant with a worsening of hemolysis, his initially mild proteinuria and hemoglobinuria progressed. On admission, laboratory tests revealed that he was positive for hepatitis C virus in his blood, though his liver function tests were all normal. The patient displayed cryoglobulinemia and hypocomplementemia with cold activation, and exhibited a biological false positive of syphilic test. Renal biopsy specimens showed signs of immune complex type nephropathy with hemosiderin deposition in the tubular epithelial cells.

CONCLUSIONS

The renal histological findings in this case are consistent with the deposition of immune complexes and hemolytic products, which might have occurred as a result of the patient's underlying autoimmune imbalance, autoimmune hemolytic anemia, and chronic hepatitis C virus infection.

Hematologic disorders associated with hepatitis C virus infection and their management

More than 4 million people in the United States are infected with hepatitis C virus (HCV). During the next 20-30 years, the burden of HCV-related mortality and morbidity will likely double. To date, the most effective treatment for chronic HCV infection is the combination of either interferon (IFN)-alpha or pegylated IFN-alpha and ribavirin. For a sustained virologic response, treatment adherence and dose maintenance are essential. However, both IFN-alpha and ribavirin induce hematologic toxicity, such as anemia, neutropenia, and thrombocytopenia, which can compromise treatment adherence and dose maintenance and could, therefore, potentially influence outcomes. Although there are currently no approved treatments for hematologic complications of HCV therapy, studies have shown that hematopoietic growth factors can provide significant benefits. This review highlights the pharmacology, risks, and benefits of recombinant hematopoietic growth factor therapy in HCV-infected patients.