Chronic hepatitis C and interferon alfa therapy: predictors of long term response

OBJECTIVE: To identify independent patient, disease and viral characteristics that predict a sustained biochemical or viral response to interferon alfa therapy in patients with chronic hepatitis C. Design: Comparison of interferon responders and non-responders by univariate and multivariate analysis. SETTING: The hepatitis clinic of the Alfred Hospital, Melbourne (a tertiary referral hospital), between July 1989 and June 1994. SUBJECTS: All patients with chronic hepatitis C who were treated with interferon alfa (IFN-alpha; 3 million IU, three times a week or more) for at least 12 weeks. OUTCOME MEASURES: Patient demographic and epidemiologic characteristics, pretreatment serum alanine aminotransferase (ALT) and 2-gamma-glutamyl transpeptidase (GGT) levels, histological grading of hepatic steatosis, necroinflammatory activity and fibrosis, serum hepatitis C virus (HCV) RNA titres and genotype and post-treatment serum ALT levels and presence of HCV RNA. Results: Of 58 patients, 13 (22%) had a sustained (six months or longer) biochemical response to IFN-alpha therapy, including 12 (21%) with a sustained viral response. Univariate analysis showed that young patients with a normal serum GGT level, grade 0-1 steatosis and fibrosis, low viral titre and infection with genotypes 3a and 2a were more likely to have a sustained response. Infection with genotypes other than 1a and 1b was the only independent variable associated with both a sustained biochemical and viral response. After adjusting for genotype, a hepatic fibrosis grade of 0-1 was also independently associated with viral response. This logistic regression model accurately predicted the virological response in 80% of cases. Conclusion: In Australian patients with chronic hepatitis C, a sustained viral response to IFN-alpha therapy is most likely in those infected with a genotype other than 1a or 1b and with minimal hepatic fibrosis.     

Prediction of response during interferon alfa 2b therapy in chronic hepatitis C patients using viral and biochemical characteristics: a comparison

Patients with chronic hepatitis C (n = 103) were treated for 24 weeks with interferon alfa 2b and followed up for 24 weeks after cessation of therapy (week 48). When hepatitis C virus (HCV) RNA at week 48 was used to assess interferon response, 15 (14.6%) were virological complete responders, and all have remained HCV RNA negative for a mean of 3 years. At week 48, 3 of 15 virological complete responders had elevated alanine transaminase (ALT) values. When serum ALT level was used at week 48 to determine response to interferon, 20 (19.4%) were biochemical complete responders. However, 8 of the 20 patients with normal ALT levels were HCV RNA positive at week 48, and 7 of these individuals have had a recurrence of elevated ALT levels within 3 years after cessation of treatment. These findings indicate that measurement of HCV RNA was more accurate than ALT in determining true responses to interferon therapy. Identification of nonresponders early during the course of interferon treatment showed that an elevated ALT level at week 12 was 92% predictive (odds ratio 3.7) but misidentified 33% (5 of 15) of the patients who were virological complete responders at week 48. In contrast, a positive HCV RNA at week 12 of treatment was 98% predictive (odds ratio 35.5) and misidentified only 6.7% (1 of 15) of the virological complete responders. Thus, positive HCV RNA at week 12 of therapy was more accurate in identifying eventual virological nonresponders than measurement of ALT at this time. Termination of interferon therapy in patients who were HCV RNA positive at week 12 would result in a 27% reduction in the direct medical costs and keep patients from undergoing unnecessary treatment. Therefore, testing for HCV RNA at week 12 to identify nonresponders and then discontinuing their treatment is practical, cost-efficient and beneficial both to patients and to third-party payers.     

Long-term follow-up of patients with chronic hepatitis C after interferon-alpha treatment

In this study, 72 patients with chronic hepatitis C virus (HCV) were followed prospectively for a mean period of 27 months after interferon treatment. Fifty-seven percent (20/35) of the patients with complete response, 18/20 with HCV-RNA-negative serum, had a sustained biochemical remission. Reactivation was seen in 43% of these patients after a mean follow-up of 7.3 months. A late relapse after more than 12 months of follow-up occurred in only 2/15 patients. Patients with a long-term complete response had significantly lower pretreatment serum HCV RNA levels than complete responders with relapse (106,239 vs. 345,649 mEq/ml, p = 0.0213). A delayed sustained biochemical remission was seen in 3/37 patients with partial or no response. Thus, long-term response is achieved in 32% of the patients treated with interferon, clearly associated with a suppression of serum HCV RNA. Patients with normal ALT values and undetectable levels of HCV RNA for more than 12 months of follow-up may usually be considered as sustained responders. Thus, for the first time, the pretreatment HCV RNA level in serum was identified as predictive of long-term response.     

Treatment of chronic hepatitis C with interferon-alpha: a preliminary report

Interferon alpha (IFN-alpha) has been indicated to be dramatically effective in some but not all patients with chronic hepatitis C virus (HCV) infection. We investigated prospectively 27 patients of chronic hepatitis C, 12 females and 15 males, treated with IFN-alpha for a better regimen of the therapy and for any effective predictor of response to the treatment. All patients were treated with 3 to 6 million units (MU) of recombinant IFN-alpha 2b (n = 15) or lymphoblastoid IFN-alpha (n = 12) given 3 times weekly for 12 to 36 weeks. Patients with normal alanine aminotransferase (ALT) value during therapy, who sustained this response throughout 6 months follow-up after treatment was completed, were grouped into the complete responders. Patients with normal ALT value during therapy but who relapsed after treatment completed, were grouped as partial responders. Non-responders were defined as patients without normal ALT value during therapy. The rates of complete response, partial response, and non-response were 29.6%, 40.8%, and 29.6%, respectively. The degree of response to IFN-alpha therapy was not related to age, sex, type of IFN-alpha, history of blood transfusion, the state of liver pathology, or pretreatment level of ALT value. The complete responsive rate to IFN-alpha was higher in patients treated with total dose above 215 MU [38.1% (8/21) vs. 0% (0/6), p = 0.06], in patients treated for at least 24 weeks [40% (8/20) vs. 0% (0/7), p < 0.05], and in patients with non-genotype 1b/II HCV infection [40% (8/20) vs. 0% (0/7), p < 0.05]. We concluded that IFN-alpha was effective in the treatment of chronic HCV infection, particularly in those other than HCV genotype 1b/II. A high-dose, and long-duration regimen may be recommended for better response of chronic hepatitis C to IFN-alpha therapy.     

Physical activity status and adverse age-related differences in coagulation and fibrinolytic factors in women

BACKGROUND/AIMS: Current criteria to predict sustained response for a patient with chronic hepatitis C virus during interferon treatment are not consistent. The aim of this study was to determine a reliable point in time to predict non-response to therapy, as a theoretical basis for early cessation of treatment. METHODS: Sera (-70 degrees C) from 66 patients treated with interferon (3 million units three times a week for 6 months) were assayed with a quantitative polymerase chain reaction (sensitivity < or =100 copies per milliliter). Evaluations were made at baseline, during treatment at weeks 1, 2, 4, 12, and 24, and at follow-up week 48. Biochemical response was defined using standard alanine aminotransferase criteria. Virologic response was defined as: sustained if loss of HCV RNA persisted through therapy and follow-up; relapse if HCV RNA became undetectable but reappeared during treatment or follow-up; and non-response if HCV RNA remained detectable during the study period. Alanine aminotransferase and HCV RNA results were analyzed at defined time intervals to determine a predictive value for non-response and sustained response. RESULTS: HCV RNA results are a more accurate predictor than alanine aminotransferase for both non-response and sustained response. Serum HCV RNA predicted non-response better than sustained response. The optimal time to predict non-response with serum HCV RNA was treatment week 12. CONCLUSIONS: Treatment week 12 results indicate that HCV RNA was a more accurate predictor for non-response than serum alanine aminotransferase. This prediction would have theoretically permitted stopping treatment for 75% of the patients in this study at treatment week 12 allowing an overall cost savings of 28%.     

Prospective comparison of four lymphoblastoid interferon alpha schedules for chronic hepatitis C. A multivariate analysis of factors predictive of sustained response to treatment

OBJECTIVE: Interferon alpha (IFN-alpha) provides effective treatment in some patients with chronic hepatitis C. Since this drug is costly and causes potentially severe side effects, there is a need for clarification of the optimal dose regimen and treatment duration and of the predictive factors of long-term response to this therapy. DESIGN: Prospective, randomized study in patients with chronic hepatitis C. SETTING: 'Crespi' Division of Medicine and Centre for Liver Diseases, Niguarda Hospital, Milan, Italy. PATIENTS AND METHODS: One hundred and forty-two patients with chronic hepatitis C were randomized to receive IFN-alpha at a dosage of 2-4 mega units/square metre of body surface area thrice weekly for 6-12 months. Eleven baseline variables that might predict sustained response to IFN-alpha were evaluated in this series. Sustained response was defined as normalization of transaminase levels observed by the fourth month of therapy and lasting for at least 6 months after treatment withdrawal. RESULTS: According to univariate analysis, variables significantly associated with sustained response to treatment were: hepatitis C virus (HCV) genotype, treatment duration, serum HCV-RNA level and duration of hepatitis. On multivariate analysis only two of these variables were found to be independently associated with sustained response to IFN-alpha: HCV genotype (P < 0.0001) and treatment duration (P = 0.0015). In the patients infected with genotype 1b, IFN-alpha was effective only when administered at the higher dosage and for the longer period. CONCLUSION: Viral genotype and treatment duration are independently related to sustained response to IFN-alpha in patients with chronic hepatitis C. The patients infected with HCV genotype 1b should receive IFN-alpha at the higher dosage and for the longer period.     

Interferon treatment for hepatitis C virus infection in patients on haemodialysis

BACKGROUND: This study examined the efficacy and tolerability of interferon alpha-2b (IFN) in the treatment of chronic hepatitis C virus (HCV) infection in patients on maintenance haemodialysis. METHODS: A 24-month prospective cohort study was performed in 11 HCV RNA-positive haemodialysis patients, who were treated with IFN at 3 MU thrice weekly for 6 months. Serial biochemical and virological monitors included serum alanine aminotransferase levels, and HCV RNA by both qualitative PCR assay and quantitative bDNA assay. HCV genotypes were determined by PCR and nucleotide sequencing. Ten patients had baseline liver biopsy. RESULTS: HCV genotypes 1b and 2b were identified in 10 and one patients respectively. Six (55%) patients had biochemical and/or histological features of chronic active hepatitis before treatment. All 11 patients became HCV RNA-negative by PCR, with normalization of deranged aminotransferase levels, within 2-8 weeks of IFN therapy. HCV RNA reappeared in eight (73%) patients 2-8 weeks after the cessation of IFN, while biochemical relapse occurred in six (55%) patients. Sustained eradication of HCV was achieved in three (27%) patients. Sustained responders were characterized by pretreatment HCV RNA level < 3.5 x 10(5) Eq/ml as determined by the bDNA assay, and less severe histological abnormalities ('Total score' 1.7 +/- 1.2 compared to 5.4 +/- 2.2 in relapsers, P < 0.05). HCV RNA levels were similar before and after IFN treatment in non-responders and relapsers. Persistent malaise and poor appetite were noted in eight (73%) patients during IFN therapy. Other side-effects of IFN included the exacerbation of anaemia, induction of resistance to erythropoietin, weight loss, and reduced serum albumin level. CONCLUSIONS: Eradication of chronic HCV infection with IFN can be achieved in 27% of haemodialysis patients. Predictors of sustained response include low baseline HCV RNA level and mild liver pathology. Virological relapse can occur despite normal liver biochemistry. Exacerbation of anaemia, erythropoietin resistance, and malnutrition constitute the side-effects of IFN that deserve special attention in uraemic subjects.     

Efficacy of interferon dose and prediction of response in chronic hepatitis C: Benelux study in 336 patients

BACKGROUND/AIMS: In an attempt to improve the limited efficacy of treatment of chronic hepatitis C with interferon-alpha 3 MU tiw, we studied the effects of double-dose therapy followed by downward titration, and analyzed the pre- and pertreatment factors associated with response or non-response. METHODS: Three hundred and fifty-four consecutive patients in 19 centers were randomized to interferon-alpha 3 MU tiw for 6 months or 6 MU tiw for 8 weeks followed by down-titration (3,1 MU tiw) till alanine aminotransferase remained normal and plasma HCV RNA was repeatedly undetectable. The primary outcome measure was sustained alanine aminotransferase and HCV RNA response 6 months after treatment. RESULTS: Three hundred and thirty-six patients received treatment. The sustained response rate for patients receiving 3 MU tiw for 6 months was 14% (9-21%,) and for patients receiving double dose tiw for 8 weeks and thereafter titrated therapy 15% (10-21%) (p=0.8). Pretreatment factors associated with a sustained alanine aminotransferase plus HCV RNA response were the absence of cirrhosis, presence of genotype 2 or 3, a low viral load and, in addition, a low alanine aminotransferase/aspartate aminotransferase ratio; a model was developed to allow estimation of the chance of response for the individual patient. The most powerful predictor of sustained response, however, was plasma HCV RNA at week 4; a positive test virtually precluded a sustained response (1.7%, 0.4-5.0%). If week 4 HCV RNA was not detectable, the chance of a sustained response was 21% (12-34%) for genotype 1 versus 40% (28-54%) for the others (p=0.02). Six MU tiw led to a significantly higher week 4 HCV RNA response (47% not detectable) than 3 MU (37%) (p=0.02). During down-titration this difference in viral on-treatment response was lost. CONCLUSIONS: In the treatment of hepatitis C, an early HCV RNA response is a prerequisite for long-term efficacy. Doubling the initial interferon dose increases this early response, but subsequent downward titration negates this effect, especially in genotype 1.     

Efficacy of interferons in treating children with chronic hepatitis C

Twenty-two children with chronic hepatitis serologically positive for hepatitis C virus (HCV) were treated with interferon-alpha (IFN-alpha). Liver biopsy showed chronic active hepatitis in 13 and chronic persistent hepatitis in 9 patients. A sustained clearance of HCV was observed in 8/22 children 12 months after the administration of IFN-alpha for 26 weeks, associated with normalization of HCV core antibody. Of these eight patients six had HCV genotype III and two HCV genotype II or IV. Hepatitis relapsed in seven other patients after completion of IFN-alpha with an increase in HCV core antibody titre, five with HCV genotype II, and two with HCV genotype III or IV. A second course of IFN-alpha suppressed the reactivation of HCV in all seven patients. Three of seven responders who relapsed after the first course remained negative for HCV RNA 12 months after their second course of IFN-alpha. However, the remaining four patients with HCV genotype II again relapsed after completing their second course of IFN-alpha. Seven children with the HCV genotype II resistant to IFN, including 8 weeks of IFN-beta administration, and showed no significant reduction in HCV core antibody titre. CONCLUSION: The genotype of HCV (III) and a reduction in the core antibody titre appear to be useful parameters for predicting the response to IFN-alpha therapy.     

Efficacy of interferon monotherapy in the treatment of relapsers and nonresponders with chronic hepatitis C infection

Results of numerous studies have demonstrated similar efficacy profiles for the interferons (IFNs) currently approved for the treatment of chronic hepatitis C virus (HCV) infection. Although it has been suggested that some IFNs are more efficacious in certain patient populations, the current data support an equivalent efficacy and safety profile for these agents. Among patients requiring retreatment, no single study has made a direct comparison of IFN alfa-2b (IFN-alpha 2b) and consensus IFN (CIFN) in patients who have relapsed or have not responded to previous IFN therapy. However, at least 11 studies using IFN-alpha 2b and 1 using CIFN have demonstrated efficacy in the relapsing and nonresponding patient populations. A review of these studies suggests that overall efficacy and tolerability are similar regardless of IFN-alpha subtype. Overall, up to 59% and 83% of relapsed patients retreated with IFN have shown sustained response rates, as measured by negative HCV RNA titer and normalization of alanine aminotransferase (ALT) levels, respectively. Up to 14% and 25% of patients who failed to respond to previous IFN therapy have shown sustained HCV RNA response and normalization of ALT, respectively, after retreatment.     

Ethanol exposure potentiates fosB and junB expression induced by muscarinic receptor stimulation in neuroblastoma SH-SY5Y cells

Hepatitis C virus (HCV)-specific cytotoxic T lymphocytes (CTL) have been shown to play a role in host defense and pathogenesis of chronic HCV infection. Our aim was to test the hypothesis that intrahepatic HCV-specific CTL activity may impact subsequent response to interferon alfa (IFN-alpha) therapy. Of the 37 patients that we have prospectively evaluated for HCV-specific CTL activity in liver, 21 received IFN therapy, and 19 completed a 6-month course and attended 6 to 18 months of follow-up. Intrahepatic CD8+ cells were isolated from liver biopsy tissue and tested against target cells expressing HCV antigens to determine intrahepatic CTL activity. The relationship between treatment response and HCV-specific CTL activity and other factors known to associate with response (genotype, viremia, histology) was analyzed. HCV-specific CTL activity was detected in 9 of 21 patients (and 9 of 19 who completed therapy). After 6 months of IFN therapy, 8 of 19 (42%) patients had normal serum alanine transaminase (ALT) (complete responders). After 18 months of follow-up, only 3 patients (16%) had a sustained biochemical response. Of the 9 patients with detectable HCV-specific CTL activity in their liver before treatment, 7 (78%) developed a complete response. In contrast, only 1 of the 10 patients with no detectable HCV-specific CTL activity developed a complete response to IFN (P < .01). In 6 of 8 patients with a complete response, including the 3 sustained responders, the CTL response appeared to be directed predominately to the HCV core region. These data suggest that the host immune response, particularly that mediated by CD8+ CTL, may be important in determining the outcome of IFN therapy for chronic HCV infection. Further understanding of the mechanism of action of IFN should impact the design of better therapeutic strategies against chronic HCV infection.     

Randomised trial of interferon alpha2b plus ribavirin for 48 weeks or for 24 weeks versus interferon alpha2b plus placebo for 48 weeks for treatment of chronic infection with hepatitis C virus. International Hepatitis Interventional Therapy Group (IHIT)

BACKGROUND: Only 15-20% of patients with chronic hepatitis C achieve a sustained virological response with interferon therapy. The aim of this study was to compare the efficacy and safety of interferon alpha2b in combination with oral ribavirin with interferon alone, for treatment of chronic infection with hepatitis C virus (HCV). METHODS: 832 patients aged 18 years or more with chronic HCV who had not been treated with interferon or ribavirin, were enrolled and randomly allocated one of three regimens: 3 mega units (MU) interferon alpha2b three times a week plus 1000-1200 mg ribavirin per day for 48 weeks; 3 MU interferon alpha2b three times a week plus 1000-1200 mg ribavirin per day for 24 weeks; or 3 MU interferon alpha2b three times a week and placebo for 48 weeks. All patients were assessed for safety, tolerance, and efficacy at the end of weeks 1, 2, 4, 6, and 8, and every 4 weeks during treatment. After treatment was completed patients were followed up on weeks 4, 8, 12, and 24. The primary endpoint was loss of detectable HCV-RNA (serum HCV-RNA <100 copies/mL) at week 24 after treatment. FINDINGS: Sustained virological response at 24 weeks after treatment, was found in 119 (43%) of the 277 patients treated for 48 weeks with the combination regimen, 97 (35%) of the 277 patients treated for 24 weeks with the combination regimen (p=O.055), and 53 (19%) of the 278 patients treated for 48 weeks with interferon alone (p<0.001 vs both combination regimens, intention-to-treat analysis). Logistic regression identified five independent factors significantly associated with response: genotype 2 or 3, viral load less than 2 million copies/mL, age 40 years or less, minimal fibrosis stage, and female sex. Among patients with fewer than three of these factors the odds ratio of sustained response was 2.6 (95% Cl 1.4-4.8; p=0.002) for the 48 week combination regimen compared with 24 weeks of the combination regimen. Discontinuation of therapy for adverse events was more frequent with combination (19%) and monotherapy (13%) given for 48 weeks than combination therapy given for 24 weeks (8%). INTERPRETATION: An interferon alpha2b plus ribavirin combination is more effective than 48 weeks of interferon alpha2b monotherapy and has an acceptable safety profile. Patients with few favourable factors benefit more from extending the duration of combination therapy to 48 weeks.     

Better efficacy of a 12-month interferon alfa-2b retreatment in patients with chronic hepatitis C relapsing after a 6-month treatment: a multicenter, controlled, randomized trial. Le Groupe D'étude et De Traitement du Virus De L'hépatite C (Get.Vhc)

We studied the efficacy of three interferon alfa-2b (IFN-2b) regimens for the retreatment of patients with chronic hepatitis C (CHC) with prior complete response followed by relapse. Consecutive patients with CHC who had a complete biochemical response but relapse after a first course of 6 months of IFN with 3 million units (MU) given subcutaneously three times per week were enrolled in the study. Six to 24 months after the end of the first treatment, the patients were randomly assigned to receive IFN with either the same regimen (group 1), a regimen of 12 months with 3 MU (group 2), or a regimen of 6 months with 10 MU (group 3). Sustained biochemical response was defined as normal serum alanine transaminase (ALT) values during the follow-up and sustained virological response as a clearance of hepatitis C virus (HCV) RNA from the serum at the end of follow-up (6 months' posttreatment). Histological improvement was defined as a decrease of 1 point in Metavir score between the first liver biopsy and a biopsy performed at 6 months' postretreatment. Two hundred forty-seven patients were randomized: 75 to group 1, 91 to group 2, and 81 to group 3. In an intent-to-treat analysis, 12%, 36.3%, and 18.5% of patients had a sustained biochemical response after retreatment in groups 1, 2, and 3, respectively (P <.001); 13. 8%, 32.4%, and 17.2% of patients had a sustained virological response after retreatment in groups 1, 2, and 3, respectively (P <. 05). A low viral load and patients in group 2 were independently associated with a sustained biochemical response. A low Knodell score index before treatment, patients with a high level of ALT before retreatment, genotype 3, low viral load, and patients in group 2 were independently associated with sustained virological response. Younger age, a high level of ALT, a low level of gamma-glutamyl transferase before retreatment, low viral load, and patients in group 2 were independently associated with sustained biochemical and virological response. Among the 80 patients with repeated liver biopsies, 47.6% had improved histological activity scores; this improvement was associated with a sustained biochemical and virological response. In patients with CHC initially treated with 3 MU of IFN given subcutaneously three times per week over a 6-month period, and who subsequently developed a relapse after a biochemical response, retreatment with a regimen of 3 MU of IFN given three times per week for 12 months produced better biochemical and virological sustained response rates than regimens involving a higher dose or a shorter duration of retreatment. The biochemical and virological sustained response was associated with histological improvement.     

Influence of labour on epidermal growth factor receptor distribution of the human chorion at term gestation

Ten patients with biopsy verified chronic hepatitis C virus (HCV) infection were treated with oral ribavirin at a dose of 1,000-1,200 mg per day in two divided doses for 12 weeks. Serum alanine aminotransferase (ALT) levels and hepatitis C viral ribonucleic acid (RNA) levels in serum were followed prior to, during, and 12 weeks posttreatment. ALT levels decreased significantly in all patients during therapy from a mean level of 3.21 mukat/l (range 1.22 to 7.79) before, to 1.25 mukat/l (range 0.78 to 2.04) at the end of treatment (P < 0.005). Hereafter, relapse to pretreatment levels was seen within 12 weeks after treatment stop. The hepatitis C viral RNA levels decreased from a mean 10 log titer of 4.1 (range 1-6) before treatment to 3.4 (range 1-5) at treatment stop. Five patients did not change their HCV RNA titers during treatment. Twelve weeks posttreatment only 3 patients had lower titers than prior to treatment. We conclude that oral ribavirin seems to reduce the viral load, at least temporarily, in some patients with chronic viremic HCV infection. Further studies are needed to evaluate fully the effect of oral ribavirin on chronic HCV infection.     

Combination therapy with interferon alpha and ribavirin for chronic hepatitis C virus infection in thalassaemic patients

Hepatitis C virus (HCV) infection is common in multi-transfused thalassaemic patients, and, in combination with transfusional iron overload, can result in progressive liver disease. Therapy with interferon-alpha causes a sustained loss of HCV in only 15-25% of patients, and there is as yet no established effective therapy for those who fail to respond. We have conducted a pilot study of combination anti-viral therapy for patients who failed to respond, or relapsed after an initial response to single-agent interferon-alpha. Patients were treated for 6 months with interferon-alpha 2b, given subcutaneously three mega units thrice weekly, together with ribavirin, orally 1 g daily. 11 patients were enrolled, their median age was 24.9 years. 8/10 evaluable patients had cirrhosis on biopsy, five were infected with HCV type 1 and all but one had initial HCV RNA titres > 10(6) genomes/ml. Five patients (45.5%) had a sustained virological response with loss of serum HCV RNA for > 6 months after finishing therapy. There was no clear association between response to therapy and age, histology, HCV genotype, or HCV RNA titre. Transfusion requirements were significantly increased during the treatment phase, probably due to ribavirin-induced haemolysis, and this necessitated intensification of iron chelation therapy. Serum ferritin levels decreased significantly in those who responded. These results suggest that combination therapy is potent in clearing HCV infection, and may provide effective second-line therapy for thalassaemic patients who have failed to respond to interferon-alpha monotherapy.     

Treatment response and durability of a double protease inhibitor therapy with saquinavir and ritonavir in an observational cohort of HIV-1-infected individuals

OBJECTIVE: To evaluate treatment response, durability and tolerance of a four-drug regimen including saquinavir and ritonavir in combination with either zidovudine/lamivudine or stavudine/lamivudine. DESIGN: Observational cohort of HIV-positive individuals. METHODS: Viral load, CD4+ and CD8+ T lymphocyte counts were assessed at intervals of 1-3 months in subjects commencing therapy between July 1996 and November 1996. Adverse events were evaluated as well as risk factors for therapeutic failures. RESULTS: A group of 56 male patients were included and followed for 48 weeks. Of these, 66% had already taken a protease inhibitor. Viral load dropped by a median 1.98 log10 HIV RNA copies/ml from baseline (interquartile range: 1.49-2.46) and became undetectable (< 400 copies/ml) in 68% of patients. Response varied: 9% were non-responders (HIV RNA reduction < 0.5 log10 copies/ml) and 23% were incomplete responders (nadir of HIV RNA > 400 copies/ml). After 48 weeks, viral load remained undetectable in 49%. Median CD4+ T lymphocyte count increased from 191 x 10(6) to 418 x 10(6) cells/l (range, 241-537 x 10(6) cells/l). Although protease inhibitor and nucleoside pretreatment selected for drug-resistant viral mutants, only the protease inhibitor experience was identified as a risk factor for therapeutic failure. Adverse events occurred in 73% of patients and led to a change of therapy in 9%. CONCLUSION: Despite advanced HIV disease and pretreatment with multiple antiretroviral drugs, a strong initial treatment response to this drug regimen was observed. However, virological failure occurred in 51% of patients after 48 weeks and frequent adverse events complicated therapy.     

Interferon therapy for acute hepatitis C viral infection--a review by meta-analysis

BACKGROUND: Hepatitis C viral (HCV) infection poses a major health problem for Australia. Currently interferon therapy is approved only for people with chronic infection, yet the literature contains a number of studies that show that there is a better response to interferon in symptomatic acute HCV. AIM: To review the response to interferon therapy in acute HCV by way of meta-analysis. METHODS: This study was a retrospective review of the data on the use of interferon therapy in acute HCV. The meta-analysis was performed using the methods of DerSimonian and Laird. Data were presented by calculating the risk difference which estimated efficacy by calculating the proportion of patients in treatment groups who responded better (0 to +1.0) or worse (0 to -1.0) than untreated control groups. RESULTS: A meta-analysis of six studies on the use of 3MU of interferon alpha 2b (IFN-alpha 2b) three times a week for six to 24 weeks showed a significant response as measured by long term (> 12 months) normalisation of alanine aminotransferase (ALT) and clearance of HCV RNA (as measured by polymerase chain reaction). The risk of difference was +0.31 (95% CI of +0.19 to +0.43, p < 0.01) and +0.33 (95% CI of +0.08 to +0.58, p < 0.001) respectively. Slightly better results were seen with daily doses of 3MU of interferon beta (IFN-beta) given intravenously over four to seven weeks. This produced a risk difference of +0.57 (95% CI of +0.26 to +0.88, p < 0.02) for normalisation of ALT and +0.83 (95% CI of +0.61 to 1.00, p < 0.001) for clearance of HCV. Results for higher daily doses of both IFN alpha and beta were limited to a few studies and most were uncontrolled. 6MU of IFN-alpha 2b three times a week for 16 to 24 weeks produced a risk difference of +0.53 (95% CI +0.17 to +0.89, p < 0.05) for normalisation of ALT and +0.44 (95% CI +0.06 to +0.82) for clearance of HCV RNA. Results with 6MU daily for eight weeks of IFN-beta in an uncontrolled study, showed up to 90% patients cleared HCV long term. Preliminary results with 10MU of IFN-alpha 2b daily for four to six weeks also showed long term clearance of HCV RNA and normalisation of ALT in 90% of treated patients. CONCLUSION: Short term (six weeks to six months) treatment of symptomatic acute HCV with interferon (both alpha and beta) produced a better long term response rate than prolonged therapy (> 12 months) in chronic HCV. Daily doses of 6MU and 10MU produced better responses than 3MU but more studies are needed to determine the optimum regime.