Response-guided therapy for chronic hepatitis C virus infection in patients coinfected with HIV: a pilot trial

BACKGROUND

To study the feasibility of a response-guided therapy for chronic hepatitis C virus (HCV) infection in patients coinfected with human immunodeficiency virus (HIV) in a tertiary care hospital.

METHODS

Treatment duration was individualized on the basis of week 4 and week 12 virologic response. Sixty patients were enrolled and received pegylated interferon alfa-2b (1.5 microg/kg per week) plus weight-based ribavirin (800-1400 mg/day). Patients who achieved a rapid virologic response, defined as viral load <50 IU/mL at treatment week 4, completed 24 weeks of therapy. Patients who did not achieve a rapid virologic response were reassessed at treatment week 12. Patients with a complete early virologic response, defined as an HCV RNA level <600 IU/mL, were treated for 48 weeks. Patients with a partial response, defined as a decrease in the viral load > or = 2 log10 and an HCV RNA level > or = 600 IU/mL, who attained an undetectable viral load at week 24 were treated for 60 weeks. The primary efficacy end point was sustained virologic response, defined as HCV RNA <50 IU/mL, 24 weeks after the end of treatment.

RESULTS

Overall, 33 (55%) of 60 patients achieved a sustained virologic response: 11 (44%) of 25 patients with HCV genotype 1, 3 (27%) of 11 patients with genotype 4, and 19 (79%) of 24 patients with genotype 3. One-third of patients showed a rapid virologic response. Of patients with genotype 1, there was a rapid virologic response in 4 (16%) of 25; with genotype 4, in 1 (9%) of 11; and with genotype 3, in 14 (58%) of 24. Of the 19 patients with a rapid virologic response, 17 (89.5%) eradicated the virus after 24 weeks of therapy. The rate of sustained virologic response was significantly higher among patients with genotype 3 and low pretreatment HCV RNA levels. A high relapse rate (46%) after 48 weeks of therapy occurred among patients infected with genotypes 1 or 4 who first achieved undetectable viral load at treatment week 12.

CONCLUSION

A response-guide therapy is feasible and may be useful to optimize the individual outcome of HCV treatment in patients coinfected with HIV.

Impact of prior pneumococcal vaccination on clinical outcomes in HIV-infected adult patients hospitalized with invasive pneumococcal disease

BACKGROUND

Recent studies in hospitalized patients with community-acquired pneumonia have found a lower risk of bacteraemia and better clinical outcomes in patients who had previously received the 23-valent pneumococcal polysaccharide vaccine (PPV) in comparison with unvaccinated individuals. The aim of this study was to assess the influence of prior PPV on clinical outcomes in HIV-infected adult patients hospitalized with invasive pneumococcal disease (IPD).

METHODS

This was an observational study of all consecutive HIV-infected adults hospitalized with IPD from January 1996 to October 2007 in three hospitals in Spain. Baseline characteristics and clinical outcome-related variables were compared according to prior PPV vaccination status.

RESULTS

A total of 162 episodes of IPD were studied. In 23 of these (14.2%), patients had previously received PPV. In both vaccinated and unvaccinated patients, most of the causal serotypes were included in the 23-valent PPV (76.9% and 84.1%, respectively). Overall, 25 patients (15.4%) died during hospitalization, 21 patients (13%) required admission to an intensive care unit (ICU) and 34 patients (21%) reached the composite outcome of death and/or admission to the ICU. None of the 23 patients who had previously received PPV died or required ICU admission, in comparison with 25 (18%; P=0.026) and 21 (15.1%; P=0.046), respectively, of the unvaccinated patients. The length of hospital stay for vaccinated patients was significantly shorter (8.48 vs. 13.27 days; P=0.011).

CONCLUSIONS

Although 23-valent PPV failed to prevent IPD in some HIV-infected patients, vaccination produced beneficial effects on clinical outcomes by decreasing illness severity and mortality related to IPD.

Contemporary epidemiology and prognosis of health care-associated infective endocarditis

BACKGROUND

The aim of this study was to describe the characteristics of health care-associated infective endocarditis (HAIE) and to establish the risk factors for mortality.

METHODS

We conducted a prospective, observational cohort study. HAIE was defined according to the following conditions: (1) symptom onset >48 h after hospitalization or within 6 months after hospital discharge; or (2) ambulatory manipulations causing endocarditis.

RESULTS

Eighty-three episodes of HAIE (accounting for 28.4% of all cases of endocarditis) were diagnosed. Compared with patients with community-acquired endocarditis, patients with HAIE were older (median age +/- standard deviation, 65.3 +/- 16.4 years vs. 57.8 +/- 17.0 years; P = .001), were in poorer health before disease onset (Charlson index, 2.5 +/- 2.3 vs. 1.7 +/- 2.1; P = .006), had more staphylococcal (55.4% vs. 28.3% of cases) and enterococcal infections (22.9% vs. 7.7% of cases; P < .005), underwent fewer surgeries (22.9% vs. 45.9% of cases; P < .005), and experienced a higher rate of in-hospital (45.8% vs. 22.0%) and 1-year mortality (59.5% vs. 29.6%; P < .005). In the HAIE cohort, independent predictors of in-hospital death were stroke (odds ratio [OR], 8.95; 95% confidence interval [CI], 2.04-39.31; P = .004), congestive heart failure (OR, 5.48; 95% CI, 1.77-17.03; P = .003), surgery indicated but not performed (OR, 3.74; 95% CI, 1.22-11.45; P = .021), and enterococcal infection (OR, 0.18; 95% CI, 0.04-0.78; P = .022). Independent predictors of 1-year mortality were surgery indicated but not performed (OR, 7.81; 95% CI, 2.06-29.67; P = .003), acute renal failure (OR, 7.18; 95% CI, 1.32-39.18; P = .023), and enterococcal infection (OR, 0.18; 95% CI, 0.04-0.81; P = .026). For the series overall (292 episodes), HAIE was an independent predictor of in-hospital (OR, 2.83; 95% CI, 1.34-5.98; P = .007) and 1-year mortality (OR, 2.59; 95% CI, 1.25-5.39; P = .011).

CONCLUSIONS

HAIE is an important health problem associated with considerable mortality. New strategies to prevent HAIE should be assessed.

Donor infection and transmission to the recipient of a solid allograft

Transmission of infection from donor to recipient is a potential complication of transplantation. More data on this issue are needed to expand the insufficient donor pool. This study evaluates the incidence of donor nonviral infection, transmission from infected donors and the effect of donor infection on 30-day recipient survival. Data from 211 infected donors contributing to 292 (8.8%) of 3322 consecutive transplant procedures within RESITRA (Spanish Research Network for the Study of Infection in Transplantation) were prospectively compiled and analyzed. Lung was the most likely transplanted organ carried out with an infected donor and Staphylococcus aureus was the most commonly isolated microorganism. In more than a half of donors, the lung was the site of infection. Donor-to-host transmission was documented in 5 patients out of 292 (1.71%), 2 of whom died of the acquired infection (40%). Nonetheless, there was no difference in 30-day patient survival when comparing transplant procedures performed with organs from infected or uninfected donors. In conclusion, donor infection is not an infrequent event, but transmission to the recipient is quite low. Hence, with careful microbiological surveillance and treatment, the number of organs available for transplantation may be increased.

Bacterial pneumonia in HIV-infected patients: use of the pneumonia severity index and impact of current management on incidence, aetiology and outcome

OBJECTIVES

Despite a recent decrease, bacterial pneumonia (BP) is still the most common admission diagnosis in HIV patients. We analyse BP incidence, characteristics and prevention measures.

METHODS

Observational study of all patients hospitalized for BP in a tertiary hospital in Barcelona, Spain, from January 2000 to December 2005. Demographic and HIV-related data, BP risk factors, characteristics of BP and outcomes are analysed.

RESULTS

One hundred and eighty-six BP episodes in 161 patients were included; patients were mainly male (73.7%) and intravenous drug users (73.7%). A decrease in BP incidence was seen during the study period, especially in vaccinated patients. The most commonly isolated microorganism was Streptococcus pneumoniae (31.7%), followed by Legionella pneumophila (5.9%). Legionella pneumophila was more likely in patients with undetectable viral load, higher CD4 cell counts or prior vaccination. Highly active antiretroviral therapy, cotrimoxazole prophylaxis and pneumococcal vaccination did not have a significant influence on bacteraemia rate, in-hospital complications or BP mortality. High Pneumonia Severity Index (PSI) predicted mortality accurately [relative risk 15.2, 95% confidence interval 3.2-71.7; P=0.001]. Mortality was 9.1%, but was significantly higher in patients with CD4 counts under 200 cells/microL (P=0.022).

CONCLUSIONS

A decline in BP incidence was seen during the study period. Combining CD4 cell count and PSI score could become a good strategy in deciding which patients have to be hospitalized.

Efficacy of recombinant interleukin-2 (rIL-2) in patients with advanced HIV-1 infection and blunted immune response to HAART

OBJECTIVE

The efficacy of recombinant interleukin-2 (rIL-2) was assessed in HIV-infected patients with advanced immune suppression and a discordant immune response to highly active antiretroviral therapy (HAART). The primary endpoint was median change in CD4+ T-cell counts at the end of treatment as compared to baseline. Secondary endpoints were safety and changes in the various T-cell subpopulations.

MATERIAL AND METHODS

In a prospective cohort study, 19 patients with HIV-RNA < 50 copies/mL and < 200 CD4+ T cells/mm3 without a significant increase in the previous 12 months were scheduled to receive 6 cycles of 4.5 x 10(6) IU subcutaneous rIL-2 daily for 5 consecutive days, every 4 weeks.

RESULTS

Median age was 43 years, and 64% had a previous AIDS-defining event. Median nadir and baseline CD4+ cell counts were 36 and 99 cells/mm3, respectively. Three patients discontinued treatment and one experienced grade 4 side effects. CD4+ T-cell counts increased to 147 cells/mm3 (range, 24-285) at 1 month following completion of treatment (P = 0.002), and 180 cells/mm3 (range, 38-280) at 18 months (P < 0.001). This improvement was associated with a significant decrease in expression rates of the activation markers, HLA-DR and CD38.

CONCLUSION

Our results suggest that in patients with advanced HIV-infection showing a blunted immune response to HAART, rIL-2 might increase the pool of CD4+ T-cells by down-regulating the status of immune activation.

Prevalence and susceptibility profile of Candida metapsilosis and Candida orthopsilosis: results from population-based surveillance of candidemia in Spain

We describe the prevalences and susceptibility profiles of two recently described species, Candida metapsilosis and Candida orthopsilosis, related to Candida parapsilosis in candidemia. The prevalences of these species (1.7% for C. metapsilosis and 1.4% for C. orthopsilosis) are significant. Differences observed in their susceptibility profiles could have therapeutic importance.

Valganciclovir as treatment for cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Cytomegalovirus (CMV) infection causes morbidity in solid organ transplant (SOT) recipients, either by direct injury or in association with chronic allograft rejection or other opportunistic infections. Ganciclovir is the treatment of choice, but this agent requires intravenous administration, which affects its feasibility for long-term use. Valganciclovir, which has an oral bioavailability of 60%, has proven to be useful for prophylaxis of CMV infection in high-risk SOT recipients and for treating retinitis in persons with acquired immunodeficiency syndrome.

OBJECTIVE

To compare the efficacy of valganciclovir (alone or as sequential therapy after a regimen of intravenous ganciclovir) with intravenous ganciclovir alone for preemptive therapy or treatment of CMV disease (viral syndrome or focal disease) in SOT recipients and to determine the incidence of adverse effects and relapses.

METHODS

In this 2-year prospective, comparative cohort study, 376 episodes of preemptive therapy or treatment of CMV disease were recorded among 334 of 3467 SOT recipients included in the Spanish Network for Research on Infection in Transplantation (RESITRA) database. Intravenous ganciclovir was the first-line treatment in 170 episodes; valganciclovir followed by intravenous ganciclovir was administered in 82 episodes, and valganciclovir alone was administered in 112 episodes.

RESULTS

Valganciclovir was used as preemptive therapy or treatment for CMV disease in 84 and 28 episodes, respectively. Duration of treatment was longer in valganciclovir recipients than in ganciclovir recipients for both preemptive therapy (21 vs. 15 days; P < .001) or viral syndrome treatment (21 vs. 18 days; P < .01). In the valganciclovir arm, 94 (83.9%) of 112 episodes were treated successfully, with no statistical difference in the success rates versus the ganciclovir arm (85.8%) or ganciclovir-valganciclovir arm (95.1%). Eighteen episodes (16.1%) treated with valganciclovir were considered to have resulted in treatment failure (because of persistent antigenemia in 4 [3.6%], on the basis of clinical decision in 7 [6.2%], and because of recurrent disease in 7 [6.2%]). There were no incidents in which valganciclovir treatment was withdrawn because of toxicity.

CONCLUSION

Valganciclovir is safe and useful for preemptive therapy and treatment of CMV disease.

Early Monitoring of Ribavirin Serum Concentration is not Useful to Optimize Hepatitis C Virus treatment in HIV-Coinfected Patients

Background

Emerging data suggest that higher ribavirin (RBV) exposure could improve early hepatitis C virus (HCV) response. Furthermore, interindividual RBV bioavailability shows high variation, and dose-limiting haemolytic anaemia is a common adverse event. Therefore, it has been suggested that monitoring RBV serum levels could be used to drive dose modification and to optimize management of HCV-infected patients receiving combination treatment.

Methods

To assess the effect of RBV serum levels on HCV RNA clearance at week 4 and 12 of treatment, and to determine the correlation between RBV serum concentration and haemoglobin decrease, RBV trough levels were measured by HPLC in stored serum samples obtained from 94 HCV-HIV-coinfected patients at week 4 and 12 of treatment with peginterferon-α2b (1.5 μg/kg/weekly) plus ribavirin (800–1,200 mg/day).

Results

The median RBV levels increased from 1.70 μg/ml at week 4 to 1.97 μg/ml at week 12 of treatment ( P=0.001) and were independently predicted by weight-adjusted dose of RBV and co-administration of tenofovir. Haemoglobin drop was higher among patients who received zidovudine and weakly correlated with RBV level. Although RBV concentration was lower in genotype 1 or 4 HCV-infected patients who cleared the virus at treatment week 4, the ability of this parameter to discriminate between responders and non-responders at treatment week 4 and 12 was poor.

Conclusion

Intracellular RBV accumulation early in treatment might improve the kinetics of HCV response in difficult to treat patients. Although this hypothesis and the potential interaction between RBV and tenofovir warrant further research, our data do not support RBV serum monitoring as a tool to optimize treatment in HCV-HIV-coinfected patients.

Correlation of the MIC and dose/MIC ratio of fluconazole to the therapeutic response of patients with mucosal candidiasis and candidemia

We report on the correlation of the outcomes for two cohorts of patients who had been treated for candidemia (126 episodes) or oropharyngeal candidiasis (110 episodes) with various doses of fluconazole and the MIC of fluconazole obtained by using the EUCAST standard for fermentative yeasts. Of 145 episodes caused by an isolate with a fluconazole MIC < or =2 mg/liter, 93.7% (136 of 145) responded to fluconazole treatment. The response for those infected with a strain with a MIC of 4 mg/liter was 66% but reached 100% when the dose was greater than 100 mg/day, whereas the response for those infected with strains with MICs > or =8 mg/liter was only 12%. Hence, a MIC of 2 mg/liter or 4 mg/liter was able to predict successful treatment. A cure rate of 93.9% (140 of 149) was achieved when the dose/MIC ratio was > or =100 but fell to 14.6% (16 of 109) when the ratio was less. The dose/MIC required to achieve a response rate of 50% (the 50% effective concentration) was 43.7 for the cohort of patients with oropharyngeal candidiasis. Classification and regression analysis indicated that a dose/MIC of 35.5 was the threshold for the prediction of cure or failure. However, an increase in exposure above this threshold further increased the probability of cure, and all patients were cured when the dose/MIC exceeded 100. Monte Carlo simulations showed a probability of target attainment of 99% at MICs < or =2 mg/liter and a pharmacodynamic target of a dose/MIC ratio of 100, which was equivalent to an unbound fraction of the fluconazole area under the curve versus the MIC of 79.

Impact of early central venous catheter removal on outcome in patients with candidaemia

Removal of central venous catheters (CVCs) from candidaemic patients is considered the reference standard of care, although this practice is not always possible. The impact of prompt catheter removal on outcome was investigated by analysing data from an active population-based surveillance study in Barcelona, Spain. Patients with candidaemia and a CVC were identified between January 2002 and December 2003. Cases with CVC removal within 2 days were classified as having early CVC removal. Outcome, defined as in-hospital mortality 2-30 days after diagnosis of candidaemia, was determined among hospitalised adults using univariate, Kaplan-Meier and multivariate logistic regression analysis. Outpatients, paediatric patients and those who died or were discharged within 2 days were excluded. The study identified 265 patients with candidaemia and a CVC. Median time from diagnosis of candidaemia to catheter removal was 1 day (range 0-29 days). Overall, 172 patients met the criteria for inclusion in the outcome study. Patients with early CVC removal differed significantly from those with delayed CVC removal. According to univariate, Kaplan-Meier and multivariate analysis, the marker most predictive of in-hospital mortality among candidaemic patients with CVCs was severity of illness. These data suggest that timing of CVC removal may best be determined after carefully considering the risks and benefits to individual patients.

Efficacy of liposomal amphotericin B for secondary prophylaxis of visceral leishmaniasis in HIV-infected patients

BACKGROUND AND OBJECTIVES

Visceral leishmaniasis (VL) is characterized by frequent relapses in HIV-infected patients, even in those who receive secondary prophylaxis. The aim of our study was to evaluate the efficacy of liposomal amphotericin B (L-AMB) for secondary prophylaxis of VL in HIV-infected patients.

METHODS

From January 2001 to December 2005, 17 HIV patients, with at least one previous episode of VL who received L-AMB as secondary prophylaxis for VL, were included in the study. Efficacy was measured as the proportion of patients remaining free (non-relapse) of VL at different time points. Relapses were analysed as time-to-relapse distribution and were evaluated by survival analysis using the Kaplan-Meier method.

RESULTS

Twenty-one episodes of VL were diagnosed and nine relapsed. The median follow-up time was 14 (5-44) months. The probability of remaining free of relapse at 6 months was 89.7% (95% CI, 76.2-100); at 12 months, the probability was 79.1% (95% CI, 61-97.2) and at 24 and 36 months, the probability was 55.9% (95% CI, 30.5-81.3). In the non-relapsing group, patients had a significant increase in CD4 cell levels of 102 (10-174) and 126 (4-159) cells/mm(3) at 12 and 24 months, respectively (P = 0.037), whereas in the relapsing group, no significant increase was observed. Prophylaxis with L-AMB was well tolerated and only three patients had a mild impairment of renal function without requiring any change in treatment.

CONCLUSIONS

L-AMB is well tolerated and useful for secondary prophylaxis of VL.

[Donor-transmitted infections]

The defence response to infectious agents is compromised in solid organ recipients because of their immunosuppressive treatment. Transmission of infection from a donor organ can result in dysfunction or loss of the allograft, and may lead to death of the recipient if adequate preventive measures are not taken. This potential risk should be thoroughly assessed, particularly in the case of organs from infected donors, in order to optimize organ use without increasing the incidence of graft dysfunction and recipient morbidity and mortality. This article reviews the current knowledge regarding screening for infection in potential donors and discusses risk-benefit considerations related to the use of organs from infected donors.

Brief communication: treatment of Enterococcus faecalis endocarditis with ampicillin plus ceftriaxone

BACKGROUND

High-level aminoglycoside resistance (HLAR) that precludes bactericidal synergism with penicillins or glycopeptides and nephrotoxicity related to aminoglycoside treatment are major problems in treating Enterococcus faecalis endocarditis.

OBJECTIVE

To evaluate the efficacy and safety of ampicillin plus ceftriaxone for treating endocarditis due to E. faecalis with and without HLAR.

DESIGN

Observational, open-label, nonrandomized, multicenter clinical trial.

SETTING

13 centers in Spain.

PATIENTS

21 patients with HLAR E. faecalis endocarditis and 22 patients with non-HLAR E. faecalis endocarditis. All were at risk for nephrotoxicity related to aminoglycoside use.

INTERVENTION

6-week course of intravenous ampicillin, 2 g every 4 hours, plus intravenous ceftriaxone, 2 g every 12 hours.

MEASUREMENTS

Clinical and microbiological outcomes.

RESULTS

The clinical cure rate at 3 months was 67.4% (29 of 43 patients) among all episodes. During treatment, 28.6% of patients with HLAR E. faecalis endocarditis and 18.2% of patients with non-HLAR E. faecalis endocarditis died of infection-related causes. The rate of clinical and microbiological cure in patients who completed the protocol was 100% in the HLAR E. faecalis endocarditis group. No episodes of breakthrough bacteremia occurred, although there were 2 relapses in the non-HLAR E. faecalis endocarditis group. Treatment was withdrawn in 1 case because of fever and skin rash.

LIMITATIONS

The study had a small sample and was observational.

CONCLUSION

The combination of ampicillin and ceftriaxone is effective and safe for treating HLAR E. faecalis endocarditis and could be a reasonable alternative for patients with non-HLAR E. faecalis endocarditis who are at increased risk for nephrotoxicity.

Peginterferon alpha-2b plus ribavirin vs interferon alpha-2b plus ribavirin for chronic hepatitis C in HIV-coinfected patients

Treatment of chronic hepatitis C in human immunodeficiency virus (HIV)-infected patients is associated with low response rates and high incidence of side effects. One hundred twenty-one hepatitis C virus (HCV)-HIV-coinfected patients were randomized to receive interferon alpha-2b (3 MU thrice weekly; n = 61) or peginterferon alpha-2b (1.5 microg/kg/week; n = 60), plus ribavirin (800 mg daily), for 24 (genotype 2 or 3) or 48 weeks (genotype 1 or 4). We assessed early virological response at 4, 8 and 12 weeks to predict sustained virological response (SVR). Safety assessment included frequent blood lactate measurement and relative quantitation of mitochondrial DNA (mtDNA) content in peripheral blood mononuclear cells. In intention-to-treat analysis, the SVR rate was higher in the peginterferon group (55%vs 26%; P = 0.002). The difference for HCV genotypes 1 and 4 was 45%vs 14% (P = 0.009) and 50%vs 27% (P = 0.387), respectively, and for genotype 2 or 3, 71%vs 43% (P = 0.12) Viral response at 4, 8 and 12 weeks of treatment was highly predictive of SVR. Among genotype 3 patients, 17 of 20 (85%) whose HCV RNA was already undetectable at 4 weeks had an SVR after 24 weeks of treatment. Hyperlactataemia occurred in 22 patients and was clinically significant in six, two of whom died. mtDNA decreased significantly 4-12 weeks after the start of treatment in patients developing clinically significant hyperlactataemia. Peginterferon alpha-2b plus ribavirin was more effective than interferon alpha-2b plus ribavirin in HIV-coinfected patients. Frequent monitoring of virological response may be very helpful to optimize treatment compliance, to tailor treatment duration and to minimize side effects.

Liver transplantation in HIV-HCV coinfected patients: a case-control study

Liver transplantation (LT) for hepatitis C virus (HCV)-associated cirrhosis in human immunodeficiency virus (HIV)-infected patients was compared with non-HIV patients. Nine patients with HIV-HCV coinfection were compared with patients transplanted before and after each HIV patient (control group). Immunosuppression consisted in tacrolimus with steroids or mycophenolate mofetil. Acute cellular rejection and three-year actuarial patient survival were respectively 44% and 87.5% in HIV group and 22% and 93.7% in the control group (P=NS). Acute hepatitis C virus occurred earlier (2.3 vs. 4.3 months) and was more cholestatic (mean bilirubin: 10.8 vs. 1.6 mg/dL) in the HIV group. Eight (100%) HIV and nine (64.3%) control patients received antiviral treatment with pegylated interferon and ribavirin. One patient (11.1%) of the control group and one patient (20%) of the HIV group presented a sustained virologic response (P=NS). Short- to midterm results of LT in HIV-HCV co-infected patients were excellent and similar to non-HIV patients.

Utility of week-4 viral response to tailor treatment duration in hepatitis C virus genotype 3/HIV co-infected patients

OBJECTIVE

To investigate the utility of a week-4 virological response for sustained response prediction in hepatitis C virus (HCV) genotype 3/HIV-co-infected patients treated with interferon and ribavirin for 24 weeks.

METHODS

Using a real-time polymerase chain reaction-based quantitative assay (COBAS AmpliPrep-COBAS-TaqMan 48; Roche Diagnostics) we retrospectively analysed samples obtained at baseline and weeks 4 and 12 from a subset of 35 HCV genotype 3-HIV co-infected patients enrolled in a randomized comparative trial of peginterferon alpha-2b versus interferon alpha-2b both in combination with ribavirin.

RESULTS

In an intention-to-treat analysis, 78% of patients treated with peginterferon and 53% of those receiving standard interferon achieved a sustained virological response (SVR) Overall, at 4 weeks, 49% of patients had HCV RNA < 50 IU/ml and 63% had < 600 IU/ml. Of these rapid responders 88 and 86% achieved a SVR, respectively, with only one patient relapsing among end-of-treatment responders. In contrast, only 44 and 31% of patients with a week-4 HCV RNA >or= 50 or >or= 600 IU/ml achieved an SVR, respectively, with relapse rates of 33 and 50%, respectively. In multivariate logistic regression analysis a serum HCV RNA level below 600 IU/ml at week 4 was the strongest independent predictor of SVR (odds ratio, 11.3; 95% confidence interval, 1.7 to 75.0; P = 0.012).

CONCLUSION

Monitoring early viral response may be useful to tailor the duration of treatment among patients with HCV genotype 3/HIV-co-infection. Patients whose HCV RNA falls below 600 IU/ml at 4 weeks are at low risk of relapse after 24 weeks of combination therapy.

Pharmacokinetic interaction between rifampicin and the once-daily combination of saquinavir and low-dose ritonavir in HIV-infected patients with tuberculosis

OBJECTIVES

To assess plasma steady-state pharmacokinetics (PK) of rifampicin, isoniazid, saquinavir and ritonavir in HIV and tuberculosis (TB) co-infected patients, and investigate potential interactions between TB drugs and protease inhibitors (PIs).

METHODS

Open-label, single-arm, sequential PK study including 22 patients with HIV infection and TB. During the first 2 months, patients received rifampicin, isoniazid and pyrazinamide, with or without ethambutol (first PK study, n = 22). Then patients stopped pyrazinamide and ethambutol and started once-daily antiretroviral therapy (ART) with didanosine, lamivudine, ritonavir (200 mg) and saquinavir (1600 mg) (second PK study, n = 18). Patients stopped all TB drugs after 9 months continuing the same ART (third PK study, n = 15). Differences between TB drug parameters in the first and second PK studies, and between PI parameters in the second and third PK studies were used to assess interactions.

RESULTS

Rifampicin and isoniazid pharmacokinetics did not change substantially with saquinavir and ritonavir. A significant 39.5%, 34.9% and 48.7% reduction in median saquinavir AUC(0-24), C(max) and C(trough), respectively, was seen with rifampicin and isoniazid. Ritonavir AUC(0-24), C(max) and C(trough) decreased 42.5%, 49.6% and 64.3%, respectively, with rifampicin and isoniazid.

CONCLUSIONS

There was a significant interaction between saquinavir, ritonavir and rifampicin, with reduction in median plasma concentrations of saquinavir and ritonavir. Saquinavir should be given with caution in patients receiving rifampicin. Twice-daily dosing or higher saquinavir doses in once-daily administration should be tested to obtain more appropriate plasma levels.