Oliviero Bosco

Antifungal prophylaxis in liver transplant patients: A systematic review and meta-analysis†

We performed a meta‐analysis to determine whether antifungal prophylaxis decreases infectious morbidity and mortality in liver transplant patients. We searched for randomized trials dealing with prophylaxis with systemic antifungal agents. We used a fixed effect model, with risk ratio (RR) and 95% confidence interval (CI); we assessed study quality for heterogeneity and publication bias. Six studies (5 double‐blind), for a total of 698 patients, compared fluconazole, itraconazole, or liposomal amphotericin to placebo (5 studies) or oral nystatin. Prophylaxis reduced colonization (RR, 0.45; CI, 0.37‐0.55), total proven fungal infections (RR, 0.31; CI, 0.21‐0.46), which included both superficial (RR, 0.27; CI, 0.16‐0.45) and invasive (RR, 0.33; CI, 0.18‐0.59) infections, and mortality attributable to fungal infection (RR, 0.30; CI, 0.12‐0.75). Prophylaxis did not affect overall mortality (RR, 1.06; CI, 0.69‐1.64) or empiric treatment for suspected fungal infection (RR, 0.80; CI, 0.39‐1.67). The beneficial effect of antifungal prophylaxis was predominantly associated with the reduction of Candida albicans infection and mortality attributable to C. albicans. Compared to controls, however, patients receiving prophylaxis experienced a higher proportion of episodes of non–albicans Candida, and in particular of C. glabrata. No beneficial effect on invasive Aspergillus infection was observed. In conclusion, our analysis shows a clear, though limited, beneficial effect of antifungal prophylaxis in liver transplant patients. Concerns about the selection of triazole‐resistant Candida strains, however, are realistic, and the potential disadvantages of prophylaxis should be weighed against the established benefits. Liver Transpl 12:850–858, 2006.

Abacavir use and cardiovascular disease events: a meta-analysis of published and unpublished data

Background:The use of abacavir (ABC) has been associated with an increased risk of cardiovascular disease in some cohort studies. However, no excess risk of myocardial infarction (MI) with ABC therapy has been observed in individual randomized clinical trials (RCTs) and in the aggregated clinical trials database maintained by the manufacturer of ABC. Objective:To combine all the evidence from RCTs by means of meta-analysis to estimate the effect of combined antiretroviral therapy (cART) containing ABC on MI and overall major cardiovascular events (CVEs). Methods:Primary outcomes included MI, CVE, adverse events requiring discontinuation of treatment, and overall mortality. We used a conventional Mantel–Haenszel method, with risk ratio and 95% confidence intervals (CIs) or, in the presence of heterogeneity, a random-effect model. Results:Data were from 28 primary RCTs (9233 participants) comparing ABC-containing cART (4376 participants) to other regimens not containing ABC (4857 controls). MI data were available from 18 trials (31 episodes in 7054 patients) and CVE data from 20 trials (79 episodes in 7899 patients). Compared to the controls, ABC use did not increase significantly the occurrence of MI (risk ratio 0.73, 95% CI 0.39–1.35; P = 0.31), CVE (risk ratio 0.95, 95% CI 0.62–1.44; P = 0.80), overall mortality (risk ratio 1.20, 95% CI 0.63–2.27; P = 0.58), and adverse events requiring discontinuation of treatment (risk ratio 0.82, 95% CI 0.67–1.00; P = 0.05). Conclusion:This meta-analysis of RCTs does not support the hypothesis that ABC-containing cART regimens carry a greater risk of MI or major cardiovascular events relative to comparator cART.

Reappraisal With Meta-Analysis of the Addition of Gram-Positive Prophylaxis to Fluoroquinolone in Neutropenic Patients

PURPOSE Past reports and meta-analyses indicate that fluoroquinolones are highly effective in preventing Gram-negative infections in neutropenic cancer patients, but offer inadequate coverage for Gram-positive infections. We evaluated by meta-analysis the efficacy of the addition of antimicrobial agents with enhanced Gram-positive activity to prophylaxis with quinolones. MATERIALS AND METHODS Randomized trials comparing fluoroquinolones alone (ciprofloxacin, ofloxacin, pefloxacin, or norfloxacin) with fluoroquinolone in combination with Gram-positive prophylaxis (rifampin, vancomycin, amoxicillin, roxithromycin, or penicillin) were retrieved. We pooled relative risks (RRs) using a fixed-effects model. RESULTS Nine trials (1,202 patients) published between 1993 and 2000 meet inclusion criteria. Compared with fluoroquinolone alone, Gram-positive prophylaxis reduced total bacteremic episodes (RR, 1.54; 95% CI, 1.26 to 1.88), streptococcal infections (RR, 2.20; 95% CI, 1.44 to 3.37), coagulase-negative staphylococcal infections (RR, 1.46; 95% CI, 1.04 to 2.04), and rate of febrile patients (RR 1.08; 95% CI, 1.00 to 1.16). Occurrence of clinically documented infections, unexplained fever, and infectious mortality was similar in the two groups. The addition of Gram-positive prophylaxis, however, significantly increased side effects (RR, 0.46; 95% CI, 0.28 to 0.76). Rifampin use resulted in a higher incidence of undesirable effects. CONCLUSION Considering the lack of cut-clear benefit on some parameters of morbidity and mortality, routine use of Gram-positive prophylaxis is not advisable. This strategy, however, should be particularly valuable in subgroups of patients at high risk of streptococcal infection (eg, those with severe and prolonged neutropenia or mucositis, and those receiving cytarabine). Problems of tolerability and the potential for the emergence of resistant microorganisms should be considered when prescribing prophylaxis with enhanced Gram-positive activity to neutropenic patients.

Serologic response to hepatitis B vaccine with high dose and increasing number of injections in HIV infected adult patients

Sixty-five HIV-infected patients received high-dose (40mug), short interval HBV vaccine. In non-responders to the initial immunization, 1-3 boosters were administered. Rate of response was 60.0% after primary vaccination, and 89.2% after boosters. However, 12 and 24 months after the last vaccination, only 63% and 32.7% of the responders, respectively, had persistence of protective anti-HBs titers (> or =10 IU/L). The results of logistic regression show that gender, CD4 count, and HIV viral load were significant predictors of vaccination outcome. This study suggests that in HIV-infected patients with relatively high CD4 count, response to high dose of HBV vaccine is suboptimal. Rate of response may be increased by vaccine boosts, but antibody titers are significantly lower in non-responders than in responders to primary vaccination. Since persistence of anti-HBs titers appears significantly related to antibody titers after the immunization procedure, monitoring of anti-HBs, particularly in patients with low level of protective antibody titers after primary vaccination or boosters, seems more than justified.

The Impact of Human Immunodeficiency Virus Type 1 on Infectiousness of Tuberculosis: A Meta-Analysis

To assess if the relative infectiousness of patients with tuberculosis is enhanced by coinfection with human immunodeficiency virus type 1 (HIV-1), data from 6 studies of 1240 health care workers who had contact with tuberculosis patients were analyzed. Overall rates of tuberculin skin test conversion were similar regardless of HIV-1 positivity of tuberculosis patients (odds ratio [OR], 1.04; 95% confidence interval [CI], 0.23-1.84). However, when only 3 studies during nosocomial outbreaks of multidrug-resistant Mycobacterium tuberculosis were analyzed, rates of skin test conversion were higher among contacts of HIV-1-positive index cases (OR, 2.85; 95% CI, 1.85-3.85; P=.0002). A second meta-analysis included data from 11 studies of 10,714 household contacts of tuberculosis patients. Prevalence of both skin test positivity (OR, 0.45; 95% CI, 0.20-1.03) and active disease (OR, 1.17; 95% CI, 0.78-1.56) were similar regardless of HIV-1 positivity of index cases. These data suggest that tuberculosis patients with HIV-1 infection are not intrinsically more infectious to their contacts than are HIV-1-negative tuberculosis patients.

Virological efficacy of abacavir: systematic review and meta-analysis

OBJECTIVES The efficacy of abacavir/lamivudine has been reported to be inferior to tenofovir/emtricitabine. Several randomized clinical trials (RCTs) investigated the effectiveness and safety of abacavir/lamivudine and tenofovir/emtricitabine combined antiretroviral treatment (cART) and we have reviewed the available evidence. DESIGN Systematic review and meta-analysis of RCTs using standard Cochrane Collaboration methodologies. METHODS We calculated risk ratios (RRs) with 95% CIs. The primary outcome was the rate of patients with viral load (VL) below the pre-defined cut-off at 48 weeks and/or at 96 weeks. Where available, results were analysed according to VL screening levels (<100,000 or >100,000 copies/mL) with conventional meta-analytical pooling by subgroups and meta-regression. RESULTS Meta-analytical pooling of RCTs with a direct comparison of abacavir/lamivudine and tenofovir/emtricitabine according to baseline VL at 48 weeks (six trials, 4118 patients) showed that the proportions of subjects with VL <50 copies/mL were similar in the overall comparison (RR 0.98; 95% CI 0.94-1.03), in the low baseline VL strata (RR 1.01; 95% CI 0.99-1.03) and in the high baseline VL strata (RR 0.96; 95% CI 0.90-1.03). Meta-regression analysis at 48 weeks confirms the results of subgroup analysis. Similar virological results were found at 96 weeks (four trials, 2003 patients). Differences in the occurrence of adverse events requiring discontinuation of treatment favoured tenofovir recipients (RR 1.26; 95% CI 0.99-1.61), but this difference, mostly related to suspected abacavir hypersensitivity reaction, was not statistically significant. CONCLUSIONS Our cumulative, cross-sectional data suggest a similar virological efficacy of abacavir/lamivudine and tenofovir/emtricitabine regardless of the baseline VL.

Structural equation modelling of viral tropism reveals its impact on achieving viral suppression within 6 months in treatment-naive HIV-1-infected patients after combination antiretroviral therapy

Objectives To evaluate the role of pre-treatment co-receptor tropism of plasma HIV on the achievement of viral suppression (plasma HIV RNA 1.69 log10 copies/mL) at the sixth month of combination antiretroviral therapy (cART) in a cohort of naive patients using, for the first time in this context, a path analysis (PA) approach. Patients and methods Adult patients with chronic infection by subtype B HIV-1 were consecutively enrolled from the start of first-line cART (T0). Genotypic analysis of viral tropism was performed on plasma and interpreted using the bioinformatic tool Geno2pheno, with a false positive rate of 10%. A Bayesian network starting from the viro-immunological data at T0 and at the sixth month of treatment (T1) was set up and this model was evaluated using a PA approach. Results A total of 262 patients (22.1% bearing an X4 virus) were included; 178 subjects (67.9%) achieved viral suppression. A significant positive indirect effect of bearing X4 virus in plasma at T0 on log10 HIV RNA at T1 was detected (P = 0.009), the magnitude of this effect was, however, over 10-fold lower than the direct effect of log10 HIV RNA at T0 on log10 HIV RNA at T1 (P = 0.000). Moreover, a significant positive indirect effect of bearing an X4 virus on log10 HIV RNA at T0 (P = 0.003) was apparent. Conclusions PA overcame the limitations implicit in common multiple regression analysis and showed the possible role of pre-treatment viral tropism at the recommended threshold on the outcome of plasma viraemia in naive patients after 6 months of therapy.

Structural-equation-modelling of the tropism impact on achieving viral suppression within six months in naïve HIV patients

Aim of the study was to evaluate the relevance of baseline (BL) plasma tropism of HIV on the achievement of a viral suppression within six months of antiviral therapy (ARV) in naïve patients by a structural‐equation‐modelling.