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.

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.

Abacavir-based triple nucleoside regimens for maintenance therapy in patients with HIV.

BACKGROUND: Regimen simplification can be defined as a change in established effective therapy to reduce pill burden and dosing frequency, to enhance tolerability, or to decrease specific food and fluid requirements. Many patients on suppressive antiretroviral therapy may be considered candidates for a simplification strategy and, among them, those who have achieved virologic suppression. Several clinical trials have evaluated the efficacy of triple nucleoside combination as a simplification therapy in patients who achieved virologic suppression OBJECTIVES: The aim of this review is to combine randomised, controlled trials to examine whether in patients with undetectable viraemia on a Protease inhibitor (PI) based regimen simplification treatment with abacavir (ABC)-based triple-nucleoside combinations has similar rates of efficacy and tolerability compared with a PI regimen or simplification with a NNRTIs (efavirenz-EFV- or nevirapine-NVP) containing regimen. Studies were included if they had at least two of the three interventions, including one 3NRTI arm. SEARCH METHODS: Electronic databases and conference proceedings were searched (1996-2012) with relevant search terms without limits to language. SELECTION CRITERIA: Randomised controlled trials (RCTs) only are included in this review. Patients population is represented by HIV-infected adult patients treated with a PI-containing regimen (PI or boosted PI),  with undetectable viral load. Patients on a PI-containing regimen had three possibilities: continue the PI regimen or switch to a simplification maintenance regimen, including switch to a NNRTI (EFV or NVP) containing regimen, or switch to a triple-NRTI regimen (ABC-zidovudine-lamivudine) DATA COLLECTION AND ANALYSIS: The primary outcomes were: proportion of patients discontinuing or switching antiretroviral therapy due to virologic failure or to adverse events; death (all cause) and AIDS defining illness; occurrence of myocardial infarction and cardiovascular disease. Secondary outcomes  were: proportion of patients maintaining an undetectable viral load (e.g. HIV-RNA <50 or <400 copies/mm(3)); change in mean CD4+ cell count; occurrence of lipodystrophy. We applied Cochrane Collaboration tools to assess each individual study for risk for bias. MAIN RESULTS: We included eight RCT, for a total of 1,610 patients. All the studies included HIV-1 infected patients virologically suppressed after a successful treatment with PI containing ART. Articles included in the analysis were published between 2001 and 2010, and could be classified as low risk of bias trials in most of the domains considered. Overall, there was no significant difference between the participants on triple nucleoside combination and controls, either PI-based or NNRTI based in terms of overall failures, death and AIDS related events, and rates of patients with viral load below the detectability cut-off. For the outcomes discontinuation for adverse events and virologic failures, the RRs were not significant , albeit  being not far from the alpha level of 0.05, thus suggesting a weak evidence of lower incidence of side effects  and an higher incidence of virologic failure in the 3NRTI group compared to controls . Change in lipids and in CD4 cells from baselines were reported in 7 studies, but inconsistency in reporting these data did not allow quantitative analysis. However, all agreed that simplification with ABC had a favourable and significant impact on lipid metabolism compared to control group. An increase in CD4 cells count from baseline was evident in all analysed studies, without significant differences between ABC and controls in individual studies. AUTHORS' CONCLUSIONS: The strategy of switching to triple nucleoside regimens shows weak evidence of lower incidence of side effects and a higher incidence of virologic failure in the 3NRTI group compared to controls. Simplification with 3NRTI holds the advantages of preserving other classes of antiretroviral drugs, to lower blood lipids, and to be cost effective and simple to administer.Thus, simplification with triple nucleoside regimens AZT + 3TC + ABC should be still considered for individuals who are unable to tolerate or have contraindications to NNRTI or PI based regimens. Additional data are needed on longer-term efficacy of triple NRTI regimens, particularly on the development of antiretroviral resistance. Though studies in the current review were conducted between 2001 and 2010, the large majority of patients from studies analysed received old PI regimens (e.g., indinavir, ritonavir, nelfinavir, saquinavir) not longer recommended by International Guidelines. Since current guidelines recommend new "lipid -friendly" PI, future studies should compare regimens containing these news PIs to triple NRTI regimens. More realistically, however, there are opportunities to examine these issues in existing cohorts.

Latent Tuberculosis Infection Cascade of Care among Asylum Seekers in Verona, Italy.

Our study aimed to assess latent tuberculosis infection (LTBI) prevalence, screening uptake, adherence to preventive treatment, and their predictors in a large cohort of asylum seekers. We retrospectively analysed data of migrants screened in 2015-2017 at the Migrant's Service in Verona, Italy. Sequential interferon-gamma-release-assay (IGRA) was performed to confirm only tuberculin-skin-test (TST) results ranking from 5 to 14 mm. Among 2,486 asylum seekers, screening adherence was 89.74% and LTBI prevalence was 28.8% (CI95% 27.0;30.5). Predictors of LTBI diagnosis were: male gender (OR 1.62), age 24 years or older (OR 1.47) and African origin (OR 1.78). Therapy completion rate was 69.6% and resulted associated with African origin (OR 1.75) and being older than 24 years (OR 2.89). Sequential IGRA testing, given its expensiveness, could be used to confirm only intermediate TST results, thus enabling further LTBI cases to be detected and avoiding unnecessary preventive treatments.

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.

Cocaine-associated increase of atrial natriuretic peptides: an early predictor of cardiac complications in cocaine users?

OBJECTIVE: Cocaine is known to produce life-threatening cardiovascular complications, and the investigation of the causes of death may be challenging in forensic medicine. The increasing knowledge of the cardiac function biomarkers and the increasing sensitivity of assays provide new tools in monitoring the cardiac life-threatening pathological conditions and in the sudden death investigation in chronic abusers. In this work, cardiac dysfunction was assessed in an animal model by measuring troponin I and natriuretic peptides as biomarkers, and considering other standard endpoints used in preclinical toxicology studies. METHODS: Lister Hooded rats were treated with cocaine in chronic self-administration studies. Troponin I (cTnI) and atrial natriuretic peptide (ANP) were evaluated at different time points and heart weight and histopathology were assessed at the end of the treatment period. Furthermore, cocaine and its main metabolites were measured in the rat fur to assess rats' cocaine exposure. All the procedures and endpoints considered were designed to allow an easy and complete translation from the laboratory animals to human beings, and the same approach was also adopted with a group of 10 healthy cocaine abuse volunteers with no cardiac pathologies. RESULTS: Cardiac troponin I values were unaffected, and ANP showed an increasing trend with time in all cocaine-treated animals considered. Similarly, in the healthy volunteers, no changes were observed in troponin serum levels, whereas the N-terminal brain natriuretic pro-peptide (NT proBNP) showed variations comparable with the changes observed in rats. CONCLUSIONS: In conclusion, natriuretic peptides could represent an early indicator of heart dysfunction liability in chronic cocaine abusers.

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

INTRODUCTION: 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. MATERIALS AND METHODS: Two-hundred and twenty-seven patients were enrolled; viral tropism on plasma was determined at baseline (BL) by sequencing and interpretation by genotopheno algorithm. Booster atazanavir or lopinavir , or efavirenz or nevirapine were used, in combination with either abacavir/lamivudine or tenofovir-emtricitabine. RESULTS: X4-tropism correlate negatively with CD4 cell count at BL and follow-up (FU), and CD4 correlate negatively with BL-plasma viremia (PLV). BL-PLV correlate positively with FU-PLV. We have developed the hypothesis that the variables BL-CD4 and BL-PLV represent a mediators chain among X4-tropism and outcome of plasma viraemia at six months. This model, after structural-equation-modelling (SEM, Stata13), is shown in Figure 1. The indirect effect of X4-tropism on Fup-PLV is significant (p<0.01) but about 10 fold lower than the direct effect by BL-PLV. X4-tropism also has a direct negative effect on BL-CD4 (p<0.001) and an indirect positive effect on BL-PLV (p<0.001), irrespective of the drug regimen. Path model explaining direct and mediated effects of "tro (tropism)," "gender," "age," "cd0 (BL-CD4)" and "lrna0 (BL-PLV)" on the final outcome ("lrna1-Fup-PLV)," where "tro," "gender," and "age" are exogenous, cd0 and lrna0 are endogenous (mediators). Numbers on the arrows indicate direct effects. Circles indicate residuals related to endogenous/dependent variables; numbers near to circles are the corresponding variances. CONCLUSIONS: This model shows the relevance of BL-tropism on the outcome of plasma viraemia in naïve patients after six months of therapy, irrespective of drug regimen used.

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.

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.

Granulocyte macrophage colony-stimulating factor as an adjuvant for hepatitis B vaccination: a meta-analysis.

The efficacy of granulocyte macrophage colony-stimulating factor (GM-CSF) to enhance the immune response to hepatitis B virus vaccine has been object of several reports. We searched for randomized controlled clinical trials comparing GM-CSF given concomitantly to hepatitis B virus vaccine to vaccine given alone or with placebo. Data on rates of seroconversion (anti-HBs titers >10 IU/ml) from 13 studies (734 subjects) produced combined estimates that favored GM-CSF as compared to controls: rate ratio after a single immunization was 1.54 [95% confidence interval (CI), 1.04-2.27] and 1.20 (95% CI, 1.02-1.42) at the end of the vaccination cycle. Using a logistic approach a significant dose/response effect of GM-CSF was seen. Moreover, in renal failure patients who have responded to the vaccine, GM-CSF increased anti-HBs titers. Our findings suggest that GM-CSF induced a significant effect in terms of response rate and achievement of an earlier seroconversion to the vaccine in the overall populations examined, in renal failure patients and in healthy individuals.

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.

Systematic review of the accuracy of the ParaSight-F test in the diagnosis of Plasmodium falciparum malaria.

BACKGROUND: The Parasight-F test is a device for the rapid diagnosis of Plasmodium falciparum malaria. In a number of field studies rather wide disparities in the performance of the test have been reported. To provide an evaluation of the quality of available reports and an overall summary of diagnostic accuracy of the Parasight-F test, we have performed a systematic review. MATERIAL/METHODS: Systematic review and meta-analysis of controlled studies evaluating the diagnostic accuracy of Parasight-F test in comparison with light microscopy. DATA SOURCES: 15,359 subjects (4,119 with falciparum malaria) studied with the Parasight-F test as reported in 32 studies from 29 publications. MAIN OUTCOME MEASURES: Summary receiving operator characteristic (SROC) curve as well as odds ratio calculated by the fixed effect model and the random effect model. Based on pooled data, the predictive values were calculated for a range of P. falciparum prevalence through a Bayesian approach. RESULTS: Overall, the Parasight-F test demonstrated 0.90 (95%, confidence intervals 0.88-0.93) sensitivity and 0.94 (0.92-0.96) specificity. Both sensitivity and specificity were significantly higher in the non-resident than in the resident population. The post-test probability indicates that in settings of low malaria prevalence, a negative test almost absolutely excludes infection, while in settings of high prevalence, the same result still gives a substantial chance of infection being present. CONCLUSIONS: The Parasight-F test is a simple and accurate test for the diagnosis of P. falciparum infection. The test could be of particular value in the diagnosis of malaria in travelers returning from endemic areas.