Treatment Strategy for Rifampin-Susceptible Tuberculosis.

BACKGROUND: Tuberculosis is usually treated with a 6-month rifampin-based regimen. Whether a strategy involving shorter initial treatment may lead to similar outcomes is unclear. METHODS: In this adaptive, open-label, noninferiority trial, we randomly assigned participants with rifampin-susceptible pulmonary tuberculosis to undergo either standard treatment (rifampin and isoniazid for 24 weeks with pyrazinamide and ethambutol for the first 8 weeks) or a strategy involving initial treatment with an 8-week regimen, extended treatment for persistent clinical disease, monitoring after treatment, and retreatment for relapse. There were four strategy groups with different initial regimens; noninferiority was assessed in the two strategy groups with complete enrollment, which had initial regimens of high-dose rifampin-linezolid and bedaquiline-linezolid (each with isoniazid, pyrazinamide, and ethambutol). The primary outcome was a composite of death, ongoing treatment, or active disease at week 96. The noninferiority margin was 12 percentage points. RESULTS: Of the 674 participants in the intention-to-treat population, 4 (0.6%) withdrew consent or were lost to follow-up. A primary-outcome event occurred in 7 of the 181 participants (3.9%) in the standard-treatment group, as compared with 21 of the 184 participants (11.4%) in the strategy group with an initial rifampin-linezolid regimen (adjusted difference, 7.4 percentage points; 97.5% confidence interval [CI], 1.7 to 13.2; noninferiority not met) and 11 of the 189 participants (5.8%) in the strategy group with an initial bedaquiline-linezolid regimen (adjusted difference, 0.8 percentage points; 97.5% CI, -3.4 to 5.1; noninferiority met). The mean total duration of treatment was 180 days in the standard-treatment group, 106 days in the rifampin-linezolid strategy group, and 85 days in the bedaquiline-linezolid strategy group. The incidences of grade 3 or 4 adverse events and serious adverse events were similar in the three groups. CONCLUSIONS: A strategy involving initial treatment with an 8-week bedaquiline-linezolid regimen was noninferior to standard treatment for tuberculosis with respect to clinical outcomes. The strategy was associated with a shorter total duration of treatment and with no evident safety concerns. (Funded by the Singapore National Medical Research Council and others; TRUNCATE-TB ClinicalTrials.gov number, NCT03474198.).

Does PET-CT Have a Role in the Evaluation of Tuberculosis Treatment in Phase 2 Clinical Trials?

Positron emission tomography-computed tomography (PET-CT) has the potential to revolutionize research in infectious diseases, as it has done with cancer. There is growing interest in it as a biomarker in the setting of early-phase tuberculosis clinical trials, particularly given the limitations of current biomarkers as adequate predictors of sterilizing cure for tuberculosis. PET-CT is a real-time tool that provides a 3-dimensional view of the spatial distribution of tuberculosis within the lung parenchyma and the nature of lesions with uptake (ie, whether nodular, consolidative, or cavitary). Its ability to provide functional data on changes in metabolism, drug penetration, and immune control of tuberculous lesions has the potential to facilitate drug development and regimen selection for advancement to phase 3 trials in tuberculosis. In this narrative review, we discuss the role that PET-CT may have in evaluating responses to drug therapy in active tuberculosis treatment and the challenges in taking PET-CT forward as predictive biomarker of relapse-free cure in the setting of phase 2 clinical trials.

Adjunctive pascolizumab in rifampicin-susceptible pulmonary tuberculosis: proof-of-concept, partially-randomised, double-blind, placebo-controlled, dose-escalation trial.

BACKGROUND: Interleukin-4 (IL-4), increased in tuberculosis infection, may impair bacterial killing. Blocking IL-4 confers benefit in animal models. We evaluated safety and efficacy of pascolizumab (humanised anti-IL-4 monoclonal antibody) as adjunctive tuberculosis treatment. METHODS: Participants with rifampicin-susceptible pulmonary tuberculosis received a single intravenous infusion of pascolizumab or placebo; and standard 6-month tuberculosis treatment. Pascolizumab dose increased in successive cohorts: [1] non-randomised 0.05 mg/kg (n = 4); [2] non-randomised 0.5 mg/kg (n = 4); [3] randomised 2.5 mg/kg (n = 9) or placebo (n = 3); [4] randomised 10 mg/kg (n = 9) or placebo (n = 3). Co-primary safety outcome was study-drug-related grade 4 or serious adverse event (G4/SAE); in all cohorts (1-4). Co-primary efficacy outcome was week-8 sputum culture time-to-positivity (TTP); in randomised cohorts (3-4) combined. RESULTS: Pascolizumab levels exceeded IL-4 50% neutralising dose for 8 weeks in 78-100% of participants in cohorts 3-4. There were no study-drug-related G4/SAEs. Median week-8 TTP was 42 days in pascolizumab and placebo groups (p = 0.185). Rate of TTP increase was greater with pascolizumab (difference from placebo 0.011 [95% Bayesian credible interval 0.006 to 0.015] log10TTP/day. CONCLUSIONS: There was no evidence to suggest blocking IL-4 was unsafe. Preliminary efficacy findings are consistent with animal models. This supports further investigation of adjunctive anti-IL-4 interventions for tuberculosis in larger phase 2 trials.

Dolutegravir or Darunavir in Combination with Zidovudine or Tenofovir to Treat HIV.

BACKGROUND: The World Health Organization recommends dolutegravir with two nucleoside reverse-transcriptase inhibitors (NRTIs) for second-line treatment of human immunodeficiency virus type 1 (HIV-1) infection. Evidence is limited for the efficacy of this regimen when NRTIs are predicted to lack activity because of drug resistance, as well as for the recommended switch of an NRTI from tenofovir to zidovudine. METHODS: In a two-by-two factorial, open-label, noninferiority trial, we randomly assigned patients for whom first-line therapy was failing (HIV-1 viral load, ≥1000 copies per milliliter) to receive dolutegravir or ritonavir-boosted darunavir and to receive tenofovir or zidovudine; all patients received lamivudine. The primary outcome was a week 48 viral load of less than 400 copies per milliliter, assessed with the Food and Drug Administration snapshot algorithm (noninferiority margin for the between-group difference in the percentage of patients with the primary outcome, 12 percentage points). RESULTS: We enrolled 464 patients at seven sub-Saharan African sites. A week 48 viral load of less than 400 copies per milliliter was observed in 90.2% of the patients in the dolutegravir group (212 of 235) and in 91.7% of those in the darunavir group (210 of 229) (difference, -1.5 percentage points; 95% confidence interval [CI], -6.7 to 3.7; P = 0.58; indicating noninferiority of dolutegravir, without superiority) and in 92.3% of the patients in the tenofovir group (215 of 233) and in 89.6% of those in the zidovudine group (207 of 231) (difference, 2.7 percentage points; 95% CI, -2.6 to 7.9; P = 0.32; indicating noninferiority of tenofovir, without superiority). In the subgroup of patients with no NRTIs that were predicted to have activity, a viral load of less than 400 copies per milliliter was observed in more than 90% of the patients in the dolutegravir group and the darunavir group. The incidence of adverse events did not differ substantially between the groups in either factorial comparison. CONCLUSIONS: Dolutegravir in combination with NRTIs was effective in treating patients with HIV-1 infection, including those with extensive NRTI resistance in whom no NRTIs were predicted to have activity. Tenofovir was noninferior to zidovudine as second-line therapy. (Funded by Janssen; NADIA ClinicalTrials.gov number, NCT03988452.).

Effects of Increasing Concentrations of Rifampicin on Different Mycobacterium tuberculosis Lineages in a Whole-Blood Bactericidal Activity Assay.

High-dose rifampicin improved bactericidal activity and culture conversion in early-phase tuberculosis (TB) trials, done mainly in Africa. We performed a whole-blood bactericidal activity (WBA) study to determine whether the effects of high-dose rifampicin differ across globally relevant TB strains and whether effects are similar in dormant bacilli that will be required for enhancing cure. Whole blood from healthy volunteers was spiked with rifampicin (range, 0.63 to 60 mg/L) and incubated with one of four Mycobacterium tuberculosis clinical strains (Haarlem, Latin American-Mediterranean [LAM], East African-Indian [EAI], and Beijing lineages) or a dormant strain (streptomycin-starved 18b [ss18b]). Change in bacterial CFU was estimated after inoculation of WBA cultures in MGIT. WBA increased with higher concentrations of rifampicin in all strains. At rifampicin concentrations up to 5 mg/L, the rates of increase in WBA per unit increase in rifampicin concentration were similar in all 4 clinical strains (P > 0.51). Above 5 mg/L, EAI (P < 0.001) and Beijing (P = 0.007) strains showed greater increases in WBA than did LAM; Haarlem was similar to LAM. The dormant strain showed a lower rate of increase in WBA than clinical strains at rifampicin concentrations up to 5 mg/L; above 5 mg/L, the rate of increase was similar to those in the LAM, Beijing, and Haarlem strains. Increasing rifampicin concentration enhanced WBA in all strains; the greatest effects were seen in strains common in Asia, suggesting that early-phase trial findings may be generalizable beyond Africa. Similar effects of high concentrations of rifampicin on the dormant strain support the concept that this intervention may enhance sterilizing activity.

Gene expression responses to anti-tuberculous drugs in a whole blood model.

BACKGROUND: There is a need for better tools to evaluate new or repurposed TB drugs. The whole blood bactericidal activity (WBA) assay has been advocated for this purpose. We investigated whether transcriptional responses in the WBA assay resemble TB responses in vivo, and whether the approach might additionally reveal mechanisms of action. RESULTS: 1422 of 1798 (79%) of differentially expressed genes in WBA incubated with the standard combination of rifampicin, isoniazid, pyrazinamide and ethambutol were also expressed in sputum (P < 0.0001) obtained from patients taking the same combination of drugs; these comprised well-established treatment-response genes. Gene expression profiles in WBA incubated with the standard drugs individually, or with moxifloxacin or faropenem (with amoxicillin and clavulanic acid) clustered by individual drug exposure. Distinct pathways were detected for individual drugs, although only with isoniazid did these relate to known mechanisms of drug action. CONCLUSIONS: Substantial agreement between whole blood cultures and sputum and the ability to differentiate individual drugs suggest that transcriptomics may add value to the whole blood assay for evaluating new TB drugs.

A blood RNA transcript signature for TB exposure in household contacts.

BACKGROUND: Current tools for diagnosing latent TB infection (LTBI) detect immunological memory of past exposure but are unable to determine whether exposure is recent. We sought to identify a whole-blood transcriptome signature of recent TB exposure. METHODS: We studied household contacts of TB patients; healthy volunteers without recent history of TB exposure; and patients with active TB. We performed whole-blood RNA sequencing (in all), an interferon gamma release assay (IGRA; in contacts and healthy controls) and PET/MRI lung scans (in contacts only). We evaluated differentially-expressed genes in household contacts (log2 fold change ≥1 versus healthy controls; false-discovery rate < 0.05); compared these to differentially-expressed genes seen in the active TB group; and assessed the association of a composite gene expression score to independent exposure/treatment/immunological variables. RESULTS: There were 186 differentially-expressed genes in household contacts (n = 26, age 22-66, 46% male) compared with healthy controls (n = 5, age 29-38, 100% male). Of these genes, 141 (76%) were also differentially expressed in active TB (n = 14, age 27-69, 71% male). The exposure signature included genes from inflammatory response, type I interferon signalling and neutrophil-mediated immunity pathways; and genes such as BATF2 and SCARF1 known to be associated with incipient TB. The composite gene-expression score was higher in IGRA-positive contacts (P = 0.04) but not related to time from exposure, isoniazid prophylaxis, or abnormalities on PET/MRI (all P > 0.19). CONCLUSIONS: Transcriptomics can detect TB exposure and, with further development, may be an approach of value for epidemiological research and targeting public health interventions.

Evolution of Protease Inhibitor Resistance in Human Immunodeficiency Virus Type 1 Infected Patients Failing Protease Inhibitor Monotherapy as Second-line Therapy in Low-income Countries: An Observational Analysis Within the EARNEST Randomized Trial.

BACKGROUND: Limited viral load (VL) testing in human immunodeficiency virus (HIV) treatment programs in low-income countries often delays detection of treatment failure. The impact of remaining on failing protease inhibitor (PI)-containing regimens is unclear. METHODS: We retrospectively tested VL in 2164 stored plasma samples from 386 patients randomized to receive lopinavir monotherapy (after initial raltegravir induction) in the Europe-Africa Research Network for Evaluation of Second-line Therapy (EARNEST) trial. Protease genotypic resistance testing was performed when VL >1000 copies/mL. We assessed evolution of PI resistance mutations from virological failure (confirmed VL >1000 copies/mL) until PI monotherapy discontinuation and examined associations using mixed-effects models. RESULTS: Median post-failure follow-up (in 118 patients) was 68 (interquartile range, 48-88) weeks. At failure, 20% had intermediate/high-level resistance to lopinavir. At 40-48 weeks post-failure, 68% and 51% had intermediate/high-level resistance to lopinavir and atazanavir; 17% had intermediate-level resistance (none high) to darunavir. Common PI mutations were M46I, I54V, and V82A. On average, 1.7 (95% confidence interval 1.5-2.0) PI mutations developed per year; increasing after the first mutation; decreasing with subsequent mutations (P < .0001). VL changes were modest, mainly driven by nonadherence (P = .006) and PI mutation development (P = .0002); I47A was associated with a larger increase in VL than other mutations (P = .05). CONCLUSIONS: Most patients develop intermediate/high-level lopinavir resistance within 1 year of ongoing viral replication on monotherapy but retain susceptibility to darunavir. Viral load increased slowly after failure, driven by non-adherence and PI mutation development. CLINICAL TRIALS REGISTRATION: NCT00988039.

Sub-clinical abnormalities detected by PET/MRI in household tuberculosis contacts.

BACKGROUND: The understanding of early events following TB exposure is limited by traditional tests that rely on detection of an immune response to infection, which is delayed, or on imaging tests with low sensitivity for early disease. We investigated for evidence of lung abnormalities in heavily exposed TB contacts using PET/MRI. METHODS: 30 household contacts of 20 index patients underwent clinical assessment, IGRA testing, chest x-ray and PET/MRI scan using 18-F-FDG. MRI images were examined by a radiology/nuclear medicine dual-qualified physician using a standardised report form, while PET/MRI images were examined independently by another radiology/nuclear medicine dual-qualified physician using a similar form. Standardised uptake value (SUV) was quantified for each abnormal lesion. RESULTS: IGRA was positive in 40%. PET/MRI scan was abnormal in 30%, predominantly FDG uptake in hilar or mediastinal lymph nodes and lung apices. We did not identify any relationship between PET/MRI findings and degree of exposure or IGRA status. CONCLUSION: PET-based imaging may provide important insights into the natural history following exposure to TB that may not be available from traditional tests of TB immune response or imaging. The clinical significance of the abnormalities is uncertain and merits further investigation in longitudinal studies.

Mapping the medical outcomes study HIV health survey (MOS-HIV) to the EuroQoL 5 Dimension (EQ-5D-3 L) utility index.

BACKGROUND: Mapping of health-related quality-of-life measures to health utility values can facilitate cost-utility evaluation. Regression-based methods tend to lead to shrinkage of variance. This study aims to map the Medical Outcomes Study HIV Health Survey (MOS-HIV) to EuroQoL 5 Dimensions (EQ-5D-3 L) utility index, and to characterize the performance of three mapping methods, including ordinary least squares (OLS), equi-percentile method (EPM), and a recently proposed method called Mean Rank Method (MRM). METHODS: This is a secondary analysis of data from a randomized HIV treatment trial. Baseline data from 421 participants were used to develop mapping functions. Follow-up data from 236 participants was used to validate the mapping functions. RESULTS: In the training dataset, MRM and OLS, but not EPM, reproduced the observed mean utility (0.731). MRM, OLS and EPM under-estimated the standard deviation by 0.3, 26.6 and 1.7%, respectively. MRM had the lowest mean absolute error (0.143) and highest intraclass correlation coefficient (0.723) with the observed utility values, whereas OLS had the lowest mean squared error (0.038) and highest R-squared (0.542). Regressing the MRM- and OLS-mapped utility values upon body mass index and log-viral load gave covariate associations comparable to those estimated from the observed utility data (all P > 0.10). EPM did not achieve this property. Findings from the validation data were similar. CONCLUSIONS: Functions are available for mapping the MOS-HIV to the EQ-5D-3 L utility values. MRM and OLS were comparable in terms of agreement with the observed utility values at the individual level. MRM had better performance at the group level in terms of describing the utility distribution. TRIAL REGISTRATION: NCT00988039 . Registered 30 September 2009.

Effectiveness of Protease Inhibitor/Nucleos(t)ide Reverse Transcriptase Inhibitor-Based Second-line Antiretroviral Therapy for the Treatment of Human Immunodeficiency Virus Type 1 Infection in Sub-Saharan Africa: A Systematic Review and Meta-analysis.

Background: In sub-Saharan Africa, 25.5 million people are living with human immunodeficiency virus (HIV), representing 70% of the global total. The need for second-line antiretroviral therapy (ART) is projected to increase in the next decade in keeping with the expansion of treatment provision. Outcome data are required to inform policy. Methods: We performed a systematic review and meta-analysis of studies reporting the virological outcomes of protease inhibitor (PI)-based second-line ART in sub-Saharan Africa. The primary outcome was virological suppression (HIV-1 RNA <400 copies/mL) after 48 and 96 weeks of treatment. The secondary outcome was the proportion of patients with PI resistance. Pooled aggregate data were analyzed using a DerSimonian-Laird random effects model. Results: By intention-to-treat analysis, virological suppression occurred in 69.3% (95% confidence interval [CI], 58.2%-79.3%) of patients at week 48 (4558 participants, 14 studies), and in 61.5% (95% CI, 47.2%-74.9%) at week 96 (2145 participants, 8 studies). Preexisting resistance to nucleos(t)ide reverse transcriptase inhibitors (NRTIs) increased the likelihood of virological suppression. Major protease resistance mutations occurred in a median of 17% (interquartile range, 0-25%) of the virological failure population and increased with duration of second-line ART. Conclusions: One-third of patients receiving PI-based second-line ART with continued NRTI use in sub-Saharan Africa did not achieve virological suppression, although among viremic patients, protease resistance was infrequent. Significant challenges remain in implementation of viral load monitoring. Optimizing definitions and strategies for management of second-line ART failure is a research priority. Prospero Registration: CRD42016048985.

Coadministration of Allopurinol To Increase Antimycobacterial Efficacy of Pyrazinamide as Evaluated in a Whole-Blood Bactericidal Activity Model.

Coadministering pyrazinamide (PZA) with the xanthine oxidase inhibitor allopurinol increases systemic levels of the active metabolite, pyrazinoic acid (POA), but the effects on bactericidal activity against tuberculosis are unknown. We randomized healthy volunteers to take a single dose of PZA (either 10 or 25 mg/kg of body weight) at the first visit and the same dose 7 days later, coadministered with allopurinol (100 mg daily; 2 days before to 1 day after the PZA dose). Blood was drawn at intervals until 48 h after each PZA dose, and drug levels were measured using liquid chromatography-tandem mass spectrometry. Whole-blood bactericidal activity (WBA) was measured by inoculating blood samples with Mycobacterium tuberculosis and estimating the change in bacterial CFU after 72 h of incubation. Allopurinol increased the POA area under the concentration-time curve from 0 to 8 h (AUC0-8) (18.32 h · µg/ml versus 24.63 h · µg/ml for PZA alone versus PZA plus allopurinol) (P < 0.001) and its peak plasma concentration (Cmax) (2.81 µg/ml versus 4.00 µg/ml) (P < 0.001). There was no effect of allopurinol on mean cumulative WBA (0.01 ± 0.02 ΔlogCFU versus 0.00 ± 0.02 ΔlogCFU for PZA alone versus PZA plus allopurinol) (P = 0.49). Higher systemic POA levels were associated with greater WBA levels (P < 0.001), but the relationship was evident only at low POA concentrations. The lack of an effect of allopurinol on WBA despite a significant increase in blood POA levels suggests that host-generated POA may be less effective than POA generated inside bacteria. Coadministration of allopurinol does not appear to be a useful strategy for increasing the efficacy of PZA in clinical practice. (This study has been registered at ClinicalTrials.gov under registration no. NCT02700347.).

Assessment of second-line antiretroviral regimens for HIV therapy in Africa.

BACKGROUND: The efficacy and toxic effects of nucleoside reverse-transcriptase inhibitors (NRTIs) are uncertain when these agents are used with a protease inhibitor in second-line therapy for human immunodeficiency virus (HIV) infection in resource-limited settings. Removing the NRTIs or replacing them with raltegravir may provide a benefit. METHODS: In this open-label trial in sub-Saharan Africa, we randomly assigned 1277 adults and adolescents with HIV infection and first-line treatment failure to receive a ritonavir-boosted protease inhibitor (lopinavir-ritonavir) plus clinician-selected NRTIs (NRTI group, 426 patients), a protease inhibitor plus raltegravir in a superiority comparison (raltegravir group, 433 patients), or protease-inhibitor monotherapy after 12 weeks of induction therapy with raltegravir in a noninferiority comparison (monotherapy group, 418 patients). The primary composite end point, good HIV disease control, was defined as survival with no new World Health Organization stage 4 events, a CD4+ count of more than 250 cells per cubic millimeter, and a viral load of less than 10,000 copies per milliliter or 10,000 copies or more with no protease resistance mutations at week 96 and was analyzed with the use of imputation of data (≤4%). RESULTS: Good HIV disease control was achieved in 60% of the patients (mean, 255 patients) in the NRTI group, 64% of the patients (mean, 277) in the raltegravir group (P=0.21 for the comparison with the NRTI group; superiority of raltegravir not shown), and 55% of the patients (mean, 232) in the monotherapy group (noninferiority of monotherapy not shown, based on a 10-percentage-point margin). There was no significant difference in rates of grade 3 or 4 adverse events among the three groups (P=0.82). The viral load was less than 400 copies per milliliter in 86% of patients in the NRTI group, 86% in the raltegravir group (P=0.97), and 61% in the monotherapy group (P<0.001). CONCLUSIONS: When given with a protease inhibitor in second-line therapy, NRTIs retained substantial virologic activity without evidence of increased toxicity, and there was no advantage to replacing them with raltegravir. Virologic control was inferior with protease-inhibitor monotherapy. (Funded by European and Developing Countries Clinical Trials Partnership and others; EARNEST Current Controlled Trials number, ISRCTN37737787, and ClinicalTrials.gov number, NCT00988039.).

Activity of faropenem with and without rifampicin against Mycobacterium tuberculosis: evaluation in a whole-blood bactericidal activity trial.

Background: Faropenem has in vitro activity against Mycobacterium tuberculosis (Mtb) and shows synergy with rifampicin. We tested this in a whole-blood bactericidal activity (WBA) trial. Methods: We randomized healthy volunteers to receive a single oral dose of faropenem (600 mg) with amoxicillin/clavulanic acid (500/125 mg) ( n = 8), rifampicin (10 mg/kg) ( n = 14) or the combination rifampicin + faropenem + amoxicillin/clavulanic acid ( n = 14). Blood was drawn at intervals to 8 h post-dose. Drug levels were measured using LC-tandem MS. WBA was measured by inoculating blood samples with Mtb and estimating the change in bacterial cfu after 72 h. Trial registration: ClinicalTrials.gov (NCT02393586). Results: There was no activity in the faropenem + amoxicillin/clavulanic acid group (cumulative WBA 0.02 Δlog cfu; P = 0.99 versus zero change). There was a suggestion of a trend favouring the rifampicin + faropenem + amoxicillin/clavulanic acid group at 8 h (cumulative WBA -0.19 ±âŸ0.03 and -0.26 ±âŸ0.03 Δlog cfu in the rifampicin and rifampicin + faropenem + amoxicillin/clavulanic acid groups, respectively; P = 0.180), which was significant in the first hour post-dose ( P = 0.032). Faropenem C max and AUC were 5.4 mg/L and 16.2 mg·h/L, respectively, and MIC for Mtb H37Rv was 5-10 mg/L. Conclusions: Faropenem is not active when used alone, possibly due to inadequate plasma levels relative to MIC. However, there was a suggestion of modest synergy with rifampicin that may merit further testing in clinical trials.

Neurocognitive Function and Neuroimaging Markers in Virologically Suppressed HIV-positive Patients Randomized to Ritonavir-boosted Protease Inhibitor Monotherapy or Standard Combination ART: A Cross-sectional Substudy From the PIVOT Trial.

BACKGROUND: To determine whether treatment with ritonavir-boosted protease inhibitor (PI) monotherapy is associated with detrimental effects on neurocognitive function or brain imaging markers compared to standard antiretroviral therapy (ART). METHODS: Neuropsychological assessment and brain magnetic resonance imaging were performed at the last study visit in a subset of participants randomized to PI monotherapy (PI-mono group) or ongoing triple ART (OT group) in the PIVOT trial. We calculated a global z-score (NPZ-7) from the average of the individual test z-scores and the proportion of participants with symptomatic neurocognitive impairment (score >1 standard deviation below normative means in ≥2 cognitive domains and neurocognitive symptoms). In a subgroup, white matter hyperintensities, bicaudate index, global cortical (GCA) and medial temporal lobe atrophy scores and single voxel (basal ganglia) N-acetylaspartate (NAA)/Choline, NAA/Creatine and myo-inositol/Creatine ratios were measured. RESULTS: 146 participants (75 PI-mono) had neurocognitive testing (median time after randomization 3.8 years), of whom 78 were imaged. We found no difference between arms in NPZ-7 score (median -0.4 (interquartile range [IQR] = -0.7; 0.1) vs -0.3 (IQR = -0.7; 0.3) for the PI-mono and OT groups respectively, P = .28), the proportion with symptomatic neurocognitive impairment (13% and 18% in the PI-mono and OT groups respectively; P = .41), or any of the neuroimaging variables (P > .05). Symptomatic neurocognitive impairment was associated with higher GCA score (OR = 6.2 per additional score; 95% confidence interval, 1.7-22.3 P = .005) but no other imaging variables. CONCLUSIONS: Based on a comprehensive neuropsychological assessment and brain imaging, PI monotherapy does not increase the risk of neurocognitive impairment in stable human immunodeficiency virus-positive patients.

A Novel Approach to CT, MR, and PET Examination of Patients with Infections Requiring Stringent Airborne Precautions.

PURPOSE: To investigate the feasibility of using a modified portable isolation chamber, which conforms to Centers for Disease Control and Prevention (CDC) isolation requirements, in the imaging of infectious patients. MATERIALS AND METHODS: This study was approved by the ethics committee, and all participants gave written informed consent. In this prospective study, the isolation chamber was assessed for computed tomographic (CT), magnetic resonance (MR), and positron emission tomographic (PET) image uniformity and noise by using uniform phantoms. For each modality, equivalent phantom examinations were performed without the isolation chamber. Paired analyses of the differences from these baseline values were conducted by finding the mean difference in the matched sections for each image quality parameter. A potential increase in CT patient dose was assessed, and MR radiofrequency (RF) interference was monitored. Eight participants with active pulmonary tuberculosis (mean age, 48.1 years; age range, 26-88 years; five men, three women) were then examined within a hybrid PET/MR imager. The 95% confidence intervals for the difference in the two matched population means were determined by using the two-sided t distribution for each of the phantom study imaging modalities. RESULTS: Phantom images were evaluated for image uniformity and noise. Increased image noise can affect low contrast resolution, which has the potential to mimic or mask abnormalities when the differences between healthy and diseased tissues are small; clinically, CT image noise is maintained at a constant level with dose modulation. Increased attenuation of annihilation photons, when not corrected for, could lead to photopenic areas on the PET image; PET image nonuniformity complied with guidelines. Artifacts on the MR image due to RF noise spikes could mask abnormalities; paired analysis of variations in MR imaging mean signal-to-noise ratio and uniformity from baseline were within 5% for both gradient-echo and spin-echo sequences. In the eight participants who underwent imaging, the increased radiation dose for the attenuation of the isolation chamber would have resulted in a mean increase in patient size-specific dose estimate of 0.32 mGy ± 0.04 (standard deviation). The RF noise assessment revealed no prominent increase at any frequency band. The eight participants were examined within the isolation chamber without incident. CONCLUSION A modified portable isolation chamber, which conforms to CDC infection control guidelines, was found to be feasible within the confines of CT, MR imaging, and PET environments.

Peripheral neuropathy in HIV patients in sub-Saharan Africa failing first-line therapy and the response to second-line ART in the EARNEST trial.

Sensory peripheral neuropathy (PN) remains a common complication in HIV-positive patients despite effective combination anti-retroviral therapy (ART). Data on PN on second-line ART is scarce. We assessed PN using a standard tool in patients failing first-line ART and for 96 weeks following a switch to PI-based second-line ART in a large Randomised Clinical Trial in Sub-Saharan Africa. Factors associated with PN were investigated using logistic regression. Symptomatic PN (SPN) prevalence was 22% at entry (N = 1,251) and was associated (p < 0.05) with older age (OR = 1.04 per year), female gender (OR = 1.64), Tuberculosis (TB; OR = 1.86), smoking (OR = 1.60), higher plasma creatinine (OR = 1.09 per 0.1 mg/dl increase), CD4 count (OR = 0.83 per doubling) and not consuming alcohol (OR = 0.55). SPN prevalence decreased to 17% by week 96 (p = 0.0002) following similar trends in all study groups (p = 0.30). Asymptomatic PN (APN) increased over the same period from 21 to 29% (p = 0.0002). Signs suggestive of PN (regardless of symptoms) returned to baseline levels by week 96. At weeks 48 and 96, after adjusting for time-updated associations above and baseline CD4 count and viral load, SPN was strongly associated with TB (p < 0.0001). In summary, SPN prevalence was significantly reduced with PI-based second-line therapy across all treatment groups, but we did not find any advantage to the NRTI-free regimens. The increase of APN and stability of PN-signs regardless of symptoms suggest an underlying trend of neuropathy progression that may be masked by reduction of symptoms accompanying general health improvement induced by second-line ART. SPN was strongly associated with isoniazid given for TB treatment.

A simple and powerful method for the estimation of intervention effects on serological endpoints using paired interval-censored data.

Clinical trials often use a binary "fold increase" endpoint defined according to the ratio of interval-censored measurement at end-of-study to that at baseline. We propose a simple yet principled analytic approach based on the linear mixed-effects model for interval-censored data for the analysis of such paired measurements. Having estimated the model parameters, the risk ratio can be estimated by explicit composite estimand and the variance is estimated using the delta method. The estimation can be implemented using the existing procedures in popular statistical software. We use antibody data from the Chloroquine for Influenza Prevention Trial for illustration.

Long-term efficacy and safety of a treatment strategy for HIV infection using protease inhibitor monotherapy: 8-year routine clinical care follow-up from a randomised, controlled, open-label pragmatic trial (PIVOT).

Background: Treatment-simplification strategies are important tools for patient-centred management. We evaluated long-term outcomes from a PI monotherapy switch strategy. Methods: Eligible participants attending 43 UK treatment centres had a viral load (VL) below 50 copies/ml for at least 24 weeks on combination ART. Participants were randomised to maintain ongoing triple therapy (OT) or switch to a strategy of physician-selected PI monotherapy (PI-mono) with prompt return to combination therapy if VL rebounded. The primary outcome, previously reported, was loss of future drug options after 3 years, defined as new intermediate/high level resistance to at least one drug to which the participant's virus was considered sensitive at trial entry. Here we report resistance and disease outcomes after further extended follow-up in routine care. The study was registered as ISRCTN04857074. Findings: We randomised 587 participants to OT (291) or PI-mono (296) between Nov 4, 2008, and July 28, 2010 and followed them for a median of more than 8 years (100 months) until 2018. At the end of this follow-up time, one or more future drug options had been lost in 7 participants in the OT group and 6 in the PI-mono group; estimated cumulative risk by 8 years of 2.7% and 2.1% respectively (difference -0.6%, 95% CI -3.2% to 2.0%). Only one PI-mono participant developed resistance to the protease inhibitor they were taking (atazanavir). Serious clinical events (death, serious AIDS, and serious non-AIDS) were infrequent; reported in a total of 12 (4.1%) participants in the OT group and 23 (7.8%) in the PI-mono group (P = 0.08) over the entire follow-up period. Interpretation: A strategy of PI monotherapy, with regular VL monitoring and prompt reintroduction of combination treatment following rebound, preserved future treatment options. Findings confirm the high genetic barrier to resistance of the PI drug class that makes them well suited for creative, patient-centred, treatment-simplification approaches. The possibility of a small excess risk of serious clinical events with the PI monotherapy strategy cannot be excluded. Funding: The National Institute for Health Research Health Technology Assessment programme.