FROG: Exploiting all-atom molecular dynamics trajectories to calculate linear and non-linear optical responses of molecular liquids within Dalton's QM/MM polarizable embedding scheme.

Quantum mechanical/molecular mechanics (QM/MM) methods are interesting to model the impact of a complex environment on the spectroscopic properties of a molecule. In this context, a FROm molecular dynamics to second harmonic Generation (FROG) code is a tool to exploit molecular dynamics trajectories to perform QM/MM calculations of molecular optical properties. FROG stands for "FROm molecular dynamics to second harmonic Generation" since it was developed for the calculations of hyperpolarizabilities. These are relevant to model non-linear optical intensities and compare them with those obtained from second harmonic scattering or second harmonic generation experiments. FROG's specificity is that it is designed to study simple molecular liquids, including solvents or mixtures, from the bulk to the surface. For the QM/MM calculations, FROG relies on the Dalton package: its electronic-structure models, response theory, and polarizable embedding schemes. FROG helps with the global workflow needed to deal with numerous QM/MM calculations: it permits the user to separate the system into QM and MM fragments, to write Dalton's inputs, to manage the submission of QM/MM calculations, to check whether Dalton's calculation finished successfully, and finally to perform averages on relevant QM observables. All molecules within the simulation box and several time steps are tackled within the same workflow. The platform is written in Python and installed as a package. Intermediate data such as local electric fields or individual molecular properties are accessible to the users in the form of Python object arrays. The resulting data are easily extracted, analyzed, and visualized using Python scripts that are provided in tutorials.

Effect of decentralising childhood tuberculosis diagnosis to primary health centre versus district hospital levels on disease detection in children from six high tuberculosis incidence countries: an operational research, pre-post intervention study.

Background: Childhood tuberculosis (TB) remains underdiagnosed largely because of limited awareness and poor access to all or any of specimen collection, molecular testing, clinical evaluation, and chest radiography at low levels of care. Decentralising childhood TB diagnostics to district hospitals (DH) and primary health centres (PHC) could improve case detection. Methods: We conducted an operational research study using a pre-post intervention cross-sectional study design in 12 DHs and 47 PHCs of 12 districts across Cambodia, Cameroon, Côte d'Ivoire, Mozambique, Sierra Leone and Uganda. The intervention included 1) a comprehensive diagnosis package at patient-level with tuberculosis screening for all sick children and young adolescents <15 years, and clinical evaluation, Xpert Ultra-testing on respiratory and stool samples, and chest radiography for children with presumptive TB, and 2) two decentralisation approaches (PHC-focused or DH-focused) to which districts were randomly allocated at country level. We collected aggregated and individual data. We compared the proportion of tuberculosis detection in children and young adolescents <15 years pre-intervention (01 August 2018-30 November 2019) versus during intervention (07 March 2020-30 September 2021), overall and by decentralisation approach. This study is registered with ClinicalTrials.gov, NCT04038632. Findings: TB was diagnosed in 217/255,512 (0.08%) children and young adolescent <15 years attending care pre-intervention versus 411/179,581 (0.23%) during intervention, (OR: 3.59 [95% CI 1.99-6.46], p-value<0.0001; p-value = 0.055 after correcting for over-dispersion). In DH-focused districts, TB diagnosis was 80/122,570 (0.07%) versus 302/86,186 (0.35%) (OR: 4.07 [1.86-8.90]; p-value = 0.0005; p-value = 0.12 after correcting for over-dispersion); and 137/132,942 (0.10%) versus 109/93,395 (0.11%) in PHC-focused districts, respectively (OR: 2.92 [1.25-6.81; p-value = 0.013; p-value = 0.26 after correcting for over-dispersion). Interpretation: Decentralising and strengthening childhood TB diagnosis at lower levels of care increases tuberculosis case detection but the difference was not statistically significant. Funding source: Unitaid, Grant number 2017-15-UBx-TB-SPEED.

Implementing long-acting injectable antiretroviral treatments in Senegal: issues, challenges and conditions for introducing them. Qualitative study with healthcare providers and patients.

Long-acting injectable antiretroviral therapy (LAI-ART) can offer people living with HIV (PLWH) a promising alternative to daily oral therapy. This article highlights the issues, challenges and conditions related to introducing LAI-ART into the social lives of PLWH and HIV-care practices in Senegal. Semi-structured interviews were conducted with 42 PLWH in two hospital care units in Dakar and with 13 healthcare providers and 6 peer educators. Interviews were transcribed, thematically coded and analysed using a cross-sectional approach. We found three key issues. First, simplifying living with HIV: PLWH respondents perceive LAI-ART as an opportunity to ease the burden associated with taking tablets. This enthusiasm may however be qualified by an ambivalent relationship with injections and is subject to certain conditions. Second, certain constraints linked to the medicalisation of care are to be anticipated, including the obligation to go to the hospital every two months for injections. These findings foreshadow the new management work for medical follow-up expected to fall on PLWH and caregivers. Third, the challenges of introducing LAI-ART in Senegal are to ensure adequate organisation of care and supply and sustainability of the program. These results clarify how to implement programs to introduce LAI-ART into real life in the West African context.

Improving early infant diagnosis for HIV-exposed infants using unmanned aerial vehicles for blood sample transportation in Conakry, Guinea: a comparative cost-effectiveness analysis.

BACKGROUND: Early infant diagnosis (EID) for HIV-exposed infants is essential due to high mortality during the first months of their lives. In Conakry (Guinea), timely EID is difficult as traffic congestion prevents the rapid transport of blood samples to the central laboratory. We investigated the cost-effectiveness of transporting EID blood samples by unmanned aerial vehicles (UAV), also known as drones. METHODS AND FINDINGS: Using Monte Carlo simulations, we conducted a cost-effectiveness comparative analysis between EID blood samples transportation by on-demand UAV transportation versus the baseline scenario (ie, van with irregular collection schedules) and compared with a hypothetic on-demand motorcycle transportation system. Incremental cost-effectiveness ratio (ICER) per life-year gained was computed. Simulation models included parameters such as consultation timing (eg, time of arrival), motorcycle and UAV characteristics, weather and traffic conditions. Over the 5-year period programme, the UAV and motorcycle strategies were able to save a cumulative additional 834.8 life-years (585.1-1084.5) and 794.7 life-years (550.3-1039.0), respectively, compared with the baseline scenario. The ICER per life-year gained found were US$535 for the UAV strategy versus baseline scenario, US$504 for the motorcycle strategy versus baseline scenario and US$1137 per additional life-year gained for the UAV versus motorcycle strategy. Respectively, those ICERs represented 44.8%, 42.2% and 95.2% of the national gross domestic product (GDP) per capita in Guinea-that is, US$1194. CONCLUSION: Compared with the baseline strategy, both transportation of EID blood samples by UAVs or motorcycles had a cost per additional life-year gained below half of the national GDP per capita and could be seen as cost-effective in Conakry. A UAV strategy can save more lives than a motorcycle one although the cost needed per additional life-year gained might need to consider alongside budget impact and feasibility considerations.

Acceptability of decentralizing childhood tuberculosis diagnosis in low-income countries with high tuberculosis incidence: Experiences and perceptions from health care workers in Sub-Saharan Africa and South-East Asia.

Decentralizing childhood tuberculosis services, including diagnosis, is now recommended by the WHO and could contribute to increasing tuberculosis detection in high burden countries. However, implementing microbiological tests and clinical evaluation could be challenging for health care workers (HCWs) in Primary Health Centers (PHCs) and even District Hospitals (DHs). We sought to assess the acceptability of decentralizing a comprehensive childhood tuberculosis diagnosis package from HCWs' perspective. We conducted implementation research nested within the TB-Speed Decentralization study. HCWs from two health districts of Cambodia, Cameroon, Côte d'Ivoire, Mozambique, Sierra Leone, and Uganda implemented systematic screening, nasopharyngeal aspirates (NPA) and stool sample collection with molecular testing, clinical evaluation and chest X-ray (CXR) interpretation. We investigated their experiences and perceptions in delivering the diagnostic package components in 2020-21 using individual semi-structured interviews. We conducted thematic analysis, supported by the Theoretical Framework of Acceptability. HCWs (n = 130, 55% female, median age 36 years, 53% nurses, 72% PHC-based) perceived that systematic screening, although increasing workload, was beneficial as it improved childhood tuberculosis awareness. Most HCWs shared satisfaction and confidence in performing NPA, despite procedure duration, need to involve parents/colleagues and discomfort for children. HCWs shared positive attitudes towards stool sample-collection but were frustrated by delayed stool collection associated with cultural practices, transport and distance challenges. Molecular testing, conducted by nurses or laboratory technicians, was perceived as providing quality results, contributing to diagnosis. Clinical evaluation and diagnosis raised self-efficacy issues and need for continuous training and clinical mentoring. HCWs valued CXR, however complained that technical and logistical problems limited access to digital reports. Referral from PHC to DH was experienced as burdensome. HCWs at DH and PHC-levels perceived and experienced decentralized childhood tuberculosis diagnosis as acceptable. Implementation however could be hampered by feasibility issues, and calls for innovative referral mechanisms for patients, samples and CXR.

Liquid Water: When Hyperpolarizability Fluctuations Boost and Reshape the Second Harmonic Scattering Intensities.

Second harmonic scattering (SHS) is a method of choice to investigate the molecular structure of liquids. While a clear interpretation of SHS intensity exists for diluted solutions of dyes, the scattering due to solvents remains difficult to interpret quantitatively. Here, we report a quantum mechanics/molecular mechanics (QM/MM) approach to model the polarization-resolved SHS intensity of liquid water, quantifying different contributions to the signal. We point out that the molecular hyperpolarizability fluctuations and correlations cannot be neglected. The intermolecular orientational and hyperpolarizability correlations up to the third solvation layer strongly increase the scattering intensities and modulate the polarization-resolved oscillation that is predicted here by QM/MM without fitting parameters. Our approach can be generalized to other pure liquids to provide a quantitative interpretation of SHS intensities in terms of short-range molecular ordering.

First hyperpolarizability of water in bulk liquid phase: long-range electrostatic effects included via the second hyperpolarizability.

The molecular first hyperpolarizability ß contributes to second-order optical non-linear signals collected from molecular liquids. For the Second Harmonic Generation (SHG) response, the first hyperpolarizability ß(2ω, ω, ω) often depends on the molecular electrostatic environment. This is especially true for water, due to its large second hyperpolarizability γ(2ω, ω, ω,0). In this study we compute the electronic γ(2ω, ω, ω,0) and ß(2ω, ω, ω) for water molecules in liquid water using QM/MM calculations. The average value of γ(2ω, ω, ω,0) is smaller than the one for the gaz phase, and its standard deviation among the molecules is relatively small. In addition, we demonstrate that the average bulk second hyperpolarizability 〈γ(2ω, ω, ω,0)〉 can be used to describe the electrostatic effects of the distant neighborhood on the first hyperpolarizability ß(2ω, ω, ω). In comparison with more complex schemes to take into account long-range effects, the approximation is simple, and does not require any modifications of the QM/MM implementation. The long-range correction can be added explicitly, using an average value of γ for water in the condensed phase. It can also be easily added implicitly in QM/MM calculations through an additional embedding electric field, without the explicit calculation of γ.

HIV stigma limits the effectiveness of PMTCT in Guinea: the ANRS 12344-DIAVINA study.

BACKGROUND: Nearly half of HIV-infected children worldwide are born in West and Central African countries where access to prevention of mother-to-child transmission of HIV (PMTCT) programmes is still limited. WHO recommends reinforced antiretroviral prophylaxis for infants at high risk of mother-to-child transmission of HIV (MTCT) but its implementation needs further investigation in the field. METHODS: The prospective ANRS 12344-DIAVINA study evaluated the feasibility of a strategy combining early infant diagnosis (EID) and reinforced antiretroviral prophylaxis in high-risk infants as identified by interviews with mothers at Ignace Deen Hospital, Conakry, Guinea. RESULTS: 6493 women were admitted for delivery, 6141 (94.6%) accepted HIV testing and 114 (1.9%) were HIV positive. Among these, 51 high-risk women and their 56 infants were included. At birth, a blood sample was collected for infant EID and reinforced antiretroviral prophylaxis was initiated in 48/56 infants (86%, 95% CI 77%-95%). Iron supplementation was given to 35% of infants for non-severe anaemia. Retrospective measurement of maternal plasma viral load (pVL) at delivery revealed that 52% of women had pVL < 400 copies/mL attributable to undisclosed HIV status and/or antiretroviral intake. Undisclosed HIV status was associated with self-stigmatization (85% versus 44%, P = 0.02). Based on the results of maternal pVL at delivery, 'real' high-risk infants were more frequently lost to follow-up (44% versus 8%, P < 0.01) in comparison with low-risk infants, and this was associated with mothers' stigmatization (69% versus 31%, P < 0.01). CONCLUSIONS: Reinforced antiretroviral prophylaxis and EID at birth are widely feasible. However, mothers' self-disclosure of HIV status and antiretroviral intake do not allow adequate evaluation of MTCT risk, which argues for maternal pVL measurement near delivery. Furthermore, actions against stigmatization are crucial to improve PMTCT.

First hyperpolarizability of water at the air-vapor interface: a QM/MM study questions standard experimental approximations.

Surface Second-Harmonic Generation (S-SHG) experiments provide a unique approach to probe interfaces. One important issue for S-SHG is how to interpret the S-SHG intensities at the molecular level. Established frameworks commonly assume that each molecule emits light according to an average molecular hyperpolarizability tensor ß(-2ω,ω,ω). However, for water molecules, this first hyperpolarizability is known to be extremely sensitive to their environment. We have investigated the molecular first hyperpolarizability of water molecules within the liquid-vapor interface, using a quantum description with explicit, inhomogeneous electrostatic embedding. The resulting average molecular first hyperpolarizability tensor depends on the distance relative to the interface, and it practically respects the Kleinman symmetry everywhere in the liquid. Within this numerical approach, based on the dipolar approximation, the water layer contributing to the Surface Second Harmonic Generation (S-SHG) intensity is less than a nanometer. The results reported here question standard interpretations based on a single, averaged hyperpolarizability for all molecules at the interface. Not only the molecular first hyperpolarizability tensor significantly depends on the distance relative to the interface, but it is also correlated to the molecular orientation. Such hyperpolarizability fluctuations may impact the S-SHG intensity emitted by an aqueous interface.

Challenges of HIV Self-Test Distribution for Index Testing When HIV Status Disclosure Is Low: Preliminary Results of a Qualitative Study in Bamako (Mali) as Part of the ATLAS Project.

Context: The rate of HIV status disclosure to partners is low in Mali, a West African country with a national HIV prevalence of 1.2%. HIV self-testing (HIVST) could increase testing coverage among partners of people living with HIV (PLHIV). The AutoTest-VIH, Libre d'accéder à la connaissance de son Statut (ATLAS) program was launched in West Africa with the objective of distributing nearly half a million HIV self-tests from 2019 to 2021 in Côte d'Ivoire, Mali, and Senegal. The ATLAS program integrates several research activities. This article presents the preliminary results of the qualitative study of the ATLAS program in Mali. This study aims to improve our understanding of the practices, limitations and issues related to the distribution of HIV self-tests to PLHIV so that they can offer the tests to their sexual partners. Methods: This qualitative study was conducted in 2019 in an HIV care clinic in Bamako. It consisted of (i) individual interviews with eight health professionals involved in the distribution of HIV self-tests; (ii) 591 observations of medical consultations, including social service consultations, with PLHIV; (iii) seven observations of peer educator-led PLHIV group discussions. The interviews with health professionals and the observations notes have been subject to content analysis. Results: HIVST was discussed in only 9% of the observed consultations (51/591). When HIVST was discussed, the discussion was almost always initiated by the health professional rather than PLHIV. HIVST was discussed infrequently because, in most of the consultations, it was not appropriate to propose partner HIVST (e.g., when PLHIV were widowed, did not have partners, or had delegated someone to renew their prescriptions). Some PLHIV had not disclosed their HIV status to their partners. Dispensing HIV self-tests was time-consuming, and medical consultations were very short. Three main barriers to HIVST distribution when HIV status had not been disclosed to partners were identified: (1) almost all health professionals avoided offering HIVST to PLHIV when they thought or knew that the PLHIV had not disclosed their HIV status to partners; (2) PLHIV were reluctant to offer HIVST to their partners if they had not disclosed their HIV-positive status to them; (3) there was limited use of strategies to support the disclosure of HIV status. Conclusion: It is essential to strengthen strategies to support the disclosure of HIV+ status. It is necessary to develop a specific approach for the provision of HIV self-tests for the partners of PLHIV by rethinking the involvement of stakeholders. This approach should provide them with training tailored to the issues related to the (non)disclosure of HIV status and gender inequalities, and improving counseling for PLHIV.

Lessons from combined experimental and theoretical examination of the FTIR and 2D-IR spectroelectrochemistry of the amide I region of cytochrome c.

Amide I difference spectroscopy is widely used to investigate protein function and structure changes. In this article, we show that the common approach of assigning features in amide I difference signals to distinct secondary structure elements in many cases may not be justified. Evidence comes from Fourier transform infrared (FTIR) and 2D-IR spectroelectrochemistry of the protein cytochrome c in the amide I range, in combination with computational spectroscopy based on molecular dynamics (MD) simulations. This combination reveals that each secondary structure unit, such as an alpha-helix or a beta-sheet, exhibits broad overlapping contributions, usually spanning a large part of the amide I region, which in the case of difference absorption experiments (such as in FTIR spectroelectrochemistry) may lead to intensity-compensating and even sign-changing contributions. We use cytochrome c as the test case, as this small electron-transferring redox-active protein contains different kinds of secondary structure units. Upon switching its redox-state, the protein exhibits a different charge distribution while largely retaining its structural scaffold. Our theoretical analysis suggests that the change in charge distribution contributes to the spectral changes and that structural changes are small. However, in order to confidently interpret FTIR amide I difference signals in cytochrome c and proteins in general, MD simulations in combination with additional experimental approaches such as isotope labeling, the insertion of infrared labels to selectively probe local structural elements will be required. In case these data are not available, a critical assessment of previous interpretations of protein amide I 1D- and 2D-IR difference spectroscopy data is warranted.

Describing, analysing and understanding the effects of the introduction of HIV self-testing in West Africa through the ATLAS programme in Côte d'Ivoire, Mali and Senegal.

BACKGROUND: The ATLAS programme aims to promote and implement HIV self-testing (HIVST) in three West African countries: Côte d'Ivoire, Mali, and Senegal. During 2019-2021, in close collaboration with the national AIDS implementing partners and communities, ATLAS plans to distribute 500,000 HIVST kits through eight delivery channels, combining facility-based, community-based strategies, primary and secondary distribution of HIVST. Considering the characteristics of West African HIV epidemics, the targets of the ATLAS programme are hard-to-reach populations: key populations (female sex workers, men who have sex with men, and drug users), their clients or sexual partners, partners of people living with HIV and patients diagnosed with sexually transmitted infections and their partners. The ATLAS programme includes research support implementation to generate evidence for HIVST scale-up in West Africa. The main objective is to describe, analyse and understand the social, health, epidemiological effects and cost-effectiveness of HIVST introduction in Côte d'Ivoire, Mali and Senegal to improve the overall HIV testing strategy (accessibility, efficacy, ethics). METHODS: ATLAS research is organised into five multidisciplinary workpackages (WPs): Key Populations WP: qualitative surveys (individual in-depth interviews, focus group discussions) conducted with key actors, key populations, and HIVST users. Index testing WP: ethnographic observation of three HIV care services introducing HIVST for partner testing. Coupons survey WP: an anonymous telephone survey of HIVST users. Cost study WP: incremental economic cost analysis of each delivery model using a top-down costing with programmatic data, complemented by a bottom-up costing of a representative sample of HIVST distribution sites, and a time-motion study for health professionals providing HIVST. Modelling WP: Adaptation, parameterisation and calibration of a dynamic compartmental model that considers the varied populations targeted by the ATLAS programme and the different testing modalities and strategies. DISCUSSION: ATLAS is the first comprehensive study on HIV self-testing in West Africa. The ATLAS programme focuses particularly on the secondary distribution of HIVST. This protocol was approved by three national ethic committees and the WHO's Ethical Research Committee.

Molecular modeling of aqueous electrolytes at interfaces: Effects of long-range dispersion forces and of ionic charge rescaling.

Molecular dynamics simulations of aqueous electrolytes generally rely on empirical force fields, combining dispersion interactions-described by a truncated Lennard-Jones (LJ) potential-and electrostatic interactions-described by a Coulomb potential computed with a long-range solver. Recently, force fields using rescaled ionic charges [electronic continuum correction (ECC)], possibly complemented with rescaling of LJ parameters [ECC rescaled (ECCR)], have shown promising results in bulk, but their performance at interfaces has been less explored. Here, we started by exploring the impact of the LJ potential truncation on the surface tension of a sodium chloride aqueous solution. We show a discrepancy between the numerical predictions for truncated LJ interactions with a large cutoff and for untruncated LJ interactions computed with a long-range solver, which can bias comparison of force field predictions with experiments. Using a long-range solver for LJ interactions, we then show that an ionic charge rescaling factor chosen to correct long-range electrostatic interactions in bulk accurately describes image charge repulsion at the liquid-vapor interface, and the rescaling of LJ parameters in ECCR models-aimed at capturing local ion-ion and ion-water interactions in bulk- describes well the formation of an ionic double layer at the liquid-vapor interface. Overall, these results suggest that the molecular modeling of aqueous electrolytes at interfaces would benefit from using long-range solvers for dispersion forces and from using ECCR models, where the charge rescaling factor should be chosen to correct long-range electrostatic interactions.

Octopus, a computational framework for exploring light-driven phenomena and quantum dynamics in extended and finite systems.

Over the last few years, extraordinary advances in experimental and theoretical tools have allowed us to monitor and control matter at short time and atomic scales with a high degree of precision. An appealing and challenging route toward engineering materials with tailored properties is to find ways to design or selectively manipulate materials, especially at the quantum level. To this end, having a state-of-the-art ab initio computer simulation tool that enables a reliable and accurate simulation of light-induced changes in the physical and chemical properties of complex systems is of utmost importance. The first principles real-space-based Octopus project was born with that idea in mind, i.e., to provide a unique framework that allows us to describe non-equilibrium phenomena in molecular complexes, low dimensional materials, and extended systems by accounting for electronic, ionic, and photon quantum mechanical effects within a generalized time-dependent density functional theory. This article aims to present the new features that have been implemented over the last few years, including technical developments related to performance and massive parallelism. We also describe the major theoretical developments to address ultrafast light-driven processes, such as the new theoretical framework of quantum electrodynamics density-functional formalism for the description of novel light-matter hybrid states. Those advances, and others being released soon as part of the Octopus package, will allow the scientific community to simulate and characterize spatial and time-resolved spectroscopies, ultrafast phenomena in molecules and materials, and new emergent states of matter (quantum electrodynamical-materials).

Tenofovir DF/emtricitabine and efavirenz combination therapy for HIV infection in patients treated for tuberculosis: the ANRS 129 BKVIR trial.

BACKGROUND: HIV-infected patients with TB need simplified, effective and well-tolerated antiretroviral regimens. METHODS: The French ANRS 129 BKVIR open trial evaluated the once-daily tenofovir DF/emtricitabine and efavirenz combination, started within 12 weeks after TB treatment initiation, in antiretroviral-naive HIV-1-infected patients. Success was defined as an HIV-1 RNA <50 copies/mL and TB cure at 48 weeks. RESULTS: TB was confirmed microbiologically (90%) or histologically (10%) in 69 patients (71% male; median age 43 years; 54% born in Africa). The median time between TB treatment initiation and antiretroviral therapy was 8 weeks (range 1-22 weeks). At baseline, median HIV-1 RNA was 5.4 log10 copies/mL and median CD4 cell count 74 cells/mm(3). In the ITT analysis, combined success at week 48 was achieved in 57/69 patients (83%, 95% CI 74-92). Twelve patients did not achieve virological success, and TB was not cured in one of them. Among the 47 patients who fully adhered to the strategy, the success rate was 96% (95% CI 90-100) and was not affected by low rifampicin and isoniazid serum concentrations. Forty-nine serious adverse events were reported in 31 patients (45%), and 11 led to antiretroviral drug interruption. All adverse events resolved. The immune reconstitution inflammatory syndrome occurred in 23 patients (33%, 95% CI 22-44), and was associated with a low baseline BMI (P = 0.03) and a low haemoglobin level (P = 0.02). CONCLUSION: These results support the use of tenofovir DF/emtricitabine and efavirenz combination therapy for HIV infection in patients with TB.

Latent Tuberculosis Infection Screening and 2-Year Outcome in Antiretroviral-Naive HIV-Infected Patients in a Low-Prevalence Country.

BACKGROUND: Diagnosis and treatment of latent tuberculous infection decrease the incidence of tuberculosis (TB) in HIV-infected patients. OBJECTIVES: To evaluate the diagnostic yield of two IFN-γ release assays and tuberculin skin testing for the screening of latent infection in HIV-infected patients. METHODS: We performed a prospective study in 29 referral centers for HIV care in France. Asymptomatic, antiretroviral-naive patients infected with HIV-1 who consented to participate underwent two commercial tests (T-SPOT.TB and QuantiFERON-TB Gold In-Tube ELISA test [QFT]) and skin test at enrollment and were followed up for clinical events during 24 months. RESULTS: Between March 2009 and 2011, 506 patients were included, of whom 415 performed the three tests. Median age was 38 years (interquartile range, 31-45 yr), with median CD4 cell count of 466/µL (337-615 µL), and HIV viral load of 4.5 log10 copies/ml (3.6-4.9 log10 copies/ml). At least one IFN-γ release assay was positive for 55 (13.5%) patients: QFT (n = 43), T-SPOT.TB (n = 34), both (n = 22). Skin test was positive (>5 mm) in 66 (15.9%) patients, with intertest agreement at 81 to 86%. On multivariate analysis, positive IFN-γ release assay was only correlated with country of birth (8.4% for France vs. 17.9% for high-prevalence countries, P = 0.004). Of the 55 patients with positive IFN-γ release assay, 8 (14.5%) developed active TB, all within 120 days. No other case of active TB was diagnosed. Once active TB was excluded, IFN-γ release assay-based latent infection prevalence was 11.8%. CONCLUSIONS: Systematic screening for latent TB infection by IFN-γ release assay identifies a population at high risk of active TB over the next months. An extensive diagnostic work-up for active TB must follow positive IFN-γ release assay, before considering treatment of latent infection. Clinical trial registered with www.clinicaltrials.gov (NCT00805272).

Biomarkers of CD4+ T-cell activation as risk factors for tuberculosis-associated immune reconstitution inflammatory syndrome.

OBJECTIVE: Patients coinfected with HIV and Mycobacterium tuberculosis frequently experience a paradoxical worsening of tuberculosis (TB) symptoms early after the initiation of combination antiretroviral therapy (cART). This immune reconstitution inflammatory syndrome (TB-IRIS) can lead to significant morbidity and needs to be distinguished from TB recurrence due to ineffective treatment. We investigated whether plasma biomarkers could predict the occurrence of TB-IRIS. DESIGN: ANRS 129 BKVIR is a single-arm multicentre trial that enrolled 69 cART-naïve HIV-1-infected patients treated for TB. The patients received once-daily tenofovir/emtricitabine/efavirenz first-line regimen. TB-IRIS cases (IRIS+) were validated by an Event Review Committee. METHODS: A panel of 26 plasma biomarkers was monitored longitudinally for 24 weeks from cART initiation onward, using multiplexed assays and high-sensitivity ELISA. Statistical analyses of biomarkers were adjusted for test multiplicity. RESULTS: One-third of patients (n=23) experienced TB-IRIS. The inflammatory cytokines and chemokines interleukin (IL)-6, IL-8, interferon-gamma-induced protein 10 (IP-10), and tumour necrosis factor-alpha (TNF-α) showed increased plasma levels at week 4 in IRIS-positive (IRIS+) patients (P<0.05 for each biomarker). The soluble IL-2 receptor sCD25, which is released upon CD4 T-cell activation, was significantly increased at week 0 in IRIS+ patients (P<0.05), and remained elevated throughout follow-up. IL-7, a key homeostatic cytokine for CD4 T-cells, showed a trend for higher values in the TB-IRIS group. Both sCD25 and IL-7 baseline levels were independently associated with a shorter time to TB-IRIS occurrence (P=0.005 and P=0.02, respectively). CONCLUSION: These findings support a role for CD4 T-cell activation prior to massive inflammation in the development of TB-IRIS.