Low-level HIV viraemia during antiretroviral therapy: Longitudinal patterns and predictors of viral suppression.

OBJECTIVES: Our objective was to characterize longitudinal patterns of viraemia and factors associated with viral suppression in people with HIV and low-level viraemia (LLV) during antiretroviral therapy (ART). METHODS: We included people with HIV in the EuResist Integrated Database with LLV following ART initiation after 2005. LLV was defined as two or more consecutive viral load (VL) measurements of 51-199 copies/mL 30-365 days apart after >12 months of ART. Viraemia patterns were analyzed over 24 months. Factors associated with viral suppression at 12 months after LLV episodes were identified using univariable and multivariable logistic regression. RESULTS: Of 25 113 people with HIV, 2474 (9.9%) had LLV. Among 1387 participants with 24 months of follow-up after LLV, 406 (29%) had persistent suppression, 669 (48%) had transient viraemic episodes, 29 (2%) had persistent LLV, and 283 (20%) had virological failure. Following LLV episodes, the proportion with detectable viraemia declined (p for trend <0.001 and 0.034, in the first and second year, respectively). At 12 months, 68% had undetectable VL, which was associated with suppression before LLV (adjusted odds ratio [aOR] 1.7; 95% confidence interval [CI] 1.2-2.4) and ART modification after LLV (aOR 1.6; 95% CI 1.0-2.4). The following factors were negatively associated with undetectable VL at 12 months: higher VL during LLV (aOR 0.57 per log10 copies/mL; 95% CI 0.37-0.89), injecting drug use (aOR 0.67; 95% CI 0.47-0.96), and regimens with protease inhibitors (aOR 0.65; 95% CI 0.49-0.87) or combined anchor drugs (aOR 0.52; 95% CI 0.32-0.85). CONCLUSION: Most people with LLV did not experience sustained viral suppression during 24-month follow-up, supporting the association between LLV and inferior treatment outcome.

Is low-level HIV-1 viraemia associated with elevated levels of markers of immune activation, coagulation and cardiovascular disease?

OBJECTIVES: The clinical significance of low-level viraemia (LLV) during antiretroviral therapy (ART) is debated. We retrospectively investigated longitudinal levels of plasma markers associated with inflammation, altered coagulation and cardiovascular disease in Swedish HIV-positive adults in relation to LLV or permanent virological suppression during long-term ART. METHODS: Plasma levels of C-reactive protein (CRP), D-dimer, vascular cell adhesion molecule 1 (VCAM-1), suppression of tumorigenicity 2 (ST2), growth differentiation factor 15 (GDF-15), soluble CD14 (sCD14), soluble CD163 (sCD163), interferon-γ-induced protein 10 (IP-10) and ß-2-microglobulin were measured in 34 individuals with LLV (viral load 50-999 HIV-1 RNA copies/mL) and in matched controls with persistent virological suppression. Biomarker levels were analysed in samples obtained during episodes of LLV and follow-up samples obtained 1 year later (with similar timing for controls). All biomarkers were analysed using an independent sample t-test and analysis of covariance (ANCOVA) after logarithmic transformation. Log-rank analysis was applied for markers with concentration values out of range. RESULTS: Compared with controls, patients with LLV had significantly higher levels of GDF-15 [geometric mean 3416 (95% confidence interval (CI) 804-14 516) pg/mL versus 2002 (95% CI 355-11 295) pg/mL in controls; P = 0.026] and D-dimer [mean 1114 (95% CI 125-9917) ng/mL versus 756 (95% CI 157-3626) ng/mL; P = 0.038] after adjustment for age, CD4 count nadir and type of ART. In the unadjusted t-test, only GDF-15 was significantly higher and in the log-rank test, both GDF-15 and D-dimer were significantly elevated. No significant differences were observed for the other biomarkers analysed. CONCLUSIONS: Although levels of inflammation markers were similar in ART recipients with and without LLV, persons with LLV had significantly higher levels of GDF-15 and D-dimer. These findings suggest a potential link between LLV and cardiovascular outcomes.

Drug-Coated Versus Plain Balloon Angioplasty In Arteriovenous Fistulas: A Randomized, Controlled Study With 1-Year Follow-Up (The Drecorest Ii-Study).

BACKGROUND AND AIMS:: Stenosis due to intimal hyperplasia and restenosis after initially successful percutaneous angioplasty are common reasons for failing arteriovenous fistulas. The aim of this study was to evaluate the effect of drug-coated balloons in the treatment of arteriovenous fistula stenosis. DESIGN:: Single-center, parallel group, randomized controlled trial. Block randomized by sealed envelope 1:1. MATERIALS AND METHODS:: A total of 39 patients with primary or recurrent stenosis in a failing native arteriovenous fistulas were randomized to drug-coated balloon (n = 19) or standard balloon angioplasty (n = 20). Follow-up was 1 year. Primary outcome measure was target lesion revascularization. RESULTS:: In all, 36 stenoses were analyzed; three patients were excluded due to technical failure after randomization. A total of 88.9% (16/18) in the drug-coated balloon group was revascularized or occluded within 1 year, compared to 22.2% (4/18) of the stenoses in the balloon angioplasty group (relative risk for drug-coated balloon 7.09). Mean time-to- target lesion revascularization was 110 and 193 days after the drug-coated balloon and balloon angioplasty, respectively (p = 0.06). CONCLUSIONS:: With 1-year follow-up, the target lesion revascularization-free survival after drug-coated balloon-treatment was clearly worse. The reason for this remains unknown, but it may be due to differences in the biological response to paclitaxel in the venous arteriovenous fistula-wall compared to its antiproliferative effect in the arterial wall after drug-coated balloon treatment of atherosclerotic occlusive lesions. Trial registration: ClinicalTrials.gov NCT03036241.

Gut microbiota utilize immunoglobulin A for mucosal colonization.

The immune system responds vigorously to microbial infection while permitting lifelong colonization by the microbiome. Mechanisms that facilitate the establishment and stability of the gut microbiota remain poorly described. We found that a regulatory system in the prominent human commensal Bacteroides fragilis modulates its surface architecture to invite binding of immunoglobulin A (IgA) in mice. Specific immune recognition facilitated bacterial adherence to cultured intestinal epithelial cells and intimate association with the gut mucosal surface in vivo. The IgA response was required for B. fragilis (and other commensal species) to occupy a defined mucosal niche that mediates stable colonization of the gut through exclusion of exogenous competitors. Therefore, in addition to its role in pathogen clearance, we propose that IgA responses can be co-opted by the microbiome to engender robust host-microbial symbiosis.

High rate of latent tuberculosis treatment completion in immigrants seeking asylum in Sweden.

BACKGROUND/AIM: Treatment of latently infected individuals at increased risk of reactivation is a cornerstone in tuberculosis control. Although asylum seekers without residence permit in Sweden are offered screening for both active tuberculosis and latent tuberculosis infection (LTBI), treatment for LTBI is often not initiated due to anticipated low rates of treatment completion. We aimed to compare completion rates for LTBI treatment between asylum seekers and other patients, and between asylum seekers with and without residence permit. METHODS: Data were collected retrospectively from tuberculosis clinic registers and medical records. For comparison of treatment completion rates, relative risks (RR) and confidence intervals (CI) were calculated. Predictors of completion were assessed by logistic regression multivariate analysis. RESULTS: Treatment completion was achieved in 506/606 subjects (83%). RR of non-completion for asylum seekers (n = 297) compared to other subjects (n = 309) was 1.13 (95% CI: 0.79-1.61; p = .51), and 0.91 (95% CI: 0.53-1.56; p = .72) for asylum seekers without residence permit (n = 217) compared to asylum seekers with residence permit (n = 80). Completion rates increased from 53% in 2008 to 92% in 2015-2016. The following factors were associated with completion: scheduled interpreter-assisted appointments throughout the course of therapy, shorter treatment duration (6 vs. 9 months), and being treated in connection with immunosuppressive therapy. CONCLUSION: Treatment completion rates were similar between asylum seekers and other subjects, supporting initiation of latent tuberculosis treatment in immigrants with recent arrival to low-endemic countries.

Peripheral Vascular Restenosis: A Retrospective Study on the Use of Drug-Eluting Balloons in Native Arteries, Vein Grafts and Dialysis Accesses.

BACKGROUND AND AIMS: The objective of this study is to analyze outcomes of the first experiences with drug-eluting balloons in native arteries, vein grafts, and vascular accesses. The study is also a pilot for our future prospective, randomized, and controlled studies regarding the use of drug-eluting balloons in the treatment of the stenosis in bypass vein graft and dialysis access. MATERIALS AND METHODS: A total of 93 consecutive patients were retrospectively analyzed and in the end 81 were included in the study. Inclusion criteria included at least one previous percutaneous angioplasty to the same lesion. Patients were divided into three groups according to the anatomical site of the lesion: native lower limb artery, vein bypass graft, or vascular access. Time from the previous percutaneous angioplasty to the drug-eluting balloon was compared to the time from the drug-eluting balloon to endpoint in the same patient. Endpoints included any new revascularization of the target lesion, major amputation, or new vascular access. RESULTS: The median time from the drug-eluting balloon to endpoint was significantly longer than the median time from the preceding percutaneous angioplasty to drug-eluting balloon in all three groups. This difference was clearest in native arteries and vein grafts, whereas the difference was smaller from the beginning and disappeared over time in the vascular access group. No significant differences were seen between the groups with regard to smoking, antiplatelet regime, diabetes, Rutherford classification, or sex. CONCLUSION: Although the setup of this study has several limitations, the results suggest that there could be benefit from drug-eluting balloons in peripheral lesions. Very little data have been published on the use of drug-eluting balloons in vein grafts and vascular accesses, and randomized and controlled prospective studies are needed to further investigate this field.

Vaccination against hepatitis B virus among people who inject drugs - A 20year experience from a Swedish needle exchange program.

BACKGROUND: People who inject drugs (PWID) are at particular risk of hepatitis B virus (HBV) acquisition, but often have poor access or adherence to HBV vaccination. Vaccination against HBV has been offered at a major Swedish needle exchange program (NEP) since 1994. The aim of this study was to evaluate vaccine completion and response rates, and the effect of sequential booster doses to non-responders to the standard vaccination schedule. METHODS: PWID enrolled in the NEP 1994-2013, without serological markers for HBV at baseline (negative for HBsAg/anti-HBc/anti-HBs), were offered a three-dose standard intramuscular vaccination schedule (Engerix®-B, GSK, 20µg/mL, intended to be received at months 0, 1 and 6). Vaccination response was defined as protective levels of anti-HBs (⩾10mIU/mL). Up to three booster doses were then offered for non-responders, each followed by anti-HBs testing. RESULTS: HBV data was available for 2352 identifiable individuals at NEP enrolment, of whom 1516 (64.5%) had no markers for previous HBV exposure or vaccination. Vaccination was initiated for 1142 (75.3%) individuals and 898 (59.2%) completed the standard vaccination schedule. Post-vaccination anti-HBs levels were available from 800 individuals, with 598 (74.8%) responding to the basic vaccination schedule. After up to three booster doses a total of 676 (84.5%) individuals achieved protective anti-HBs levels. Non-response to vaccination was associated with higher age and anti-HCV positivity (p<0.001). Eighteen incident cases of HBV infection were observed among vaccine non-responders, as well as 30 cases among those who had not completed vaccination. CONCLUSION: We demonstrate the feasibility of including HBV vaccination in the services offered by a NEP, with completion of vaccination in a majority of HBV-susceptible PWID. The response to HBV vaccination among PWID was relatively low; however, the addition of up to three booster doses improved the response rate from 74.8 to 84.5%.

Drift of the HIV-1 envelope glycoprotein gp120 toward increased neutralization resistance over the course of the epidemic: a comprehensive study using the most potent and broadly neutralizing monoclonal antibodies.

Extending our previous analyses to the most recently described monoclonal broadly neutralizing antibodies (bNAbs), we confirmed a drift of HIV-1 clade B variants over 2 decades toward higher resistance to bNAbs targeting almost all the identified gp120-neutralizing epitopes. In contrast, the sensitivity to bNAbs targeting the gp41 membrane-proximal external region remained stable, suggesting a selective pressure on gp120 preferentially. Despite this evolution, selected combinations of bNAbs remain capable of neutralizing efficiently most of the circulating variants.

A Clinical Scoring Algorithm for Determination of the Risk of Tuberculosis in HIV-Infected Adults: A Cohort Study Performed at Ethiopian Health Centers.

BACKGROUND: The World Health Organization (WHO) tuberculosis (TB) symptom screening instrument (WHO-TB) can identify human immunodeficiency virus (HIV)-infected individuals at low risk of tuberculosis (TB); however, many patients report WHO-TB symptoms and require further TB investigations. We hypothesized that further clinical scoring could classify subjects with a positive WHO-TB screening result (WHO-TB(+)) for the likelihood of TB. METHODS: HIV-infected adults eligible to initiate antiretroviral therapy (ART) were recruited and prospectively followed at 5 Ethiopian health centers. Irrespective of symptoms, all participants underwent sputum bacteriological testing for TB. Symptoms, physical findings, hemoglobin, and CD4 cell count results were compared between subjects with and those without bacteriologically confirmed TB. Variables associated with TB in WHO-TB(+) individuals were used to construct a scoring algorithm with multiple logistic regression analysis. RESULTS: Among 812 participants, 137 (16.9%) had TB. One hundred fifty-nine persons (20%) had a negative WHO-TB screen, 10 of whom had TB (negative predictive value [NPV], 94% [95% confidence interval {CI}, 90%-97.5%]). For WHO-TB(+) subjects, the following variables were independently associated with TB, and were assigned 1 point each in the clinical scoring algorithm: cough, Karnofsky score ≤80, mid-upper arm circumference <20 cm, lymphadenopathy, and hemoglobin <10 g/dL. Among subjects with 0-1 points, 20 of 255 had TB (NPV, 92% [95% CI, 89%-95%]), vs 19 of 34 participants with ≥4 points (positive predictive value, 56% [95% CI, 39%-73%]). The use of WHO-TB alone identified 159 of 784 (20%) with a low risk of TB, vs 414 of 784 (53%) using WHO-TB followed by clinical scoring (P< .001). The difference in proportions of confirmed TB in these subsets was nonsignificant (6.3% vs 7.2%; P= .69). CONCLUSIONS: Clinical scoring can further classify HIV-infected adults with positive WHO-TB screen to assess the risk of TB, and would reduce the number of patients in need of further TB investigations before starting ART. CLINICAL TRIALS REGISTRATION: NCT01433796.

Dynamic tailoring of treatment durations improves efficiency of hepatitis C treatment with pegylated interferon and ribavirin.

The treatment durations for hepatitis C are guided by the analysis of hepatitis C virus (HCV) RNA in blood at certain time points. This multicentre, randomized open label trial evaluated the utility and performance of individualized treatment durations guided by viral decline rates in 103 patients with HCV genotype 1 infection. Pegylated interferon 2a and ribavirin were given as standard of care (SOC) for 24, 48 or 72 weeks or as dynamic treatment (DT) for 24-72 weeks. The DT duration was based on the time point when log HCV RNA would reach 0 log copies/mL, as estimated by the second-phase decline. The rate of sustained virologic response was 63% for SOC and 54% for DT, but this difference was not significant in multiple regression analysis taking predictive factors such as interleukin-28B genotypes, age and baseline viremia into account (P = 0.45). The mean required treatment time per cured patient was 51 weeks for DT as compared with 58 weeks for SOC (P = 0.22) when given per protocol (n = 95) and was significantly shorter (42 vs 51 weeks) among patients who achieved undetectable HCV RNA (P = 0.01). We conclude that DT was feasible and increased efficiency. The estimated time point for 0 log viral copies/mL is a new and quantitative response variable, which may be used as a complement to the qualitative variable rapid virologic response. The outcome parameter treatment weeks per cured patient could become a useful tool for comparing treatment efficiency also in the era of directly acting antivirals.

Long-term course of Mycobacterium tuberculosis infection in Swedish birth cohorts during the twentieth century.

SETTING: Sweden under transition from high to low tuberculosis (TB) incidence from 1920 to 2009. OBJECTIVE: To correlate estimates of TB infection in birth cohorts with the longitudinal incidence of active TB to assess the long-term risk and time pattern of reactivated TB. DESIGN: Time trend analysis on TB incidence using age-cohort modelling. RESULTS: The overall TB incidence decreased from 700 per 100,000 population in 1920 to 1.4 in 2009 in the Sweden-born population. The estimated disease rate (number of cases divided by the estimated number of infected in 1967), for each birth cohort between 1920 and 1940, was stable on a level between 9.8% and 10.7%. The reactivation rate of latent TB infection (LTBI) was 2% after 1967, when indigenous transmission had disappeared. CONCLUSION: Although approximately 10% of persons with LTBI developed active TB, the majority of cases occurred shortly after infection, and the rates of reactivation declined over time. This indicates extensive spontaneous clearance of LTBI.

Minimal transmission of HIV despite persistently high transmission of hepatitis C virus in a Swedish needle exchange program.

The aim of this study was to examine the prevalence and incidence of HIV and hepatitis B and C (HBV and HCV) among injecting drug users in a Swedish needle exchange programme (NEP) and to identify risk factors for blood-borne transmission. A series of serum samples from NEP participants enrolled from 1997 to 2005 were tested for markers of HIV, HBV and HCV (including retrospective testing for HCV RNA in the last anti-HCV-negative sample from each anti-HCV seroconverter). Prevalence and incidence were correlated with self-reported baseline characteristics. Among 831 participants available for follow-up, one was HIV positive at baseline and two seroconverted to anti-HIV during the follow-up of 2433 HIV-negative person-years [incidence 0.08 per 100 person-years at risk (pyr); compared to 0.0 in a previous assessment of the same NEP covering 1990-1993]. The corresponding values for HBV were 3.4/100 pyr (1990-1993: 11.7) and for HCV 38.3/100 pyr (1990-1993: 27.3). HCV seroconversions occurred mostly during the first year after NEP enrolment. Of the 332 cases testing anti-HCV negative at enrolment, 37 were positive for HCV RNA in the same baseline sample (adjusted HCV incidence 31.5/100 pyr). HCV seroconversion during follow-up was significantly associated with mixed injection use of amphetamine and heroin, and a history of incarceration at baseline. In this NEP setting, HIV prevalence and incidence remained low and HBV incidence declined because of vaccination, but transmission of HCV was persistently high. HCV RNA testing in anti-HCV-negative NEP participants led to more accurate identification of timepoints for transmission.

Acceptance of HIV testing among women attending antenatal care in south-western Uganda: risk factors and reasons for test refusal.

A problem commonly encountered in programs for prevention of mother-to-child-transmission (PMTCT) of HIV in sub-Saharan Africa is low rates of HIV test acceptance among pregnant women. In this study, we examined risk factors and reasons for HIV test refusal among 432 women attending three antenatal care clinics offering PMTCT in urban and semi-urban parts of the Mbarara district, Uganda. Structured interviews were performed following pre-test counselling. Three-hundred-eighty women were included in the study, 323 (85%) of whom accepted HIV testing. In multivariate analysis, testing site (Site A: OR = 1.0; Site B: OR = 3.08; 95%CI: 1.12-8.46; Site C: OR = 5.93; 95%CI: 2.94-11.98), age between 30 and 34 years (<20 years: OR = 1.0; 20-24 years: OR = 1.81; 95%CI: 0.58-5.67; 25-29 years: OR = 2.15; 95%CI: 0.66-6.97; 30-34 years: OR = 3.88; 95%CI: 1.21-13.41), mistrust in reliability of the HIV test (OR = 20.60; 95%CI: 3.24-131.0) and not having been tested for HIV previously (OR = 2.15; 95%CI: 1.02-4.54) were associated with test refusal. Testing sites operating for longer durations had higher rates of acceptance. The most common reasons claimed for test refusal were: lack of access to antiretroviral therapy (ART) for HIV-infected women (88%; n=57), a need to discuss with partner before decision (82%; n=57) and fear of partner's reaction (54%; n=57). Comparison with previous periods showed that the acceptance rate increased with the duration of the program. Our study identified risk factors for HIV test refusal among pregnant women in Uganda and common reasons for not accepting testing. These findings may suggest modifications and improvements in the performance of HIV testing in this and similar populations.

Silver enhancement of Nanogold particles during freeze substitution for electron microscopy.

Recent advances in rapid freezing and fixation by freeze substitution have allowed structural cell biologists to apply these reliable modes of sample preparation to a wide range of specimens and scientific problems. Progress in electron tomography has produced cellular images with resolution approaching 4 nm in 3D, but our ability to localize macromolecules in these well-fixed, well-resolved samples has remained limited. When light fixation and low temperature embedding are employed with appropriate resins, immuno-localizations can recognize antigens at a section's surface, but labelling is therefore confined, not throughout the section's depth. Small, electron-dense markers, like Nanogold(R), will often enter a living cell, serving as reliable tracers for endocytic activity, but these markers are usually too small to be visible in the context of a cell. We have developed a method for the silver enhancement of Nanogold particles that works during freeze substitution in organic solvents at low temperature. Here, we describe the development of this method, based on in vitro tests of reagents and conditions. We then show results from application of the method to an in vivo system, using Nanogold to track the internalization of immunoglobulin by neonatal murine intestinal epithelium, a specific example of receptor-mediated membrane traffic.

Structural insights into antibody-mediated mucosal immunity.

The mucosal regions of the body are responsible for defense against environmental pathogens. Particularly in the lumen of the gut, antibody-mediated immune responses are critical for preventing invasion by pathogens. In this chapter, we review structural studies that have illuminated various aspects of mucosal immunity. Crystal structures of IgA1-Fc and IgA-binding fragments of the polymeric immunoglobulin receptor and Fc alphaRI, combined with models of intact IgA and IgM from solution scattering studies, reveal potential mechanisms for immune exclusion and induction of inflammatory responses. Other recent structures yield insights into bacterial mechanisms for evasion of the host immune response.

A case-control study of transmission routes for GB virus C/hepatitis G virus in Swedish blood donors lacking markers for hepatitis C virus infection.

BACKGROUND AND OBJECTIVES: The transmission routes for GB virus-C (GBV-C)/hepatitis G virus (HGV) in blood donors unexposed to hepatitis C virus (HCV) are unknown. We performed a case-control study of risk factors for GBV-C/HGV exposure in blood donors. MATERIALS AND METHODS: After testing stored sera from 458 HCV-negative blood donors for GBV-C/HGV RNA and GBV-C/HGV E2 antibodies, 66 donors with GBV-C/HGV markers and 125 age- and gender-matched controls were interviewed regarding risk factors for viral transmission. RESULTS: Exposure to GBV-C/HGV was strongly associated with previous treatment for a sexually transmitted disease (odds ratio [OR] 4.6; 95% confidence interval [CI] 2.2-9.8), with multiple sexual partners (OR 2.9; 95% CI 1.4-5.7) and with a past history of endoscopy (OR 7.0; 95% CI 3.0-16.4). CONCLUSIONS: In blood donors with GBV-C/HGV markers, sexual contacts and medical procedures appear to be the main transmission routes.

Molecular competition for NKG2D: H60 and RAE1 compete unequally for NKG2D with dominance of H60.

NKG2D is a potent activating receptor on natural killer cells, T cells, and macrophages. Mouse NKG2D interacts with two cell surface ligands related to class I MHC molecules: RAE1 and H60. We used soluble versions of NKG2D, RAE1, and H60 to characterize their interactions. RAE1 and H60 each bind NKG2D with nanomolar affinities, indicating tighter binding than most cell surface immune interactions, but NKG2D binds to H60 with approximately 25-fold higher affinity than to RAE1. RAE1 and H60 compete directly for occupancy of NKG2D, and, thus, NKG2D can be occupied by only one ligand at a time. The NKG2D-H60 interaction is more temperature dependent and makes greater use of electrostatic interactions than the NKG2D-RAE1 interaction. The distinct thermodynamic profiles provide insights into the different molecular mechanisms of the binding interactions.