Preferential selection of viral escape mutants by CD8+ T cell 'sieving' of SIV reactivation from latency.

HIV rapidly rebounds after interruption of antiretroviral therapy (ART). HIV-specific CD8+ T cells may act to prevent early events in viral reactivation. However, the presence of viral immune escape mutations may limit the effect of CD8+ T cells on viral rebound. Here, we studied the impact of CD8 immune pressure on post-treatment rebound of barcoded SIVmac293M in 14 Mamu-A*01 positive rhesus macaques that initiated ART on day 14, and subsequently underwent two analytic treatment interruptions (ATIs). Rebound following the first ATI (seven months after ART initiation) was dominated by virus that retained the wild-type sequence at the Mamu-A*01 restricted Tat-SL8 epitope. By the end of the two-month treatment interruption, the replicating virus was predominantly escaped at the Tat-SL8 epitope. Animals reinitiated ART for 3 months prior to a second treatment interruption. Time-to-rebound and viral reactivation rate were significantly slower during the second treatment interruption compared to the first. Tat-SL8 escape mutants dominated early rebound during the second treatment interruption, despite the dominance of wild-type virus in the proviral reservoir. Furthermore, the escape mutations detected early in the second treatment interruption were well predicted by those replicating at the end of the first, indicating that escape mutant virus in the second interruption originated from the latent reservoir as opposed to evolving de novo post rebound. SL8-specific CD8+ T cell levels in blood prior to the second interruption were marginally, but significantly, higher (median 0.73% vs 0.60%, p = 0.016). CD8+ T cell depletion approximately 95 days after the second treatment interruption led to the reappearance of wild-type virus. This work suggests that CD8+ T cells can actively suppress the rebound of wild-type virus, leading to the dominance of escape mutant virus after treatment interruption.

Treatment of Multidrug-resistant or Rifampicin-resistant Tuberculosis With an All-oral 9-month Regimen Containing Linezolid or Ethionamide in South Africa: A Retrospective Cohort Study.

BACKGROUND: In 2019, the South African tuberculosis program replaced ethionamide with linezolid as part of an all-oral 9-month regimen. We evaluated treatment outcomes for patients assigned to regimens including linezolid in 2019 and ethionamide in 2017. METHODS: This retrospective cohort study included patients treated for multidrug-resistant/rifampicin-resistant tuberculosis throughout South Africa between 1 January and 31 December 2017 and 1 January to 31 December 2019. The cohort treated with a 9-month regimen containing ethionamide for four months, was compared with a cohort treated with a 9-month regimen containing linezolid for 2 months. The regimens were otherwise identical. Inverse probability weighting of propensity scores was used to adjust for potential confounding. A log-binomial regression model was used to estimate adjusted relative risk (aRR) comparing 24-month outcomes between cohorts including treatment success, death, loss to follow up, and treatment failure. Adverse event data were available for the linezolid cohort. FINDINGS: In total, 817 patients were included in the cohort receiving ethionamide and 4244 in the cohort receiving linezolid. No evidence for a difference was observed between linezolid and ethionamide regimens for treatment success (aRR = 0.96, 95% confidence interval [CI] .91-1.01), death (aRR = 1.01, 95% CI .87-1.17) or treatment failure (aRR = 0.87, 95% CI .44-1.75). Loss to follow-up was more common in the linezolid group, although estimates were imprecise (aRR = 1.22, 95% CI .99-1.50). CONCLUSIONS: No significant differences in treatment success and survival were observed with substitution of linezolid for ethionamide as a part of an all-oral 9-month regimen. Linezolid is an acceptable alternative to ethionamide in this shorter regimen for treatment of multidrug-resistant/rifampicin-resistant tuberculosis.

Correlates of Protection, Thresholds of Protection, and Immunobridging among Persons with SARS-CoV-2 Infection.

Several studies have shown that neutralizing antibody levels correlate with immune protection from COVID-19 and have estimated the relationship between neutralizing antibodies and protection. However, results of these studies vary in terms of estimates of the level of neutralizing antibodies required for protection. By normalizing antibody titers, we found that study results converge on a consistent relationship between antibody levels and protection from COVID-19. This finding can be useful for planning future vaccine use, determining population immunity, and reducing the global effects of the COVID-19 pandemic.

Markers of Immune Activation and Inflammation Are Associated with Higher Levels of Genetically-Intact HIV in HIV-HBV Co-Infected Individuals.

Co-infection with hepatitis B (HBV) and human immunodeficiency virus (HIV) increases overall and liver-related mortality. In order to identify interactions between these two viruses in vivo, full-length HIV proviruses were sequenced from a cohort of HIV-HBV co-infected participants and from a cohort of HIV mono-infected participants recruited from Bangkok, Thailand, both before the initiation of antiretroviral therapy (ART) and after at least 2 years of ART. The co-infected individuals were found to have higher levels of genetically-intact HIV proviruses than did mono-infected individuals pre-therapy. In these co-infected individuals, higher levels of genetically-intact HIV proviruses or proviral genetic-diversity were also associated with higher levels of sCD14 and CXCL10, suggesting that immune activation is linked to more genetically-intact HIV proviruses. Three years of ART decreased the overall level of HIV proviruses, with fewer genetically-intact proviruses being identified in co-infected versus mono-infected individuals. However, ART increased the frequency of certain genetic defects within proviruses and the expansion of identical HIV sequences. IMPORTANCE With the increased availability and efficacy of ART, co-morbidities are now one of the leading causes of death in HIV-positive individuals. One of these co-morbidities is co-infection with HBV. However, co-infections are still relatively understudied, especially in countries where such co-infections are endemic. Furthermore, these countries have different subtypes of HIV circulating than the commonly studied HIV subtype B. We believe that our study serves this understudied niche and provides a novel approach to investigating the impact of HBV co-infection on HIV infection. We examine co-infection at the molecular level in order to investigate indirect associations between the two viruses through their interactions with the immune system. We demonstrate that increased immune inflammation and activation in HBV co-infected individuals is associated with higher HIV viremia and an increased number of genetically-intact HIV proviruses in peripheral blood cells. This leads us to hypothesize that inflammation could be a driver in the increased mortality rate of HIV-HBV co-infected individuals.

Cellular Activation, Differentiation, and Proliferation Influence the Dynamics of Genetically Intact Proviruses Over Time.

Human immunodeficiency virus (HIV) persists in cells despite antiretroviral therapy; however, the influence of cellular mechanisms such as activation, differentiation, and proliferation upon the distribution of proviruses over time is unclear. To address this, we used full-length sequencing to examine proviruses within memory CD4+ T-cell subsets longitudinally in 8 participants. Over time, the odds of identifying a provirus increased in effector and decreased in transitional memory cells. In all subsets, more activated (HLA-DR-expressing) cells contained a higher frequency of intact provirus, as did more differentiated cells such as transitional and effector memory subsets. The proportion of genetically identical proviruses increased over time, indicating that cellular proliferation was maintaining the persistent reservoir; however, the number of genetically identical proviral clusters in each subset was stable. As such, key biological processes of activation, differentiation, and proliferation influence the dynamics of the HIV reservoir and must be considered during the development of any immune intervention.

Landscape of Human Immunodeficiency Virus Neutralization Susceptibilities Across Tissue Reservoirs.

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) sequence diversity and the presence of archived epitope muta-tions in antibody binding sites are a major obstacle for the clinical application of broadly neutralizing antibodies (bNAbs) against HIV-1. Specifically, it is unclear to what degree the viral reservoir is compartmentalized and if virus susceptibility to antibody neutralization differs across tissues. METHODS: The Last Gift cohort enrolled 7 people with HIV diagnosed with a terminal illness and collected antemortem blood and postmortem tissues across 33 anatomical compartments for near full-length env HIV genome sequencing. Using these data, we applied a Bayesian machine-learning model (Markov chain Monte Carlo-support vector machine) that uses HIV-1 envelope sequences and approximated glycan-occupancy information to quantitatively predict the half-maximal inhib-itory concentrations (IC50) of bNAbs, allowing us to map neutralization resistance pattern across tissue reservoirs. RESULTS: Predicted mean susceptibilities across tissues within participants were relatively homogenous, and the susceptibility pattern observed in blood often matched what was predicted for tissues. However, selected tissues, such as the brain, showed ev-idence of compartmentalized viral populations with distinct neutralization susceptibilities in some participants. Additionally, we found substantial heterogeneity in the range of neutralization susceptibilities across tissues within and between indi-viduals, and between bNAbs within individuals (standard deviation of log2(IC50) >3.4). CONCLUSIONS: Blood-based screening methods to determine viral susceptibility to bNAbs might underestimate the presence of resistant viral variants in tissues. The extent to which these resistant viruses are clinically relevant, that is, lead to bNAb therapeutic failure, needs to be further explored.

Psychological predictors of advanced cancer patients' preferences for return of results from comprehensive tumor genomic profiling.

This study assessed the psychological predictors of preferences for return of comprehensive tumor genomic profiling (CTGP) results in patients with advanced cancers, enrolled in the Molecular Screening and Therapeutics Program. Patients completed a questionnaire prior to undergoing CTGP. Of the 1434 who completed a questionnaire, 96% would like to receive results that can guide treatment for their cancer, and preference for receiving this type of result was associated with lower tolerance of uncertainty. Sixty-four percent would like to receive results that cannot guide treatment, and lower tolerance of uncertainty, self-efficacy, and perceived importance were associated with this preference. Fifty-nine percent would like to receive variants of unknown significance, which was associated with lower tolerance of uncertainty, higher self-efficacy, and perceived importance. Eighty-six percent wanted to receive germline results that could inform family risk. This was associated with higher self-efficacy, perceived importance, and perceived susceptibility. Although most patients wanted to receive all types of results, given the differing patient preferences regarding the return of results depending on the utility of the different types of results, it appears critical to safeguard patient understanding of result utility to achieve informed patient choices. This should be accompanied by appropriate consent processes.

Validation of the multidimensional impact of Cancer Risk Assessment Questionnaire to assess impact of waiting for genome sequencing results.

OBJECTIVE: To determine whether the existing Multidimensional Impact of Cancer Risk Assessment (MICRA) scale, which assesses impact of receiving genetic test results on individuals being assessed for cancer risk, can be successfully adapted to cancer patients experiencing prolonged waiting for results of germline genome sequencing (GS). METHODS: Patients previously diagnosed with likely hereditary cancer (n = 250) who were waiting for germline GS results completed questionnaires 3 months after baseline. We adapted the MICRA to measure anxiety associated with waiting for results, and assessed factor structure, internal consistency, test-retest reliability and construct validation. RESULTS: Factor analysis revealed four factors: distress, positive experience, family support and uncertainty. Internal consistency for each sub-scale was high with the values of Cronbach's alpha for the distress, positive experiences, family support and uncertainty sub-scales 0.92, 0.88, 0.92 and 0.87, respectively. Test-retest reliability was poor, with intra-class correlations of 0.53, 0.13, 0.33 and 0.52 for the four factors, respectively. Construct validation showed large correlations between the MICRA distress and uncertainty sub-scale scores and the Impact of Events score intrusion (0.42 and 0.62, respectively) and IES avoidant thinking sub-scales (0.40 and 0.58, respectively) but not the Hospital Anxiety and Depression Scale sub-scales. CONCLUSIONS: The adapted MICRA identified test-related anxiety and uncertainty in a population of cancer patients waiting for germline GS results. Results suggest that the distress and uncertainty sub-scales of the adapted measure are most useful in this context.

Value of whole-genome sequencing to Australian cancer patients and their first-degree relatives participating in a genomic sequencing study.

Genomic Sequencing (GS) to identify high cancer risk will soon enter clinical practice at significant cost to the health system. This study aimed to quantify perceived value of GS to Australian cancer patients and their first-degree relatives participating in a genomic sequencing study, and factors associated with value. Participants were recruited upon consent to the genomics study. Eligible participants (with cancer of likely genetic etiology, or a first-degree relative) completed a questionnaire prior to GS. Willingness to pay was assessed via hypothetical trade-off scenarios of actionable result return rates of 1%, 10%, 20%, 30%, 40% or 50%. Of 348 probands and 213 relatives (92% and 93% response rate), 81% would consistently have GS for as little as a 1% actionable return rate. Participants would pay a median of $1,000 for return rates of at least 20% (probands) or 30% (relatives), and $300 for lower return rates. Probands with common cancers and negative attitudes to uncertainty were more likely to have GS; those with higher education were more willing to pay $1,000 and $3,000 for lower return rates. This study found high interest in, but lower willingness to pay for GS in cancer patients and their first-degree relatives, possibly due to inability to pay. Further research is needed to improve our understanding of how individuals in different risk circumstances, trade-off the risks, harms, and benefits of GS.

Fate mapping reveals the age structure of the peripheral T cell compartment.

Accumulating evidence indicates that the immune system does not develop in a linear fashion, but rather as distinct developmental layers formed from sequential waves of hematopoietic stem cells, each giving rise to unique populations of immune cells at different stages of development. Although recent studies have indicated that conventional CD8+ T cells produced in early life persist into adulthood and exhibit distinct roles during infection, the developmental architecture of the peripheral T cell compartment remains undefined. In this study, we used a mouse model to permanently label CD8+ T cells produced during distinct windows of development and traced their history to generate fate maps of CD8+ T cells produced during different stages of life. We then used mathematical modeling to understand the age structure of the CD8+ T cell compartment across the lifespan. Interestingly, we found that survival rate of CD8+ T cells depends on both the age and developmental origin of the cells. Recently produced cells show an initial rapid decay rate, which slows with age of the animal at which the cells were produced. For cells produced at any age, the rate of decay also slows with the age of the cell. We derive a function to describe this and predict the "age distribution" of the CD8+ T cell pool for animals of any given age. These data provide a quantitative framework for understanding the ontogeny of the CD8+ T cell compartment and help to contextualize age-related changes in the CD8+ T cell response to infection.

Validation of multiplex PCR sequencing assay of SIV.

BACKGROUND: The generation of accurate and reproducible viral sequence data is necessary to understand the diversity present in populations of RNA viruses isolated from clinical samples. While various sequencing methods are available, they often require high quality templates and high viral titer to ensure reliable data. METHODS: We modified a multiplex PCR and sequencing approach to characterize populations of simian immunodeficiency virus (SIV) isolated from nonhuman primates. We chose this approach with the aim of reducing the number of required input templates while maintaining fidelity and sensitivity. We conducted replicate sequencing experiments using different numbers of quantified viral RNA (vRNA) or viral cDNA as input material. We performed assays with clonal SIVmac239 to detect false positives, and we mixed SIVmac239 and a variant with 24 point mutations (SIVmac239-24X) to measure variant detection sensitivity. RESULTS: We found that utilizing a starting material of quantified viral cDNA templates had a lower rate of false positives and increased reproducibility when compared to that of quantified vRNA templates. This study identifies the importance of rigorously validating deep sequencing methods and including replicate samples when using a new method to characterize low frequency variants in a population with a small number of templates. CONCLUSIONS: Because the need to generate reproducible and accurate sequencing data from diverse viruses from low titer samples, we modified a multiplex PCR and sequencing approach to characterize SIV from populations from non-human primates. We found that increasing starting template numbers increased the reproducibility and decreased the number of false positives identified, and this was further seen when cDNA was used as a starting material. Ultimately, we highlight the importance of vigorously validating methods to prevent overinterpretation of low frequency variants in a sample.

Longitudinal patterns in fear of cancer progression in patients with rare, advanced cancers undergoing comprehensive tumour genomic profiling.

INTRODUCTION: Fear of cancer progression (FCP) impacts quality of life and is a prevalent unmet need in patients diagnosed with advanced cancer, particularly as treatment options are reduced. We aimed to identify longitudinal patterns in FCP over 6 months in patients with advanced cancer receiving comprehensive tumour genomic profiling (CTGP) results, and their correlates. METHODS: Patients with pathologically confirmed metastatic disease (∼70% rare cancers) receiving or post their last line of standard therapy completed questionnaires at T0 (prior to CTGP), T1 (immediately post CTGP results) and T2 (2 months later). RESULTS: High stable (N = 52; 7.3%) and low/moderate stable (N = 56; 7.8%) FCP patterns over time typified the largest participant groups (N = 721). Those with an immediately actionable variant versus a non-actionable variant (p = 0.045), with higher FCP (p < 0.001), and lower Functional Assessment of Chronic Illness Therapy-Spiritual Well-being (FACIT-Sp) scores (p = 0.006) at T0, had higher FCP at T1. Those with higher FCP at T0 (p < 0.001) and at T1 (p < 0.001), lower FACIT-Sp scores at T1 (p = 0.001), lower education (p = 0.031) and female gender (p = 0.027) had higher FCP at T2. DISCUSSION: Routine screening for psychological/spiritual characteristics in those about to undergo CTGP may help to identify patients who may benefit from closer monitoring and provision of psychosocial support. Future studies should explore interventions to best address FCP in this vulnerable group, as interventions assessed to date have almost all addressed patients with curative cancers or newly diagnosed advanced disease.

Advanced cancer patient preferences for receiving molecular profiling results.

OBJECTIVE: This study aimed to discern preferences for receiving somatic molecular profiling (MP) results in cancer patients who have given consent to undergo testing. METHODS: We conducted a mixed-methods study to explore patients' views on which MP results they would like to receive and why. Advanced cancer patients (n = 1299) completed questionnaires after giving consent to participate in a parent genomics study and undergoing MP. A subset of patients (n = 20) participated in qualitative interviews. RESULTS: Almost all (96%) participants were interested in receiving results which would direct cancer treatment (ie, were actionable). A smaller majority wanted to access results which were not actionable (64%) or were variants of unknown significance (60%). Most (86%) were interested in finding out about germline findings, though not as a priority. Themes identified in interview data were: (a) Cancer is the focus; (b) Trust in clinicians; and (c) Respect for a right not to know. CONCLUSIONS: The majority of advanced cancer patients undergoing MP prioritised results which would lead to treatment options. They trusted their oncologists to help them navigate the results return process. While there was interest in knowing about other results, this was a lesser priority. Nevertheless, given high levels of interest in receiving all results, ethical aspects of not providing uninformative results requires further research, including a consideration of patient rationales for desiring this information and what health professionals can and should do to support patients in the absence of meaningful information being available.

Meta-transcriptomics reveals a diverse antibiotic resistance gene pool in avian microbiomes.

BACKGROUND: Antibiotic resistance is rendering common bacterial infections untreatable. Wildlife can incorporate and disperse antibiotic-resistant bacteria in the environment, such as water systems, which in turn serve as reservoirs of resistance genes for human pathogens. Anthropogenic activity may contribute to the spread of bacterial resistance cycling through natural environments, including through the release of human waste, as sewage treatment only partially removes antibiotic-resistant bacteria. However, empirical data supporting these effects are currently limited. Here we used bulk RNA-sequencing (meta-transcriptomics) to assess the diversity and expression levels of functionally viable resistance genes in the gut microbiome of birds with aquatic habits in diverse locations. RESULTS: We found antibiotic resistance genes in birds from all localities, from penguins in Antarctica to ducks in a wastewater treatment plant in Australia. Comparative analysis revealed that birds feeding at the wastewater treatment plant carried the greatest resistance gene burden, including genes typically associated with multidrug resistance plasmids as the aac(6)-Ib-cr gene. Differences in resistance gene burden also reflected aspects of bird ecology, taxonomy, and microbial function. Notably, ducks, which feed by dabbling, carried a higher abundance and diversity of resistance genes than turnstones, avocets, and penguins, which usually prey on more pristine waters. CONCLUSIONS: These transcriptome data suggest that human waste, even if it undergoes treatment, might contribute to the spread of antibiotic resistance genes to the wild. Differences in microbiome functioning across different bird lineages may also play a role in the antibiotic resistance burden carried by wild birds. In summary, we reveal the complex factors explaining the distribution of resistance genes and their exchange routes between humans and wildlife, and show that meta-transcriptomics is a valuable tool to access functional resistance genes in whole microbial communities.

Does functional assessment predict everyday visual functioning? Visual function testing and quality of life in mild/moderate age-related macular degeneration.

PURPOSE: To prospectively assess correlations between self-reported vision-related quality of life (VR-QoL) and clinical functional assessments in mild/moderate age-related macular degeneration (AMD). METHODS: Cross-sectional analysis of 64 participants with bilateral mild/moderate AMD. Microperimetry (MP), flicker perimetry (FP), multifocal electroretinogram (mfERG) findings, best-corrected visual acuity (BCVA) and the National Eye Institute Visual-Function Questionnaire-25 (NEI VFQ-25) were assessed for correlation between clinical testing results and NEI VFQ-25 findings. RESULTS: MP findings in the better eye were weakly correlated with NEI VFQ-25 subscales for colour, general, near and distance vision (p < 0.05 and R2 < 0.3 for all). FP findings and mfERG response density were not correlated with any subscale, apart from mfERG ring 1 response density and general health (p < 0.05, R2 = 0.41). mfERG latency was weakly correlated with general vision in the better eye in rings 2 and 4 (p < 0.05, R2 < 0.2). CONCLUSION: Functional assessment in mild/moderate AMD is at best, weakly correlated with patient-reported VR-QoL. Despite the growing awareness of the importance of VR-QoL outcomes in improving patient outcomes and satisfaction, surrogate markers of these outcomes remain elusive, and testing of VR-QoL in regular clinical settings remains difficult.

A Simple Method to Detect Candidate Overlapping Genes in Viruses Using Single Genome Sequences.

Overlapping genes in viruses maximize the coding capacity of their genomes and allow the generation of new genes without major increases in genome size. Despite their importance, the evolution and function of overlapping genes are often not well understood, in part due to difficulties in their detection. In addition, most bioinformatic approaches for the detection of overlapping genes require the comparison of multiple genome sequences that may not be available in metagenomic surveys of virus biodiversity. We introduce a simple new method for identifying candidate functional overlapping genes using single virus genome sequences. Our method uses randomization tests to estimate the expected length of open reading frames and then identifies overlapping open reading frames that significantly exceed this length and are thus predicted to be functional. We applied this method to 2548 reference RNA virus genomes and find that it has both high sensitivity and low false discovery for genes that overlap by at least 50 nucleotides. Notably, this analysis provided evidence for 29 previously undiscovered functional overlapping genes, some of which are coded in the antisense direction suggesting there are limitations in our current understanding of RNA virus replication.

Interaction between maternally derived antibodies and heterogeneity in exposure combined to determine time-to-first Plasmodium falciparum infection in Kenyan infants.

BACKGROUND: Studies of the association between the level of anti-malarial antibody and protection from malaria infection can yield conflicting results if they fail to take into account differences in the malaria transmission rate. This can occur because high malaria exposure may drive high antibody responses, leading to an apparent positive association between immune response and infection rate. The neonatal period provides a unique window to study the protective effects of antibodies, because waning maternally-derived antibodies lead to different levels of protection with time. METHODS: This study uses data from two well-defined infant cohorts in Western Kenya with different burdens of malaria transmission. Survival models were used to assess how the magnitude of maternally derived malaria-specific IgG antibody (to 24 malaria antigens measured using Luminex beads) affected the time-to-first Plasmodium falciparum infection (detected by PCR). In addition, mathematical models were used to assess how the frequency of malaria infection varied between the cohorts with different exposure levels. RESULTS: Despite differences in underlying malaria incidence in the two regions, there was no difference in time-to-first malaria infection between the cohorts. However, there was a significant period of protection observed in children with high initial MSP1 (42 kDa fragment)-specific antibody levels, but this protection was not observed in children with low antibody levels. Children from the high transmission cohort had both longer initial periods of protection from malaria (attributable to higher initial antibody levels), but more rapid time-to-first-infection once malaria specific maternal antibodies declined below protective levels (attributable to higher exposure rates). CONCLUSION: This study demonstrates the complex interaction between passive (maternally-derived) immunity and the degree of malaria exposure in infants. Children from regions of high malaria transmission had higher levels of maternally-derived antibodies in early life, which led to a significant protection for several months. However, once this immunity waned, the underlying higher frequency of infection was revealed. A better understanding of the interaction between malaria exposure, immunity, and transmission risk will assist in identifying protective immune responses in P. falciparum infection.

Saffron therapy for the treatment of mild/moderate age-related macular degeneration: a randomised clinical trial.

PURPOSE: To assess the efficacy and safety of oral saffron, a natural antioxidant, in treating mild/moderate age-related macular degeneration (AMD). METHODS: Randomised, double-blinded, placebo-controlled crossover trial of 100 adults (> 50 years) with mild/moderate AMD and vision > 20/70 Snellen equivalent in at least one eye. Exclusion criteria included confounding visual lesions, or significant gastrointestinal disease impairing absorption. Participants were given oral saffron supplementation (20 mg/day) for 3 months or placebo for 3 months, followed by crossover for 3 months. Participants already consuming Age-Related Eye Diseases Study (AREDS) supplements or equivalent maintained these. Primary outcomes included changes in best-corrected visual acuity (BCVA) and changes in multifocal electroretinogram (mfERG) response density and latency. Secondary outcomes included safety outcomes and changes in mfERG and BCVA amongst participants on AREDS supplements. RESULTS: Mean BCVA improved 0.69 letters (p = 0.001) and mean-pooled mfERG latency reduced 0.17 ms (p = 0.04) on saffron compared to placebo. Amongst participants on AREDS supplements, mean BCVA improved 0.73 letters p = 0.006) and mean-pooled mfERG response density improved 2.8% (p = 0.038). There was no significant difference in adverse event occurrence (p > 0.10). CONCLUSION: Saffron supplementation modestly improved visual function in participants with AMD, including those using AREDS supplements. Given the chronic nature of AMD, longer-term supplementation may produce greater benefits.

AFLIBERCEPT FOR PERSISTENT DIABETIC MACULAR EDEMA: Forty-Eight-Week Outcomes.

PURPOSE: To evaluate functional and anatomical outcomes after a switch from intravitreal bevacizumab to aflibercept in patients with persistent diabetic macular edema. METHODS: Prospective, single-arm, open-label clinical trial of patients with persistent diabetic macular edema, despite previous treatment with bevacizumab. Five loading doses of intravitreal aflibercept were administered every 4 weeks with subsequent injections administered every 8 weeks. Patients were reviewed every 4 weeks, and best-corrected visual acuity and central macular thickness were recorded. Primary outcome measures included change in central macular thickness and best-corrected visual acuity at week 48 compared with baseline. Paired t-tests were used to assess change between baseline and follow-up visits. RESULTS: At baseline, 43 eyes from 43 patients were recruited with a median (interquartile range) of 12 (7-24) previous intravitreal anti-vascular endothelial growth factor injections over a period of 18 (8-34) months. Mean ± SD central macular thickness reduced by 59 ± 114 µm (P = 0.002), and best-corrected visual acuity improved by 3.9 ± 7.0 letters (P = 0.001) after 48 weeks in the 41 patients who completed the trial. Best-corrected visual acuity improvements were more marked in patients who gained ≥5 letters after the first injection (8.9 ± 5.7 vs. 1.8 ± 6.5 letter gain at 48 weeks, P = 0.002), a difference which remained significant after regression analysis with baseline best-corrected visual acuity . Vision gains and central macular thickness reduction were similar in 9 fellow eyes eligible for inclusion being concurrently treated for diabetic macular edema with bevacizumab. CONCLUSION: Intravitreal aflibercept was effective in improving anatomical and visual outcomes among patients with an incomplete response to intravitreal bevacizumab with 48 weeks of follow-up. Patients with a good early response subsequent to switching had a better improvement in vision at 48 weeks.

No detectable effect of Wolbachia wMel on the prevalence and abundance of the RNA virome of Drosophila melanogaster.

Wolbachia is an endosymbiotic bacterium that can block viral infections in arthropods, generating interest in its potential to control the spread of mosquito-borne disease. Drosophila melanogaster is model organism for Wolbachia infection, and the wMel strain of Wolbachia can improve host survival following viral infection. However, it is unclear whether wMel induces anti-viral blocking against the broader native virome of D. melanogaster, or whether the major effect of Wolbachia is a reduction in viral abundance rather than viral clearance. We examined the effect of Wolbachia on viral abundance by comparing the total transcriptome of wMel-positive and wMel-negative D. melanogaster populations sampled from six locations in Australia. In addition, we examined the impact of wMel on individual flies by obtaining transcriptome data from 20 wMel-positive and 20 wMel-negative D. melanogaster from the location (Melbourne) with highest density of wMel. These data revealed high viral abundance in both Wolbachia-positive and -negative populations and individuals. Notably, none of the viral species identified, representing RNA viruses from at least nine families/floating genera, showed evidence of protection by wMel. Although the viral loads of picorna-like viruses are reduced by wMel under experimental conditions, we observed no such effect here. These data show that D. melanogaster can harbour abundant RNA viruses regardless of its Wolbachia status and imply that the interaction between Wolbachia and viruses in nature is more complex than simple blocking.