Molecular markers of artemisinin resistance during falciparum malaria elimination in Eastern Myanmar.

BACKGROUND: Artemisinin resistance in Plasmodium falciparum threatens global malaria elimination efforts. To contain and then eliminate artemisinin resistance in Eastern Myanmar a network of community-based malaria posts was instituted and targeted mass drug administration (MDA) with dihydroartemisinin-piperaquine (three rounds at monthly intervals) was conducted. The prevalence of artemisinin resistance during the elimination campaign (2013-2019) was characterized. METHODS: Throughout the six-year campaign Plasmodium falciparum positive blood samples from symptomatic patients and from cross-sectional surveys were genotyped for mutations in kelch-13-a molecular marker of artemisinin resistance. RESULT: The program resulted in near elimination of falciparum malaria. Of 5162 P. falciparum positive blood samples genotyped, 3281 (63.6%) had K13 mutations. The prevalence of K13 mutations was 73.9% in 2013 and 64.4% in 2019. Overall, there was a small but significant decline in the proportion of K13 mutants (p < 0.001). In the MDA villages there was no significant change in the K13 proportions before and after MDA. The distribution of different K13 mutations changed substantially; F446I and P441L mutations increased in both MDA and non-MDA villages, while most other K13 mutations decreased. The proportion of C580Y mutations fell from 9.2% (43/467) before MDA to 2.3% (19/813) after MDA (p < 0.001). Similar changes occurred in the 487 villages where MDA was not conducted. CONCLUSION: The malaria elimination program in Kayin state, eastern Myanmar, led to a substantial reduction in falciparum malaria. Despite the intense use of artemisinin-based combination therapies, both in treatment and MDA, this did not select for artemisinin resistance.

A Review of the Current State and Future Directions for Management of Scalp and Facial Vascular Malformations.

Vascular malformations are structural abnormalities that are thought to result from errors in vasculogenesis and angiogenesis during embryogenesis. Vascular malformations of the scalp present unique management challenges due to aesthetic and functional implications. This review examines the pathophysiology, clinical presentation, and management techniques for six common types of vascular malformations of the face and scalp : infantile hemangioma, capillary malformations, venous malformations, lymphatic malformations, arteriovenous malformations, and arteriovenous fistulas. These lesions range from common to rare, and have very different natural histories and management paradigms. There has been increasing understanding of the molecular pathways that are altered in association with these vascular lesions and these molecular targets may represent novel strategies of treating lesions that have historically been approached from a structural perspective only.

Canadian Network for Mood and Anxiety Treatments (CANMAT) 2023 Update on Clinical Guidelines for Management of Major Depressive Disorder in Adults: Réseau canadien pour les traitements de l'humeur et de l'anxiété (CANMAT) 2023 : Mise à jour des lignes directrices cliniques pour la prise en charge du trouble dépressif majeur chez les adultes.

BACKGROUND: The Canadian Network for Mood and Anxiety Treatments (CANMAT) last published clinical guidelines for the management of major depressive disorder (MDD) in 2016. Owing to advances in the field, an update was needed to incorporate new evidence and provide new and revised recommendations for the assessment and management of MDD in adults. METHODS: CANMAT convened a guidelines editorial group comprised of academic clinicians and patient partners. A systematic literature review was conducted, focusing on systematic reviews and meta-analyses published since the 2016 guidelines. Recommendations were organized by lines of treatment, which were informed by CANMAT-defined levels of evidence and supplemented by clinical support (consisting of expert consensus on safety, tolerability, and feasibility). Drafts were revised based on review by patient partners, expert peer review, and a defined expert consensus process. RESULTS: The updated guidelines comprise eight primary topics, in a question-and-answer format, that map a patient care journey from assessment to selection of evidence-based treatments, prevention of recurrence, and strategies for inadequate response. The guidelines adopt a personalized care approach that emphasizes shared decision-making that reflects the values, preferences, and treatment history of the patient with MDD. Tables provide new and updated recommendations for psychological, pharmacological, lifestyle, complementary and alternative medicine, digital health, and neuromodulation treatments. Caveats and limitations of the evidence are highlighted. CONCLUSIONS: The CANMAT 2023 updated guidelines provide evidence-informed recommendations for the management of MDD, in a clinician-friendly format. These updated guidelines emphasize a collaborative, personalized, and systematic management approach that will help optimize outcomes for adults with MDD.

Summer alcohol-related emergency department workload and occupancy in Australasia 2019-2022.

OBJECTIVE: Alcohol is a major public health issue and the ACEM funds regular 'snapshot' surveys of the prevalence of alcohol-related presentations in EDs. The present study uses these data to investigate ED occupancy and alcohol- and methamphetamine-related presentations at the time of the COVID-19 pandemic. METHODS: Survey-based point prevalence study of EDs in Australia and New Zealand conducted at 02:00 hours local time on the Saturday of the weekend before Christmas in 2019-2022. Primary outcomes were ED occupancy, the number of alcohol-related presentations and methamphetamine-related presentations in each ED at the time of survey. RESULTS: Seventy eight of a possible 152 hospitals answered all four surveys (51%, 95% confidence interval 43-59, individual yearly response rates ranged from 70.5% to 83.3%). The mean number of alcohol-related presentations in EDs at the snapshot time was 4.2 (95% confidence interval 3.2-5.2) in the 2019 survey and 3.8 (3.1-4.6) in 2022 with no significant variation over time. There was also no change in methamphetamine-related presentations which occurred at a lower level. There was a major increase in reported total ED occupancy - from 31.4 to 43.5 in Australia (P < 0.0001, paired t test) and from 22.8 to 38.7 in New Zealand (P = 0.0001). Subgroup analysis showed that both the number being treated and the number waiting to be seen increased, with little change in the number in observation units. CONCLUSIONS: The present study demonstrates that the COVID-19 pandemic did not affect summer alcohol-related ED presentations in Australasia but was associated with an unsustainable increase in ED crowding.

Effect of Routine Child Physical Abuse Screening Tool on Emergency Department Efficiency.

OBJECTIVES: Physical abuse is a significant cause of morbidity and mortality for children. Routine screening by emergency nurses has been proposed to improve recognition, but the effect on emergency department (ED) workflow has not yet been assessed. We sought to evaluate the feasibility of routine screening and its effect on length of stay in a network of general EDs. METHODS: A 2-question child physical abuse screening tool was deployed for children <6 years old who presented for care in a system of 27 general EDs. Data were compared for the 6 months before and after screening was deployed (4/1/2019-10/2/2019 vs 10/3/2019-3/31/2020). The main outcome was ED length of stay in minutes. RESULTS: There were 14,133 eligible visits in the prescreening period and 16,993 in the screening period. Screening was completed for 13,404 visits (78.9%), with 116 (0.7%) screening positive. The mean ED length of stay was not significantly different in the prescreening (95.9 minutes) and screening periods (95.2 minutes; difference, 0.7 minutes; 95% CI, -1.5, 2.8). Among those who screened positive, 29% were reported to child protective services. On multivariable analysis, implementation of the screening tool did not impact overall ED length of stay. There were no significant differences in resource utilization between the prescreening and screening periods. CONCLUSIONS: Routine screening identifies children at high risk of physical abuse without increasing ED length of stay or resource utilization. Next steps will include determining rates of subsequent serious physical abuse in children with or without routine screening.

Genomic analyses of a new baculovirus isolated from the wheat armyworm, Mythimna sequax (Franclemont) (Lepidoptera: Noctuidae).

We report the genomic analysis of a novel alphabaculovirus, Mythimna sequax nucleopolyhedrovirus isolate CNPSo-98 (MyseNPV-CNPSo-98), obtained from cadavers of the winter crop pest, Mythimna sequax Franclemont (Lepidoptera: Noctuidae). The insects were collected from rice fields in Southern Brazil in the 1980's and belongs to the 'EMBRAPA-Soja' Virus Collection. High-throughput sequencing reads of DNA from MyseNPV occlusion bodies and assembly of the data yielded an AT-rich circular genome contig of 148,403 bp in length with 163 annotated opening reading frames (ORFs) and four homologous regions (hrs). Phylogenetic inference based on baculovirus core protein sequence alignments indicated that MyseNPV-CNPSo-98 is a member of Alphabaculovirus genus that clustered with other group II noctuid-infecting baculoviruses, including viruses isolated from Helicoverpa armigera and Mamestra spp. The genomes of the clade share strict collinearity and high pairwise nucleotide identity, with a common set of 149 genes, evolving under negative selection, except a bro gene. Branch lengths and Kimura-2-parameter pairwise nucleotide distances indicated that MyseNPV-CNPSo-98 represents a distinct lineage that cannot be classified in any of the currently listed species in the genus.

On-treatment analysis of torsemide versus furosemide for patients hospitalized for heart failure: A post-hoc analysis of TRANSFORM-HF.

AIM: The TRANSFORM-HF trial demonstrated no significant outcome differences between torsemide and furosemide following hospitalization for heart failure (HF), but may have been impacted by non-adherence to the randomized diuretic. The current study sought to determine the treatment effect of torsemide versus furosemide using an on-treatment analysis inclusive of all randomized patients except those confirmed non-adherent to study diuretic. METHODS AND RESULTS: TRANSFORM-HF was an open-label, pragmatic randomized trial of 2859 patients hospitalized for HF from June 2018 through March 2022. Patients were randomized to a loop diuretic strategy of torsemide versus furosemide with investigator-selected dosage. This post-hoc on-treatment analysis included all patients alive with either known or unknown diuretic status, and excluded patients confirmed to be non-adherent to study diuretic. This modified on-treatment definition was applied separately at time of hospital discharge and 30-day follow-up. All-cause mortality and hospitalization outcomes were assessed over 12 months. Overall, 2570 (89.9%) and 2374 (83.0%) patients were included in on-treatment analyses at discharge and 30-day follow-up, respectively. There was no significant difference in all-cause mortality between torsemide and furosemide in patients on-treatment at discharge (17.5% vs. 17.8%; hazard ratio [HR] 1.01 [95% confidence interval [CI] 0.83-1.22], p = 0.96) and at 30-day follow-up (14.5% vs. 15.0%; HR 1.02 [95% CI 0.81-1.27], p = 0.90). All-cause mortality or all-cause hospitalization was similar between torsemide and furosemide in patients who were on-treatment at discharge (58.3% vs. 61.3%; HR 0.92 [95% CI 0.82-1.03]) and 30-day follow-up (60.9% vs. 64.4%; HR 0.93 [95% CI 0.82-1.05]). In patients who were on-treatment at 30-day follow-up, there were 677 total hospitalizations in the torsemide group and 686 total hospitalizations in the furosemide group (rate ratio 0.99 [95% CI 0.86-1.14], p = 0.87). CONCLUSIONS: In TRANSFORM-HF, a post-hoc on-treatment analysis did not meaningfully differ from the original trial results. Among those deemed compliant with the assigned diuretic, there remained no significant difference in mortality or hospitalization after HF hospitalization with a strategy of torsemide versus furosemide. CLINICAL TRAIL REGISTRATION: ClinicalTrials.gov Identifier: NCT03296813.

Dust sprinkling as an effective method for infecting layer chickens with wild-type Salmonella Typhimurium and changes in host gut microbiota.

Role of dust in Salmonella transmission on chicken farms is not well characterised. Salmonella Typhimurium (ST) infection of commercial layer chickens was investigated using a novel sprinkling method of chicken dust spiked with ST and the uptake compared to a conventional oral infection. While both inoculation methods resulted in colonisation of the intestines, the Salmonella load in liver samples was significantly higher at 7 dpi after exposing chicks to sprinkled dust compared to the oral infection group. Infection of chickens using the sprinkling method at a range of doses showed a threshold for colonisation of the gut and organs as low as 1000 CFU/g of dust. Caecal content microbiota analysis post-challenge showed that the profiles of chickens infected by the sprinkling and oral routes were not significantly different; however, both challenges induced differences when compared to the uninfected negative controls. Overall, the study showed that dust sprinkling was an effective way to experimentally colonise chickens with Salmonella and alter the gut microbiota than oral gavage at levels as low as 1000 CFU/g dust. This infection model mimics the field scenario of Salmonella infection in poultry sheds. The model can be used for future challenge studies for effective Salmonella control.

Role of Gut Microbiome in Neoadjuvant Chemotherapy Response in Urothelial Carcinoma: A Multi-Institutional Prospective Cohort Evaluation.

Neoadjuvant chemotherapy (NAC) is linked with clinical advantages in urothelial carcinoma for patients with muscle-invasive bladder cancer (MIBC). Despite comprehensive research into the influence of tumor mutation expression profiles and clinicopathological factors on chemotherapy response, the role of the gut microbiome (GM) in bladder cancer(BC) chemotherapy response remains poorly understood. This study examines the variance in the gut microbiome(GM) of BC patients compared to healthy adults, and investigates GM compositional differences between patients who respond to chemotherapy versus those who exhibit residual disease. Our study reveals distinct clustering, effectively separating the BC and healthy cohorts. However, no significant differences were observed between chemotherapy responders and non-responders within community subgroups. Machine Learning models based on responder status outperformed clinical variables in predicting complete response (AUC 0.88 vs AUC 0.50), although no single microbial species emerged as a fully reliable biomarker. The evaluation of short-chain fatty acid (SCFA) concentration in blood and stool revealed no correlation with responder status. Still, SCFA analysis showed a higher abundance of Akkermansia (rs = 0.51, p = 0.017) and Clostridia (rs = 0.52, p = 0.018), which correlated with increased levels of detectable fecal isobutyric acid. Higher levels of fecal Lactobacillus (rs = 0.49, p=0.02) and Enterobacteriaceae (rs = 0.52, p < 0.03) correlated with increased fecal propionic acid. In conclusion, our study constitutes the first large-scale, multi-center assessment of GM composition, suggesting the potential for a complex microbial signature to predict patients more likely to respond to NAC based on multiple taxa.

The link between insurance and blood pressure control in U.S. stroke survivors.

BACKGROUND: After a stroke, poorly controlled blood pressure (BP) is associated with a higher risk of recurrent vascular events. Despite the importance of controlling BP to avert recurrent vascular events, fewer than half of stroke survivors in the United States achieve BP control. It is unclear to what extent insurance status affects BP levels after stroke. METHODS: We assessed BP control among adults with a history of stroke who participated in the National Health and Nutrition Examination Surveys from 1999 through 2016. The relationship between insurance type and BP level (low normal: <120/80 mmHg and normal: <140/90 mmHg) were evaluated using logistic regression before and after adjusting for sociodemographic characteristics and medical comorbidities for those <65 years and ≥ 65 years. RESULTS: Among 1646 adult stroke survivors (weighted n = 5,586,417), 30% had BP in the low normal range while 64% had BP in the normal range. Among 613 stroke survivors <65 years (weighted n = 2,396,980), only those with other government insurance (CHAMPVA, CHAMPUS/TRICARE) had better BP control than the uninsured (adjusted HR 2.68, 95% CI 0.99-7.25). Among 1033 participants ≥65 years (weighted n = 3,189,437), those with private insurance plus Medicare trended toward better normal BP compared to Medicare alone (adjusted HR 1.34, 95% CI 0.94-1.90). CONCLUSIONS: Only stroke survivors with CHAMPVA, CHAMPUS/TRICARE government insurance in the United States have lower odds of controlled BP compared to no insurance among those <65 years. Insurance alone does not improve BP control among stroke survivors.

An NMR crystallographic characterisation of solid (+)-usnic acid.

We use a combination of one- and two-dimensional solid-state nuclear magnetic resonance (NMR) spectroscopy and density functional theory (DFT) calculations to obtain a full assignment of the 1H and 13C signals for solid (+)-usnic acid, which contains two molecules in the asymmetric unit. By combining through-space 1H-1H correlation data with computation it is possible to assign signals not just to the same molecules (relative assignment) but to assign the signals to specific crystallographic molecules (absolute assignment). Variable-temperature measurements reveal that there is some variation in many of the 13C chemical shifts with temperature, likely arising from varying populations of different tautomeric forms of the molecule. The NMR spectrum of crystalline (+)-usnic acid is then compared with that of ground Usnea dasopoga lichen (the source material of the usnic acid). The abundance of usnic acid is so great in the lichen that this natural product can be observed directly in the NMR spectrum without further purification. This natural sample of usnic acid appears to have the same crystalline form as that in the pure commercial sample.

Effects of repetitive transcranial magnetic stimulation on individual variability of resting-state functional connectivity in major depressive disorder.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for major depressive disorder (MDD), but substantial heterogeneity in outcomes remains. We examined a potential mechanism of action of rTMS to normalize individual variability in resting-state functional connectivity (rs-fc) before and after a course of treatment. METHODS: Variability in rs-fc was examined in healthy controls (baseline) and individuals with MDD (baseline and after 4-6 weeks of rTMS). Seed-based connectivity was calculated to 4 regions associated with MDD: left dorsolateral prefrontal cortex (DLPFC), right subgenual anterior cingulate cortex (sgACC), bilateral insula, and bilateral precuneus. Individual variability was quantified for each region by calculating the mean correlational distance of connectivity maps relative to the healthy controls; a higher variability score indicated a more atypical/idiosyncratic connectivity pattern. RESULTS: We included data from 66 healthy controls and 252 individuals with MDD in our analyses. Patients with MDD did not show significant differences in baseline variability of rs-fc compared with controls. Treatment with rTMS increased rs-fc variability from the right sgACC and precuneus, but the increased variability was not associated with clinical outcomes. Interestingly, higher baseline variability of the right sgACC was significantly associated with less clinical improvement (p = 0.037, uncorrected; did not survive false discovery rate correction).Limitations: The linear model was constructed separately for each region of interest. CONCLUSION: This was, to our knowledge, the first study to examine individual variability of rs-fc related to rTMS in individuals with MDD. In contrast to our hypotheses, we found that rTMS increased the individual variability of rs-fc. Our results suggest that individual variability of the right sgACC and bilateral precuneus connectivity may be a potential mechanism of rTMS.

Muesli Intake May Protect Against Coronary Artery Disease: Mendelian Randomization on 13 Dietary Traits.

BACKGROUND: Diet is a key modifiable risk factor of coronary artery disease (CAD). However, the causal effects of specific dietary traits on CAD risk remain unclear. With the expansion of dietary data in population biobanks, Mendelian randomization (MR) could help enable the efficient estimation of causality in diet-disease associations. OBJECTIVES: The primary goal was to test causality for 13 common dietary traits on CAD risk using a systematic 2-sample MR framework. A secondary goal was to identify plasma metabolites mediating diet-CAD associations suspected to be causal. METHODS: Cross-sectional genetic and dietary data on up to 420,531 UK Biobank and 184,305 CARDIoGRAMplusC4D individuals of European ancestry were used in 2-sample MR. The primary analysis used fixed effect inverse-variance weighted regression, while sensitivity analyses used weighted median estimation, MR-Egger regression, and MR-Pleiotropy Residual Sum and Outlier. RESULTS: Genetic variants serving as proxies for muesli intake were negatively associated with CAD risk (OR: 0.74; 95% CI: 0.65-0.84; P = 5.385 × 10-4). Sensitivity analyses using weighted median estimation supported this with a significant association in the same direction. Additionally, we identified higher plasma acetate levels as a potential mediator (OR: 0.03; 95% CI: 0.01-0.12; P = 1.15 × 10-4). CONCLUSIONS: Muesli, a mixture of oats, seeds, nuts, dried fruit, and milk, may causally reduce CAD risk. Circulating levels of acetate, a gut microbiota-derived short-chain fatty acid, could be mediating its cardioprotective effects. These findings highlight the role of gut flora in cardiovascular health and help prioritize randomized trials on dietary interventions for CAD.

Intermittent fasting influences immunity and metabolism.

Intermittent fasting (IF) modifies cell- and tissue-specific immunometabolic responses that dictate metabolic flexibility and inflammation during obesity and type 2 diabetes (T2D). Fasting forces periods of metabolic flexibility and necessitates increased use of different substrates. IF can lower metabolic inflammation and improve glucose metabolism without lowering obesity and can influence time-dependent, compartmentalized changes in immunity. Liver, adipose tissue, skeletal muscle, and immune cells communicate to relay metabolic and immune signals during fasting. Here we review the connections between metabolic and immune cells to explain the divergent effects of IF compared with classic caloric restriction (CR) strategies. We also explore how the immunometabolism of metabolic diseases dictates certain IF outcomes, where the gut microbiota triggers changes in immunity and metabolism during fasting.

The intrinsic substrate specificity of the human tyrosine kinome.

Phosphorylation of proteins on tyrosine (Tyr) residues evolved in metazoan organisms as a mechanism of coordinating tissue growth1. Multicellular eukaryotes typically have more than 50 distinct protein Tyr kinases that catalyse the phosphorylation of thousands of Tyr residues throughout the proteome1-3. How a given Tyr kinase can phosphorylate a specific subset of proteins at unique Tyr sites is only partially understood4-7. Here we used combinatorial peptide arrays to profile the substrate sequence specificity of all human Tyr kinases. Globally, the Tyr kinases demonstrate considerable diversity in optimal patterns of residues surrounding the site of phosphorylation, revealing the functional organization of the human Tyr kinome by substrate motif preference. Using this information, Tyr kinases that are most compatible with phosphorylating any Tyr site can be identified. Analysis of mass spectrometry phosphoproteomic datasets using this compendium of kinase specificities accurately identifies specific Tyr kinases that are dysregulated in cells after stimulation with growth factors, treatment with anti-cancer drugs or expression of oncogenic variants. Furthermore, the topology of known Tyr signalling networks naturally emerged from a comparison of the sequence specificities of the Tyr kinases and the SH2 phosphotyrosine (pTyr)-binding domains. Finally we show that the intrinsic substrate specificity of Tyr kinases has remained fundamentally unchanged from worms to humans, suggesting that the fidelity between Tyr kinases and their protein substrate sequences has been maintained across hundreds of millions of years of evolution.

Computationally restoring the potency of a clinical antibody against Omicron.

The COVID-19 pandemic underscored the promise of monoclonal antibody-based prophylactic and therapeutic drugs1-3 and revealed how quickly viral escape can curtail effective options4,5. When the SARS-CoV-2 Omicron variant emerged in 2021, many antibody drug products lost potency, including Evusheld and its constituent, cilgavimab4-6. Cilgavimab, like its progenitor COV2-2130, is a class 3 antibody that is compatible with other antibodies in combination4 and is challenging to replace with existing approaches. Rapidly modifying such high-value antibodies to restore efficacy against emerging variants is a compelling mitigation strategy. We sought to redesign and renew the efficacy of COV2-2130 against Omicron BA.1 and BA.1.1 strains while maintaining efficacy against the dominant Delta variant. Here we show that our computationally redesigned antibody, 2130-1-0114-112, achieves this objective, simultaneously increases neutralization potency against Delta and subsequent variants of concern, and provides protection in vivo against the strains tested: WA1/2020, BA.1.1 and BA.5. Deep mutational scanning of tens of thousands of pseudovirus variants reveals that 2130-1-0114-112 improves broad potency without increasing escape liabilities. Our results suggest that computational approaches can optimize an antibody to target multiple escape variants, while simultaneously enriching potency. Our computational approach does not require experimental iterations or pre-existing binding data, thus enabling rapid response strategies to address escape variants or lessen escape vulnerabilities.

A Functional RNA-Origami as Direct Thrombin Inhibitor with Fast-acting and Specific Single-Molecule Reversal Agents in vivo model.

Injectable anticoagulants are widely used in medical procedures to prevent unwanted blood clotting. However, many lack safe, effective reversal agents. Here, we present new data on a previously described RNA origami-based, direct thrombin inhibitor (HEX01). We describe a new, fast-acting, specific, single-molecule reversal agent (antidote) and present in vivo data for the first time, including efficacy, reversibility, preliminary safety, and initial biodistribution studies. HEX01 contains multiple thrombin-binding aptamers appended on an RNA origami. It exhibits excellent anticoagulation activity in vitro and in vivo. The new single-molecule, DNA antidote (HEX02) reverses anticoagulation activity of HEX01 in human plasma within 30 seconds in vitro and functions effectively in a murine liver laceration model. Biodistribution studies of HEX01 in whole mice using ex vivo imaging show accumulated mainly in the liver over 24 hours and with 10-fold lower concentrations in the kidneys. Additionally, we show that the HEX01/HEX02 system is non-cytotoxic to epithelial cell lines and non-hemolytic in vitro. Furthermore, we found no serum cytokine response to HEX01/HEX02 in a murine model. HEX01 and HEX02 represent a safe and effective coagulation control system with a fast-acting, specific reversal agent showing promise for potential drug development.

Spontaneous immunological activities in the target tissue of vitiligo-prone Smyth and vitiligo-susceptible Brown lines of chicken.

Introduction: Vitiligo is an acquired de-pigmentation disorder characterized by the post-natal loss of epidermal melanocytes (pigment-producing cells) resulting in the appearance of white patches in the skin. The Smyth chicken is the only model for vitiligo that shares all the characteristics of the human condition including: spontaneous post-natal loss of epidermal melanocytes, interactions between genetic, environmental and immunological factors, and associations with other autoimmune diseases. In addition, an avian model for vitiligo has the added benefit of an easily accessible target tissue (a growing feather) that allows for the repeated sampling of an individual and thus the continuous monitoring of local immune responses over time. Methods: Using a combination of flow cytometry and gene expression analyses, we sought to gain a comprehensive understanding of the initiating events leading to expression of vitiligo in growing feathers by monitoring the infiltration of leukocytes and concurrent immunological activities in the target tissue beginning prior to visual onset and continuing throughout disease development. Results: Here, we document a sequence of immunologically significant events, including characteristic rises in infiltrating B and αß T cells as well as evidence of active leukocyte recruitment and cell-mediated immune activities (CCL19, IFNG, GZMA) leading up to visual vitiligo onset. Examination of growing feathers from vitiligo-susceptible Brown line chickens revealed anti-inflammatory immune activities which may be responsible for preventing vitiligo (IL10, CTLA4, FOXP3). Furthermore, we detected positive correlations between infiltrating T cells and changes in their T cell receptor diversity supporting a T cell-specific immune response. Conclusion: Collectively, these results further support the notion of cell-mediated immune destruction of epidermal melanocytes in the pulp of growing feathers and open new avenues of study in the vitiligo-prone Smyth and vitiligo-susceptible Brown line chickens.