Cingulate dynamics track depression recovery with deep brain stimulation.

Deep brain stimulation (DBS) of the subcallosal cingulate (SCC) can provide long-term symptom relief for treatment-resistant depression (TRD)1. However, achieving stable recovery is unpredictable2, typically requiring trial-and-error stimulation adjustments due to individual recovery trajectories and subjective symptom reporting3. We currently lack objective brain-based biomarkers to guide clinical decisions by distinguishing natural transient mood fluctuations from situations requiring intervention. To address this gap, we used a new device enabling electrophysiology recording to deliver SCC DBS to ten TRD participants (ClinicalTrials.gov identifier NCT01984710). At the study endpoint of 24 weeks, 90% of participants demonstrated robust clinical response, and 70% achieved remission. Using SCC local field potentials available from six participants, we deployed an explainable artificial intelligence approach to identify SCC local field potential changes indicating the patient's current clinical state. This biomarker is distinct from transient stimulation effects, sensitive to therapeutic adjustments and accurate at capturing individual recovery states. Variable recovery trajectories are predicted by the degree of preoperative damage to the structural integrity and functional connectivity within the targeted white matter treatment network, and are matched by objective facial expression changes detected using data-driven video analysis. Our results demonstrate the utility of objective biomarkers in the management of personalized SCC DBS and provide new insight into the relationship between multifaceted (functional, anatomical and behavioural) features of TRD pathology, motivating further research into causes of variability in depression treatment.

Subcallosal cingulate deep brain stimulation evokes two distinct cortical responses via differential white matter activation.

Subcallosal cingulate (SCC) deep brain stimulation (DBS) is an emerging therapy for refractory depression. Good clinical outcomes are associated with the activation of white matter adjacent to the SCC. This activation produces a signature cortical evoked potential (EP), but it is unclear which of the many pathways in the vicinity of SCC is responsible for driving this response. Individualized biophysical models were built to achieve selective engagement of two target bundles: either the forceps minor (FM) or cingulum bundle (CB). Unilateral 2 Hz stimulation was performed in seven patients with treatment-resistant depression who responded to SCC DBS, and EPs were recorded using 256-sensor scalp electroencephalography. Two distinct EPs were observed: a 120 ms symmetric response spanning both hemispheres and a 60 ms asymmetrical EP. Activation of FM correlated with the symmetrical EPs, while activation of CB was correlated with the asymmetrical EPs. These results support prior model predictions that these two pathways are predominantly activated by clinical SCC DBS and provide first evidence of a link between cortical EPs and selective fiber bundle activation.

Advances in Deep Brain Stimulation: From Mechanisms to Applications.

Deep brain stimulation (DBS) is an effective therapy for various neurologic and neuropsychiatric disorders, involving chronic implantation of electrodes into target brain regions for electrical stimulation delivery. Despite its safety and efficacy, DBS remains an underutilized therapy. Advances in the field of DBS, including in technology, mechanistic understanding, and applications have the potential to expand access and use of DBS, while also improving clinical outcomes. Developments in DBS technology, such as MRI compatibility and bidirectional DBS systems capable of sensing neural activity while providing therapeutic stimulation, have enabled advances in our understanding of DBS mechanisms and its application. In this review, we summarize recent work exploring DBS modulation of target networks. We also cover current work focusing on improved programming and the development of novel stimulation paradigms that go beyond current standards of DBS, many of which are enabled by sensing-enabled DBS systems and have the potential to expand access to DBS.

The expanding role of blood and tissue establishments in the development of advanced therapy medicinal products.

BACKGROUND AIMS: The relationship between blood establishments and advanced cellular therapies is evident in several European countries, with some involved in research and development and/or in manufacturing. The aim of the present study was to understand the advanced therapy medicinal product (ATMP) infrastructural, regulatory and logistic requirements needed for the Irish Blood Transfusion Service to support advanced therapeutics in Ireland. METHODS: An online survey consisting of 13 questions was distributed in a targeted manner to the identified ATMP stakeholders in Ireland, namely those working in industry, health care, regulatory agencies or education. Subject matter experts in the field were approached and interviewed to gain further insight into the relationship between blood and tissue establishments (BTEs) and ATMPs, to explore the advantages these institutions have in development and to highlight potential challenges for implementation. RESULTS: In total, 84.9% of survey respondents stated that BTEs have a role in the development of advanced therapeutics. Key BTE services identified as applicable to the ATMP sector from both surveys and interviews include the provision of starting materials for research and manufacturing, donor management, use of existing quality and traceability frameworks, product logistic strategies and Good Manufacturing Practice. Challenges for BTE expansion into the sector currently include high costs associated with ATMPs, lack of expertise in these therapies, limited therapeutic populations and no national ATMP strategic plan for Ireland. CONCLUSIONS: Blood establishments have services and expertise that can be extended into the advanced therapy sector. The existing knowledge and skill base of BTEs in Ireland should be leveraged to accelerate the development of ATMP strategies for industry and healthcare.

The effect of gradual extinction training on the renewal of electrodermal conditional responses.

Extinction, the repeated presentation of a conditional stimulus (CS) without the unconditional stimulus (US), is the standard paradigm to reduce conditional responding acquired by the repeated pairing of CS and US in acquisition. However, this reduction of conditional responding is prone to relapse. In rodent fear-conditioning, gradual extinction, the fading out of CS-US pairings during extinction, has been shown to reduce the return of fear. The current study replicated the gradual extinction procedure in human fear conditioning and assessed whether it reduced the return of fear due to ABA renewal and reacquisition. During extinction, one group received standard extinction, a second received gradual extinction (increasing the spacing of USs presented after the 1st, 3rd, 6th, 10th, and 15th CS+ trials), and a third received reversed extinction training (decreasing the spacing of USs presented after the 1st, 6th, 10th, 13th, and 15th CS+ trials). Larger renewal and faster reacquisition of differential electrodermal responses to CS+ and CS- were expected after standard and reversed extinction than after gradual extinction training. The results were inconclusive due to the failure to find extinction of differential electrodermal responses and US expectancy ratings in both gradual and reversed extinction groups. Despite successful extinction in group standard, renewal was only observed in US expectancy. Visualization of US expectancy ratings during extinction suggested that potential identification of the US presentation patterns during extinction in the gradual and reversed groups delayed extinction learning.

Exploring latent clusters in pediatric OCD based on symptoms, severity, age, gender, and comorbidity.

Given diverse symptom expression and high rates of comorbid conditions, the present study explored underlying commonalities among OCD-affected children and adolescents to better conceptualize disorder presentation and associated features. Data from 830 OCD-affected participants presenting to OCD specialty centers was aggregated. Dependent mixture modeling was used to examine latent clusters based on their age- and gender adjusted symptom severity (as measured by the Children's Yale-Brown Obsessive-Compulsive Scale; CY-BOCS), symptom type (as measured by factor scores calculated from the CY-BOCS symptom checklist), and comorbid diagnoses (as assessed via diagnostic interviews). Fit statistics favored a four-cluster model with groups distinguished primarily by symptom expression and comorbidity type. Fit indices for 3-7 cluster models were only marginally different and characteristics of the clusters remained largely stable between solutions with small clusters of distinct presentations added in more complex models. Rather than identifying a single classification system, the findings support the utility of integrating dimensional, developmental, and transdiagnostic information in the conceptualization of OCD-affected children and adolescents. Identified clusters point to the centrality of contamination concerns to OCD, relationships between broader symptom expression and higher levels of comorbidity, and the potential for complex/neurodevelopmental presentations.

Daily use of digital technologies to feel better: Adolescents' digital emotion regulation, emotions, loneliness, and recovery, considering prior emotional problems.

INTRODUCTION: Adolescents report using digital technologies for emotion regulation (digital ER), with the aim of feeling better (i.e., improving emotions and reducing loneliness). In this 7-day diary study, we investigated associations of digital ER, emotions, and loneliness, and tested whether prior emotional problems moderated these associations. METHOD: Participants were 312 Australian adolescents (Mage = 13.91, SD = 1.52; 44% boys). Daily surveys measured digital ER; end-of-day happiness, sadness, worry, anger, and loneliness; and peak sadness, worry, and anger. End-of day emotions were subtracted from peak emotions to calculate emotion recovery for sadness, worry, and anger. Participants were randomly selected from two symptom strata (high/low) defined by depression and social anxiety measures collected before the diary. Data were analyzed using multilevel path modeling. Cross-level interactions tested whether symptom strata moderated associations. RESULTS: Digital ER was associated with more recovery from peak to end-of-day sadness and worry, but also with increased sadness, worry, anger, and loneliness by the next end-of-day. Higher end-of-day loneliness was associated with increased next-day digital ER. Prior emotional symptoms were not a significant moderator of daily digital ER and emotion associations. CONCLUSION: Adolescents who report more digital ER in a day show more recovery from the peak of negative emotion that day, but this recovery dissipates, with digital ER also associated with increased negative emotion and loneliness by the next day for all adolescents, regardless of prior symptom status. Lonelier adolescents use more digital ER by the next day, suggesting they need support to make social connections-online or offline.

Reaching Young People in Urban and Rural Communities with Mental Health and Wellbeing Support Within a Youth Sports Development Program: Integrating In-Person and Remote Modes of Service Delivery.

Embedding mental health and wellbeing programs within youth sports development programs can help provide more young people with mental health support. However, delivering such programs in multiple locations across metropolitan, regional, and rural areas requires novel solutions to overcome geographic and logistical barriers. We examined the delivery of an integrated system delivered within an Australian junior rugby league program. The program included online assessment and feedback about youth mental health, as well as connection with evidence-informed resources and referral sources via parent telephone and email support. There were four methods of delivering player workshops during training sessions: (a) In-person Delivery Only, (b) In-person + Remote Real-time (video-conferenced), (c) In-person + Remote Prerecorded (video-recorded), and (d) Remote Delivery Only (video-conferenced and/or video-recorded). In-person delivered player workshops were facilitated by local rugby league personnel. Remote delivered workshops were facilitated by psychologists from the mental health research team. Participants were 671 boys (12-15 years; M age = 13.35; SD = 0.35) in 21 metropolitan, regional and rural locations. Regardless of delivery condition, players with elevated anxiety, depression and behavioural problems reported significant declines in symptoms from pre- to post-program, and those within healthy ranges did not change from pre- to post-program. Player workshop enjoyment ratings were higher in the In-person + Remote Real-time condition and the Remote Delivery Only condition than the In-person Delivery Only condition. However, non-completion of the post-program assessment across all conditions was higher than in prior studies and a comparison group of players who did not complete the program was not included. Mental health benefits may be observed across in-person and remote modes of delivering mental health workshops within youth sports programs. However, the involvement of mental health personnel, whether in-person or remotely, and mixed delivery modes, may be important for young people's retention and satisfaction.

A management model in blood, tissue and cell establishments to ensure rapid and sustainable patient access to advanced therapy medicinal products in Europe.

Blood, tissue and cell establishments (BTCs) stand out in the management of donor selection, procurement and processing of all types of substances of human origin (SoHO). In the last decades, the framework created around BTCs, including hospitals and national health system networks, and their links to research, development and innovation organizations and agencies have spurred their involvement in the study of groundbreaking advanced therapy medicinal products (ATMP). To further improve strategic synergies in the development of ATMPs, it will be required to promote intra- and inter-European collaborations by creating an international network involving BTCs and major stakeholders (i.e., research organizations, hospitals, universities, patient associations, public agencies). This vision is already shared with the European Blood Alliance, the association of non-profit blood establishments, with 26 member states throughout the European Union and European Free Trade Association states. Herein we present and analyze the "BTC for ATMP Development And Manufacture" (BADAM) model, an ethically responsible business model based on the values and missions of BTCs and their commitment to health equity, patient access and education (based on voluntary donation of SoHO to address unmet clinical needs, while contributing to training professionals and scientific literacy of our Society).

Fear learning and extinction predicts anxiety in daily life: a study of Pavlovian conditioning and ecological momentary assessment.

BACKGROUND: The association between anxious mood and aberrant fear learning mechanisms has not been fully elucidated. Studying how fear conditioning and extinction constructs relate to anxiety symptoms and reactivity to stressful and benign moments in everyday life provides a powerful addition to experimental paradigms. METHOD: Fifty-one young adults completed laboratory-based differential conditioning and extinction tasks with (CS + ) and without (CS-) an aversive unconditional stimulus (US). Electrodermal skin conductance responses were measured during each phase, followed by ecological momentary assessment (EMA) tapping anxiety and stressors six times daily for seven days (2, 142 moments). RESULTS: Conditioned electrodermal reactivity to the CS + and overgeneralisation to the CS- were associated with greater change in anxiety (measured via EMA), across non-stressful situations, remaining the same across stressful situations. Likewise, during extinction when the CS + is now safe, more electrodermal reactivity to the CS + was associated with more anxiety change across non-stressful situations and remained the same across stressful situations. Also, during extinction when threat is absent, more electrodermal reactivity at the late stage of the CS- was associated with less momentary anxiety change in response to stressful situations; more electrodermal activity at the late stage of the CS + was associated with more anxiety change across non-stressful situations and remained the same across stressful situations. CONCLUSIONS: Sampling 'in vivo' emotion and stress experiences, study findings revealed links between conditioned electrodermal reactivity and overgeneralisation to safe stimuli and heightened anxious reactivity during non-stressful (i.e. safe) moments in daily life, coupled with less change in response to actual stressors.

Serologic reactivity of unidentified specificity in antenatal testing and hemolytic disease of the fetus and newborn: The BEST collaborative study.

BACKGROUND: The clinical significance of serologic reactivity of unidentified specificity (SRUS) in pregnancy is not clear based on available literature. The aim of this study is to determine if SRUS is associated with hemolytic disease of the fetus and newborn (HDFN). STUDY DESIGN AND METHODS: Retrospective data were collected from eight institutions over an 11-year study period (2010-2020), when available (5/8 sites). The outcome of the pregnancies with SRUS-no, mild, moderate, or severe HDFN-was determined. RESULTS: SRUS was demonstrated in 589 pregnancies. After excluding those with incomplete data, a total of 284 pregnancies were included in the primary HDFN outcome analysis. SRUS was detected in 124 (44%) pregnancies in isolation, and none were affected by HDFN. Of 41 pregnancies with SRUS and ABO incompatibility, 37 (90%) were unaffected, and 4 (10%) were associated with mild HDFN. Of 98 pregnancies with SRUS and concurrent identifiable antibody reactivity(s), 80 (81%) were unaffected, and 19 (19%) were associated with mild to severe HDFN. There was 1 case of mild HDFN and 1 case of severe HDFN in the 21 pregnancies with SRUS, ABO incompatibility, and concurrent identifiable antibody reactivity(s), and 19 (90%) were unaffected by HDFN. Among all patients with repeat testing, newly identified alloantibodies or other antibodies were identified in 63 of 212 (30%) patients. Although most were not clinically significant, on occasion SRUS preceded clinically significant antibody(s) associated with HDFN (3%, 5/188). CONCLUSION: The antenatal serologic finding of SRUS in isolation is not associated with HDFN but may precede clinically significant antibodies.

The impact of donor biological variation on the quality and function of cold-stored platelets.

BACKGROUND AND OBJECTIVES: Room temperature-stored platelets (RTPs) maximize platelet viability but limit shelf life. The aims of this study were to investigate the impact of donor variability on cold-stored platelets (CSPs) and RTP, to determine whether RTP quality markers are appropriate for CSP. MATERIALS AND METHODS: Double platelet donations (n = 10) were collected from consented regular male donors stored in 100% plasma. A full blood count, donor age, weight, height and body mass index (BMI) were collected at the time of donation. Platelet donations were split equally into two bags, and assigned to non-agitated CSP or agitated RTP. The quality and function of platelets were assessed throughout the standard 7 days of storage and at expiry (day 8). Non-parametric statistical analyses were used to analyse results given the small sample size. RESULTS: As expected, there were significant differences between CSP and RTP throughout storage including a reduction in CSP concentration as well as a loss of swirling. Furthermore, a significant increase in CSP exhibiting activation and apoptotic markers was observed. Platelet concentrations were further impacted by donor BMI, and donors with the highest BMI (>29) had the lowest platelet concentration and activation response at the end of CSP storage. CONCLUSION: Platelet quality and functionality play a vital role in transfusion outcomes; however, blood components are inherently variable. This study demonstrated, for the first time, the specific impact of donor BMI on CSP quality and function and highlights the requirement for novel quality markers for assessing CSPs.

Does irritability predict attention biases toward threat among clinically anxious youth?

Aberrant threat processing is a known cognitive characteristic of anxiety disorders and irritability. Youth with more severe symptomatology show greater allocation of attention towards threat relative to neutral stimuli. Although irritability contributes to poorer outcomes among anxious youths, irritability has not been considered as a contributing factor to threat processing in anxiety disorders. Thus, the current study examined the role of irritability in predicting attention biases for threat among clinically anxious youth. Our study included 84 clinically anxious youth (M = 9.31 years old, SD = 2.44) who completed a dot-probe task to determine attention biases. Anxiety disorders were assessed using semi-structured diagnostic interviews. Well validated measures were used to assess the severity of anxiety and irritability symptoms via child- and parent-report, respectively. Findings indicated that more severe irritability predicted greater attention biases toward threat among clinically anxious youth, covarying for age, anxiety severity, and the number of comorbid diagnoses. At a trend-level, anxiety severity also predicted attention bias for threat. Among clinically anxious youth, irritability severity was the strongest predictor of attention bias toward threat. Findings point to the salience of irritability, and to some extent anxiety severity, in relation to threat processing among youth with clinical anxiety disorders.

A pattern-centered analysis of adolescents' concerns and hopes about future crises: Differences in ways of coping and personal adjustment.

INTRODUCTION: Many adolescents are concerned about global and future crises, such as the health of the planet or terrorism/safety. Yet, adolescents can also express hope about the future. Thus, asking adolescents about their concern and hope could yield subgroups with different ways of coping and personal adjustment. METHOD: Australian adolescents (N = 863; age 10-16) completed surveys to report their concern (worry and anger) and hope about the planet, safety, jobs, income, housing, and technology, as well as their active and avoidant coping, depression, and life satisfaction. RESULTS: Four distinct subgroups were identified using cluster analysis: Hopeful (low on concern and high on hope across all issues, 32%), Uninvolved (low in concern and hope; 26%), Concerned about the Planet (CP, 27%), and Concerned about Future Life (CFL, 15%). When compared (adjusting for age, sex, and COVID timing), the CP subgroup was highest in active coping (e.g., taking action) but moderate in personal adjustment. Hopeful had the most positive adjustment, whereas CFL had the poorest adjustment. Uninvolved were lowest in coping but moderate in adjustment. CONCLUSIONS: Findings suggest ways of coping and adjustment may not always align, in that CP is connected with more active coping but also some cost to personal adjustment, whereas Hopeful is associated with optimal adjustment but perhaps at the cost of active coping. In addition, although CFL adolescents emerged as the at-risk group, the low levels of hope and coping in Uninvolved adolescents raise the possibility that they are at risk of future problems.

Adolescent Anxiety, Depression and Flourishing before and During COVID-19 and the Predictive Role of Baseline Psychological Capital (PsyCap) on Student Mental Health and Subjective Wellbeing During the Pandemic.

Studies indicate the COVID-19 pandemic has resulted in rises in adolescent mental health symptoms globally, although the impact of the pandemic on subjective wellbeing is under-researched in this population. Psychological capital (PsyCap), a cluster of four positive psychological constructs comprising hope, efficacy, resilience and optimism (HERO), has demonstrated preventative and promotive qualities on mental health symptoms and subjective wellbeing outcomes with adult populations (employees, university students). However, PsyCap's influence on these outcomes in young people is unclear. The present exploratory study investigated changes in self-reported anxiety and depressive symptoms (measured via the RCADS-SV) and subjective wellbeing (measured by the Flourishing Scale) from pre-pandemic levels to 3 months into the pandemic and explored gender differences at each time point in a sample of Australian Year 10 students (N = 56, Mage = 14.93 years, SD = 0.50, 51.8% male). The longitudinal predictive role of baseline PsyCap on follow-up assessments of anxiety symptoms, depressive symptoms and flourishing were also examined. There were no significant changes in levels of anxiety and depressive symptoms between the timepoints, but flourishing significantly declined from T1 to T2. Baseline PsyCap was not a significant predictor of T2 anxiety and depressive symptoms but was a significant predictor of T2 flourishing. Further, different baseline HERO constructs predicted T2 mental health symptoms and flourishing. Future larger studies building on the current preliminary findings investigating the roles of student PsyCap, mental health and subjective wellbeing are warranted to better understand these constructs in the COVID-19 era and beyond.

Using Nightly Sleep Guidelines to Address Links Between Adolescents' Self-Reported Weekly Sleep Patterns and Anxiety and Depression Symptoms.

Short and long nightly sleep durations are associated with anxiety and depression symptoms among adolescents. However, studies have not used recommended hours of nightly sleep or focused on sleep patterns across weekdays and weekends in examining links with anxiety and depression symptoms. The present study included 709 adolescents in Grade 11 (402 females; 307 males) who self-reported hours of sleep on weeknights and weekends and anxiety and depression symptoms. Using the recommended 8-10 h to define average nightly sleep for adolescents, sleep patterns across weekdays and weekends were categorised into seven classes: short stable, short increasing, average decreasing, average stable, average increasing, long decreasing, and long stable. Relative to average stable sleepers, short stable, short increasing, and long stable sleepers had significantly higher anxiety and depression. Adolescents require 8-10 h of sleep on weeknights, regardless of weekends, for optimal emotional wellbeing.

Preliminary Effectiveness of a Brief School-Based HERO Intervention: Improving the Wellbeing of Final Year Adolescent Female Students.

Young people face multiple challenges, including appearance dissatisfaction, academic stressors, anxiety and depression. These challenges may increase during the final year of high school and may have become further exacerbated by the COVID-19 pandemic. This study examines the preliminary effectiveness of a brief, uncontrolled school-based intervention aimed at enhancing Psychological Capital (PsyCap), consisting of positive resources of hope, self-efficacy, resilience and optimism (HERO), and reducing mental health symptoms among female year 12 students (n = 95, Mage = 16.78, SD = 0.45). Outcomes on measures of HERO and secondary outcomes of flourishing, appearance dissatisfaction, anxiety and depression were measured at pre and post-intervention. In the overall cohort, no significant changes were found on the HERO outcomes or flourishing post-intervention, while symptoms of depression, anxiety and appearance dissatisfaction decreased significantly. For students with higher baseline anxiety, optimism and anxiety symptoms improved significantly at post-intervention. However, students with lower baseline anxiety experienced significant decreases in self-efficacy and optimism, as well as a significant increase in anxiety symptoms post-intervention. Baseline depression levels did not impact intervention outcomes. The findings, although mixed and limited by the lack of control group, suggest that a brief intervention grounded in PsyCap theory may improve student wellbeing under challenging circumstances.

Feasibility of an Intensive, Disorder-Specific, Group-Based Cognitive Behavioural Therapy Intervention for Adolescents with Social Anxiety Disorder.

This study examined the preliminary acceptability and efficacy of an intensive, group-based, disorder-specific cognitive behavioural therapy (CBT) intervention for adolescents with social anxiety disorder (SAD). Fourteen Australian adolescents with SAD (78.6% female, M age = 13.93 years) and their parents completed the program plus measures of treatment satisfaction, and provided feedback. Clinical interviews and surveys were administered pre-treatment, post-treatment, and at 6-month follow-up to determine diagnostic status and assess related variables. Post-treatment satisfaction scores were very high for adolescents and parents. Post-treatment, 32.3% of participants no longer met criteria for SAD diagnosis, increasing to 42.9% at follow-up. Participants showed sizeable reductions in comorbid diagnoses, significant improvements in global functioning, social anxiety symptoms, and internalising symptoms from pre- to post-treatment (maintained at follow-up), and significant improvements in social skills and social competence from pre-treatment to follow-up. This study supports the use of an intensive CBT program for adolescents with SAD.

Human T-lymphotropic virus in Irish blood donors: Impact on future testing strategy.

AIM: A risk-based approach to the testing of blood donations for Human T-Lymphotropic Virus (HTLV) should include an assessment of blood donation seroepidemiology. The objectives of the present study were to determine the proportion of HTLV positive units in Irish blood donations, and subsequently, to estimate the current risk of transfusion transmitted HTLV (TT-HTLV). METHODS: Over 3 million donations screened between 1996 and 2020, were included in the study (n = 3,666,253). Factors considered in the assessment of TT-HTLV risk included: (I) HTLV seropositivity, (ii) probability of a leucodepletion failure, and (iii) the HTLV testing strategy. RESULTS: Six HTLV positive donations were detected throughout the study period, all of them in previously unscreened blood donors (0.000164%; n = 6/3,666,253), 3 of whom had donated prior to the introduction of HLTV antibody testing. On average 0.11% of manufactured blood components assessed, failed to satisfy the leucodepletion quality assurance criteria of less than 1 × 106 cells/unit. In using these values to model the risk of TT-HTLV, it was shown that the combination of leucodepletion with either universal screening of all = donors, or selective testing of first-time donors, a possible HTLV transfusion transmitted infection would be prevented every 468-3776 years. CONCLUSIONS: This is the first report on the proportion of HTLV positive in Irish blood donations (1996-2020) and will be used to inform blood donation screening policy in Ireland. Evidence is provided for recommending a selective HTLV donor screening algorithm in Ireland that is accompanied by a robust framework for continued surveillance of leucodepletion failure rate.

The oxygen saturation of red blood cell concentrates: The basis for a novel index of red cell oxidative stress.

BACKGROUND: Oxidative stress is a major driving force in the development of storage lesions in red cell concentrates (RCCs). Unlike manufactured pharmaceuticals, differences in component preparation methods and genetic/physiological status of donors result in nonuniform biochemical characteristics of RCCs. Various characteristics of donated blood on oxygen saturation (SO2 ) distribution were investigated, and a model to estimate potential oxidative stress burden of stored RCC at transfusion is proposed. STUDY DESIGN AND METHODS: The oxygen content of freshly prepared RCCs (770) was quantified noninvasively as fractional hemoglobin saturation (SO2 ) with visible reflectance spectrometry. Using separate RCCs and mimicking typical handling of RCCs during routine storage, evolution of SO2 was followed for construction of an empirical model. Based on this model, the oxygen exposure index (OEI) was formulated to estimate the accumulated oxygen exposure burden of RCC at the time of transfusion. RESULTS: The SO2 of RCCs varied widely at donation (mean 43% ± 1.3%; range 20%-93%). Multivariate regression model showed that sex and processing method had small effects on SO2 (R2  = 0.12), indicating that variability was mainly attributed to other individual donor characteristics. Storage simulation model indicated that median SO2 increased gradually over 6 weeks (approx. 1.3 fold), while OEI increased at a faster rate (approx. eight-fold). CONCLUSION: In addition to storage age, the OEI provides a potential new metric to assess the quality of RCCs at the time of transfusion in terms of their oxidative stress. In future studies, a single noninvasive measurement during storage could link OEI to clinical outcomes in transfusion recipients.