Revised criteria for diagnosis and staging of Alzheimer's disease: Alzheimer's Association Workgroup.

The National Institute on Aging and the Alzheimer's Association convened three separate work groups in 2011 and single work groups in 2012 and 2018 to create recommendations for the diagnosis and characterization of Alzheimer's disease (AD). The present document updates the 2018 research framework in response to several recent developments. Defining diseases biologically, rather than based on syndromic presentation, has long been standard in many areas of medicine (e.g., oncology), and is becoming a unifying concept common to all neurodegenerative diseases, not just AD. The present document is consistent with this principle. Our intent is to present objective criteria for diagnosis and staging AD, incorporating recent advances in biomarkers, to serve as a bridge between research and clinical care. These criteria are not intended to provide step-by-step clinical practice guidelines for clinical workflow or specific treatment protocols, but rather serve as general principles to inform diagnosis and staging of AD that reflect current science. HIGHLIGHTS: We define Alzheimer's disease (AD) to be a biological process that begins with the appearance of AD neuropathologic change (ADNPC) while people are asymptomatic. Progression of the neuropathologic burden leads to the later appearance and progression of clinical symptoms. Early-changing Core 1 biomarkers (amyloid positron emission tomography [PET], approved cerebrospinal fluid biomarkers, and accurate plasma biomarkers [especially phosphorylated tau 217]) map onto either the amyloid beta or AD tauopathy pathway; however, these reflect the presence of ADNPC more generally (i.e., both neuritic plaques and tangles). An abnormal Core 1 biomarker result is sufficient to establish a diagnosis of AD and to inform clinical decision making throughout the disease continuum. Later-changing Core 2 biomarkers (biofluid and tau PET) can provide prognostic information, and when abnormal, will increase confidence that AD is contributing to symptoms. An integrated biological and clinical staging scheme is described that accommodates the fact that common copathologies, cognitive reserve, and resistance may modify relationships between clinical and biological AD stages.

Metabolically active neutrophils represent a permissive niche for Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb)-infected neutrophils are often found in the airways of patients with active tuberculosis (TB), and excessive recruitment of neutrophils to the lung is linked to increased bacterial burden and aggravated pathology in TB. The basis for the permissiveness of neutrophils for Mtb and the ability to be pathogenic in TB has been elusive. Here, we identified metabolic and functional features of neutrophils that contribute to their permissiveness in Mtb infection. Using single-cell metabolic and transcriptional analyses, we found that neutrophils in the Mtb-infected lung displayed elevated mitochondrial metabolism, which was largely attributed to the induction of activated neutrophils with enhanced metabolic activities. The activated neutrophil subpopulation was also identified in the lung granulomas from Mtb-infected non-human primates. Functionally, activated neutrophils harbored more viable bacteria and displayed enhanced lipid uptake and accumulation. Surprisingly, we found that interferon-γ promoted the activation of lung neutrophils during Mtb infection. Lastly, perturbation of lipid uptake pathways selectively compromised Mtb survival in activated neutrophils. These findings suggest that neutrophil heterogeneity and metabolic diversity are key to their permissiveness for Mtb and that metabolic pathways in neutrophils represent potential host-directed therapeutics in TB.

Bariatric surgeons' views on pre-operative factors associated with improved health-related quality of life following surgery.

Bariatric surgery is an effective treatment for severe obesity, affording significant improvements in weight loss and health-related quality of life. However, bariatric surgeons' views on whether certain pre-operative factors predict improvements in post-operative health-related quality of life, and if so, which ones, are largely unknown. This cross-sectional survey study examined the views of 58 bariatric surgeons from Australia and New Zealand. A total of 18 factors were selected for exploration based on their mention in the literature. Participants rated the extent to which they thought these pre-operative factors would improve post-operative health-related quality of life. Responses showed that bariatric surgeons held diverse perspectives and revealed a lack of consensus regarding "predictive" factors. Generally, respondents agreed that better than average health literacy, higher socioeconomic status, good physical and psychological health, and positive social support were predictors of improved health-related quality of life following surgery. However, poor eating behaviours, smoking, and the use of alcohol or other substances were deemed negative predictors. Interestingly, aside from higher socioeconomic status, good psychological health, and positive social support, none of the aforementioned views aligned with existing literature. This study offers an initial insight into bariatric surgeons' views on the influence of different pre-operative factors on post-operative health-related quality of life. The array of views identified suggests that there may be an opportunity for medical education, but the findings warrant caution due to the sample size. Replication with a larger survey may be useful, especially as predicted health-related quality of life outcomes could guide decisions regarding surgical (non)progression.

A comprehensive systematic literature review of the burden of illness of Lennox-Gastaut syndrome on patients, caregivers, and society.

Fully elucidating the burden that Lennox-Gastaut syndrome (LGS) places on individuals with the disease and their caregivers is critical to improving outcomes and quality of life (QoL). This systematic literature review evaluated the global burden of illness of LGS, including clinical symptom burden, care requirements, QoL, comorbidities, caregiver burden, economic burden, and treatment burden (PROSPERO ID: CRD42022317413). MEDLINE, Embase, and the Cochrane Library were searched for articles that met predetermined criteria. After screening 1442 deduplicated articles and supplementary manual searches, 113 articles were included for review. A high clinical symptom burden of LGS was identified, with high seizure frequency and nonseizure symptoms (including developmental delay and intellectual disability) leading to low QoL and substantial care requirements for individuals with LGS, with the latter including daily function assistance for mobility, eating, and toileting. Multiple comorbidities were identified, with intellectual disorders having the highest prevalence. Although based on few studies, a high caregiver burden was also identified, which was associated with physical problems (including fatigue and sleep disturbances), social isolation, poor mental health, and financial difficulties. Most economic analyses focused on the high direct costs of LGS, which arose predominantly from medically treated seizure events, inpatient costs, and medication requirements. Pharmacoresistance was common, and many individuals required polytherapy and treatment changes over time. Few studies focused on the humanistic burden. Quality concerns were noted for sample representativeness, disease and outcome measures, and reporting clarity. In summary, a high burden of LGS on individuals, caregivers, and health care systems was identified, which may be alleviated by reducing the clinical symptom burden. These findings highlight the need for a greater understanding of and better definitions for the broad spectrum of LGS symptoms and development of treatments to alleviate nonseizure symptoms.

Impact of the COVID-19 pandemic on diagnosis of renal cell carcinoma and disease stage at presentation.

INTRODUCTION: Renal cell carcinoma (RCC) is often associated with significant morbidity and mortality, with overall survival contingent on multiple factors - most importantly, disease stage at diagnosis. Disruptions in healthcare delivery during the COVID-19 pandemic have resulted in various reported diagnostic and treatment delays, which have had detrimental impacts on malignancies such as RCC. METHODS: Surgically managed cases of RCC at our center were identified using a retrospective chart review of all nephrectomies conducted from March 1, 2018, to February 28, 2023. Examination of disease characteristics in three time period cohorts (before, during, and following the COVID-19 pandemic) was undertaken. Timeframes were consistent with implementation and abolition of public health restrictions in the province of Newfoundland and Labrador. RESULTS: A total of 483 surgically managed RCC cases were identified during the study period. The median age was 65 years (interquartile range [IQR] 56-71), and 62.3% of patients were male. Demographics did not vary across timeframes. Before and during the pandemic, pathologic stage 3 (pT3) disease was reported in 38.9% and 35.4% of cases, respectively, whereas the post-pandemic period saw this presentation in 50.0% of patients. Surgical wait times increased significantly across study timeframes (p=0.003). CONCLUSIONS: The first year following the COVID-19 pandemic saw an 11.1% increase in patients presenting with pT3 RCC. These findings are suggestive of a clinically significant stage migration, which paired with prolonged wait times for surgery, provide critical consideration in the urgency of diagnostic and treatment decisions for RCC in the immediate future.

A systematic literature review on the global epidemiology of Dravet syndrome and Lennox-Gastaut syndrome: Prevalence, incidence, diagnosis, and mortality.

Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) are rare developmental and epileptic encephalopathies associated with seizure and nonseizure symptoms. A comprehensive understanding of how many individuals are affected globally, the diagnostic journey they face, and the extent of mortality associated with these conditions is lacking. Here, we summarize and evaluate published data on the epidemiology of DS and LGS in terms of prevalence, incidence, diagnosis, genetic mutations, and mortality and sudden unexpected death in epilepsy (SUDEP) rates. The full study protocol is registered on PROSPERO (CRD42022316930). After screening 2172 deduplicated records, 91 unique records were included; 67 provided data on DS only, 17 provided data on LGS only, and seven provided data on both. Case definitions varied considerably across studies, particularly for LGS. Incidence and prevalence estimates per 100 000 individuals were generally higher for LGS than for DS (LGS: incidence proportion = 14.5-28, prevalence = 5.8-60.8; DS: incidence proportion = 2.2-6.5, prevalence = 1.2-6.5). Diagnostic delay was frequently reported for LGS, with a wider age range at diagnosis reported than for DS (DS, 1.6-9.2 years; LGS, 2-15 years). Genetic screening data were reported by 63 studies; all screened for SCN1A variants, and only one study specifically focused on individuals with LGS. Individuals with DS had a higher mortality estimate per 1000 person-years than individuals with LGS (DS, 15.84; LGS, 6.12) and a lower median age at death. SUDEP was the most frequently reported cause of death for individuals with DS. Only four studies reported mortality information for LGS, none of which included SUDEP. This systematic review highlights the paucity of epidemiological data available for DS and especially LGS, demonstrating the need for further research and adoption of standardized diagnostic criteria.

P2X7-Mediated Antigen-Independent Activation of CD8+ T Cells Promotes Salt-Sensitive Hypertension.

BACKGROUND: CD8+ T cells (CD8Ts) have been implicated in hypertension. However, the specific mechanisms are not fully understood. In this study, we explore the contribution of the P2X7 (purinergic receptor P2X7) receptor to CD8T activation and subsequent promotion of sodium retention in the kidney. METHODS: We used mouse models of hypertension. Wild type were used as genetic controls, OT1 and Rag2/OT1 mice were utilized to determine antigen dependency, and P2X7-knockout mice were studied to define the role of P2X7 in activating CD8Ts and promoting hypertension. Blood pressure was monitored continuously and kidneys were obtained at different experimental end points. Freshly isolated CD8Ts from mice for activation assays and ATP stimulation. CD8T activation-induced promotion of sodium retention was explored in cocultures of CD8Ts and mouse DCTs. RESULTS: We found that OT1 and Rag2/OT1 mice, which are nonresponsive to common antigens, still developed hypertension and CD8T-activation in response to deoxycorticosterone acetate/salt treatment, similar to wild-type mice. Further studies identified the P2X7 receptor on CD8Ts as a possible mediator of this antigen-independent activation of CD8Ts in hypertension. Knockout of the P2X7 receptor prevented calcium influx and cytokine production in CD8Ts. This finding was associated with reduced CD8T-DCT stimulation, reversal of excessive salt retention in DCTs, and attenuated development of salt-sensitive hypertension. CONCLUSIONS: Our findings suggest a novel mechanism by which CD8Ts are activated in hypertension to exacerbate salt retention and infer that the P2X7 receptor on CD8Ts may represent a new therapeutic target to attenuate T-cell-mediated immunopathology in hypertension.

The impact of sputum quality on Xpert positivity in active case-finding for TB.

BACKGROUND: Studies evaluating sputum quality and Xpert® MTB/RIF positivity in the context of active case finding are scarce. We aimed to determine whether sputum quality is associated with Xpert positivity and whether the association differed according to demographic and clinical characteristics.METHODS: A cross-sectional analysis using data from a mass screening programme in Brazilian prisons was conducted from 2017 to 2021. We administered a standardised questionnaire, obtained a chest X-ray and collected a spot sputum sample for Xpert testing. Sputum quality was classified as 'salivary', 'mucoid/mucopurulent' or 'blood-stained'. We used log binomial regressions to estimate the relationship between sputum quality and Xpert positivity, assessing interactions with participant characteristics.RESULTS: Among 4,368 participants for whom sputum quality was assessed, 957 (21.9%) produced salivary specimens, 3,379 (77.4%) had mucoid/mucopurulent sputum and 32 (0.7%) had blood-stained sputum. Xpert positivity was higher among those with mucoid/mucopurulent sputum than among those with salivary samples (12.0% vs. 3.7%). Mucopurulent sputum independently predicted Xpert positivity among individuals with and without symptoms, current smoking and abnormal chest radiographs on CAD4TB.CONCLUSIONS: In our study, sputum appearance independently predicted Xpert positivity, and could be used together with chest X-ray and symptom screening to inform use of Xpert in individual or pooled testing.

Expectations and clinical meaningfulness of randomized controlled trials.

Alzheimer's disease (AD) clinical trials are designed and powered to detect the impact of a therapeutic intervention, and there has been considerable discussion on what constitutes a clinically meaningful change in those receiving treatment versus placebo. The pathology of AD is complex, beginning many years before clinical symptoms are detectable, with multiple potential opportunities for therapeutic engagement. Introducing treatment strategies early in the disease and assessing meaningful change over the course of an 18-month clinical trial are critical to understanding the value to an effective intervention. With new clinical trial data expected soon on emerging therapeutics from several AD studies, the Alzheimer's Association convened a work group of experts to discuss key considerations for interpreting data from cognitive and functional measures and what is considered a clinically meaningful benefit or meaningful slowing of this fatal disease. Our expectations of outcomes from therapeutic interventions in AD may need to be modified.

Breathe In, Breathe Out: Metabolic Regulation of Lung Macrophages in Host Defense Against Bacterial Infection.

Lung macrophages are substantially distinct from other tissue-resident macrophages. They act as frontier sentinels of the alveolar-blood interface and are constantly exposed to various pathogens. Additionally, they precisely regulate immune responses under homeostatic and pathological conditions to curtail tissue damage while containing respiratory infections. As a highly heterogeneous population, the phenotypes and functions of lung macrophages with differing developmental ontogenies are linked to both intrinsic and extrinsic metabolic processes. Importantly, targeting these metabolic pathways greatly impacts macrophage functions, which in turn leads to different disease outcomes in the lung. In this review, we will discuss underlying metabolic regulation of lung macrophage subsets and how metabolic circuits, together with epigenetic modifications, dictate lung macrophage function during bacterial infection.

Making remote measurement technology work in multiple sclerosis, epilepsy and depression: survey of healthcare professionals.

BACKGROUND: Epilepsy, multiple sclerosis (MS) and depression are long term, central nervous system disorders which have a significant impact on everyday life. Evaluating symptoms of these conditions is problematic and typically involves repeated visits to a clinic. Remote measurement technology (RMT), consisting of smartphone apps and wearables, may offer a way to improve upon existing methods of managing these conditions. The present study aimed to establish the practical requirements that would enable clinical integration of data from patients' RMT, according to healthcare professionals. METHODS: This paper reports findings from an online survey of 1006 healthcare professionals currently working in the care of people with epilepsy, MS or depression. The survey included questions on types of data considered useful, how often data should be collected, the value of RMT data, preferred methods of accessing the data, benefits and challenges to RMT implementation, impact of RMT data on clinical practice, and requirement for technical support. The survey was presented on the JISC online surveys platform. RESULTS: Among this sample of 1006 healthcare professionals, respondents were positive about the benefits of RMT, with 73.2% indicating their service would be likely or highly likely to benefit from the implementation of RMT in patient care plans. The data from patients' RMT devices should be made available to all nursing and medical team members and could be reviewed between consultations where flagged by the system. However, results suggest it is also likely that RMT data would be reviewed in preparation for and during a consultation with a patient. Time to review information is likely to be one of the greatest barriers to successful implementation of RMT in clinical practice. CONCLUSIONS: While further work would be required to quantify the benefits of RMT in clinical practice, the findings from this survey suggest that a wide array of clinical team members treating epilepsy, MS and depression would find benefit from RMT data in the care of their patients. Findings presented could inform the implementation of RMT and other digital interventions in the clinical management of a range of neurological and mental health conditions.

The IFNγ-PDL1 Pathway Enhances CD8T-DCT Interaction to Promote Hypertension.

BACKGROUND: Renal T cells contribute importantly to hypertension, but the underlying mechanism is incompletely understood. We reported that CD8Ts directly stimulate distal convoluted tubule cells (DCTs) to increase NCC (sodium chloride co-transporter) expression and salt reabsorption. However, the mechanistic basis of this pathogenic pathway that promotes hypertension remains to be elucidated. METHODS: We used mouse models of DOCA+salt (DOCA) treatment and adoptive transfer of CD8+ T cells (CD8T) from hypertensive animals to normotensive animals in in vivo studies. Co-culture of mouse DCTs and CD8Ts was used as in vitro model to test the effect of CD8T activation in promoting NCC-mediated sodium retention and to identify critical molecular players contributing to the CD8T-DCT interaction. Interferon (IFNγ)-KO mice and mice receiving renal tubule-specific knockdown of PDL1 were used to verify in vitro findings. Blood pressure was continuously monitored via radio-biotelemetry, and kidney samples were saved at experimental end points for analysis. RESULTS: We identified critical molecular players and demonstrated their roles in augmenting the CD8T-DCT interaction leading to salt-sensitive hypertension. We found that activated CD8Ts exhibit enhanced interaction with DCTs via IFN-γ-induced upregulation of MHC-I and PDL1 in DCTs, thereby stimulating higher expression of NCC in DCTs to cause excessive salt retention and progressive elevation of blood pressure. Eliminating IFN-γ or renal tubule-specific knockdown of PDL1 prevented T cell homing into the kidney, thereby attenuating hypertension in 2 different mouse models. CONCLUSIONS: Our results identified the role of activated CD8Ts in contributing to increased sodium retention in DCTS through the IFNγ-PDL1 pathway. These findings provide a new mechanism for T cell involvement in the pathogenesis of hypertension and reveal novel therapeutic targets.

The Patient Voice: Exploring Treatment Preferences in Participants with Mild Cognitive Concerns to Inform Regulatory Decision Making.

OBJECTIVE: We aimed to assess the feasibility of developing a discrete-choice experiment survey to elicit preferences for a treatment to delay cognitive decline among people with a clinical syndrome consistent with early Alzheimer's disease, including the development of self-reported screening criteria to recruit the sample. METHODS: Using input from qualitative interviews, we developed a discrete-choice experiment survey containing a multifaceted beneficial treatment attribute related to slowing cognitive decline for respondents with self-reported cognitive concerns. In two rounds of in-person pretest interviews, we tested and revised the survey text and discrete-choice experiment questions, including examples, language, and levels associated with the Alzheimer's Disease Assessment Scale-Cognitive Subscale, along with a set of de novo self-reported questions for identifying respondents who had neither too mild nor too advanced cognitive decline. Self-reported memory and thinking problems were compared with symptoms from studies of patients with early Alzheimer's disease (e.g., mild cognitive impairment, mild Alzheimer's disease) to determine whether those studies' recruited patients were similar to our anticipated target population. Round 1 pretest interviews resulted in significant simplifications in the survey instrument, revisions to the inclusion and exclusion criteria, and revisions to the screening process. In round 2 of the pretest interviews, the ability of participants to provide consistent responses to the self-reported screening questions was further assessed. In addition, to evaluate participants' ability to understand and independently complete the discrete-choice experiment survey, two interviewers independently evaluated each participant's ability to make trade-offs in the discrete-choice experiment questions and to understand the content of the survey. RESULTS: Round 1 (15 pretest interviews) identified challenges with the survey instrument related to the complexity of the choice questions. The screening process did not screen out seven respondents with more advanced cognitive decline, as determined qualitatively by the interviewers and by these participants' inability to complete the survey. The survey instrument and screening criteria were revised, and an initial online screener was added to the screening process before round 2 pretests. In round 2 pretests, 12 participants reported cognitive problems similar to the target population for the survey but were judged able to understand and independently complete the discrete-choice experiment survey. CONCLUSIONS: We developed self-reported screening criteria that identified a sample of individuals with memory and thinking concerns who were similar to individuals with clinical symptoms of early Alzheimer's disease and who were able to independently complete a simplified discrete-choice experiment survey. Quantitative patient preference studies provide important information on patients' willingness to trade off treatment benefits/risks. Adapting the technique for patients with cognitive decline requires careful testing and adjustments to survey instruments. This work suggests it is the severity of cognitive impairment, rather than its presence, that determines the ability to complete a simplified discrete-choice experiment survey.

Weight and BMI Patterns in a Biologicals-Treated IBD Cohort.

BACKGROUND: Biologic therapies are effective at inducing and maintaining remission in people with inflammatory bowel disease (IBD). Previous studies have associated TNF-a inhibitors with weight gain, however, it is unclear if this is a class-specific effect or a manifestation of good disease control. To clarify this issue, a retrospective study was undertaken to examine weight changes over time during therapy with different biologic agents. METHODS: Adult patients with IBD who received any biological therapy for at least 12 months, between 2008 and 2020, were identified at two specialised IBD services. Demographic, disease, and therapy-related data were examined. Weight change and patterns thereof were examined for each specific therapy and relationships amongst weight outcomes and various predictive factors explored. RESULTS: Of 294 patients (156 females), 165 received Infliximab (IFX), 68 Adalimumab (ADA), 36 Vedolizumab (VDZ) and 25 Ustekinumab (UST). There was a statistically significant weight gain over time in the IFX and VDZ groups and more weight gain in the IFX vs ADA and VDZ vs ADA at most time points. Three weight trajectories were identified: around 95% of patients had small weight loss or a modest weight gain but 5% of patients, most of whom were on IFX had marked weight gain (24.3 kg). Having a baseline high BMI, being female, having an initiation CRP ≤ 5 or albumin > 35 reduced the odds of major weight gain. CONCLUSION: Weight gain in biologic treated IBD patients appears to be associated with clinical factors (male gender, high CRP, low albumin) and therapy-specific factors.

The effect of incarceration on TB treatment outcomes.

BACKGROUND: TB notifications in Latin American prisons have more than doubled over the past two decades; however, treatment outcomes and their determinants among incarcerated individuals in this region are not well understood.METHODS: Newly diagnosed drug-susceptible TB cases reported to Brazil´s Information System for Notifiable Diseases (Sistema de Informação de Agravos de Notificação, SINAN) between January 2015 and December 2017 were included. Multivariate logistic regression was used to assess socio-economic and clinical factors associated with treatment success among incarcerated individuals.RESULTS: Incarcerated individuals (n = 17,776) had greater treatment success than non-incarcerated individuals (n = 160,728; 82.2% vs. 75.1%; P < 0.0001), including after adjusting for demographic and clinical risk factors (adjusted odds ratio aOR 1.27, 95% CI 1.19-1.34). These differences were partially mediated by increased use of directly observed therapy among incarcerated individuals (DOT) (61% vs. 47%; P < 0.001), which was associated with greater efficacy in the incarcerated population (aOR 2.56 vs. aOR 2.17; P < 0.001). DOT was associated with improved treatment success among incarcerated subpopulations at elevated risk of poor outcomes.CONCLUSION: TB treatment success among incarcerated individuals in Brazil is higher than non-incarcerated individuals, but both fall below WHO targets. Expanding the use of DOT and services for socially and medically vulnerable individuals may improve outcomes in carceral settings.

The impact of data from remote measurement technology on the clinical practice of healthcare professionals in depression, epilepsy and multiple sclerosis: survey.

BACKGROUND: A variety of smartphone apps and wearables are available both to help patients monitor their health and to support health care professionals (HCPs) in providing clinical care. As part of the RADAR-CNS consortium, we have conducted research into the application of wearables and smartphone apps in the care of people with multiple sclerosis, epilepsy, or depression. METHODS: We conducted a large online survey study to explore the experiences of HCPs working with patients who have one or more of these conditions. The survey covered smartphone apps and wearables used by clinicians and their patients, and how data from these technologies impacted on the respondents' clinical practice. The survey was conducted between February 2019 and March 2020 via a web-based platform. Detailed statistical analysis was performed on the answers. RESULTS: Of 1009 survey responses from HCPs, 1006 were included in the analysis after data cleaning. Smartphone apps are used by more than half of responding HCPs and more than three quarters of their patients use smartphone apps or wearable devices for health-related purposes. HCPs widely believe the data that patients collect using these devices impacts their clinical practice. Subgroup analyses show that views on the impact of this data on different aspects of clinical work varies according to whether respondents use apps themselves, and, to a lesser extent, according to their clinical setting and job role. CONCLUSIONS: Use of smartphone apps is widespread among HCPs participating in this large European survey and caring for people with epilepsy, multiple sclerosis and depression. The majority of respondents indicate that they treat patients who use wearables and other devices for health-related purposes and that data from these devices has an impact on clinical practice.

Formation of Supported Lipid Bilayers (SLBs) from Buffers Containing Low Concentrations of Group I Chloride Salts.

Supported lipid bilayers (SLBs) are a useful tool for studying the interactions between lipids and other biomolecules that make up a cell membrane. SLBs are typically formed by the adsorption and rupture of vesicles from solution. Although it is known that many experimental factors can affect whether SLB formation is successful, there is no comprehensive understanding of the mechanism. In this work, we have used a quartz crystal microbalance (QCM) to investigate the role of the salt in the buffer on the formation of phosphatidylcholine SLBs on a silicon dioxide (SiO2) surface. We varied the concentration of sodium chloride in the buffer, from 5 to 150 mM, to find the minimum concentration of NaCl that was required for the successful formation of an SLB. We then repeated the experiments with other group I chloride salts (LiCl, KCl, and CsCl) and found that at higher salt concentrations (150 mM) SLB formation was successful for all of the salts used, and the degree of deformation of the adsorbed vesicles at the critical vesicle coverage was cation-dependent. The results showed that at an intermediate salt concentration (50 mM) the critical vesicle coverage was cation-dependent and at low salt concentrations (12.5 mM) the cation used determined whether SLB formation was successful. We found that the successful formation of SLBs could occur at lower electrolyte concentrations for KCl and CsCl than it did for NaCl. To understand these results, we calculated the magnitude of the vesicle-surface interaction energy using the Derjaguin-Landau-Verwey-Overbeek (DLVO) and extended-DLVO theory. We managed to explain the results obtained at higher salt concentrations by including cation-dependent surface potentials in the calculations and at lower salt concentrations by the addition of a cation-dependent hydration force. These results showed that the way that different cations in solution affect the 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)-SiO2 surface interaction energy depends on the ionic strength of the solution.