How do deep-learning models generalize across populations? Cross-ethnicity generalization of COPD detection.

OBJECTIVES: To evaluate the performance and potential biases of deep-learning models in detecting chronic obstructive pulmonary disease (COPD) on chest CT scans across different ethnic groups, specifically non-Hispanic White (NHW) and African American (AA) populations. MATERIALS AND METHODS: Inspiratory chest CT and clinical data from 7549 Genetic epidemiology of COPD individuals (mean age 62 years old, 56-69 interquartile range), including 5240 NHW and 2309 AA individuals, were retrospectively analyzed. Several factors influencing COPD binary classification performance on different ethnic populations were examined: (1) effects of training population: NHW-only, AA-only, balanced set (half NHW, half AA) and the entire set (NHW + AA all); (2) learning strategy: three supervised learning (SL) vs. three self-supervised learning (SSL) methods. Distribution shifts across ethnicity were further assessed for the top-performing methods. RESULTS: The learning strategy significantly influenced model performance, with SSL methods achieving higher performances compared to SL methods (p < 0.001), across all training configurations. Training on balanced datasets containing NHW and AA individuals resulted in improved model performance compared to population-specific datasets. Distribution shifts were found between ethnicities for the same health status, particularly when models were trained on nearest-neighbor contrastive SSL. Training on a balanced dataset resulted in fewer distribution shifts across ethnicity and health status, highlighting its efficacy in reducing biases. CONCLUSION: Our findings demonstrate that utilizing SSL methods and training on large and balanced datasets can enhance COPD detection model performance and reduce biases across diverse ethnic populations. These findings emphasize the importance of equitable AI-driven healthcare solutions for COPD diagnosis. CRITICAL RELEVANCE STATEMENT: Self-supervised learning coupled with balanced datasets significantly improves COPD detection model performance, addressing biases across diverse ethnic populations and emphasizing the crucial role of equitable AI-driven healthcare solutions. KEY POINTS: Self-supervised learning methods outperform supervised learning methods, showing higher AUC values (p < 0.001). Balanced datasets with non-Hispanic White and African American individuals improve model performance. Training on diverse datasets enhances COPD detection accuracy. Ethnically diverse datasets reduce bias in COPD detection models. SimCLR models mitigate biases in COPD detection across ethnicities.

Morphologic Spectrum of HPV-associated Sinonasal Carcinomas.

BACKGROUND: High-risk human papillomavirus (HR-HPV) infection has been increasingly recognized as a risk factor for sinonasal tract carcinomas. However the prevalence and prognostic significance of HPV-associated sinonasal carcinomas is not well known due to limited studies and inconsistency in HPV testing modalities in literatures. Morphologically, HPV-associated sinonasal carcinomas encompass a diverse group of tumors. HPV-associated sinonasal adenocarcinoma has not been reported. The purpose of this study was to determine the prevalence, morphologic spectrum and prognostic implication of HPV-associated sinonasal carcinomas. METHODS: This cohort included 153 sinonasal carcinomas. Tissue microarrays were constructed. P16 immunohistochemistry and HR-HPV E6/7 in-situ Hybridization (ISH) were performed. Carcinomas were deemed HPV-associated based on a positive ISH testing. Clinicopathologic data was collected. RESULTS: 28/153 (18%) sinonasal carcinomas were HPV-associated. HPV-associated carcinomas consisted of 26 (93%) squamous cell carcinomas and variants, 1 (3.5%) HPV-related multiphenotypic sinonasal carcinoma and 1 (3.5%) adenocarcinoma. The HPV-associated adenocarcinoma closely resembled HPV-associated endocervical adenocarcinoma morphologically. HPV-associated carcinomas occurred in 8 (29%) women and 20 (71%) men with a median age of 66 years old. HPV-associated carcinomas were predominantly located at nasal cavity. A trend toward improved overall survival and progression free survival in HPV-associated carcinomas patients was observed, yet without statistical significance. CONCLUSION: Our study identifies a novel HPV-associated sinonasal adenocarcinoma subtype, highlights the broad morphologic spectrum of HPV-associated sinonasal carcinomas, and supports routine p16 testing during pathology practice regardless of tumor subtype followed by a confirmatory HR-HPV testing. This practice is critical for studying the clinical behavior of HPV-associated sinonasal carcinomas.

Therapeutic potential of Garcinia kola against experimental toxoplasmosis in rats.

Cerebral toxoplasmosis, the most common opportunistic infection in immunocompromised individuals, is increasingly reported in immunocompetent individuals due to mutant strains of Toxoplasma gondii, which, furthermore, are reported to be resistant to available treatments. We assessed the therapeutic potential of Garcinia kola, a medicinal plant reported to have antiplasmodial and neuroprotective properties, against experimental toxoplasmosis in rats. Severe toxoplasmosis was induced in male Wistar rats (156.7 ± 4.1 g) by injecting them with 10 million tachyzoites in suspension in 500 µl of saline (intraperitoneal), and exclusive feeding with a low-protein diet [7% protein (weight by weight)]. Then, animals were treated with hexane, dichloromethane, and ethyl acetate fractions of Garcinia kola. Footprints were analysed and open-field and elevated plus maze ethological tests were performed when symptoms of severe disease were observed in the infected controls. After sacrifice, blood samples were processed for Giemsa staining, organs were processed for haematoxylin and eosin staining, and brains were processed for Nissl staining and cell counting. Compared with non-infected animals, the infected control animals had significantly lower body weights (30.27%↓, P = 0.001), higher body temperatures (P = 0.033) during the sacrifice, together with signs of cognitive impairment and neurologic deficits such as lower open-field arena centre entries (P < 0.001), elevated plus maze open-arm time (P = 0.029) and decreased stride lengths and step widths (P < 0.001), as well as neuronal loss in various brain areas. The ethyl acetate fraction of Garcinia kola prevented or mitigated most of these signs. Our data suggest that the ethyl acetate fraction of Garcinia kola has therapeutic potential against cerebral toxoplasmosis.

Property and Activity Refinement of Dihydroquinazolinone-3-carboxamides as Orally Efficacious Antimalarials that Target PfATP4.

To contribute to the global effort to develop new antimalarial therapies, we previously disclosed initial findings on the optimization of the dihydroquinazolinone-3-carboxamide class that targets PfATP4. Here we report on refining the aqueous solubility and metabolic stability to improve the pharmacokinetic profile and consequently in vivo efficacy. We show that the incorporation of heterocycle systems in the 8-position of the scaffold was found to provide the greatest attainable balance between parasite activity, aqueous solubility, and metabolic stability. Optimized analogs, including the frontrunner compound S-WJM992, were shown to inhibit PfATP4-associated Na+-ATPase activity, gave rise to a metabolic signature consistent with PfATP4 inhibition, and displayed altered activities against parasites with mutations in PfATP4. Finally, S-WJM992 showed appreciable efficacy in a malaria mouse model and blocked gamete development preventing transmission to mosquitoes. Importantly, further optimization of the dihydroquinazolinone class is required to deliver a candidate with improved pharmacokinetic and risk of resistance profiles.

Defining minimum work priorities in emergency general surgery in a national cohort.

INTRODUCTION: Emergency general surgery is typically delivered in addition to routine elective care. Models such as acute surgical assessment units and reduced elective working have been explored to reduce the conflict between these competing demands. We aim to identify the models used, the cohorts of patients seen, and the staffing levels in each system. METHODS: Data on general surgery activities were obtained from the National Quality Assurance and Improvement System (NQAIS) and previously published data. The mode of delivery of acute services in other countries was collated from national surgical bodies and published position statements. RESULTS: National on-call services are supra-elective or parallel to elective streams with little dedicated on-call. Internationally, many similar countries are moving to separate acute and elective care to ensure both are performing optimally. Staff in Model 3 hospitals are frequently on call with variable but small operative numbers but represent a combination of high and low acuity. These consultants need a wider breadth of surgical skills than Model 4 hospitals due to a lack of local specialists. CONCLUSION: The majority of national hospitals still work a traditional on-call model, with limited adoption of separate on-call and elective workstreams. Preserving the elective workload is likely to require separation of these priorities, which is difficult with current staffing levels. The use of Acute Surgical Assessment Units (ASAUs) within emergency surgical networks may improve patient outcomes by regionalising the delivery of higher acuity care.

Racial and ethnic associations with interstitial lung disease and healthcare utilization in patients with systemic sclerosis.

OBJECTIVE: Racial and ethnic differences in presentation and outcomes have been reported in systemic sclerosis (SSc) and SSc-interstitial lung disease (ILD). However, prior studies have limited diversity. We aim to evaluate if there are racial/ethnic differences associated with ILD, time intervals between SSc and ILD and with emergency department (ED) visit or hospitalization rates. METHODS: Clinical and sociodemographic variables were extracted for 756 patients with SSc from longitudinal health records in an integrated health-system. Logistic regression models analyzed the association of covariates with ILD and age at SSc-ILD. Healthcare outcomes were analyzed with complementary log-log regression models. RESULTS: Overall, 33.7% of patients in the cohort had an ILD code, with increased odds for Asian (odds ratio [OR], 2.60; 95% confidence interval [CI], 1.29-5.28; p=0.008) compared with White patients. The predicted age in years of SSc-ILD was younger for Hispanic (estimate, -6.5; 95% CI, -13--0.21; p = 0.04) and Black/African American patients (-10; 95% CI -16--4.9; p < 0.001) compared with White patients. Black/African American patients were more likely to have an ILD code before an SSc code (59% compared with 20.6% of White patients), and the shortest interval from SSc to ILD (3 months). Black/African American (HR, 2.59; 95% CI 1.47-4.49; p = 0.001) and Hispanic patients (HR 2.29; 95% CI 1.37- 3.82; p = 0.002) had higher rates of an ED visit. CONCLUSION: We found that odds of SSc-ILD differed by racial/ethnic group, minoritized patients had earlier age of presentation, and greater rates of an ED visit.

Targeting microbial pathogenic mechanisms as a novel therapeutic strategy in IBD.

BACKGROUND: Current therapy for patients suffering from inflammatory bowel diseases (IBD) is focused on inflammatory mechanisms exclusively and not the dysbiotic microbiota, despite growing evidence implicating a role for intestinal microbes in disease. MAIN BODY: Ongoing research into the intestinal microbiota of IBD patients, using new technologies and/or deeper application of existing ones, has identified a number of microorganisms whose properties and behaviors warrant consideration as causative factors in disease. Such studies have implicated both bacteria and fungi in the pathogenesis of disease. Some of these organisms manifest mechanisms that should be amenable to therapeutic intervention via either conventional or novel drug discovery platforms. Of particular note is a deeper characterization of microbial derived proteases and their destructive potential. CONCLUSION: Given the steady progress on the mechanistic role of the microbiota in inflammatory diseases, it is reasonable to anticipate a future in which therapeutics targeting microbial derived pathogenic factors play an important role in improving the lives of IBD patients.

Chemical Immobilization Effects on Cougar (Felis concolor) Movement.

Capturing and handling wildlife is a common practice for both management and research. As telemetry use has become common, the need to capture and chemically immobilize wildlife has increased. Understanding how long the effects of immobilizing agents last after releasing the animal is often poorly understood but needed to ensure that analyses use data that reflect natural behavior. Between 2016 and 2021, 87 cougars (Puma concolor) were chemically immobilized with medetomidine, zolazepam, and tiletamine (MZT) and collared across west-central Alberta, Canada, 27 of which were individuals being recollared. We examined the distance an individual traveled per day and compared equivalent periods before and after the recollaring event to determine whether postcapture movement rates were significantly different from precapture rates. Within 1 d of the recollaring, daily movement rates had returned to precapture rates (t20=2.09, P=0.18). Our results provide insight on how MZT used in cougars affects their postcapture movement and thus may be helpful in interpreting movement data after release.

Diffusion tensor analysis of white matter tracts is prognostic of persisting post-concussion symptoms in collegiate athletes.

BACKGROUND AND OBJECTIVES: After a concussion diagnosis, the most important issue for patients and loved ones is how long it will take them to recover. The main objective of this study is to develop a prognostic model of concussion recovery. This model would benefit many patients worldwide, allowing for early treatment intervention. METHODS: The Concussion Assessment, Research and Education (CARE) consortium study enrolled collegiate athletes from 30 sites (NCAA athletic departments and US Department of Defense service academies), 4 of which participated in the Advanced Research Core, which included diffusion-weighted MRI (dMRI) data collection. We analyzed the dMRI data of 51 injuries of concussed athletes scanned within 48 h of injury. All athletes were cleared to return-to-play by the local medical staff following a standardized, graduated protocol. The primary outcome measure is days to clearance of unrestricted return-to-play. Injuries were divided into early (return-to-play < 28 days) and late (return-to-play >= 28 days) recovery based on the return-to-play clinical records. The late recovery group meets the standard definition of Persisting Post-Concussion Symptoms (PPCS). Data were processed using automated, state-of-the-art, rigorous methods for reproducible data processing using brainlife.io. All processed data derivatives are made available at https://brainlife.io/project/63b2ecb0daffe2c2407ee3c5/dataset. The microstructural properties of 47 major white matter tracts, 5 callosal, 15 subcortical, and 148 cortical structures were mapped. Fractional Anisotropy (FA) and Mean Diffusivity (MD) were estimated for each tract and structure. Correlation analysis and Receiver Operator Characteristic (ROC) analysis were then performed to assess the association between the microstructural properties and return-to-play. Finally, a Logistic Regression binary classifier (LR-BC) was used to classify the injuries between the two recovery groups. RESULTS: The mean FA across all white matter volume was negatively correlated with return-to-play (r = -0.38, p = 0.00001). No significant association between mean MD and return-to-play was found, neither for FA nor MD for any other structure. The mean FA of 47 white matter tracts was negatively correlated with return-to-play (rµ = -0.27; rσ = 0.08; rmin = -0.1; rmax = -0.43). Across all tracts, a large mean ROC Area Under the Curve (AUCFA) of 0.71 ± 0.09 SD was found. The top classification performance of the LR-BC was AUC = 0.90 obtained using the 16 statistically significant white matter tracts. DISCUSSION: Utilizing a free, open-source, and automated cloud-based neuroimaging pipeline and app (https://brainlife.io/docs/tutorial/using-clairvoy/), a prognostic model has been developed, which predicts athletes at risk for slow recovery (PPCS) with an AUC=0.90, balanced accuracy = 0.89, sensitivity = 1.0, and specificity = 0.79. The small number of participants in this study (51 injuries) is a significant limitation and supports the need for future large concussion dMRI studies and focused on recovery.

The role of helper lipids in optimising nanoparticle formulations of self-amplifying RNA.

Lipid nanoparticle (LNP) formulation plays a vital role in RNA vaccine delivery. However, further optimisation of self-amplifying RNA (saRNA) vaccine formulation could help enhance seroconversion rates in humans and improve storage stability. Altering either the ionisable or helper lipid can alter the characteristics and performance of formulated saRNA through the interplay of the phospholipid's packing parameter and the geometrical shape within the LNP membrane. In this study, we compared the impact of three helper lipids (DSPC, DOPC, or DOPE) used with two different ionisable lipids (MC3 and C12-200) on stability, transfection efficiency and the inflammation and immunogenicity of saRNA. While helper lipid identity altered saRNA expression across four cell lines in vitro, this was not predictive of an ex vivo or in vivo response. The helper lipid used influenced LNP storage where DSPC provided the best stability profile over four weeks at 2-8 °C. Importantly, helper lipid impact on LNP storage stability was the best predictor of expression in human skin explants, where C12-200 in combination with DSPC provided the most durable expression. C12-200 LNPs also improved protein expression (firefly luciferase) and humoral responses to a SARS-CoV-2 spike saRNA vaccine compared to MC3 LNPs, where the effect of helper lipids was less apparent. Nevertheless, the performance of C12-200 in combination with DSPC appears optimal for saRNA when balancing preferred storage stability requirements against in vivo and ex vivo potency. These data suggest that helper lipid influences the stability and functionality of ionisable lipid nanoparticle-formulated saRNA.

Association Between Serial B-Type Natriuretic Peptide Levels, Vasoactive Drug Weaning, and Adverse Cardiovascular Outcomes in Pediatric Heart Failure.

BACKGROUND: Children hospitalized with acute decompensated heart failure (ADHF) frequently require intravenous vasoactive (IVV) support drugs and are at risk for adverse cardiovascular (ACV) outcomes. We wished to assess whether serial changes in B-type natriuretic peptide (BNP) levels are associated with successful weaning off IVV support and/or prespecified ACV outcomes in children hospitalized with ADHF. METHODS AND RESULTS: Children hospitalized with ADHF from 2005 to 2021 at our institution were assessed for serial changes in BNP, weaning off of IVV support, and ACV outcomes. Changes in BNP level were evaluated using linear mixed-effects modeling. Bonferroni correction was used to adjust for multiple hypothesis testing. In 131 hospitalizations of children with ADHF, the median age was 4.8 years, with 74% receiving IVV support. ACV outcomes occurred in 62 children. IVV support was associated with lower admission left ventricular ejection fraction (26.7% versus 32%, P=0.002), more severe left ventricular dilation (left ventricular internal diastolic dimension Z score 5.9 versus 3.1, P=0.021) moderate or more mitral regurgitation (41.3% versus 20.6%, P=0.038), and qualitative right ventricular systolic dysfunction (in 45.4% versus 11.8%, P<0.001). Decline in BNP levels was more rapid in patients who were successfully weaned from IVV support (-0.20 versus -0.03 2log pg/mL per day, P<0.001) and in the non-ACV group (-0.17 versus -0.03 2log pg/mL per day, P<0.001). Right ventricular systolic dysfunction was an independent risk factor for ACV (odds ratio, 2.49; P=0.045). CONCLUSIONS: The declining rate of serial BNP levels was associated with weaning from IVV support and no ACV outcomes in children hospitalized with ADHF. Right ventricular systolic dysfunction was associated with ACV outcomes.

Hip Arthroscopy Versus Physical Therapy for the Treatment of Symptomatic Acetabular Labral Tears in Patients Older Than 40 Years: 24-Month Results From a Randomized Controlled Trial.

BACKGROUND: The indications for hip arthroscopy in patients aged ≥40 years remain controversial, as observational studies have suggested that advanced age portends poor functional outcomes, poor durability of improvement, and high rates of conversion to total hip arthroplasty. PURPOSE: To compare hip arthroscopy versus nonoperative management for symptomatic labral tears in patients aged ≥40 years with limited radiographic osteoarthritis. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: This single-surgeon, parallel randomized controlled trial included patients aged ≥40 years with limited osteoarthritis (Tönnis grades 0-2) who were randomized 1:1 to arthroscopic surgery with postoperative physical therapy (SPT) or physical therapy alone (PTA). Patients who received PTA and achieved unsatisfactory improvement were permitted to cross over to SPT after completing ≥14 weeks of physical therapy (CO). The primary outcomes were the International Hip Outcome Tool-33 score and modified Harris Hip Score at 24 months after surgery, and secondary outcomes included other patient-reported outcome measures and the visual analog scale for pain. The primary analysis was performed on an intention-to-treat basis using linear mixed-effects models. Sensitivity analyses included modified as-treated and treatment-failure analyses. RESULTS: A total of 97 patients were included, with 52 (53.6%) patients in the SPT group and 45 (46.4%) patients in the PTA group. Of the patients who underwent PTA, 32 (71.1%) patients crossed over to arthroscopy at a mean of 5.10 months (SD, 3.3 months) after physical therapy initiation. In both intention-to-treat and modified as-treated analyses, the SPT group displayed superior mean patient-reported outcome measure and pain scores across the study period for nearly all metrics relative to the PTA group. In the treatment-failure analysis, the SPT and CO groups showed greater improvement across all metrics compared with PTA; however, post hoc analyses revealed no significant differences in improvement between the SPT and CO groups. No significant differences were observed between groups in rates of total hip arthroplasty conversion. CONCLUSION: In patients ≥40 years of age with limited osteoarthritis, hip arthroscopy with postoperative physical therapy led to better outcomes than PTA at a 24-month follow-up. However, additional preoperative physical therapy did not compromise surgical outcomes and allowed some patients to avoid surgery. When surgery is indicated, age ≥40 years should not be considered an independent contraindication to arthroscopic acetabular labral repair. REGISTRATION: NCT03909178 (ClinicalTrials.gov identifier).

Survival Outcomes in Patients with Resectable Gastric Cancer Treated with Total Neoadjuvant Therapy.

BACKGROUND: Perioperative chemotherapy has become the standard of care for locally advanced gastric cancer. Total neoadjuvant therapy (TNT), including both chemotherapy and chemoradiation, is utilized in other gastrointestinal malignancies. We determined survival in a contemporary cohort of gastric cancer patients treated with TNT. METHODS: Using a prospective institutional database, patients diagnosed with cT2-4 or cN+ gastric adenocarcinoma (January 2012 to June 2022) who underwent staging laparoscopy, received TNT, and underwent gastrectomy were identified. Overall survival (OS) and disease-specific survival (DSS) were determined using standard statistical methods. RESULTS: The study included 203 patients. The most common TNT sequence was induction chemotherapy followed by chemoradiation (n = 186 [91.6%]). A total of 195 (96.1%) patients completed planned neoadjuvant treatments. Surgery included total gastrectomy in 108 (53.2%), extended (D1+/D2) lymphadenectomy in 193 (95.1%), and adjacent organ resection in 19 (9.4%) patients. Pathologic complete response (pCR) was achieved in 32 (15.8%) patients. The 5-year OS rate was 65.2% (95% confidence interval [CI] 57.8-73.5%), and the 5-year DSS rate was 70.8% (95% CI 63.6-78.9%) in the study cohort. Among patients with pCR, the 5-year OS rate was 89.1% (95% CI 78.1-100.0%), and the 5-year DSS rate was 96.9% (95% CI 91-100%). Posttreatment pathologic N and M stages were the strongest prognostic indicators associated with both OS and DSS. CONCLUSIONS: Total neoadjuvant therapy for resectable gastric cancer is associated with a high rate of treatment completion and promising survival outcomes. Prospective comparisons with perioperative treatment are needed to identify patients most likely to benefit from TNT.

A conserved oomycete effector RxLR23 triggers plant defense responses by targeting ERD15La to release NbNAC68.

Oomycete pathogens deliver many effectors to enhance virulence or suppress plant immunity. Plant immune networks are interconnected, in which a few effectors can trigger a strong defense response when recognized by immunity-related proteins. How effectors activate plant defense response remains poorly understood. Here we report Phytophthora capsici effector RxLR23KM can induce plant cell death and plant immunity. RxLR23KM specifically binds to ERD15La, a regulator of abscisic acid and salicylic acid pathway, and the binding intensity depends on the amino acid residues (K93 and M320). NbNAC68, a downstream protein of ERD15La, can stimulate plant immunity that is compromised after binding with ERD15La. Silencing of NbNAC68 substantially prevents the activation of plant defense response. RxLR23KM binds to ERD15La, releasing NbNAC68 to activate plant immunity. These findings highlight a strategy of plant defense response that ERD15La as a central regulator coordinates RxLR23KM to regulate NbNAC68-triggered plant immunity.

Impact of sex on clinical outcome in early Multiple Sclerosis.

BACKGROUND: Previous evidence suggests sex differences in the clinical course of relapsing remitting multiple sclerosis (RRMS), but comprehensive early-stage prospective studies are lacking. We aim to quantify the impact of sex on clinical outcomes in early-stage RRMS. METHODS: Utilizing prospective cohort data, we assessed the impact of biological sex on time-to-relapse, disability progression (Expanded Disability Status Scale [EDSS]), extremity function (Nine-Hole Peg Test, Timed-25-food walk test), cognition (Paced Auditory Serial Addition Test, Symbol Digit Modalities Test), quality-of-life (Hamburg Quality of Life Questionnaire in Multiple Sclerosis, Short-Form-36), fatigue (Fatigue Severity Scale, Fatigue Scale for Motor and Cognitive functions), and depression (Beck Depression Inventory-II) in clinically isolated syndrome (CIS) or RRMS patients. Inclusion was within 12 months of symptom onset. Linear, negative binomial, mixed, and Cox models estimated male vs. female effects at the four-year follow-up including baseline-to-follow-up course. RESULTS: We included 149 patients (65.1 % female). Eighty-five completed four-year follow-up. No sex differences in time-to-relapse emerged (HR = 0.91;95 %CI = 0.53-1.58). Males had no increased risk of EDSS worsening (OR = 0.75;95 %CI = 0.21-2.35) compared to females. Similarly, minor/no sex differences emerged in other outcomes. CONCLUSIONS: Four years after first manifestation, neither disease activity (disability progression and relapse rate) nor patient-reported outcomes showed sex-related disparities in this early-MS-cohort. GOV IDENTIFIER: NCT01371071.

Excess Folic Acid and Vitamin B12 Deficiency: Clinical Implications?

BACKGROUND: In the 1940s to 1950s, high-dose folic acid supplements (>5 mg/d) were used clinically to reverse the megaloblastic anemia of vitamin B12 deficiency caused by pernicious anemia. However, this treatment strategy masked the underlying B12 deficiency and possibly exacerbated its neuropathological progression. The issue of masking and exacerbating B12 deficiency has recently been rekindled with the institution of folic acid fortification and the wide-spread use of folic acid supplements. OBJECTIVES: The objectives of this review are to describe clinical and epidemiological evidence that excess folic acid exacerbates B12 deficiency, to summarize a hypothesis to explain this phenomenon, and to provide guidance for clinicians. RESULTS: Cognitive function test scores are lower and blood homocysteine and methylmalonic acid concentrations are higher in people with low B12 and elevated folate than in those with low B12 and nonelevated folate. High-dose folic acid supplementation in patients with pernicious anemia or epilepsy cause significant reductions in serum B12. It is hypothesized that high-dose folic acid supplements cause depletion of serum holotranscobalamin and thus exacerbate B12 deficiency. CONCLUSION: The evidence for excess folic acid exacerbating B12 deficiency is primarily correlative or from uncontrolled clinical observations, and the hypothesis to explain the phenomenon has not yet been tested. Nonetheless, the evidence is sufficiently compelling to warrant increased vigilance for identifying B12 deficiency in at risk individuals, including older adults and others with low B12 intake or conditions that are associated with B12 malabsorption, who also ingest excessive folic acid or are prescribed folic acid in high doses.

Plain language titleExcess Folic Acid and Vitamin B12 Deficiency: Clinical Implications?Plain language summaryIt has been known for many decades that high doses of the B vitamin supplement, folic acid, can alleviate the anemia of vitamin B12 deficiency, at least temporarily. However, by alleviating the anemia, such folic acid supplements were said to "mask" the underlying vitamin B12 deficiency, thus allowing neurological damage to continue or possibly be exacerbated. Consequently, treating vitamin B12 deficiency with high dose folic acid was discontinued in the 1970s. The issue of whether folic acid supplements can exacerbate vitamin B12 deficiency reemerged in the 1990s with folic acid fortification of cereals and grains in the United States and Canada (and now in over 80 countries around the world) to prevent spina bifida and other birth defects. This narrative review summarizes the results of studies that have assessed the relationships between folic acid and folate and vitamin B12 status in patients and in populations. A recent hypothesis on how folic acid might exacerbate vitamin B12 deficiency is summarized, and recommendations to clinicians are made for increased vigilance in assessing vitamin B12 status in certain groups at risk of vitamin B12 deficiency, including older adults, people with gastrointestinal issues and other factors that cause vitamin B12 malabsorption, people with unexplained neurological problems, and people who follow vegan or vegetarian diets which are naturally low in vitamin B12.

2023 American College of Rheumatology (ACR)/American College of Chest Physicians (CHEST) Guideline for the Treatment of Interstitial Lung Disease in People with Systemic Autoimmune Rheumatic Diseases.

OBJECTIVE: We provide evidence-based recommendations regarding the treatment of interstitial lung disease (ILD) in adults with systemic autoimmune rheumatic diseases (SARDs). METHODS: We developed clinically relevant population, intervention, comparator, and outcomes questions. A systematic literature review was then performed, and the available evidence was rated using the Grading of Recommendations, Assessment, Development, and Evaluation methodology. A panel of clinicians and patients reached consensus on the direction and strength of the recommendations. RESULTS: Thirty-five recommendations were generated (including two strong recommendations) for first-line SARD-ILD treatment, treatment of SARD-ILD progression despite first-line ILD therapy, and treatment of rapidly progressive ILD. The strong recommendations were against using glucocorticoids in systemic sclerosis-ILD as a first-line ILD therapy and after ILD progression. Otherwise, glucocorticoids are conditionally recommended for first-line ILD treatment in all other SARDs. CONCLUSION: This clinical practice guideline presents the first recommendations endorsed by the American College of Rheumatology and American College of Chest Physicians for the treatment of ILD in people with SARDs.

2023 American College of Rheumatology (ACR)/American College of Chest Physicians (CHEST) Guideline for the Screening and Monitoring of Interstitial Lung Disease in People with Systemic Autoimmune Rheumatic Diseases.

OBJECTIVE: We provide evidence-based recommendations regarding screening for interstitial lung disease (ILD) and the monitoring for ILD progression in people with systemic autoimmune rheumatic diseases (SARDs), specifically rheumatoid arthritis, systemic sclerosis, idiopathic inflammatory myopathies, mixed connective tissue disease, and Sjögren disease. METHODS: We developed clinically relevant population, intervention, comparator, and outcomes questions related to screening and monitoring for ILD in patients with SARDs. A systematic literature review was performed, and the available evidence was rated using the Grading of Recommendations, Assessment, Development, and Evaluation methodology. A Voting Panel of interdisciplinary clinician experts and patients achieved consensus on the direction and strength of each recommendation. RESULTS: Fifteen recommendations were developed. For screening people with these SARDs at risk for ILD, we conditionally recommend pulmonary function tests (PFTs) and high-resolution computed tomography of the chest (HRCT chest); conditionally recommend against screening with 6-minute walk test distance (6MWD), chest radiography, ambulatory desaturation testing, or bronchoscopy; and strongly recommend against screening with surgical lung biopsy. We conditionally recommend monitoring ILD with PFTs, HRCT chest, and ambulatory desaturation testing and conditionally recommend against monitoring with 6MWD, chest radiography, or bronchoscopy. We provide guidance on ILD risk factors and suggestions on frequency of testing to evaluate for the development of ILD in people with SARDs. CONCLUSION: This clinical practice guideline presents the first recommendations endorsed by the American College of Rheumatology and American College of Chest Physicians for the screening and monitoring of ILD in people with SARDs.