[Posted 31/May/2023]

AUDIENCE: Hematology, Infectious Disease

DETAILS: The U.S. Food and Drug Administration finalized recommendations for assessing blood donor eligibility using a set of individual risk-based questions to reduce the risk of transfusion-transmitted HIV. These questions will be the same for every donor, regardless of sexual orientation, sex or gender. Blood establishments may now implement these recommendations by revising their donor history questionnaires and procedures.

This updated policy is based on the best available scientific evidence and is in line with policies in place in countries like the United Kingdom and Canada. It will potentially expand the number of people eligible to donate blood, while also maintaining the appropriate safeguards to protect the safety of the blood supply.

These final recommendations are consistent with the policy initially proposed in January. The FDA worked diligently to review and consider all comments submitted to the agency to finalize these recommendations as quickly as possible. "The FDA has worked diligently to evaluate our policies and ensure we had the scientific evidence to support individual risk assessment for donor eligibility while maintaining appropriate safeguards to protect recipients of blood products. The implementation of these recommendations will represent a significant milestone for the agency and the LGBTQI+ community," said Peter Marks, M.D., PhD., director of the FDA’s Center for Biologics Evaluation and Research. "The FDA is committed to working closely with the blood collection industry to help ensure timely implementation of the new recommendations and we will continue to monitor the safety of the blood supply once this individual risk-based approach is in place."

This policy eliminates time-based deferrals and screening questions specific to men who have sex with men (MSM) and women who have sex with MSM. Under the final guidance issued today, all prospective blood donors will answer a series of individual, risk-based questions to determine eligibility. All prospective donors who report having a new sexual partner, or more than one sexual partner in the past three months, and anal sex in the past three months, would be deferred to reduce the likelihood of donations by individuals with new or recent HIV infection who may be in the window period for detection of HIV by nucleic acid testing.

Additionally, under these final recommendations, those taking medications to treat or prevent HIV infection (e.g., antiretroviral therapy (ART), pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP)), will also be deferred. Though these antiretroviral drugs are safe, effective, and an important public health tool, the available data demonstrate that their use may delay detection of HIV by currently licensed screening tests for blood donations, which may potentially give false negative results. Although HIV is not transmitted sexually by individuals with undetectable viral levels, this does not apply to transfusion transmission of HIV because a blood transfusion is administered intravenously, and a transfusion involves a large volume of blood compared to exposure with sexual contact. As stated in the guidance, individuals should not stop taking their prescribed medications, including PrEP, or PEP, in order to donate blood. The FDA remains committed to evaluating additional data and new technological developments as they become available to inform our donor eligibility recommendations.

The FDA has been evaluating alternatives to time-based deferrals for MSM and helping to facilitate the generation of scientific evidence that would support an individual risk based- assessment blood donor questionnaire. This scientific information has given the agency a solid foundation to support this new policy. The FDA strongly believes the implementation of an individual risk-based approach will not adversely affect the safety or availability of the U.S. blood supply.

The FDA carefully reviewed numerous data sources, including data from countries with similar HIV epidemiology that have implemented an individual risk-based approach for assessing donor eligibility, surveillance information obtained from the Transfusion Transmissible Infections Monitoring System, performance characteristics of nucleic acid testing for HIV and the FDA-funded Assessing Donor Variability And New Concepts in Eligibility study. The ADVANCE study examined the rates of HIV risk factors, such as anal sex and rates of HIV infection, as well as the usage of medications to treat or prevent HIV infection, among MSM study participants.

Copyright © FDA. All rights reserved.

Source: FDA Finalizes Move to Recommend Individual Risk Assessment to Determine Eligibility for Blood Donations. FDA. Published: May 11, 2023.

[Posted 27/May/2025]

AUDIENCE: Gastroenterology, Ob/Gyn, Internal Medicine

KEY FINDINGS: Pregnancy MDC exposures may increase risk of liver injury and steatosis, particularly in children. Adequate FA supplementation and maternal cobalt levels may attenuate these associations.

BACKGROUND: Scarce knowledge about the impact of metabolism-disrupting chemicals (MDCs) on steatotic liver disease limits opportunities for intervention. We evaluated pregnancy MDC-mixture associations with liver outcomes, and effect modification by folic acid (FA) supplementation in mother-child pairs.

DETAILS: Authors studied ~200 mother-child pairs from the Mexican PROGRESS cohort, with 43 MDCs measured during pregnancy (estimated air pollutants, blood/urine metals or metalloids, urine high- and low-molecular-weight phthalate [HMWPs, LMWPs] and organophosphate-pesticide metabolites), and serum liver enzymes (ALT, AST) at ~9 years post-parturition. Outcomes included elevated liver enzymes in children and established clinical scores for steatosis and fibrosis in mothers (i.e., AST:ALT, FLI, HSI, FIB-4). Bayesian-weighted quantile sum regression assessed MDC-mixture associations with liver outcomes. We further examined chemical-chemical interactions and effect modification by self-reported FA supplementation. In children, many MDC-mixtures were associated with liver injury. Per quartile HMWP-mixture increase, ALT increased by 10.1% (95% CI 1.67%, 19.4%) and AST by 5.27% (95% CI 0.80%, 10.1%). LMWP-mixtures and air pollutant-mixtures were associated with higher AST and ALT, respectively. Air pollutant and non-essential metal/element associations with liver enzymes were attenuated by maternal cobalt blood concentrations (p-interactions <0.05). In mothers, only the LMWP-mixture was associated with odds for steatosis (odds ratio = 1.53, 95% CI 1.01-2.28 for HSI >36, and odds ratio 1.62, 95% CI 1.05-2.49 for AST:ALT <1). In mothers and children, most associations were attenuated (null) at FA supplementation >=600 µg/day (p-interactions <0.05).

Copyright © Elsevier Inc. All rights reserved.

Source: India-Aldana, S., Midya, V., Betanzos-Robledo, L., et al. Impact of Metabolism-Disrupting Chemicals and Folic Acid Supplementation on Liver Injury and Steatosis in Mother-Child Pairs. Journal of Hepatology. 2025; 82(6): 956-966. Published: June, 2025. DOI: 10.1016/j.jhep.2024.11.050 .

A Cohort Study From the EINSTEIN-Jr Phase 3 Trial

[Posted 18/May/2025]

AUDIENCE: Hematology, Pediatric

KEY FINDINGS: Incidences of recurrent venous thromboembolism and bleeding during extended-phase anticoagulant treatment were low and similar to those observed during acute-phase treatment and adult studies on extended-phase anticoagulant treatment, providing valuable information for clinical practice on extended anticoagulation in children.

BACKGROUND: Extended-phase anticoagulation of venous thromboembolism in children is not well documented nor systematically reported. Previously, we reported on recurrent venous thromboembolism and bleeding during acute-phase anticoagulation in EINSTEIN-Jr, a randomised controlled study in 500 children with venous thromboembolism comparing rivaroxaban to standard anticoagulants. The aim of the present study was to evaluate the efficacy and safety of extended-phase anticoagulant therapy in children and to characterise factors associated with the decision to extend anticoagulation.

DETAILS: Children aged 17 years or younger, who were enrolled in the EINSTEIN-Jr trial (NCT02234843) from 107 paediatric hospitals in 28 countries, and who had previously completed a 3-month acute anticoagulation treatment phase (1-month in children <2 years with catheter-related venous thromboembolism) for acute venous thromboembolism within the trial were included in this cohort study. After completion of the preceding acute anticoagulation treatment phase, children could extend study treatment for up to 9 months (or up to 2 months for children <2 years with catheter-related venous thromboembolism). Study anticoagulants were bodyweight-adjusted rivaroxaban (tablets or suspension) in a 20 mg equivalent dose or standard anticoagulants (heparin or vitamin K antagonist). The main outcomes were suspected recurrent venous thromboembolism (primary efficacy outcome) and clinically relevant bleeding (principal safety outcome), both confirmed or refuted by appropriate objective testing. Cumulative incidences of efficacy and safety outcomes are reported for children who received extended anticoagulation within the framework of the study. We also compared demographic and clinical characteristics of those administered any extended-phase anticoagulation (whether within or outside the framework of the study) with those not administered extended-phase anticoagulation, applying multivariable logistic regression. 248 (51%) children received extended-phase anticoagulation between Nov 14, 2014, and Jan 15, 2019, 214 within the study and 34 outside the framework of the study. During extended-phase anticoagulant treatment, recurrent venous thromboembolism occurred in three (1%) of the 214 children within the study (cumulative incidence 3.0%; 95% CI 0.9-9.8). Clinically relevant non-major bleeding occurred in four (2%) of 214 children (3.3%; 1.2-9.2). Fatal venous thromboembolism or major bleeding did not occur. Outcome rates were similar with rivaroxaban or standard anticoagulants. Symptomatic index venous thromboembolism (odds ratio 1.88; 95% CI 1.14-3.11), unprovoked venous thromboembolism or persistent risk factor (2.16; 1.46-3.19), and residual thrombosis on repeat imaging (3.79; 2.52-5.71) were associated with the decision to extend anticoagulation.

Copyright © Elsevier Ltd. All rights reserved.

Source: Male, C., Lensing, A. W. A., Chan, A. K. C., et al. Extended-Phase Anticoagulant Treatment of Acute Venous Thromboembolism in Children: A Cohort Study From the EINSTEIN-Jr Phase 3 Trial. The Lancet Haematology. 2025; 12(5):5, e357-e364. Published: April, 2025. DOI: PIIS2352-3026(25)00067-5.

A Meta-analysis of Diagnostic Test Accuracy

[Posted 12/May/2025]

AUDIENCE: Gastroenterology, Internal Medicine

KEY FINDINGS: Study establishes evidence of the superior diagnostic accuracy of conventional SATs over rapid SATs for detecting H. pylori infection in adults. Also, authors provide valuable insights into the impact of using monoclonal or polyclonal antibodies and different assessment techniques on diagnostic accuracy measures.

BACKGROUND: The stool antigen test (SAT) is a convenient noninvasive option for the diagnosis of Helicobacter pylori (H. pylori) infection. However, despite having been previously evaluated, there is currently a lack of evidence regarding the comparative accuracy of conventional and rapid SATs utilizing monoclonal or polyclonal antibodies in adults. Here, authors perform a thorough statistical synthesis to determine and compare the diagnostic accuracy of conventional and rapid SATs for the diagnosis of H. pylori infection in adults.

DETAILS: Authors conducted independent searches through July 25, 2023, for studies evaluating the accuracy of SAT against a reference standard. Authors assessed methodological quality using Quality Assessment of Diagnostic Accuracy Studies-2 and calculated overall accuracy measures using the bivariate random-effect model. Authors also conducted subgroup analyses based on model and assessment technique, and Spearman correlation analysis to investigate a possible threshold effect. Authors generated summary receiver operating characteristic curves to assess heterogeneity and evaluated publication bias. Conventional SAT demonstrated superior sensitivity (92.19% vs 85.79%), specificity (92.93% vs 91.18%), likelihood ratios (LR+ 9.68 vs 8.16; LR- 0.10 vs 0.15), and area under the curve (0.958 vs 0.940) compared with rapid SAT. Notably, the diagnostic odds ratio for conventional SAT (114.70) significantly outperformed rapid SAT (diagnostic odds ratio: 57.72). Correlation analysis revealed no threshold effect and summary receiver operating characteristic curves showed consistent accuracy for both tests.

Copyright © Wolters Kluwer Health, Inc. All rights reserved.

Source: Silva Luz, M., Tianeze de Castro, C., Bueno Lemos, F. F., et al. (20245). Stool Antigen Test for Helicobacter Pylori Infection in Adults: A Meta-analysis of Diagnostic Test Accuracy. Journal of Clinical Gastroenterology. 2025; 59(5): 393-404. Published: May/June 2025, 2025. DOI: 10.1097/MCG.0000000000002102.

[Posted 25/Mar/2025]

AUDIENCE: Pediatric, Family Medicine

KEY FINDINGS: Authors report a prospective study involving children that showed overestimation of saturation by pulse oximetry that was attributable to skin tone. This overestimation could lead to undertreatment of hypoxemia and contribute to racial inequities in outcomes. Additional studies are needed in populations with a greater proportion of persons with darker skin tone. The findings emphasize that current FDA guidance for pulse-oximeter validation (https://www.fda.gov/media/72470/download?attachment), which recommends only limited involvement of persons with darkly pigmented skin without a formal definition, is inadequate in ensuring equity in pulse-oximetry accuracy. New guidance is currently under consideration. On the basis of these results, there is potential for improvement in both bias and precision.

BACKGROUND: Findings from the Pulse Oximetry and Skin Tone in Children (POSTer-Child) study were published February 12, 2025 in a letter to the editor of The New England Journal of Medicine. First author Joseph Starnes, MD, MPH, is a fellow in Pediatric Cardiology.

DETAILS: Retrospective studies have shown overestimation of oxygen saturation by pulse oximetry in adult and pediatric patients from races that may be associated with darker skin. These retrospective studies share key limitations, including race as a poor surrogate for skin tone and paired measurements of oxygen saturation as assessed by pulse oximetry (SpO2) and of arterial oxygen saturation (SaO2) in the medical record. Limited prospective laboratory-based and clinical studies that used measured skin tone in adults have shown worse pulse-oximeter performance among patients with darker skin than among those with lighter skin. Very few prospective studies have involved children.

In the Pulse Oximetry and Skin Tone in Children (POSTer-Child) study, authors enrolled 320 patients younger than 21 years of age undergoing cardiac catheterization in 2024. Skin tone was measured with the use of a spectrophotometer. SpO₂ was recorded with the use of two pulse oximeters (Nellcor and Masimo) at the exact time of blood sampling for measurement of fractional saturation by co-oximetry. Pulse-oximetry bias (SpO₂-SaO₂), precision (standard deviation of bias), and accuracy root mean square error (ARMS) were calculated (for all three measures, higher values indicate worse pulse-oximeter performance), as was the percentage of patients with occult hypoxemia (SaO₂ of <88% when SpO₂ is >=92%). Additional methodologic details are provided in the Supplementary Appendix, available with the full text of this letter at NEJM.org. The population was similar to the U.S. population but showed relative underrepresentation of Hispanic children. A total of 48 of 319 patients (15.0%) identified as Black, and 44 (13.8%) identified as Hispanic.

Average bias was 1.32 percentage points for the Nellcor device and 1.88 percentage points for the Masimo device. Bias was higher among children with darker skin (individual typology angle [ITA] category 5 or 6) than among those with lighter skin (ITA category 1 or 2) for both pulse oximeters (P<0.001). Precision and ARMS were also higher for children with darker skin. ARMS was substantially higher than the Food and Drug Administration (FDA) cutoff of three for children in ITA category 5 or 6. Occult hypoxemia was present in 4 of 56 children (7%) in ITA category 5 or 6 for the Nellcor device and in 5 of 60 children (8%) for the Masimo device, as compared with 0 of 81 children and 3 of 88 children (3%), respectively, in ITA category 1 or 2.

Copyright © Massachusetts Medical Society. All rights reserved.

Source: Starnes, J., Welch, W., Henderson, C. C., et al. (2024). Pulse Oximetry and Skin Tone in Children. NEJM. 2025; 392: 1033-1034; Published: February 17, 2025. DOI: 10.1056/NEJMc2414937.

[Posted 14/Mar/2025]

AUDIENCE: Gastroenterology, Oncology, Internal Medicine

KEY FINDINGS: IQGAP3 knockdown suppressed the RAS-TGFβ signalling crosstalk, leading to a significant reduction of the tumour microenvironment. In particular, IQGAP3 maintains functional heterogeneity of cancer cells to enhance malignant growth. IQGAP3 is thus a highly relevant therapy target in GC.

BACKGROUND: The elevation of IQGAP3 expression in diverse cancers indicates a key role for IQGAP3 in carcinogenesis. Although IQGAP3 was established as a proliferating stomach stem cell factor and a regulator of the RAS-ERK pathway, how it drives cancer growth remains unclear.

DETAILS: Goal of the study is to define the function of IQGAP3 in gastric cancer (GC) development and progression. Authors studied the phenotypic changes caused by IQGAP3 knockdown in three molecularly diverse GC cell lines by RNA-sequencing. In vivo tumorigenesis and lung metastasis assays corroborated IQGAP3 as a mediator of oncogenic signalling. Spatial analysis was performed to evaluate the intratumoral transcriptional and functional differences between control tumours and IQGAP3 knockdown tumours. Transcriptomic profiling showed that IQGAP3 inhibition attenuates signal transduction networks, such as KRAS signalling, via phosphorylation blockade. IQGAP3 knockdown was associated with significant inhibition of MEK/ERK signalling-associated growth factors, including TGFβ1, concomitant with gene signatures predictive of impaired tumour microenvironment formation and reduced metastatic potential. Xenografts involving IQGAP3 knockdown cells showed attenuated tumorigenesis and lung metastasis in immunodeficient mice. Accordingly, immunofluorescence staining revealed significant reductions of TGFβ/SMAD signalling and αSMA-positive stromal cells; digital spatial analysis indicated that IQGAP3 is indispensable for the formation of two phenotypically diverse cell subpopulations, which played crucial but distinct roles in promoting oncogenic functions.

Copyright © BMJ Publishing Group Ltd & British Society of Gastroenterology. All rights reserved.

Source: Shimura, M., Matsuo, J., Pang, S.,et al. (2024). IQGAP3 Signalling Mediates Intratumoral Functional Heterogeneity to Enhance Malignant Growth. Gut. 2025; 74(3): 364-386. Published: March, 2025. DOI: 10.1136/gutjnl-2023-330390.