Blood Spot Samples Research Articles

A validated method for capillary phosphatidylethanol (PEth) 16:0/18:1 quantification with two different 10 µL volumetric absorptive microsample (VAMS) devices in the same set-up.

There is a growing interest for quantification of drugs in capillary blood. Phosphatidylethanol (PEth) is a biomarker for alcohol intake measured in whole blood, thus making it a candidate for capillary sampling. Our laboratory has been running a method for PEth quantification in venous blood since 2016 and we aimed to expand this method to also include capillary dried blood spot (DBS) samples. Two 10 µL volumetric absorptive microsampling (VAMS) devices, Capitainer®B Vanadate and Mitra® were included in the method development and validated. Calibrators and quality controls were spiked during the automatic sample extraction without the VAMS devices present, making it possible to extract and analyze both types of VAMS samples in the same set-up. With the Mitra device all pre-established validation criteria were fulfilled in the measuring range 0.03-4.0 µM (21-2812 ng/mL), including method comparison with our venous blood method. Capitainer fulfilled all validation criteria, except for the accuracy of samples with PEth levels ≥ 0.5 µM (≥ 352 ng/mL) (deviation -17.1 to -20.5%). The correlation analysis between Capitainer and the venous blood results showed no constant bias, but an acceptable small proportional mean difference of -7.6%. Overall, the method validation results for both Capitainer and Mitra were considered acceptable. Both devices were found suitable for the analyses of PEth.

Evaluation of Lyso-Gb1 as a biomarker for Gaucher disease treatment outcomes using data from the Gaucher Outcome Survey

BackgroundPatients with Gaucher disease (GD) require continual monitoring; however, lack of specific disease biomarkers was a significant challenge in the past. Glucosylsphingosine (lyso-Gb1) has been shown to be a reliable, key, specific, and sensitive biomarker for diagnosis, prognosis, and treatment response in clinical studies of patients with GD. We evaluated the change in lyso-Gb1 concentration over time following enzyme replacement therapy in patients with confirmed GD using real-world data from the Gaucher Outcome Survey disease registry.MethodsData for patients aged ≥ 18 years with a confirmed diagnosis of GD and at least two lyso-Gb1 assessments were analyzed retrospectively. Patients were stratified by treatment status at baseline (time of first lyso-Gb1 assessment). Lyso-Gb1 concentrations were measured from dried blood spot (DBS) samples by Centogene AG. Assessments included change in lyso-Gb1 concentration, hemoglobin concentration, platelet counts, and spleen and liver volume from baseline to the last lyso-Gb1 assessment.ResultsOf 2007 patients enrolled in the Gaucher Outcome Survey as of February 25, 2022, 435 met the inclusion criteria and were included in the study: 318 treated (‘all treated’; 277 receiving treatment at baseline, 41 treatment naive at baseline), 38 receiving treatment at baseline who stopped treatment before the last lyso-Gb1 assessment, and 79 untreated. Lyso-Gb1 concentrations decreased from baseline to the last lyso-Gb1 assessment for all treated patients (median change − 8.6 ng/mL), and increased for untreated patients (median change 25.0 ng/mL) and those who stopped treatment (median change 19.5 ng/mL). Decreases were greater for all treatment-naive than previously treated patients (median change − 120.5 vs. − 3.3 ng/mL) and for velaglucerase alfa–treated patients vs. the overall treated cohort (–32.6 vs. − 8.6 ng/mL). Small improvements in hemoglobin concentrations, platelet counts, and spleen volume were observed for treated patients but not untreated/stopped treatment cohorts.ConclusionsIn this study, changes in lyso-Gb1 concentrations from DBS were reflective of responses to enzyme replacement therapy initiation or withdrawal in most patients. These findings confirm that the use of DBS samples for routine monitoring of lyso-Gb1 concentrations in patients with GD is feasible in real-world settings and may be useful to assess treatment response.

Islet Autoantibody Screening Throughout Australia Using In-Home Blood Spot Sampling: 2-Year Outcomes of Type1Screen.

Type1Screen offers islet autoantibody testing to Australians with a family history of type 1 diabetes (T1D) with the dual aims of preventing diabetic ketoacidosis (DKA) and enabling use of disease-modifying therapy. We describe screening and monitoring outcomes 2 years after implementing in-home capillary blood spot sampling. Data from 2,064 participants who registered between July 2022 and June 2024 were analyzed: 1,507 and 557 chose blood spot and venipuncture screening respectively. We compared baseline characteristics and outcomes for 1,243 participants (967 blood spot and 276 venipuncture) whose samples were tested by June 2024. One blood spot and five venous participants reported unsuccessful sample collections. The median (quartile 1, quartile 3) age of blood spot registrants was lower (12.1 [7.1, 27.1] vs. 17.2 [9, 38.4] years; P < 0.0001), and a higher proportion lived in regional Australia (39% vs. 29%; P = 0.0037). Among 72 participants (5.9%) with a positive screening test, 5 screened by blood spot and 2 by venipuncture had no autoantibodies on confirmatory testing. Blood spot screening identified the expected 2.1% prevalence of multiple autoantibodies and a 2.5% prevalence of a single autoantibody compared with 1.5% and 4.1%, respectively, for venipuncture screening. Clinical diabetes developed in 12 participants. All had screened positive and none had DKA. Type1Screen has national reach. In-home blood spot screening is feasible, particularly for younger participants living regionally, and identifies the expected prevalence of preclinical T1D. The lower cost, increased convenience, and greater reach of blood spot screening could help meet increasing demand for early T1D diagnosis.

P-1952. SARS-CoV-2 Self-Testing Modalities Demonstrate Concerning Inaccuracies Among Rural, Minority Populations: The ALL-IN SC Study

Abstract Background At-home, diagnostic self-test assays provide a unique opportunity to reduce healthcare disparities by providing low-cost, immediate access to disease testing. Despite their utility, their real-world accuracy is unknown. Therefore, this study aimed to evaluate multiple testing modalities among diverse, marginalized populations in a large, multi-year, state-wide randomized controlled trial. Methods From 2022 to 2023, 2,195 individuals participated in testing events across South Carolina, USA. Participants provided medical personnel collected samples for gold standard laboratory comparison and were assigned to one of three groups for a matching self-test comparison. These groups were 1) no assistance self-test (only provided manufacturer self-test instructions), 2) unassisted hybrid (collected their own samples according to manufacturer instructions and mailed-in samples to laboratory), and 3) assisted (medical personnel verbally explained the manufacturer’s instructions). A robust statistical analysis plan was executed; however, only the results from multivariate regression are described here. Results Participants in the unassisted groups were significantly more likely to have an incorrect self-test result. Conversely, participants with assistance were 32% more likely to have a correct self-test result, regardless of testing modality (saliva, dried blood spot, nasal swab). Self-collection of saliva samples to send to a laboratory for testing had the highest odds of inaccuracy (OR=9.21, p-value &amp;lt; 0.001). Self-collection of dried blood spot samples sent for laboratory testing had the lowest odds of inaccuracy (OR=1.52, p-value&amp;lt; 0.021). Demographic risk factors varied by testing modality, with females, black, and lower income participants statistically more likely to have inaccurate testing results. Select infection symptoms at the time of testing also increased the odds of inaccuracy. Conclusion This study provides critical evidence that self-tests are a viable option for addressing health care access disparities, but telemedicine and/or community assistance programs must also be provided to ensure tests are conducted and interpreted correctly. Disclosures All Authors: No reported disclosures

Acceptability and Feasibility of Self-Collected Dried Blood Spot Specimens for Viral Load Monitoring among Rural Older People Living with HIV.

Self-collected dried blood spot (DBS) samples may be useful in monitoring viral load (VL) in research studies or clinically given that they eliminate the need for participants to travel to study sites or laboratories. Despite this, little information exists about monitoring VL using DBS self-collected at home, and no information exists on DBS for this use among older rural people living with HIV (PLH), a population that could benefit from self-collection given difficulty accessing care. We report on the feasibility and acceptability of self-collected DBS samples, DBS VL results, concordance between self-reported and DBS VL, and factors associated with DBS detectable VL in a rural Southern U.S. sample of PLH aged 50 years and older. Between 2021 and 2022, 61 older rural PLH from 9 Southern U.S. states (Mage = 58, 25% female) completed survey measures and self-collected DBS specimens at home; 51 of these participants completed the same procedures at 3-month follow-up. Nearly all participants (96-98%) collected DBS specimens that could be successfully analyzed for VL, and participants found self-collection highly acceptable. Approximately one quarter of participants had quantifiable detectable VL (≥ 839 copies/mL) at each time point. Concordance between self-reported and DBS VL was 69% at baseline and 82% at follow-up; the majority of those with DBS detectable VL self-reported undetectable VL (86% at baseline and 60% at follow-up). Self-collection of DBS specimens for VL monitoring can add value to research conducted remotely, including research associated with the care of rural and/or older PLH.

Sudden Death of a Four-Day-Old Newborn Due to Mitochondrial Trifunctional Protein/Long-Chain 3-Hydroxyacyl-CoA Dehydrogenase Deficiencies and a Systematic Literature Review of Early Deaths of Neonates with Fatty Acid Oxidation Disorders

Mitochondrial trifunctional protein (MTP) and long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiencies have been a part of the Slovenian newborn screening (NBS) program since 2018. We describe a case of early lethal presentation of MTPD/LCHADD in a term newborn. The girl was born after an uneventful pregnancy and delivery, and she was discharged home at the age of 3 days, appearing well. At the age of 4 days, she was found without signs of life. Resuscitation was not successful. The NBS test performed using tandem mass spectrometry (MS/MS) showed a positive screen for MTPD/LCHADD. Genetic analysis performed on a dried blood spot (DBS) sample identified two heterozygous variants in the HADHA gene: a nucleotide duplication introducing a premature termination codon (p.Arg205Ter) and a nucleotide substitution (p.Glu510Gln). Post-mortem studies showed massive macro-vesicular fat accumulation in the liver and, to a smaller extent, in the heart, consistent with MTPD/LCHADD. A neonatal acute cardiac presentation resulting in demise was suspected. We conducted a systematic literature review of early neonatal deaths within 14 days postpartum attributed to confirmed fatty acid oxidation disorders (FAODs), which are estimated to account for 5% of sudden infant deaths. We discuss the pitfalls of the NBS for MTPD/LCHADD.

Haplotypes of Chloroquine Resistance Marker Genes Among Uncomplicated Malaria Cases in Lagos, Nigeria.

Drug resistance resulting from mutations in Plasmodium falciparum, that caused the failure of previously effective malaria drugs, has continued to threaten the global malaria elimination goal. This study describes the profiles of P. falciparum chloroquine resistance transporter (Pfcrt) and P. falciparum multidrug resistance 1 (Pfmdr1), the genetic markers associated with 4-aminoquinoline resistance, among P. falciparum isolates from Lagos, Nigeria. Genomic DNA was extracted from the dried blood spot samples obtained from individuals with microscopically confirmed P. falciparum infection in health facilities and communities in Lagos State, Nigeria. The DNA was amplified using nested polymerase chain reaction, and sequence analysis was performed to identify single nucleotide polymorphisms in the pfcrt and pfmdr1 genes. The study showed that 82.4% (178) of the isolates had pfmdr1 wild-type, while mutations were observed at codons N86Y (11.6%) and D1246Y (3.2%). Other mutations seen were at codons Y23S (0.5%), E130K (2.3%), and S149P (0.5%). 30.8% (64) of the isolates had pfcrt wild-type (CVMNK), while 62.0% (129) had CVIET (mutant) haplotype. Other pfcrt haplotypes detected include; CVIDT (1.9%); CVMDT (1.4%); CVIKT (1.0%); CVINT (0.5%); CVMET (0.5%); CVMKT (0.5%); CVMNT (1.0%); and CVMEK (0.5%). The findings underscore the presence of uncommon pfcrt haplotypes and a high prevalence of drug-resistant pfcrt haplotypes (CVIET), alongside a high prevalence of wild-type pfmdr in Lagos. This study highlights the need for ongoing surveillance of these genetic markers to provide data that can inform decisions on malaria case management and preserve the efficacy of artemisinin combination therapies (ACTs) in Nigeria.

Detection of low frequency artemisinin resistance mutations, C469Y, P553L and A675V, and fixed antifolate resistance mutations in asymptomatic primary school children in Kenya

BackgroundTo understand the emergence and spread of drug-resistant parasites in malaria-endemic areas, accurate assessment and monitoring of antimalarial drug resistance markers is critical. Recent advances in next-generation sequencing (NGS) technologies have enabled the tracking of drug-resistant malaria parasites.MethodsIn this study, we used Targeted Amplicon Deep Sequencing (TADS) to characterise the genetic diversity of the Pfk13, Pfdhfr, Pfdhps, and Pfmdr1 genes among primary school-going children in 15 counties in Kenya (Bungoma, Busia, Homa Bay, Migori, Kakamega, Kilifi, Kirinyaga, Kisii, Kisumu, Kwale, Siaya, Tana River, Turkana, Vihiga and West Pokot). A total of 920 dried blood spot (DBS) samples collected from 121 selected primary schools within the country were used to extract genomic DNA. A nested polymerase chain reaction (PCR) was used to generate amplicons that were sequenced to determine the prevalence of known and novel polymorphisms.ResultsPfk13 mutations associated with artemisinin resistance were present as mixed genotype infections for the C469Y mutation in 23 samples (4%), the A675V mutation in 2 samples (1.7%), and the P553L mutation in 7 samples (1.2%). The A578S mutation, was also identified in mixed infections, appearing in 15.2% of the 87 samples analysed. The Pfdhfr 51I and 108 N pyrimethamine-resistance mutations were at fixation (100% frequency), and the Pfmdr1 Y184F mutation, which is linked to reduced susceptibility to several antimalarial drugs, especially those used in combination therapies for malaria treatment, was detected in 97.5% of the samples as mixed-genotype infections.ConclusionThe genomic surveillance of asymptomatic school children in Kenya provides an early warning signal of at least 1 of the 3 validated artemisinin resistance mutations circulating in all regions in Western Kenya sampled except Homa Bay and Kisii Counties. These signals in asymptomatic and mixed infections would have been missed without deep sequencing.

Outcomes of a Pilot Newborn Screening Program for Spinal Muscular Atrophy in the Valencian Community.

Spinal muscular atrophy (SMA) is a degenerative neuromuscular condition resulting from a homozygous deletion of the survival motor neuron 1 (SMN1) gene in 95% of patients. A timely diagnosis via newborn screening (NBS) and initiating treatment before the onset of symptoms are critical for improving health outcomes in affected individuals. We carried out a screening test by quantitative PCR (qPCR) to amplify the exon seven of SMN1 using dried blood spot (DBS) samples. From October 2021 to August 2024, a total of 31,560 samples were tested in the Valencian Community (Spain) and 4 of them were positive for SMA, indicating an incidence of 1/7890. Genetic confirmation was performed using multiplex ligation-dependent probe amplification (MLPA) and AmplideX PCR/CE SMN1/2 Plus kit, in parallel obtaining concordant results in survival motor neuron 2 (SMN2) gene copy number. Within the first few weeks of their lives, two of the four patients detected by NBS showed signs of severe hypotonia, becoming ineligible for treatment. The other two patients were the first presymptomatic patients with two copies of SMN2 to receive treatment with Risdiplam in Spain. In order to treat positive cases in their early stages, we conclude that the official deployment of SMA newborn screening is necessary.

Rapid Determination of Acylcarnitine Metabolic Diseases by Trifluoroacetic Acid-Doped Extraction Coupled with Nanoelectrospray Ionization Mass Spectrometry.

Newborn screening for acylcarnitine-related inherited metabolic diseases (IMDs) is a critical test after birth. Conventional extraction methods require shaking with heating, centrifugation, nitrogen blowing, redissolution, etc., and the total time is more than 1 h. Herein, a small amount of trifluoroacetic acid (TFA)-doped extraction method for acylcarnitines coupled with nanoelectrospray ionization mass spectrometry was developed. This simplified approach successfully quantified 21 acylcarnitines in both serum and dried blood spot samples through a fast, three-step process requiring only 7 min, achieving nearly 1-2 orders of magnitude in sensitivity enhancement compared with conventional methods. The performance was further verified by the recommended liquid chromatography-tandem mass spectrometry procedure. Furthermore, the TFA-doped extraction technique was tested on serum and whole blood samples from six healthy individuals. Mechanistic studies using inductively coupled plasma mass spectrometry, ultraviolet-visible spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy showed that TFA promotes the coprecipitation of proteins and inorganic salts. These findings suggest that TFA-doped extraction with nanoelectrospray ionization mass spectrometry is a rapid, sensitive alternative for acylcarnitine screening, highlighting its considerable potential for clinical newborn IMD screening applications.

Complementarity of biomarker screening and genetic analyses based on the case of an attenuated multiple sulfatase deficiency.

Multiple sulfatase deficiency (MSD) is an ultra-rare lysosomal disease caused by defective activation of cellular sulfatases comprising clinical features of mucopolysaccharidoses, sphingolipidoses, and other sulfatase deficiencies. We present a case of an infant with feeding difficulties related to autism spectrum disorder (ASD) who was diagnosed at 10months of age with MSD by next-generation sequencing (NGS). Biochemical results obtained in dried blood spot (DBS) samples were inconsistent and not suggesting MSD in the light of identified pathogenic SUMF1 variants. However, follow-up analyses at 20months of age revealed an increased concentration of sulfatides in DBS. It should be noted that biochemical tests, routinely used as screening methods, have a risk of false negative results, especially regarding mild/attenuated phenotypes, as presented in our report.

Evaluation of metabolite stability in dried blood spot stored at different temperatures and times

Dried blood spot (DBS) sampling offers significant advantages over conventional blood collection methods, such as reduced sample volume, minimal invasiveness, suitability for home-based sampling, and ease of transport. However, understanding the effects of variable storage temperatures and times on metabolite stability is crucial due to varying intervals and delivery conditions between sample collection and metabolomics analysis. To minimize biological variances, all samples were collected from the same individual simultaneously and stored at three different temperatures (4 °C, 25 °C, and 40 °C) for diverse time points (3, 7, 14, and 21 days). Metabolic profiling was conducted an untargeted gas chromatography-mass spectrometry (GC-MS) and ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS)-based multi-platform metabolomics. Principal component analysis (PCA) showed alterations in metabolite stability at different temperatures, with phosphatidylcholines (PCs) and triglycerides (TAGs) as the first principal component (PC1). Specifically, we identified 69 metabolites that remained stable across all three temperatures over the 21-day period, while 78 metabolites exhibited instability. Furthermore, linear correlations between metabolite intensity and storage time were observed. Overall, our study elucidated the influence of storage temperature and time on specific metabolite stability in DBS samples, providing valuable insights for study design, biomarker selection, and data improvement.

Tacrolimus- and Mycophenolate-Mediated Toxicity: Clinical Considerations and Options in Management of Post-Transplant Patients.

Tacrolimus and mycophenolate are important immunosuppressive agents used to prevent organ rejection in post-transplant patients. While highly effective, their use is associated with significant toxicity, requiring careful management. Tacrolimus, a calcineurin inhibitor, is linked to nephrotoxicity, neurotoxicity, metabolic disturbances such as diabetes mellitus and dyslipidemia, and cardiovascular complications such as hypertension and arrhythmias. Mycophenolate, a reversible inhibitor of inosine monophosphate dehydrogenase, frequently causes gastrointestinal disturbances, including diarrhea and colitis, as well as hematologic side effects like anemia and leukopenia, which increase infection risk. Therapeutic drug monitoring (TDM) and pharmacogenomics have emerged as essential strategies for mitigating these toxicities. TDM ensures tacrolimus trough levels are maintained within a therapeutic range, minimizing the risks of nephrotoxicity and rejection. Pharmacogenomic insights, such as CYP3A5 polymorphisms, allow for personalized tacrolimus dosing based on individual metabolic profiles. For mycophenolate, monitoring inosine monophosphate dehydrogenase activity provides a pharmacodynamic approach to dose optimization, reducing gastrointestinal and hematologic toxicities. Emerging tools, including dried blood spot sampling and pharmacokinetic modeling, offer innovative methods to simplify monitoring and enhance precision in outpatient settings. Despite their utility, the toxicity profiles of these drugs, including those of early immunosuppressants such as cyclosporine and azathioprine, necessitate further consideration of alternative immunosuppressants like sirolimus, everolimus, and belatacept. Although promising, these newer agents require careful patient selection and further research. Future directions in immunosuppressive therapy include integrating individual pharmacogenetic data to refine dosing, minimize side effects, and improve long-term graft outcomes. This narrative review underscores the importance of personalized medicine and advanced monitoring in optimizing post-transplant care.

First pilot study for newborn screening of severe T and B lymphopenias in Colombia

Congenital lymphopenias cause increased susceptibility to infections in children apparently healthy at birth. Earlier detection of these conditions would facilitate prompt treatment, prevent potentially serious disease complications and early deaths, and save healthcare resources. To perform a pilot study for neonatal screening of congenital lymphopenias by the quantification of TREC and KREC –T- and B-cell receptor excision circles– in peripheral blood samples from newborns in Medellín, Colombia. Blood samples from 1,092 newborns and six referred patients with suspected lymphopenia were collected by heel or toe-finger prick and dropped onto a filter paper. Thereafter, DNA was extracted and levels of TRECs and KRECs were measured by qPCR. The six patients with suspected lymphopenia showed undetectable or very low TREC levels. All newborns screened presented normal TREC and KREC levels. A positive correlation was found between TREC or KREC values quantified from two different filter papers. Detectable levels of the receptor excision circles decrease considerably after 24 weeks of the dried blood spot sample storage. We identified a positive association between low TREC levels and low birth weight; and a negative correlation between KREC values and prematurity. Finally, no statistical differences were found between TREC or KREC levels and delivery method. We describe the first preliminary study for the early detection of lymphopenias in Colombia. We proposed to use a cut-off value of 119 and 69 copies/μl blood of TREC and KREC, respectively for future newborn screening programs in our country.

Dried blood spot LC-MS/MS quantification of voclosporin in renal transplant recipients using volumetric dried blood spot sampling.

Voclosporin is a potent immunosuppressive agent currently approved for treating active lupus nephritis. Based on its potential antiviral activity, it has also been investigated as immunosuppressive agent in an investigator-initiated study in SARS-CoV2 positive kidney transplant recipients. As with many immunosuppressive agents, optimizing dosing regimens to achieve therapeutic efficacy while minimizing toxicity remains a critical challenge in clinical practice. To prevent organ rejection as well as infections, the prescribed immunosuppression needs to be well balanced. Dried blood spot (DBS) sampling has enabled development of remote voclosporin therapeutic drug monitoring. Here, we report on the development and analytical validation of a liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for quantification of voclosporin in dried blood spots. Method development was based on previously developed assays for the quantification of tacrolimus, everolimus, sirolimus, cyclosporin, mycophenolic acid, creatinine and iohexol in DBS and voclosporin in whole blood using LC-MS/MS. HemaXis™ volumetric blood spot devices were used for sample collection. The sample purification was based on the extraction of voclosporin from the DBS samples. Stable isotopically labeled voclosporin-D4 was used as an internal standard prior to sample purification. Bland Altman and Passing bablok analysis were performed for cross validation between whole blood and DBS samples. The method was successfully validated following the current ICH M10 guidelines. The dynamic range for the analyte was 10-600 µg/L with an excellent mean coefficient of correlation of 0.9978. The within run and between run precision and accuracy were both within the acceptance criteria. The cross-validation against the whole blood method shows that the quantified voclosporin results are promising. This developed dried blood spot LC-MS/MS method was successfully validated and provides an easy, efficient workflow for therapeutic drug monitoring in kidney transplant patients or remote pharmacokinetic studies in lupus nephritis patients treated with voclosporin.

Proteomic profiling of neonatal herpes simplex virus infection on dried blood spots

Background:Neonatal herpes simplex virus (HSV) infection is life-threatening, with a mortality of up to 70–80% when disseminated, often due to vague symptoms and delayed treatment. Neonatal screening using dried blood spot (DBS) samples is among the most impactful preventative health measures ever implemented, but screening for HSV has not been investigated.Methods:We investigated high throughput multiplexed proteomics on DBS samples collected on days 2–3 of life from a nationwide cohort of neonates with HSV infection (n = 53) and matched controls. We measured 2941 proteins using the Olink Explore 3072 panels and proximity extension assays, followed by differential protein expression by Analysis of Variance with post-hoc correction and functional annotation.Results:Here, we show distinct protein profiles in neonates with disseminated HSV disease, with differences in 20 proteins compared to controls. These proteins are associated with innate and adaptive immune responses and cytokine activation.Conclusions:Our findings indicate the potential of neonatal screening for disseminated HSV disease to ensure early treatment and reduce the high mortality.

Antibody Levels from High-Throughput Variant-Specific SARS-CoV-2 Anti-Spike IgG and ACE2 Neutralization Assays Correlate with COVID Infection Risk in a Large Population.

SARS-CoV-2 antibody levels have been proposed as a correlate of protection (CoP) from infection. Yet, large-scale prospective studies of cost-effective scalable antibody measures as predictors of infection under real-world conditions are limited. We examined whether antibody levels measured using high-throughput variant-specific SARS-CoV-2 anti-spike immunoglobulin G (IgG) and ACE2-neutralization assays correlate with cell-based neutralizing antibody (NAb) measurements, and whether they can serve as a reasonable CoP from SARS-CoV-2 infection. We conducted a large, institutional cohort study between January 2022 and March 2023. Participants (n=2,513) provided dried blood spot (DBS) samples for assessment of anti-spike IgG and ACE2 inhibition levels using high-throughput assays. Comparison with authentic cell-based SARS-CoV-2 NAb assays was conducted using serum samples (n=105). Associations between antibody levels and risk of infection were evaluated. Correlation between serum and DBS sampling, and cell-based neutralizing and high-throughput antibody binding assays, was high for both anti-spike IgG and ACE2 neutralization, though the degree of correlation varied by variant. Longitudinal evaluation suggested both DBS-based IgG and ACE2 inhibition levels were anticorrelated with infection risk, with higher sensitivity noted for ACE2 inhibition and variant-matched measures. Both IgG and ACE2 inhibition levels decreased over time, with more durable responses observed in participants whose most recent priming event was infection versus vaccination. Findings suggest that variant-specific SARS-CoV-2 antibody levels may be a useful CoP for infection, which has important implications for vaccination recommendations and evaluating infection risk. High-throughput assays measured via DBS may have utility in timing of boosters, either at the population or an individual level.

Practical Recommendations for the Diagnosis and Management of Lysosomal Acid Lipase Deficiency with a Focus on Wolman Disease.

Lysosomal acid lipase deficiency (LAL-D) is an ultra-rare lysosomal storage disease with two distinct phenotypes, an infantile-onset form (formerly Wolman disease) and a later-onset form (formerly cholesteryl ester storage disease). The objective of this narrative review is to examine the most important aspects of the diagnosis and treatment of LAL-D and to provide practical expert recommendations. The infantile-onset form occurs in the first weeks of life and is characterized by malnourishment and failure to thrive due to gastrointestinal impairment (vomiting, diarrhea, malabsorption), as well as systemic inflammation, hepatosplenomegaly, and adrenal calcifications. Mortality is close to 100% before one year of life in the absence of specific treatment. The later-onset form can be diagnosed in childhood or adulthood and is characterized by chronic liver injury and/or lipid profile alterations. When LAL-D is suspected, enzyme activity should be determined to confirm the diagnosis, with analysis from a dried blood spot sample being the quickest and most reliable method. In infantile-onset LAL-D, the initiation of enzyme replacement therapy (sebelipase α) and careful nutritional management with a low-lipid diet is very urgent, as prognosis is directly linked to the early initiation of specific treatment. In recent years, our knowledge of the management of LAL-D has increased considerably, with improvements regarding the initial enzyme replacement therapy dose and careful nutritional treatment with a low-lipid diet to decrease lipid deposition and systemic inflammation, leading to better outcomes. In this narrative review we offer a quick guide for the initial management of infantile-onset LAL-D.

Newborn Screening for Acid Sphingomyelinase Deficiency: Prevalence and Genotypic Findings in Italy.

Acid sphingomyelinase deficiency (ASMD) is a rare lysosomal storage disorder with a broad clinical spectrum. Early diagnosis and initiation of treatment are crucial for improving outcomes, yet the disease often goes undiagnosed due to its rarity and phenotypic heterogeneity. This study aims to evaluate the feasibility and disease incidence of newborn screening (NBS) for ASMD in Italy. Dried blood spot samples from 275,011 newborns were collected between 2015 and 2024 at the Regional Center for Expanded NBS in Padua. Acid sphingomyelinase activity was assayed using tandem mass spectrometry. Deidentified samples with reduced enzyme activity underwent second-tier testing with LysoSM quantification and SMPD1 gene analysis. Two samples were identified with reduced sphingomyelinase activity and elevated LysoSM levels. Both carried two SMPD1 variants, suggesting a diagnosis of ASMD. Molecular findings included novel and previously reported variants, some of uncertain significance. The overall incidence was 1 in 137,506 newborns and the PPV was 100%. This study demonstrates the feasibility of NBS for ASMD in Italy and provides evidence of a higher disease incidence than clinically reported, suggesting ASMD is an underdiagnosed condition. Optimized screening algorithms and second-tier biomarker testing can enhance the accuracy of NBS for ASMD. The long-term follow-up of identified cases is necessary for genotype-phenotype correlation and improving patient management.

Protocol for a feasibility and acceptability study for UK general population paediatric type 1 diabetes screening-the EarLy Surveillance for Autoimmune diabetes (ELSA) study.

The EarLy Surveillance for Autoimmune (ELSA) study aims to explore the feasibility and acceptability of UK paediatric general population screening for type 1 diabetes. We aim to screen 20,000 children aged 3-13 years for islet-specific autoantibodies through dried blood spot sample collection at home, hospital or community settings. Children with two or more autoantibodies are offered metabolic staging via oral glucose challenge testing. Feasibility assessments will compare recruitment modalities and uptake according to demographic factors (age, gender, ethnicity, level of deprivation and family history of diabetes) to determine optimal approaches for general population screening. The study is powered to identify 60 children (0.3%) with type 1 diabetes (stage 1-3). Parents are invited to qualitative interviews following ELSA completion (child screened negative or positive, single autoantibody or multiple, stage 1-3) to share their screening experience, strengths of the programme and any areas for improvement (acceptability assessments). Parents who decline screening or withdraw from participation are invited to interview to explore any concerns. Finally, we will interview professional stakeholders delivering the ELSA study to explore barriers and facilitators to implementation. Early detection of type 1 diabetes allows insulin treatment to be started sooner, avoids diagnosis as an emergency, gives families time to prepare and the opportunity to benefit from future prevention trials and treatments. ELSA will provide essential feasibility and acceptability assessments for UK general population screening to inform a future national screening programme for paediatric type 1 diabetes.