Search Results (677)

The sphingolipidoses Fabry disease, Gaucher disease and Acid sphingomyelinase deficiency (ASMD) are the three most common lysosomal storage diseases for which treatment is currently available. Timely diagnosis with estimation of the disease severity and possibilities of follow-up of patients, whether or not under therapy, is crucial for providing good care and for the prevention of possible lethal complications. With this research we provide an efficient and sensitive detection method; its implementation in clinical practice could optimize the diagnosis and follow-up of patients with Gaucher, Fabry and ASMD. This detection method on dried blood spots (DBS) was validated according to the international Clinical and Laboratory Standards Institute (CLSI) guidelines, looking at reproducibility, linearity, carry-over and lower limit of quantification. Analogously, validation and subsequent comparison of the method validation results using another matrix, the Capitainer blood sampling cards (Capitainers), was fulfilled. The results showed that this detection method is fully applicable clinically when using DBS as well as Capitainers. In addition, even additional improvements of some validation parameters were found when using the Capitainers. Twenty-six patient samples and fifteen healthy samples were analyzed for case finding control. All patient cases were detected without ambiguity. We present a high-resolution mass spectrometry method that provides an accurate analysis for targeted screening, aiming for improved/accelerated diagnosis when added in the diagnostic pathway and monitoring of Fabry, Gaucher and ASMD in DBS as well as in Capitainers, with the main advantages of a small volume of blood samples, guaranteeing stability and easy transportation from the collection site to the laboratory. Full article

Pyridoxine-dependent epilepsy (PDE) represents a group of rare developmental and epileptic encephalopathies. The most common PDE is caused by biallelic pathogenic variants in ALDH7A1 (PDE-ALDH7A1; OMIM #266100), which encodes α-aminoadipate semialdehyde (α-AASA) dehydrogenase, a key enzyme in lysine catabolism. Affected individuals present with seizures unresponsive to conventional anticonvulsant medications but responsive to high-dose of pyridoxine (vitamin B6). Adjunctive lysine restriction and arginine supplementation have also shown potential in improving neurodevelopmental outcomes. Given the significant benefit of early intervention, PDE-ALDH7A1 is a strong candidate for newborn screening (NBS). However, traditional biomarkers are biochemically unstable at room temperature (α-AASA and piperideine-6-carboxylate) or lack sufficient specificity (pipecolate), limiting their utility for biomarker-based NBS. The recent identification of two novel and stable biomarkers, 2S,6S-/2S,6R-oxopropylpiperidine-2-carboxylate (2-OPP) and 6-oxo-pipecolate (oxo-PIP), offers renewed potential for biochemical NBS. We evaluated the feasibility of incorporating 2-OPP, oxo-PIP, and pipecolate into routine butylated FIA-MS/MS workflows used for biochemical NBS. A total of 9402 dried blood spots (DBS), including nine confirmed PDE-ALDH7A1 patients and 9393 anonymized controls were analyzed using a single multiplex assay. 2-OPP emerged as the most sensitive biomarker, identifying all PDE-ALDH7A1 patients with 100% sensitivity and a positive predictive value (PPV) of 18.4% using a threshold above the 99.5th percentile. Combining elevated 2-OPP (above the 99.5th percentile) with either pipecolate or oxo-PIP (above the 85.0th percentile) as secondary marker detected within the same multiplex FIA-MS/MS assay further improved the PPVs to 60% and 45%, respectively, while maintaining compatibility with butanol-derivatized method. Notably, increasing the 2-OPP threshold above the 99.89th percentile, in combination with either pipecolate or oxo-PIP above the 85.0th percentile resulted in both 100% sensitivity and 100% PPV. This study supports the strong potential of 2-OPP-based neonatal screening for PDE-ALDH7A1 within existing NBS infrastructures. The ability to multiplex 2-OPP, pipecolate and oxo-PIP within a single assay offers a robust, practical, high-throughput and cost-effective approach. These results support the inclusion of PDE-ALDH7A1 in existing biochemical NBS panels. Further prospective studies in larger cohorts are needed to refine cutoffs and confirm clinical performance. Full article

Everolimus (EVE), an mTOR inhibitor, is widely used in solid organ transplantation (SOT) because of its immunosuppressive properties. Due to its narrow therapeutic window and significant pharmacokinetic variability, therapeutic drug monitoring (TDM) is essential for achieving optimal outcomes. We developed and thoroughly validated a robust LC-MS/MS method to measure EVE levels in venous whole blood (WB) and capillary blood collected using two microsampling devices: Mitra™ (volumetric absorptive microsampling, VAMS) and Capitainer^® (quantitative dried blood spot, qDBS). The validation followed EMA and IATDMCT guidelines, assessing linearity (1.27–64.80 ng/mL for WB and 0.50–60 ng/mL for VAMS/qDBS), as well as selectivity, accuracy, precision, matrix effects, recovery, stability, and incurred sample reanalysis. Clinical validation involved 66 matched samples from 33 adult SOT recipients. The method demonstrated high accuracy and precision across all matrices, with no significant carryover or matrix interference. Statistical analysis using Passing–Bablok regression and Bland–Altman plots showed excellent agreement between the microsampling methods and the venous reference. Hematocrit effects were tested both in laboratory conditions and on clinical samples and were found to be negligible. This study provides the first comprehensive analytical and clinical validation of the Mitra and Capitainer devices for EVE monitoring. The validated LC-MS/MS microsampling method supports decentralized, patient-centred TDM, offering a reliable alternative to conventional blood sampling in transplant care. Full article

Human cytomegalovirus (HCMV) establishes lifelong latency in the host, with the bone marrow (BM) CD34+ cells serving as a key reservoir. To investigate tissue-specific immune responses to CMV, we analysed paired peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMMNCs) from HCMV-seropositive donors using multiparametric flow cytometry and cytokine FluroSpot assays. We assessed immune cell composition, memory T cell subsets, cytokine production, cytotoxic potential, activation marker expression, and checkpoint inhibitory receptor (CIR) profiles, both ex vivo and following stimulation with lytic and latent HCMV antigens. BMMNCs were enriched in CD34+ progenitor cells and exhibited distinct T cell memory subset distributions. HCMV-specific responses were compartmentalised: IFN-γ responses predominated in PBMCs following lytic antigen stimulation, while IL-10 and TNF-α responses were more prominent in BMMNCs, particularly in response to latent antigens. US28-specific T cells in the BM showed elevated expression of CD39, PD-1, BTLA, CTLA-4, ICOS, and LAG-3 on CD4+ T cells and increased expression of PD-1, CD39, BTLA, TIGIT, LAG-3, and ICOS on CD8+ T cell populations, suggesting a more immunoregulatory phenotype. These findings highlight functional and phenotypic differences in HCMV-specific T cell responses between blood and bone marrow, underscoring the role of the BM niche in shaping antiviral immunity and maintaining viral latency. Full article

Background: Measuring frequencies of antigen-specific memory B cells (B_mem), their immunoglobulin (Ig) class and subclass usage, cross-reactivity, and affinity can provide insights into the efficacy of future antibody responses in case of antigen re-encounter. B cell ImmunoSpot^® assays can provide such information; however, like most cell-based tests, they require considerable amounts of blood to be drawn from the donor and this has hindered their inclusion in clinical trials and routine immune diagnostics. Methods: We introduce strategies for reducing the cell numbers required to 2–3 million peripheral blood mononuclear cells (PBMCs) per antigen, obtainable from 2–3 mL of blood from healthy adult donors. Results: Except when B_mem frequencies were very low, we found that testing PBMCs in singlet wells, but in serial dilution, enables as reliable B_mem frequency assessments as when testing replicate wells at a single fixed cell number. Additionally, B cell ImmunoSpot^® assays can be multiplexed for detecting four Ig classes, or IgG subclasses, simultaneously and without loss of sensitivity. The requirement for low cell numbers and the retention of B cell functionality by cryopreserved PBMCs equivalent to freshly isolated material implies that fewer than the standard 10 million PBMCs per vial can be frozen. This would reduce the number of individuals who could not be tested for B_mem due to insufficient availability of PBMCs, a common problem with such assays. Conclusions: The predictable need for and recovery of cryopreserved PBMCs facilitates planning of and optimal cell utilization in B cell ImmunoSpot^® assays and increases the practical feasibility of extensive B_mem characterization in larger cohorts. Full article

Background/Objectives: Epilepsy affects approximately 50 million people worldwide, with antiepileptic drugs (AEDs) remaining the cornerstone of treatment. Due to their narrow therapeutic windows, AEDs are ideal candidates for therapeutic drug monitoring (TDM). Oral fluid is increasingly considered a viable alternative to blood and urine, as it reflects the free (active) concentration of many AEDs. Its non-invasive collection, which does not require trained personnel, makes it particularly suitable for TDM in paediatric and geriatric populations. However, as samples are often stored for extended periods before analysis, analyte stability becomes a critical concern. This study aimed to evaluate the stability of four commonly used AEDs in dried saliva spot (DSS) samples. Methods: Phenobarbital, phenytoin, carbamazepine, and carbamazepine-10,11-epoxide were analysed in oral fluid samples collected via spitting and stored as DSSs. Quantification was performed using high-performance liquid chromatography with diode array detection (HPLC-DAD). Design of experiments tools were used to assess the effects of preservatives, storage temperatures, light exposure, and storage durations on analyte stability. Results: Optimal conditions were refrigeration in the dark, with a low concentration of ascorbic acid as preservative. Samples at 10 µg/mL remained stable for 14 days longer than those without preservative or reported in previous studies. Unexpectedly, at 0.5 µg/mL, analytes in samples without preservative showed greater stability. Conclusions: To our knowledge, this is the first study combining DSS and HPLC-DAD to assess the stability of these AEDs in oral fluid, providing valuable insights for non-invasive TDM strategies and supporting the feasibility of saliva-based monitoring in clinical settings. Full article

In Brazil, dried blood spots (DBSs) for newborn screening (NBS) should be collected between the 3rd and 5th days of life at local Basic Health Units (BHUs). This study reports the experience of face-to-face training at BHUs in southern Brazil during a pilot study for tandem mass spectrometry (MS/MS) inclusion in the NBS program. The pilot project involved screening for 22 inborn errors of metabolism (IEMs). The professionals at the BHUs were instructed to carry out the following: (a) explain the study to parents or guardians; (b) collect additional DBS samples on a different collection card (research card); and (c) deliver results to families. In-person visits were conducted at all 137 BHUs. These visits included an overview of the pilot project and distribution of educational materials, including a list of the 22 IEMs and informational leaflets on MS/MS-based NBS. Among the 486 healthcare professionals who participated, 91.2% were women. Overall, 97.1% of the BHUs reported being satisfied with the project. Questions regarding IEMs were raised in 40.1% of BHUs, and 13.1% reported complaints about the research card due to its lighter texture and drying difficulty. Training primary healthcare professionals in IEMs remains an urgent priority in Brazil, particularly in the context of expanded NBS using MS/MS, since they are the frontline professionals in the NBS program. Full article

Background/Objectives: Autism Spectrum Disorder (ASD) etiology is complex, involving genetics and environmental factors, and associated with impaired energy metabolism. Mitochondrial fatty acid oxidation (mFAO) is instrumental to energy production through the oxidation of acylcarnitines (ACs). We performed a comprehensive investigation of blood AC profiles in a pediatric ASD cohort, aiming to define ASD subgroups based on AC profiles and link these profiles to key clinical features and comorbidities using a phenotype-first approach. Methods: Blood levels of 31 ACs (μmol/L) collected from 102 ASD patients and 117 healthy controls (HCs) were evaluated via tandem mass spectrometry. The percentile distribution of blood AC levels in HC samples was computed to define the normal reference range (RR) and identify values corresponding to the 10th and 90th percentiles. Cognitive levels, emotional–behavioral disturbances and the severity of ASD symptoms (Autism Diagnostic Observation Schedule-Calibrated Severity Score ADOS-CSS) were assessed. Clinical correlates of ASD groups based on AC profiles were evaluated. Results: Three ASD subgroups were identified based on the percentile distribution of AC levels: group A (ACs < 10th percentile), group B (ACs 10th–90th percentile) and group C (ACs > 90th percentile) (abnormal AC number ≥ 3). Out of the thirty-one analyzed ACs in DBSs, fifteen (48.4%) were significantly different when comparing ASD group A to ASD group C. There was a significant difference in the severity of autism symptoms (ADOS CSS) related to the repetitive and restricted behaviors domain (CSS RRB) among the different groups (χ²(2) = 6.26; p = 0.044). The post hoc Dunn’s test with Bonferroni correction showed that ADOS-CSS RRB was significantly higher in ASD group A compared to ASD group B (p = 0.013). AC C14 was more frequently decreased (<10th pc) in patients with more severe symptoms (p = 0.006); C10:1 tended to be more frequently increased (>90th pc) in patients with lower clinical severity (p = 0.052). Conclusions: This study highlights differences across blood AC levels in children with ASD and conveys novel information on clinical severity in ASD patients with abnormal blood AC profiles. Thus, examining metabolic profiles may provide helpful insights to understand the variability of ASD symptoms. Full article

In recent years, as gene therapy technology has rapidly developed, there has been growing concern that it could be misused by athletes as a means of doping. However, current testing methods for gene doping have a range of limitations and require further improvement. Furthermore, significant progress has been made in the fields of blood storage, next-generation sequencing (NGS), and LabDroid (experimental robots). Against this background, this study was implemented to develop a test method for gene doping using dried blood spot (DBS), NGS, and the LabDroid ”Maholo”. As a first step, recombinant adeno-associated virus containing the human erythropoietin gene (hEPO) was injected into mice to establish a gene doping model. Subsequently, DBS was created using whole blood. Maholo was used to extract DNA from the DBS and to create DNA libraries for NGS. NGS in combination with bioinformatic analysis clearly identified DNA fragments that provided definitive evidence of gene doping in the mouse model, which were absent in the control mouse. To the best of our knowledge, this is the first attempt to use a biological model of hEPO gene doping in conjunction with Maholo, NGS, and DBS. This method should facilitate the further development of gene doping tests. Full article

Nitrite is a common pollutant in aquaculture systems and can pose serious threats to fish health, especially under high-temperature conditions. This study aimed to investigate the impact of nitrite stress on the growth, glycolipid metabolism, and hepatic metabolomic profiles in the spotted seabass fry (Lateolabrax maculatus) under elevated temperature conditions at 33 °C. A total of 450 fish (28.52 ± 0.84 g) were randomly distributed into nine tanks and exposed to three nitrite concentrations (0, 8, and 16 mg/L), with samples collected on days 1, 3, 7, 14, 21, and 28. Results showed that higher nitrite levels significantly reduced final body weight, weight gain, survival rate, hepatosomatic index, and viscerosomatic index. Blood glucose and triglyceride levels, whole-body crude lipid, liver total cholesterol, and hepatic glycogen content also declined significantly under higher nitrite stress. In contrast, hepatic lactate and lactate dehydrogenase increased in the high-nitrite group. Gene expression analysis revealed suppressed lipid synthesis and enhanced lipolysis under nitrite exposure. Metabolomic analysis further demonstrated disruptions in key energy-related pathways, including the TCA cycle, pentose phosphate pathway, and insulin signaling. These findings indicate that nitrite stress impairs growth and energy metabolism in spotted seabass, which respond by mobilizing energy reserves to cope with combined stress of high temperature and nitrite. Full article

Background: SMN1 and SMN2 are causative and modifier genes, respectively, for spinal muscular atrophy (SMA). The incidence of SMN1 homozygous deletion in Japan is 1 in 20,000. However, the incidence of SMN2 homozygous deletion in Japan remains unknown. Methods: To clarify the incidence of homozygous SMN2 deletion in Japan, real-time polymerase chain reaction (PCR) was performed on dried blood spot (DBS) samples collected from newborns nationwide. Samples with positive or ambiguous results were retested using PCR-restriction fragment length polymorphism (PCR-RFLP) and nucleotide sequence analysis. Results: Of the 1000 DBS samples that were screened using real-time PCR, 51 were positive. Retesting using PCR-RFLP analysis identified 10 false results: six false positives and four false negatives. Therefore, there were 49 true positives among the 1000 samples. Notably, nucleotide sequence analysis revealed that the false negatives were caused by the cross-reactivity of SMN2 primers with SMN1 sequences. Conclusions: The incidence of homozygous SMN2 deletion in Japan is approximately 1 in 20 people. This incidence is much higher than that of homozygous SMN1 deletion and may reflect the vulnerability of the SMN2 region. Importantly, the results of the present study suggest that false negatives in the screening process were caused by cross-reactivity with non-target gene sequences. Full article

Saliva was used as non-invasive alternative to blood for diagnosing pathophysiological conditions. This study aimed to assess changes in protein profile in people with obesity after bariatric surgery and to assess the impact of exercise on these changes. The saliva proteome was determined from two-dimensional gels of twenty adults (ten people with normal weight and ten people with obesity). The effects of bariatric surgery and exercise were assessed. A decrease in body weight, body mass index, and waist-to-height ratio was observed after bariatric surgery. Low levels of carbonic anhydrase VI (CA-VI), short palate, lung, and nasal epithelium clone 2 (SPLUNC2), and haptoglobin were observed. One month after bariatric surgery, spots of haptoglobin and SPLUNC2 increased, although one CA-VI spot decreased. Zn-alpha-2 glycoprotein, immunoglobulin chains, and actin-related protein-3, which are high in people with obesity, decreased 1 month after bariatric surgery. Five months after bariatric surgery, the most significant change was the amylase decrease. The exercise-induced changes in salivary proteins increased SPLUNC, CA-VI, type S cystatins, actin cytoplasmic 1, and zinc alpha-2 glycoprotein levels and decrease Ig kappa chain C region and Rab GDP dissociation inhibitor beta. It can be concluded that the salivary proteins change between people with normal weight vs. patients with obesity, as well as after bariatric surgery and exercise programmes. Salivary proteins may be useful biomarkers in non-invasive samples for monitoring and assessing the impact of interventions on people with obesity. Full article

Background: Acute appendicitis (AA) is a common surgical emergency worldwide. Over the past few decades, diagnostic imaging has become a cornerstone in the identification of acute appendicitis, significantly contributing to the reduction in unnecessary laparotomies and associated healthcare costs. This study aimed to investigate the influence of serum and spot urine 5-hydroxyindoleacetic acid (5-HIAA) levels, as well as other established clinical and biochemical parameters on the diagnosis of acute appendicitis. Methods: This prospective study was conducted between January and November 2023, evaluating 97 patients diagnosed with acute appendicitis. Serum and spot urine 5-HIAA levels, level of white blood cell (WBC), neutrophils, lymphocytes, platelets, C-reactive protein (CRP), and Alvarado score were analyzed. Patients were further allocated to subgroups based on their Alvarado scores, the onset time of the symptoms, and pathological findings to statistically assess the relationship between the parameters. Results: The mean age of the patients was 34.6 ± 14.8 years. Of the patients, 57 (58.8%) were male, and 40 (41.2%) were female. Spot urine 5-HIAA levels exhibited statistically significant variation among different symptom onset time groups, with elevated levels observed in patients presenting within the first 12 h of symptom onset (p < 0.001). Neutrophil counts were significantly different among Alvarado score groups (p < 0.001), whereas CRP levels significantly increased with the onset time of the symptoms (p < 0.001). Conclusions: Increased spot urine 5-HIAA is supportive of the diagnosis of AA in patients presenting within the first 12 h of symptom onset. Hematological parameters, especially CRP, may provide more reliable information regarding disease severity and progression. Full article

Newborn bloodspot screening for one or more lysosomal storage disorders (NBS-LSD) is currently performed by many public health NBS laboratories globally. The screening tests measure activities of selected lysosomal enzymes on dried blood spot (DBS) specimens collected from newborns by the heel stick method Because these assays measure enzyme activity, the quantitative results are dependent on the particular analytical method. DBS quality control (DBS QC) materials with assay-specific certified values that span the relevant range from typical to LSD-affected newborns are an important component of quality assurance in NBS laboratories. The Newborn Screening Quality Assurance Program (NSQAP) at the U.S. Centers for Disease Control and Prevention (CDC) provides public health NBS laboratories with DBS QC sets for NBS-LSD comprising four admixtures of pooled umbilical cord blood and a base pool made from leukodepleted peripheral blood and heat-inactivated serum. To evaluate the suitability of these materials for use with digital microfluidics fluorometry (DMF) assays which can currently measure the activity of four enzymes (acid α-galactosidase (GLA); acid β-glucocerebrosidase (GBA); acid α-glucosidase (GAA); and iduronidase (IDUA)), CDC collaborated with the Newborn Screening Unit at the Missouri State Public Health Laboratory (MSPHL). Using MSPHL criteria, we found that the certified results from each of two DBS QC lots collectively spanned the range from typical (screen negative) to enzyme deficient (screen positive) newborn DBS levels for each of the four lysosomal enzymes measured. The range included borderline results that would require repeat screening of the newborn under the MSPHL protocol. We conclude that these DBS QC preparations are suitable for use as external quality control materials for DMF assays used to detect LSDs in newborns. Full article

Background/Objectives: Oxidative stress plays a pivotal role in skin aging and carcinogenesis. Phytochemicals such as sulforaphane (SF, from broccoli sprouts or seeds) or curcumin (CUR, from turmeric) can be highly protective against this stress. They each induce a suite of cytoprotective and antioxidant enzymes that are coordinately transcribed via the Keap1-Nrf2-ARE pathway in mammals, such as the prototypical cytoprotective enzyme NAD(P)H dehydrogenase 1 (NQO1). Methods: Eighteen healthy human volunteers (9 males, 9 females, aged 18–69. were randomized to receive daily glucoraphanin (GR), which is converted to SF upon ingestion (450 mg; 1 mmol), CUR (1000 mg; 2.7 mmol), or both (450 mg GR + 1000 mg CUR), as oral supplements. After 8 days of a diet low in both compounds, blood and urine were collected for compliance and biomarker measurements. Randomized spots on the buttock’s skin were exposed to 2 x M.E.D. of UVB, and punch biopsies were obtained 1 and 3 days later for biomarker and histological measurement. Erythema was measured with a chromameter daily for 3 consecutive days following UVB. The process was repeated after receiving oral supplements, both with and without UVB exposure. Results: Compared to baseline, each treatment (n = 6 for each) induced NQO1 mRNA levels in skin biopsies: 3.1-fold with GR, 3.3-fold with CUR, and 3.6-fold with the combination of GR and CUR. Across all treatments (n = 18), expression of the pro-inflammatory cytokines IL-1β and TNF-α were reduced, as were IL-6, IL-17, STING, and CYR61, though less robustly. Modulation of these biomarkers persisted, but was less pronounced, in biopsies taken following UV exposure. The presence of SF and its metabolites in the skin post-treatment was confirmed by examining 6 of 12 subjects who ingested GR. Supplement effects on erythema following UV exposure were not significant, and no significant changes were measured in the same biomarkers in blood cells (PBMC), or by counting dyskeratotic keratinocytes. Supplements were well tolerated and compliance was excellent. Conclusions: Oral GR and CUR are well tolerated and have for the first time been shown to result in increased expression of cytoprotective genes and reduced expression of inflammatory cytokine genes in human skin in vivo. This mechanism-based clinical study suggests that an antioxidant, anti-inflammatory, and cytoprotective benefit from these oral supplements is delivered to the skin in humans. Full article