Search Results (85)

Background/Objectives: Gaucher disease (GD) is a lysosomal disorder caused by a deficiency of β-glucosidase. Disease-modifying therapies (DMTs) include enzyme replacement therapy (ERT) and substrate reduction therapy (SRT). Glucosylsphingosine (lyso-Gb1) is a biomarker with high sensitivity and specificity in GD. Methods: In GD patients attending a specialist centre, we evaluated dried blood spot lyso-Gb1 levels (normal values ≤ 6.8 ng/mL) by treatment status, sex, GD type and genotype, ERT dose, DMT type and duration, spleen status, and association with other GD biomarkers. Results: A total of 111 patients were screened; 100 (54M:46F; 93 GD1 and 7 GD3; median age 45.2 years, IQR 34.2–57.2; 7 naive and 93 patients on DMTs for a median of 10.4 years, IQR 5.7–21.2) had at least one lyso-Gb1 measurement. Median lyso-Gb1 values were higher in naïve (195, IQR 48.6–388) patients than treated patients (47.1, IQR 23.1–89.7), p = 0.015; higher in those treated ≥ 15 years (62.9, IQR 36.6–103) than in those treated < 15 years (35.1, IQR 20.3–73.9), p = 0.006; and higher in splenectomised (83.4, IQR 34.7–224.5) patients than non-splenectomised patients (40.7, IQR 21.4–77.1), p = 0.044. ERT dose > 60 U/kg had high median lyso-Gb1 values (87.3, IQR 19.7–126), reflecting greater disease burden, and this high dose was only used in patients with GD3. Lyso-Gb1 correlated with chitotriosidase (r = 0.495; p < 0.001) and haemoglobin (r = −0.231; p = 0.022). In a subset of 50 patients with paired values, lyso-Gb1 decreased from baseline (median −1.7 ng/mL, IQR −24.5–14.8). Conclusions: Whilst there was a modest decrease in lyso-Gb1 over time on DMTs, the values remained significantly above the normal range, which may be driven by underlying mechanisms such as inflammation. Full article

Background: Fabry disease (FD) is an X-linked lysosomal storage disorder caused by GLA mutations, leading to deficient α-galactosidase A (α-Gal A) activity and progressive glycosphingolipid accumulation. While α-Gal A activity is the diagnostic gold standard, its sensitivity is reduced in late-onset or heterozygous patients. Conventional biomarkers such as lyso-Gb3 provide only limited insight into disease progression and therapeutic response. Exosomes, as stable carriers of disease-specific proteins, may offer complementary biomarkers for early detection and longitudinal monitoring. Methods: Twenty-one pediatric FD patients with confirmed GLA mutations were enrolled. Clinical, enzymatic, renal, and cardiac parameters were assessed. Plasma-derived exosomes were characterized by transmission electron microscopy and proteomic profiling. Differentially expressed proteins were identified using mass spectrometry, analyzed using GO/KEGG enrichment, and validated using RT-PCR, ELISA, and immunofluorescence in patient samples and Gla^−/− mice. Results: Male patients showed markedly reduced α-Gal A activity and elevated lyso-Gb3 compared with females. Although overt renal and cardiac dysfunction was uncommon, several patients exhibited early abnormalities such as proteinuria, an elevated LVMI, or increased cTnI levels. Proteomic analysis identified 2553 proteins, of which 188 were differentially expressed. Fibrosis- and inflammation-related proteins, including THBS1 and CFHR5, were upregulated, while protective factors such as APM1, SERPINA10, and CAB39 were downregulated. IGFBP3 was also elevated and closely linked to tissue remodeling. Enriched pathways were involved in PPAR/AMPK signaling, lipid metabolism, and complement activation. Conclusions: Exosomal proteomic profiling revealed early molecular signatures of cardiorenal involvement in pediatric FD. Key proteins such as THBS1, CFHR5, IGFBP3, APM1, and CAB39 show strong potential as biomarkers for risk stratification, disease monitoring, and therapeutic evaluation. Full article

Background/Objectives: Gaucher disease type 1 is an autosomal recessive lysosomal storage disorder caused by pathogenic variants in the GBA1 gene. Although enzyme replacement therapy has improved patient outcomes, there is limited long-term real-world data on taliglucerase alfa. This study aimed to evaluate the long-term efficacy and safety of taliglucerase alfa in both treatment-naïve and previously treated patients with Gaucher disease type 1 over a 10-year period. Methods: This prospective, single-centre cohort study involved 29 patients (13 treatment-naïve and 16 previously treated with imiglucerase) who received taliglucerase alfa from 2015 to 2024. Clinical, hematological, visceral, skeletal, and biochemical parameters were assessed at baseline and at 12, 60, and 120 months. Biomarkers included chitotriosidase and glucosylsphingosine. Safety was evaluated through adverse event reporting and anti-drug antibody testing. Results: Hemoglobin and platelet counts improved or remained stable in all patients. By 60 months, liver volume had normalised in treatment-naïve patients (mean reduction: 23.1%), while spleen volume had decreased by up to 47.3%. Lyso-Gb1 levels decreased by 86.1% in patients who had not previously received treatment and by 59.5% overall, with a strong correlation to adherence. Bone mineral density improved in most cases. 137 adverse events were reported, 24% of which were mild infusion-related reactions. Anti-drug antibody developed in two patients, including one with a reduced therapeutic response. Conclusions: Taliglucerase alfa offers sustained long-term clinical, hematological and biochemical benefits in both treatment-naïve and previously treated Gaucher disease type 1 patients, with a favorable safety profile. Glucosylsphingosine proved to be a highly sensitive biomarker for monitoring therapeutic efficacy and detecting treatment response. Full article

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

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by mutations in the GLA gene, resulting in a deficient activity of the enzyme α-galactosidase A (α-Gal A). This deficiency leads to the progressive accumulation of globotriaosylceramide (Gb3) and its deacylated form, globotriaosylsphingosine (Lyso-Gb3), in various tissues, contributing to a broad spectrum of clinical manifestations. Recent evidence highlights the crucial role of inflammation in the pathophysiology of FD, influencing disease progression and clinical outcomes. This review provides a comprehensive overview of the relationship between inflammation and FD, with a particular focus on the impact of inflammatory processes on disease progression and complications. Full article

Background: Fabry disease (FD) is an X-linked lysosomal storage disorder caused by mutations in the GLA gene, resulting in α-galactosidase A (α-Gal A) deficiency and progressive accumulation of globotriaosylceramide (Gb3). Current therapies, such as enzyme replacement and chaperone therapy, have limitations, including incomplete biodistribution and mutation-specific efficacy. Gene therapy using adeno-associated virus (AAV) vectors presents a promising alternative. Methods: In this study, we assessed the dose-dependent effects of AAV8 and AAV9 vectors encoding human GLA in Gla knockout (Gla^−/y) mice by measuring α-Gal A activity and monitoring safety. To evaluate therapeutic efficacy, symptomatic Fabry mice (G3S^Tg/+Gla^−/y) were used. Results: AAV9-GLA produced significantly higher and more sustained enzyme activity than AAV8-GLA across plasma, liver, heart, and kidney. In symptomatic mice, AAV9-GLA achieved superior reductions in serum Gb3 and lyso-Gb3 levels, greater Gb3 clearance in heart and kidney tissues, and improved proteinuria. Anti-GLA IgG titers remained below threshold for the first four weeks and increased modestly by week eight, indicating a limited humoral immune response. No significant clinical signs or weight loss were observed in Gla^−/y mice over the 3.5-month study period, supporting the favorable safety profile of AAV-mediated gene therapy. Conclusions: These findings demonstrate that AAV9 provides enhanced biodistribution and therapeutic efficacy compared to AAV8, supporting its potential for the treatment of Fabry disease. Full article

Lysosomal storage diseases are caused by defective lysosomal function, such as impaired lysosomal enzyme activities, which include more than 70 different diseases. Although biomarkers and therapies have been developed to date for some of them, many others remain challenging to diagnose and treat. In this study, an elevated level of Globotriaosylsphingosine (Lyso-Gb3), an already known biomarker for Fabry disease, was confirmed in the knock-out cells of the GLA, GNPTAB, and PSAP genes and models for Fabry, mucolipidosis II/III (ML II/III), and combined saposin deficiency, respectively. Lyso-Gb3 was high in ML II/III patient skin fibroblasts compared with normal cells and was decreased after total lysosomal enzyme supplementation. There have been no useful biomarkers reported in ML II/III until now. This study shows that Lyso-Gb3 is elevated in ML II/III patient cells and is decreased by treatment, indicating that Lyso-Gb3 is a potential biomarker for ML II/III. Full article

Eliglustat (Cerdelga^®) is a potent and specific inhibitor of the enzyme glucosylceramide synthase and serves as a substrate reduction therapy for adult patients with Gaucher disease type 1 (GD1). It prevents the accumulation of several lipids, including glucosylsphingosine (also known as Lyso-Gb1). In addition to its role in diagnostics, Lyso-Gb1 has been proven to be a reliable biomarker for assessing disease severity and monitoring treatment efficacy. We present the case of an obese, splenectomized GD1 patient on long-term enzyme replacement therapy (ERT) who reported worsening fatigue and showed a progressive increase in Lyso-Gb1 levels after switching treatment from ERT to eliglustat. We provide a discussion of the potential clinical factors contributing to this outcome. As seen with ERT, Lyso-Gb1 levels during eliglustat treatment appear to respond earlier than other biochemical and clinical parameters. An increase in Lyso-Gb1 may signal early compromised clinical efficacy of the treatment. Data on biochemical and clinical outcomes in splenectomized or obese patients treated with eliglustat are limited, and the role of specific genotypes requires further clarification. The variability in responses to eliglustat highlights the complexity of GD and underscores the need for personalized approaches to treatment and monitoring. Full article

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by mutations in the GLA gene, leading to α-galactosidase A deficiency and subsequent accumulation of glycosphingolipids, including globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3), in multiple organs. This accumulation can result in multisystemic disease and life-threatening complications. FD presents with a broad phenotypic spectrum, ranging from the classic form, with early and severe symptoms, to a later-onset form with variable manifestations. The severity of the disease in females is more variable due to X-chromosome inactivation (XCI). Renal involvement is a key feature, and kidney biopsy remains a valuable tool for diagnosing FD and assessing the extent of nephropathy. Although molecular genetic testing is the gold standard for diagnosis, kidney biopsy aids in confirming renal involvement, detecting coexisting conditions, and determining the pathogenicity of variants of uncertain significance (VUSs). Moreover, kidney biopsy can serve as a prognostic tool by identifying early markers of nephropathy, such as foot process effacement and glomerular sclerosis, which predict disease progression. Emerging technologies, including machine learning, offer the potential to enhance the analysis of renal histology, improving diagnostic accuracy and patient stratification. Despite the challenges posed by overlapping diseases and potential misdiagnoses, kidney biopsy remains an essential component of FD diagnosis and management, facilitating early detection, the monitoring of disease progression, and the evaluation of therapeutic responses. Full article

Background: Gaucher disease (GD) is an autosomal recessive lysosomal disease. Extended neonatal screening currently includes GD in several different regions. Decision on when to start enzyme replacement therapy (ERT) upon confirmed diagnosis or upon appearance of first clinical manifestation of the disease remains an unmet need. Methods: We report our preliminary experience in tightly monitoring blood levels of glucosyl-sphingosine (lyso-Gb1), on DBS at birth and then every 4 weeks, in the absence of ERT in three consecutive newborns identified for GD as part of a screening program. Results: Initial lyso-Gb1 values were above cut-off. In two cases, lyso-Gb1 levels showed a reduction during the first 3 months of life and, by month 4, they had reached a value lower than the upper normal value. In the case of the third child, after an initial drop to less than 50% of the initial value, lyso-Gb1 levels remained pretty stable at the following four time-points. At the time of writing, all remain free from any disease manifestation at the age of 20, 11 and 8 months, respectively, with normal physical growth and blood count; therefore, ERT has not been started yet. Conclusions: A specific threshold for lyso-Gb1 value to be considered as associated with non-reversible progression to disease is not yet defined. We hypothesize that a trend toward stable increase of this biomarker, confirmed at repeated evaluation, rather than a single threshold, could be convincing for starting ERT even before clinical manifestation of the disease. Full article

Fabry disease, the second most common lysosomal storage disorder, is caused by a deficiency of α-galactosidase A (α-Gal A), which leads to an accumulation of glycosphingolipids (GSL), mainly globotriaosylceramide (also known as Gb3). This aberrant GSL metabolism subsequently causes cellular dysfunction; however, the underlying cellular and molecular mechanisms are still unknown. There is growing evidence that damage to organelles, including lysosomes, mitochondria, and plasma membranes, is associated with substrate accumulation. Current methods for the detection of Gb3 are based on anti-Gb3 antibodies, the specificity and sensitivity of which are problematic for glycan detection. This study presents a robust method using lectins, specifically the B-subunit of Shiga toxin (StxB) from Shigella dysenteriae and LecA from Pseudomonas aeruginosa, as alternatives for Gb3 detection in Fabry fibroblasts by flow cytometry and confocal microscopy. StxB and LecA showed superior sensitivity, specificity, and consistency in different cell types compared to all anti-Gb3 antibodies used in this study. In addition, sphingolipid metabolism was analyzed in primary Fabry fibroblasts and α-Gal A knockout podocytes using targeted tandem liquid chromatography-mass spectrometry. Our findings establish lectins as a robust tool for improved diagnostics and research of Fabry disease and provide evidence of SL changes in cultured human cells, filling a knowledge gap. Full article

Background/Objectives: Fabry disease (FD) is a rare X-linked lysosomal storage disorder characterised by progressive glycolipid accumulation affecting multiple organs, including the peripheral nervous system. The dorsal root ganglia (DRG) play a key role in Fabry-related neuropathy, but non-invasive biomarkers of DRG involvement and their association with overall disease severity remain limited. This study evaluated lumbosacral DRG T2 relaxation time (DRG-T2) in FD patients as a potential imaging biomarker of FD severity. Methods: In a prospective, single-centre study, 80 genetically confirmed FD patients underwent 3T MRI with quantitative T2 mapping of the lumbosacral DRG. DRG-T2 was analysed in relation to sex, genetic subtype and Fabry-specific biomarkers. Results: Results showed that DRG-T2 was higher in patients with classical FD mutations than in those with nonclassical mutations (p = 0.03). Furthermore, DRG-T2 showed a negative correlation with body weight (ρ = −0.31, p = 0.005) and BMI (ρ = −0.32, p = 0.004), while no associations were found with lyso-Gb3 levels or alpha-galactosidase A activity. The inter-rater and test–retest reliability of DRG-T2 were good to excellent (ICC = 0.76 and 0.89, respectively). Conclusions: These results demonstrate DRG-T2 as a marker of neuronal involvement, making it a strong and reliable imaging biomarker of disease severity in FD. However, future studies need to correlate its changes with clinical and histological studies. Full article

Fabry disease (FD) is a lysosomal disorder due to alpha-galactosidase-A enzyme deficiency, accumulation of globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3) which lead to proinflammatory effects. Males develop progressive hypertrophic cardiomyopathy (HCM) followed by fibrosis; females develop nonconcentric hypertrophy and/or early fibrosis. The inflammatory response to Gb3/lyso-Gb-3 accumulation is one of the suggested pathogenic mechanisms in FD cardiomyopathy when the secretion of inflammatory and transforming growth factors with infiltration of lymphocytes and macrophages into tissue promotes cardiofibrosis. This study aims to evaluate inflammation-driving cytokines and cardio-hypertrophic remodeling biomarkers contributing to sex-specific HCM progression. Biomarkers were studied in 20 healthy subjects and 45 FD patients. IL-2, IL-10, TNF-α, and IFN-γ were elevated in all patients, while IL-1α, MCP-1, and TNFR2 showed sex-specific differences. The increased cytokines were associated with the NF-kB pathway in FD males with HCM, revealing a correlation between MCP-1, IFN-γ, VEGF, GM-CSF, IL-10, and IL-2. In female patients, the impaired TNFα/TNFR2/TGFβ cluster with correlations to MCP-1, VEGF, GM-CSF, and IL-1α was observed. The activation of cytokines and the NF-kB pathway indicates significant inflammation during HCM remodeling in FD males. The TNFα/TNFR2/TGFβ signaling cluster may explain early fibrosis in females with FD cardiomyopathy. Sex-specific inflammatory responses in FD influence the severity and progression of HCM. Full article

Anderson–Fabry disease is a hereditary, progressive, multisystemic lysosomal storage disorder caused by a functional deficiency of the enzyme α-galactosidase A (α-GalA). This defect is due to mutations in the GLA gene, located in the long arm of the X chromosome (Xq21-22). Functional deficiency of the α-GalA enzyme leads to reduced degradation and accumulation of its substrates, predominantly globotriaosylceramide (Gb3), which accumulate in the lysosomes of numerous cell types, giving rise to the symptomatology. Clinical diagnosis can still be difficult today due to the peculiarities of the disease, which presents with clinical manifestations that overlap with those of other pathologies and a wide possibility of differential diagnoses, which lead to missed diagnoses, misdiagnosis, or a diagnostic delay. Patients with clinical suspicion of Fabry disease undergo a diagnostic workup that includes an evaluation of α-GALA enzyme activity, genetic analysis of the GLA gene, and the measurement of blood Lyso-Gb3, a soluble derivative of Gb3. In this paper, we describe four novel mutations identified in the GLA gene which are associated with absent or reduced α-GalA activity, pathological accumulation of the specific substrate, and characteristic clinical manifestations of Fabry disease. We identified two mutations (c.583insGAATA and p.Y207X) that result in the formation of a premature translation stop codon, resulting in a truncated protein and thus a completely non-functional enzyme. The other two identified gene alterations (p.G261C and c.786G>T, which determine p.W262C) are missense mutations that cause reduced α-GALA activity, the accumulation of blood Lyso-Gb3, and symptoms consistent with Fabry disease, and therefore may be associated with this disorder. The identification of these new mutations in patients with symptoms attributable to Fabry disease increases the molecular knowledge of the GLA gene and provides important support to the clinician, for a more accurate and timely diagnosis of the pathology. Full article

Anderson–Fabry (or Fabry) disease is a rare lysosomal storage disorder caused by a functional deficiency of the enzyme alpha-galactosidase A. The partial or total defect of this lysosomal enzyme, which is caused by variants in the GLA gene, leads to the accumulation of glycosphingolipids, mainly globotriaosylceramide in the lysosomes of different cell types. The clinical presentation of Fabry disease is multisystemic and can vary depending on the specific genetic variants associated with the disease. To date, more than 1000 different variants have been identified in the human GLA gene, including missense and nonsense variants, as well as small and large insertions or deletions. The identification of novel variants in individuals exhibiting symptoms indicative of Fabry disease, expands the molecular comprehension of the GLA gene, providing invaluable insights to physicians in the diagnosis of the disease. In this article, we present the case of two members of the same family, mother and son, in whom a new pathogenic variant was identified. This variant has not been previously described in the literature and is not present in databases. The two family members presented with a number of typical clinical manifestations of the disease, including cornea verticillata, neuropathic pain, left ventricular hypertrophy, angiokeratomas and abdominal pain. The son, but not his mother, showed reduced alpha-galactosidase A activity, while high levels of Lyso-Gb3 in the blood, a specific substrate accumulation biomarker, were found in both. Sequencing of the GLA gene revealed the presence of a variant, c.484delT, which is characterised by the deletion of a single nucleotide, a thymine, in exon 3 of the gene. This results in a frameshift variant, which introduces a premature stop codon, thereby generating a truncated and consequently non-functional protein. Therefore, the clinical and laboratory data indicate that the novel p.W162Gfs*3 variant described herein is associated with the classical form of Fabry disease. Full article