Search Results (412)

Background: Exocrine pancreatic insufficiency (EPI or PEI) may be prevalent in as many as 3 of 10 people with diabetes due to exocrine pancreatic function being reduced as early as the time of diagnosis. EPI can be treated with pancreatic enzyme replacement therapy (PERT), but the symptom burden of EPI remains high and improved screening and diagnosis methods are needed. Methods: An online survey (n = 324) evaluated the gastrointestinal symptom experiences of people with (n = 155) and without (n = 169) EPI using a novel symptom tool, the Exocrine Pancreatic Insufficiency Symptom Score (EPI/PEI-SS). A large sub-group (n = 120) of people with diabetes with EPI (Type 1, n = 14, Type 2, n = 20) or without EPI (Type 1, n = 78; Type 2; n = 6) was characterized and compared to those without diabetes (n = 204) in a sub-analysis of the larger EPI/PEI-SS study. Results: The symptom burden of EPI is similar, irrespective of diabetes. Like those without diabetes, people with type 1 diabetes with EPI had a statistically significant (p < 0.001) higher mean score (range 0–225) on the EPI/PEI-SS (100.86, SD: 48.92) than people with T1D without EPI (31.59, SD: 28.25), distinct from other GI conditions (p < 0.001). Similar patterns occurred in those with T2D. Conclusions: High EPI/PEI-SS scores seem to distinguish between likely EPI and other GI conditions among people with diabetes, and the EPI/PEI-SS should be further studied as a possible screening method for EPI at a population level. It should also be evaluated as a tool to aid individuals with diabetes in tracking changes to EPI symptoms over time based on PERT titration. Full article

Pompe disease is a rare autosomal-recessive neuromuscular disorder caused by a deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA), leading to the pathological accumulation of glycogen and impaired autophagy. Enzyme replacement therapy (ERT) with recombinant human alpha-glucosidase (rhGAA) has been available since 2006, but may lead to the formation of anti-drug antibodies (ADAs) against the recombinant human enzyme, which, in turn, may adversely affect the response to ERT. Knowledge of the antigenic determinants of rhGAA involved in interaction with ADAs may facilitate the development of strategies to attenuate the anti-drug immune response in patients. Here, we determined the rhGAA ADA epitopes in the plasma of Pompe disease patients using a series of affinity purifications combined with epitope extraction and label free quantitation LC-MS. Full article

Gaucher disease (GD) is an autosomal recessive disorder caused by the deficient activity of the lysosomal enzyme glucocerebrosidase (GCase). Although enzyme replacement therapy (ERT) remains the standard of care for non-neuropathic GD patients, its high cost significantly limits accessibility. To enhance production efficiency, we developed a lentiviral system encoding a codon-optimized GCase gene driven by the human elongation factor 1a (hEF1α) promoter for stable production in human cell lines. A functional lentiviral vector, LV_EF1α_GBA_Opt, was generated at a titer of 7.88 × 10⁸ LV particles/mL as determined by qPCR. Six transduction cycles were performed at a multiplicity of infection of 30–50. The transduced heterogeneous human cell population showed GCase-specific activity of 307.5 ± 53.49 nmol/mg protein/h, which represents a 3.21-fold increase compared to wild-type 293FT cells (95.58 ± 16.5 nmol/mg protein/h). Following single-cell cloning, two clones showed specific activity of 763.8 ± 135.1 and 752.0 ± 152.1 nmol/mg/h (clones 15 and 16, respectively). These results show that codon optimization, a lentiviral delivery system, and clonal selection together enable the establishment of stable human cell lines capable of producing high levels of biologically active, synthetic recombinant GCase in vitro. Further studies are warranted for the functional validation in GD patient-derived fibroblasts and animal models. Full article

Objectives: This systematic literature review aimed to identify studies assessing the clinical efficacy and real-world effectiveness of current and emerging treatments for Fabry disease. Methods: Searches of the MEDLINE, EMBASE, and Cochrane library databases, as well as relevant congress proceedings, were conducted to identify publications reporting on studies in patients of any age, sex, race, or ethnicity who received any approved or experimental treatment for Fabry disease, published before 17 June 2024. Results: Of 1881 publications screened, 234 reported data on renal, cardiac, cerebrovascular, and disease severity outcomes from 225 studies. The majority of reported studies were observational in nature (n = 150; 67%) and involved only adults (n = 172; 74%). Study designs and patient populations were highly heterogeneous, and cross-study conclusions about the effectiveness of different therapies could not be made. Enzyme replacement therapy (ERT) with agalsidase alfa or agalsidase beta stabilized renal function and cardiac structure in patients with Fabry disease. Early initiation of ERT in childhood or young adulthood was associated with better renal and cardiac outcomes than treatment initiation at a later age. The small number of comparator studies of agalsidase alfa and agalsidase beta suggested similar efficacy. Patients treated with migalastat and pegunigalsidase alfa also maintained stable renal function and cardiac structure. Conclusions: Overall, current treatments slow the progression of renal and cardiac decline in patients with Fabry disease. Large cohort studies with long-term follow-up and baseline stratification based on clinical phenotype are needed to address evidence gaps and provide clinicians with robust data to inform treatment decisions. Full article

Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disorder causing systemic skeletal dysplasia due to a deficiency of N-acetyl-galactosamine-6-sulfate sulfatase (GALNS) enzyme activity, leading to the impaired degradation and accumulation of glycosaminoglycans (GAGs), keratan sulfate (KS) and chondroitin-6-sulfate. While treatments such as enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT) are available, they have significant limitations regarding efficacy in skeletal tissues and long-term safety, highlighting the need for more effective therapies. We evaluated a novel gene therapy approach using a dual Integrase-deficient lentiviral vector (IDLV) to deliver an expression cassette that includes human GALNS cDNA and Cas9 sgRNA, targeting the upstream region of the mouse Galns initial codon. This approach leverages the endogenous promoter to drive transgene expression. We assessed in vitro transduction, editing, and functional correction in NIH3T3 and MPS IVA mouse fibroblasts. In vivo efficacy was successfully evaluated via the facial vein injection in MPS IVA newborn mice. In vitro, this IDLV platform demonstrated supraphysiological GALNS activity in cell lysate, resulting in the normalization of KS levels. In vivo direct IDLV platform in newborn MPS IVA mice led to sustained plasma GALNS activity, reduced plasma KS, and favorable biodistribution. Partial correction of heart and bone pathology was observed, with no vector toxicity and minimal antibody responses. This dual IDLV-CRISPR/Cas9 approach effectively mediated targeted GALNS knock-in, yielding sustained enzyme activity, reduced KS storage, and partial pathological amelioration in MPS IVA mice. In conclusion, IDLVs represent an efficient, safe platform for delivering the CRISPR/Cas9 gene editing system for MPS IVA. Full article

Lysosomal storage disorders (LSDs) constitute a group of monogenic systemic diseases resulting from deficiencies in specific lysosomal enzymes that cause the intralysosomal accumulation of non- or partially degraded substrates, leading to lysosomal dysfunction. In some cases of LSDs, the bone is more severely affected, thus producing skeletal manifestations in patients. Current therapies, such as enzyme replacement therapy (ERT) and gene therapy (GT), show limited efficacy in correcting skeletal abnormalities. Increasing evidence suggests that microenvironmental disturbances also contribute significantly to disease pathogenesis. Therefore, therapeutic strategies targeting lysosomal dysfunction and microenvironmental dysregulation are needed. Mesenchymal stem-cell-derived extracellular vesicles (MSC-EVs) are emerging as promising candidates in regenerative medicine due to their immunomodulatory, pro-regenerative, and paracrine properties. MSC-EVs have shown potential to modulate the microenvironment and favor tissue repair in bone-related disorders such as osteoarthritis and osteoporosis. Interestingly, MSC-EVs can be engineered to reach the bone and carry therapeutics, including ERT- and GT-related molecules, enabling targeted delivery to hard-to-reach bone regions. This review describes the main features of MSC-EVs and discusses the therapeutic potential of MSC-EVs as a potential cell-free strategy for bone-affected LSDs. 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

Background/Objectives: Diabetic ketoacidosis (DKA) is an acute and severe complication of diabetes mellitus, marked by hyperglycemia, ketosis, and acidosis. It is associated with significant metabolic and inflammatory adjustments that can impact multiple biochemical pathways. This study aimed to determine the serum sphingolipid profile in DKA and investigate its relationship with neutral sphingomyelinase (N-SMase), pro-inflammatory cytokines, β-hydroxybutyrate (β-OHB), and lactate levels. Methods: Thirty-three participants were divided into three groups: control (BMI ≤ 30, no health issues), obese (BMI > 30), and DKA (BMI ≤ 30). Sphingomyelins (16:0–24:0 SMs) and ceramides (C16–C24 CERs) were measured using ultra-fast liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). N-SMase, interleukin 1 beta (IL-1β), and tumor necrosis factor alpha (TNF-α) levels were assessed by enzyme-linked immunosorbent assay. Evaluations were done in the DKA group before and after standard clinical treatment for DKA (post-DKA group), which included intravenous insulin therapy, fluid resuscitation, and electrolyte replacement, as per established clinical guidelines. Results: β-OHB levels were significantly higher in the DKA group than in the control, obese, and post-DKA groups. Although β-OHB levels decreased in the post-DKA group, they remained elevated compared to the control and obese groups. Lactate levels were also higher in the DKA group, with a significant decrease in the post-DKA group. TNF-α and IL-1β were higher in the obese group compared to control and DKA groups, and TNF-α decreased significantly in the post-DKA group compared to DKA. N-SMase, 16:0–18:0 SMs, and C18-C24 CER levels were lower in the DKA and post-DKA groups compared to obese and control groups. Serum β-OHB and lactate levels were significantly correlated with S1P, total CER, total SM, and N-SMase values. Conclusions: The study reveals significant metabolic and inflammatory differences in DKA and post-DKA states, suggesting a relationship between sphingolipids, N-SMase, and these alterations, which could offer insights into DKA pathophysiology and therapeutic targets. Full article

Tay–Sachs disease (TSD) is a rare and severe neurodegenerative disorder inherited in an autosomal recessive manner. It is caused by a deficiency of the enzyme hexosaminidase A, which is responsible for the degradation of GM2 gangliosides—lipids that accumulate in the nerve cells of the central nervous system. The inability to break down these lipids leads to their progressive accumulation, resulting in irreversible brain damage. Mechanistically, TSD is caused by mutations in the HEXA gene, which encodes the alpha subunit of hexosaminidase A. These mutations disrupt enzyme activity and alter cellular pathways involved in lysosomal lipid degradation. Although Tay–Sachs specifically involves the alpha subunit, similar clinical features can be seen in Sandhoff disease, a related disorder caused by mutations in the HEXB gene, which encodes the beta subunit shared by hexosaminidase A and B. Tay–Sachs is classified into three clinical forms according to age of onset and symptom severity: the classic infantile form, which is the most common and severe; a juvenile (subacute) form; and an adult-onset form, which progresses more slowly and tends to present with milder symptoms. Diagnosis is based on enzymatic testing showing reduced or absent hexosaminidase A activity, confirmed by genetic testing. Prenatal diagnosis and genetic counseling play a key role in prevention and reproductive decision-making, especially in high-risk populations. Although no curative treatment currently exists, ongoing research is exploring gene therapy, enzyme replacement, and pharmacological approaches. Certain compounds, such as gemfibrozil, have shown potential to slow symptom progression. Early diagnosis and multidisciplinary care are essential to improving quality of life, although therapeutic options remain limited due to the progressive nature of the disease. 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

The hypertrophic cardiomyopathy (HCM) clinical phenotype includes sarcomeric HCM, which is the most common form of inherited cardiomyopathy with a population prevalence of 1:500, and phenocopies such as cardiac amyloidosis and Anderson–Fabry disease, which are considered rare diseases. Identification of cardiac and non-cardiac red flags in the context of multi-organ syndrome, multimodality imaging, including echocardiography, cardiac magnetic resonance, and genetic testing, has a central role in the diagnostic pathway. Identifying the specific disease underlying the hypertrophic phenotype is very important since many disease-modifying therapies are currently available, and phase 3 trials for new treatments have been completed or are ongoing. In particular, many chemotherapy agents (alkylating agents, proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies targeting clonal cells) allowing one to treat AL amyloidosis, transthyretin stabilizers (tafamidis and acoramidis), and gene silencers (patisiran and vutrisiran) are available in transthyretin cardiac amyloidosis, and enzyme replacement therapies (agalsidase-alpha, agalsidase-beta, and pegunigalsidase-alpha) or oral chaperone therapy (migalastat) can be used in Anderson–Fabry disease. In addition, the introduction of cardiac myosin inhibitors (mavacamten and aficamten) has deeply modified the treatment of hypertrophic obstructive cardiomyopathy. The aim of this review is to describe the new disease-modifying treatments available in HCM and phenocopies in light of current scientific evidence. Full article

Background: Lysosomal storage disorders (LSDs) are rare inherited metabolic diseases characterized by defects in lysosomal enzyme function or membrane transport. These defects lead to substrate accumulation and multisystemic manifestations. This review focuses on gastrointestinal (GI) involvement in LSDs, which is a significant but often overlooked aspect of these disorders. Methods: A comprehensive literature review was conducted to examine the pathophysiology, clinical presentation, diagnosis and management of GI manifestations in several LSDs, including Fabry disease, Gaucher disease, Pompe disease, Niemann–Pick disease type C, mucopolysaccharidoses and Wolman disease. Results: The pathogenesis of GI involvement in LSDs varies and encompasses substrate accumulation in enterocytes, mesenteric lymphadenopathy, mass effects, smooth muscle dysfunction, vasculopathy, neuropathy, inflammation and alterations to the microbiota. Clinical presentations range from non-specific symptoms, such as abdominal pain, diarrhea and malabsorption, to more severe complications, such as protein-losing enteropathy and inflammatory bowel disease. Diagnosis often requires a high level of suspicion, as GI symptoms may precede the diagnosis of the underlying LSD or be misattributed to more common conditions. Management strategies include disease-specific treatments, such as enzyme replacement therapy or substrate reduction therapy, as well as supportive care and targeted interventions for specific GI complications. Conclusions: This review highlights the importance of recognizing and properly managing GI manifestations in LSDs to improve patient outcomes and quality of life. It also emphasizes the need for further research to develop more effective treatments for life-threatening GI complications associated with these rare genetic disorders. Full article

CLN2 disease (neuronal ceroid lipofuscinosis type 2) is an ultra-rare lysosomal storage disorder caused by mutations in the TPP1/CLN2 gene, resulting in impaired tripeptidyl peptidase 1 (TPP1) activity. The timely initiation of enzyme replacement therapy is pivotal for attenuating progressive and irreversible neurodegeneration. This study aimed to benchmark the performance of Oxford Nanopore long-read sequencing (ONT-LRS) for targeted TPP1 mutation detection in a Turkish CLN2 cohort and to assess its concordance with orthogonal validation methods, including Sanger sequencing and enzymatic activity assays. Using a custom-designed primer panel, the entire TPP1 gene (6846 bp) was sequenced on the Oxford Nanopore (ONT) MinIon platform in seven clinically confirmed CLN2 index patients and sixteen unaffected family members. Detected variants were validated via Sanger sequencing and correlated with TPP1 enzyme activity in leucocytes and dried blood spots. Four pathogenic or likely pathogenic TPP1 variants were identified: c.622C>T (p.Arg208*), c.857A>G (p.Asn286Ser), c.1204G>T (p.Glu402*), and c.225A>G (p.Gln75=), along with fourteen additional benign variants. Variant allele frequencies were 50% for c.622C>T, 28.6% for c.1204G>T, 14.3% for c.857A>G, and 7.1% for c.225A>G. Notably, this is the first report to document the homozygous state of the c.857A>G variant and the compound heterozygous configuration of the c225A>G and c.622C>T variants in CLN2 patients, thereby expanding the known mutational landscape. In contrast, the globally common variant c.509-1G>C was not observed, suggesting regional variation in TPP1 mutation patterns. Consistent with the prior Turkish studies, c.622C>T (p.Arg208*) was the most prevalent variant, followed by c.1204G>T (p.Glu402*). TPP1 enzymatic activity was significantly reduced in all affected individuals (p < 0.0001), supporting the functional relevance of the identified variants. ONT-LRS offers a robust, cost-effective platform for high-resolution analysis of the TPP1 gene. Integrating molecular and biochemical data improves diagnostic precision and supports timely, targeted interventions for CLN2 disease, particularly in regions with high consanguinity and limited diagnostic infrastructure. Full article

Mucopolysaccharidosis type IVA (MPS IVA, Morquio A syndrome) is a rare inherited disorder characterized by skeletal dysplasia due to deficient N-acetylgalactosamine-6-sulfate sulfatase activity, resulting in glycosaminoglycan (GAG) accumulation. Identifying accurate biomarkers reflecting clinical severity and therapeutic response remains challenging. This study evaluated potential surrogate biomarkers, including N-terminal pro-C-type natriuretic peptide (NT-proCNP), collagen types I and II, mono-sulfated keratan sulfate (KS), di-sulfated KS, and chondroitin-6-sulfate (C6S), in blood and urine samples from 60 patients ranging from 1 to 62 years of age. NT-proCNP levels were significantly elevated in patients of all ages and negatively correlated with growth impairment, especially after 8 years of age. Collagen type I levels significantly increased in adult patients, whereas collagen type II showed age-dependent elevations. Urinary KS, in mono- and di-sulfated forms, demonstrated moderate negative correlations with growth impairment. Moreover, NT-proCNP, mono- and di-sulfated KS in plasma, and urinary di-sulfated KS were not affected by enzyme replacement therapy in patients younger than 12 years, unlike urinary mono-sulfated KS. In conclusion, NT-proCNP has emerged as a promising independent biomarker reflecting the severity of skeletal dysplasia and possibly the near-future growth rate. These findings highlight the potential role of NT-proCNP in clinical assessment and monitoring therapeutic efficacy, addressing current unmet needs in MPS IVA management. Full article

Morquio A syndrome is a lysosomal disorder caused by the deficiency of the lysosomal enzyme N-acetylgalactosamine 6-sulfatase (GALNS, EC 3.1.6.4). Currently, enzyme replacement therapy (ERT) is used to treat Morquio A through the infusion of the recombinant enzyme VIMIZIM^® (elosulfase alfa, BioMarin). Unfortunately, the recombinant enzyme exhibits low conformational stability in vivo. A promising approach to address this issue is the coadministration of recombinant human GALNS (rhGALNS) with a pharmacological chaperone (PC), a molecule that selectively binds to the misfolded protein, stabilizes its conformation, and assists in the restoration of the impaired function. We report in this work the synthesis of a library of multivalent glycomimetics exploiting the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between several dendrimeric scaffolds armed with terminal alkynes and azido ending iminosugars of different structures (pyrrolidines, piperidines, and pyrrolizidines) or simple azido ending carbohydrates as bioactive units. The biological evaluation identified pyrrolidine-based nonavalent dendrimers 1 and 36 as the most promising compounds, able both to bind the native enzyme with IC₅₀ in the micromolar range and to act as enzyme stabilizers toward rhGALNS in a thermal denaturation study, thus identifying promising compounds for a combined PC/ERT therapy. Full article