Evaluation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Analysis of Glucosylceramide and Galactosylceramide Isoforms in Cerebrospinal Fluid of Parkinson's Disease Patients.

Mutations in GBA1, encoding glucocerebrosidase beta 1 (GCase), are the most common genetic risk factor for Parkinson's disease (PD). GCase dysfunction leads to an accumulation of glucosylceramide (GluCer) substrates in different organs and fluids. Despite the challenges in quantifying GluCer isoforms in biological samples, their potential clinical interest as PD biomarkers justifies the development of robust assays. An extensively evaluated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for quantifying 14 GluCer and galactosylceramide (GalCer) isoforms in human cerebrospinal fluid (CSF) samples is presented. Sample pretreatment, HPLC, and MS/MS parameters were optimized. Evaluation was performed according to the recommendations of the Clinical and Laboratory Standards Institute and European Medicines Agency guidelines. Four 7-point calibration curves were generated, with a linearity interval from 2.5 to 200 nM (R2 ≥ 0.995). The limit of quantification was set at 5 nM. Between-run precision and accuracy were up to 12.5 and 9%, respectively. After method validation, we measured the levels of GluCer and GalCer isoforms in CSF human samples, including 6 healthy controls (HC), 22 idiopathic GBA1 wild-type PD (iPD) patients, and 5 GBA1-associated PD (PD-GBA) patients. GluCer/GalCer median ratios were found to be higher in the CSF of PD-GBA patients, particularly in severe GBA1 mutations, than those in iPD and HC. The observed trends in GluCer/GalCer ratios among groups provide novel information for the comprehensive analysis of sphingolipids as potential biomarkers of PD.

Influence of initial clinical suspicion on the diagnostic yield of laboratory enzymatic testing in lysosomal storage disorders. Experience from a multispecialty hospital.

Lysosomal storage disorders (LSD) are a group of inherited metabolic diseases mainly caused by a deficiency of lysosomal hydrolases, resulting in a gradual accumulation of non-degraded substrates in different tissues causing the characteristic clinical manifestations of such disorders. Confirmatory tests of suspected LSD individuals include enzymatic and genetic testing. A well-oriented clinical suspicion can improve the cost-effectiveness of confirmatory tests and reduce the time expended to achieve the diagnosis. Thus, this work aims to retrospectively study the influence of clinical orientation on the diagnostic yield of enzymatic tests in LSD by retrieving clinical, biochemical, and genetic data obtained from subjects with suspicion of LSD. Our results suggest that the clinical manifestations at the time of diagnosis and the initial clinical suspicion can have a great impact on the diagnostic yield of enzymatic tests, and that clinical orientation performed in specialized clinical departments can contribute to improve it. In addition, the analysis of enzymatic tests as the first step in the diagnostic algorithm can correctly guide subsequent confirmatory genetic tests, in turn increasing their diagnostic yield. In summary, our results suggest that initial clinical suspicion plays a crucial role on the diagnostic yield of confirmatory enzymatic tests in LSD.

Implementation of programmes for the transition of adolescents to adult care.

Up to 15-20% of adolescents have a chronic health problem. Adolescence is a period of particular risk for the development or progression of chronic diseases for both individuals with more prevalent conditions and those affected by rare diseases. The transition from paediatric to adult care begins with preparing and training the paediatric patient, accustomed to supervised care, to assume responsibility for their self-care in an adult care setting. The transition takes place when the young person is transferred to adult care and discharged from paediatric care services. It is only complete when the youth is integrated and functioning competently within the adult care system. Adult care providers play a crucial role in welcoming and integrating young adults. A care transition programme can involve transitions of varying complexity, ranging from those required for common and known diseases such as asthma, whose management is more straightforward, to rare complex disorders requiring highly specialized personnel. The transition requires teamwork with the participation of numerous professionals: paediatricians and adult care physicians, nurses, clinical psychologists, health social workers, the pharmacy team and administrative staff. It is essential to involve adolescents in decision-making and for parents to let them take over gradually. A well-structured transition programme can improve health outcomes, patient experience, the use of health care resources and health care costs.

An Integral Approach to the Molecular Diagnosis of Tuberous Sclerosis Complex: The Role of Mosaicism and Splicing Variants.

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder characterized by the presence of hamartomas in multiple organs. At the molecular level, the disease is caused by pathogenic variants in the TSC1 and TSC2 genes, and only 10% to 25% of clinically diagnosed patients remain negative after multiplex ligation-dependent probe amplification and exon sequencing of both genes. Here, to improve the molecular diagnosis of TSC, we developed an integral approach that includes multiplex ligation-dependent probe amplification and deep-coverage next-generation sequencing of the entire TSC1 and TSC2 genes, along with an adapted bioinformatic pipeline to detect variants at low allele frequencies (>1%). Using this workflow, the molecular cause was identified in 29 of 42 patients with TSC, describing here, for the first time, 12 novel pathogenic variants in TSC genes. These variants included seven splicing variants, five of which were studied at the cDNA level, determining their effect on splicing. In addition, 8 of the 29 pathogenic variants were detected in mosaicism, including four patients with previous negative study results who presented extremely low mosaic variants (allele frequency, <16%). We demonstrate that this integral approach allows the molecular diagnosis of patients with TSC and improves the conventional one by adapting the technology to the detection of low-frequency mosaics.

Clinical Outcomes of Patients with Chronic Neuropathic Form of Gaucher Disease in the Spanish Real-World Setting: A Retrospective Study.

This was a retrospective, multicenter study that aimed to report the characteristics of type 3 Gaucher disease (GD3) patients in Spain, including the genotype, phenotype, therapeutic options, and treatment responses. A total of 19 patients with GD3 from 10 Spanish hospitals were enrolled in the study (14 men, 5 women). The median age at disease onset and diagnosis was 1 and 1.2 years, respectively, and the mean age at follow-up completion was 12.37 years (range: 1-25 years). Most patients exhibited splenomegaly (18/19) and hepatomegaly (17/19) at the time of diagnosis. The most frequent neurological abnormalities at onset were psychomotor retardation (14/19) and extrinsic muscle disorders (11/19), including oculomotor apraxia, supranuclear palsy, and strabismus. The L444P (c.1448T>C) allele was predominant, with the L444P (c.1448T>C) homozygous genotype mainly associated with visceral manifestations like hepatosplenomegaly, anemia, and thrombocytopenia. All patients received enzyme replacement therapy (ERT); other treatments included miglustat and the chaperone (ambroxol). Visceral manifestations, including hepatosplenomegaly and hematological and bone manifestations, were mostly controlled with ERT, except for kyphosis. The data from this study may help to increase the evidence base on this rare disease and contribute to improving the clinical management of GD3 patients.

Switching to Glycerol Phenylbutyrate in 48 Patients with Urea Cycle Disorders: Clinical Experience in Spain.

Background and objectives: Glycerol phenylbutyrate (GPB) has demonstrated safety and efficacy in patients with urea cycle disorders (UCDs) by means of its clinical trial program, but there are limited data in clinical practice. In order to analyze the efficacy and safety of GPB in clinical practice, here we present a national Spanish experience after direct switching from another nitrogen scavenger to GPB. Methods: This observational, retrospective, multicenter study was performed in 48 UCD patients (age 11.7 ± 8.2 years) switching to GPB in 13 centers from nine Spanish regions. Clinical, biochemical, and nutritional data were collected at three different times: prior to GPB introduction, at first follow-up assessment, and after one year of GPB treatment. Number of related adverse effects and hyperammonemic crisis 12 months before and after GPB introduction were recorded. Results: GPB was administered at a 247.8 ± 102.1 mg/kg/day dose, compared to 262.6 ± 126.1 mg/kg/day of previous scavenger (46/48 Na-phenylbutyrate). At first follow-up (79 ± 59 days), a statistically significant reduction in ammonia (from 40.2 ± 17.3 to 32.6 ± 13.9 µmol/L, p < 0.001) and glutamine levels (from 791.4 ± 289.8 to 648.6 ± 247.41 µmol/L, p < 0.001) was observed. After one year of GPB treatment (411 ± 92 days), we observed an improved metabolic control (maintenance of ammonia and glutamine reduction, with improved branched chain amino acids profile), and a reduction in hyperammonemic crisis rate (from 0.3 ± 0.7 to less than 0.1 ± 0.3 crisis/patients/year, p = 0.02) and related adverse effects (RAE, from 0.5 to less than 0.1 RAEs/patients/year p < 0.001). Conclusions: This study demonstrates the safety of direct switching from other nitrogen scavengers to GPB in clinical practice, which improves efficacy, metabolic control, and RAE compared to previous treatments.

Biomarkers in Fabry Disease. Implications for Clinical Diagnosis and Follow-up.

Fabry disease (FD) is a lysosomal storage disorder caused by deficient alpha-galactosidase A activity in the lysosome due to mutations in the GLA gene, resulting in gradual accumulation of globotriaosylceramide and other derivatives in different tissues. Substrate accumulation promotes different pathogenic mechanisms in which several mediators could be implicated, inducing multiorgan lesions, mainly in the kidney, heart and nervous system, resulting in clinical manifestations of the disease. Enzyme replacement therapy was shown to delay disease progression, mainly if initiated early. However, a diagnosis in the early stages represents a clinical challenge, especially in patients with a non-classic phenotype, which prompts the search for biomarkers that help detect and predict the evolution of the disease. We have reviewed the mediators involved in different pathogenic mechanisms that were studied as potential biomarkers and can be easily incorporated into clinical practice. Some accumulation biomarkers seem to be useful to detect non-classic forms of the disease and could even improve diagnosis of female patients. The combination of such biomarkers with some response biomarkers, may be useful for early detection of organ injury. The incorporation of some biomarkers into clinical practice may increase the capacity of detection compared to that currently obtained with the established diagnostic markers and provide more information on the progression and prognosis of the disease.

Leucocytoclastic vasculitis in a patient with COVID-19 with positive SARS-CoV-2 PCR in skin biopsy.

Main skin manifestations of COVID-19 have been recently classified. However, little is known about cutaneous histopathological patterns and the presence of SARS-CoV-2 in these skin lesions. We present a healthy 29-year-old man who developed a leucocytoclastic vasculitis for COVID-19 with positive SARS-CoV-2 PCR in skin biopsy.

Implementación de programas de transición de la adolescencia a la edad adulta / Implementation of programmes for the transition of adolescents to adult care

Hasta un 15-20% de adolescentes tienen algún problema de salud crónico. La adolescencia representa un periodo de riesgo especial para la evolución de las enfermedades crónicas, tanto en aquellos con padecimientos con mayor prevalencia como en los afectados por enfermedades raras. La transición de la asistencia pediátrica a la adulta empieza con la preparación y capacitación del paciente pediátrico, acostumbrado a los cuidados tutelados, para que asuma la responsabilidad de su autocuidado en una unidad de adultos. La transferencia es el momento en el que la persona joven pasa a los servicios de adultos y es dada de alta de los servicios pediátricos. La transición sólo se completa cuando los jóvenes están integrados y funcionan con total competencia dentro del servicio de adultos. Los profesionales de adultos tienen un rol crucial al momento de recibir e integrar a los adultos jóvenes. Un programa de transición puede incluir transiciones de diferente complejidad, desde enfermedades frecuentes y conocidas como el asma, que requieren un proceso más sencillo, hasta enfermedades raras complejas con necesidad de participación de personal muy especializado. La transición requiere un trabajo en equipo con participación de numerosos profesionales: pediatras y médicos de adultos, enfermeras, psicólogos clínicos, trabajadores sociales sanitarios, equipo de Farmacia, y personal administrativo. Es importante implicar a los adolescentes en la toma de decisiones y que los padres los dejen ir progresivamente. Un programa de transición bien estructurado puede mejorar los resultados en salud, la experiencia del paciente y la utilización y coste de los cuidados sanitarios.(AU)

Up to 15%–20% of adolescents have a chronic health problem. Adolescence is a period of particular risk for the development or progression of chronic diseases for both individuals with more prevalent conditions and those affected by rare diseases. The transition from paediatric to adult care begins with preparing and training the paediatric patient, accustomed to supervised care, to assume responsibility for their self-care in an adult care setting. The transition takes place when the young person is transferred to adult care and discharged from paediatric care services. It is only complete when the youth is integrated and functioning competently within the adult care system. Adult care providers play a crucial role in welcoming and integrating young adults. A care transition programme can involve transitions of varying complexity, ranging from those required for common and known diseases such as asthma, whose management is more straightforward, to rare complex disorders requiring highly specialized personnel.(AU)