The Impact of Excluding Nonrandomized Studies From Systematic Reviews in Rare Diseases: "The Example of Meta-Analyses Evaluating the Efficacy and Safety of Enzyme Replacement Therapy in Patients With Mucopolysaccharidosis".

Nonrandomized studies are usually excluded from systematic reviews. This could lead to loss of a considerable amount of information on rare diseases. In this article, we explore the impact of excluding nonrandomized studies on the generalizability of meta-analyses results on mucopolysaccharidosis (MPS) disease. A comprehensive search of systematic reviews on MPS patients up to May 2020 was carried out (CRD42020191217). The primary endpoint was the rate of patients excluded from systematic reviews if only randomized studies were considered. Secondary outcomes included the differences in patient and study characteristics between randomized and nonrandomized studies, the methods used to combine data from studies with different designs, and the number of patients excluded from systematic reviews if case reports were not considered. More than 50% of the patients analyzed have been recruited in nonrandomized studies. Patient characteristics, duration of follow-up, and the clinical outcomes evaluated differ between the randomized and nonrandomized studies. There are feasible strategies to combine the data from different randomized and nonrandomized designs. The analyses suggest the relevance of including case reports in the systematic reviews, since the smaller the number of patients in the reference population, the larger the selection bias associated to excluding case reports. Our results recommend including nonrandomized studies in the systematic reviews of MPS to increase the representativeness of the results and to avoid a selection bias. The recommendations obtained from this study should be considered when conducting systematic reviews on rare diseases.

Genomic testing in 1019 individuals from 349 Pakistani families results in high diagnostic yield and clinical utility.

We implemented a collaborative diagnostic program in Lahore (Pakistan) aiming to establish the genetic diagnosis, and to asses diagnostic yield and clinical impact in patients with suspected genetic diseases. Local physicians ascertained pediatric patients who had no previous access to genetic testing. More than 1586 genetic tests were performed in 1019 individuals (349 index cases, 670 relatives). Most frequently performed tests were exome/genome sequencing (ES/GS, 284/78 index cases) and specific gene panels (55 index cases). In 61.3% of the patients (n = 214) a genetic diagnosis was established based on pathogenic and likely pathogenic variants. Diagnostic yield was higher in consanguineous families (60.1 vs. 39.5%). In 27 patients, genetic diagnosis relied on additional biochemical testing, allowing rapid assessment of the functional effect of the variants. Remarkably, the genetic diagnosis had a direct impact on clinical management. Most relevant consequences were therapy related such as initiation of the appropriated treatment in a timely manner in 51.9% of the patients (n = 111). Finally, we report 12 candidate genes among 66 cases with no genetic diagnosis. Importantly, three of these genes were validated as 'diagnostic' genes given the strong evidence supporting causality derived from our data repository (CAP2-dilated cardiomyopathy, ITFG2-intellectual disability and USP53-liver cholestasis). The high diagnostic yield, clinical impact, and research findings demonstrate the utility of genomic testing, especially when used as first-line genetic test. For patients with suspected genetic diseases from resource-limited regions, ES can be considered as the test of choice to achieve genetic diagnosis.

The Value of Case Reports in Systematic Reviews from Rare Diseases. The Example of Enzyme Replacement Therapy (ERT) in Patients with Mucopolysaccharidosis Type II (MPS-II).

BACKGROUND: Case reports are usually excluded from systematic reviews. Patients with rare diseases are more dependent on novel individualized strategies than patients with common diseases. We reviewed and summarized the novelties reported by case reports in mucopolysaccharidosis type II (MPS-II) patients treated with enzyme replacement therapy (ERT). METHODS: We selected the case reports included in a previous meta-analysis of patients with MPS-II treated with ERT. Later clinical studies evaluating the same topic of those case reports were reported. Our primary aim was to summarize novelties reported in previous case reports. Secondary objectives analyzed the number of novelties evaluated in subsequent clinical studies and the time elapsed between the publication of the case report to the publication of the clinical study. RESULTS: We identified 11 innovative proposals in case reports that had not been previously considered in clinical studies. Only two (18.2%) were analyzed in subsequent nonrandomized cohort studies. The other nine novelties (81.8%) were analyzed in later case reports (five) or were not included in ulterior studies (four) after more than five years from their first publication. CONCLUSIONS: Case reports should be included in systematic reviews of rare disease to obtain a comprehensive summary of the state of research and offer valuable information for healthcare practitioners.

Critical clinical situations in adult patients with Mucopolysaccharidoses (MPS).

BACKGROUND: Mucopolysaccharidoses (MPS) are rare, inherited disorders associated with enzyme deficiencies that result in glycosaminoglycan (GAG) accumulation in multiple organ systems. Management of MPS is evolving as patients increasingly survive to adulthood and undergo multiple surgeries throughout their lives. As surgeries in these patients are considered to be high risk, this can result in a range of critical clinical situations in adult patients. RESULTS: We discuss strategies to prepare for and manage critical clinical situations in adult patients with MPS, including supporting the multidisciplinary team, preoperative and airway assessments, surgical preparations, and postoperative care. We also present eight critical clinical cases (age range: 21-38 years) from four leading inherited metabolic disease centres in Europe to highlight challenges and practical solutions to optimise the care of adult patients with MPS. Critical clinical situations included surgical procedures, pregnancy and a thrombus in a port-a-cath. CONCLUSIONS: Individualised strategies to manage critical clinical situations need to be developed for each patient to compensate for the heterogeneous symptoms that may be present and the potential complications that may occur. These strategies should include input from the wider MDT, and be coordinated by metabolic specialists with expertise in the management of MPS disorders and surgery in adult patients with MPS.

Agreement between results of meta-analyses from case reports and clinical studies, regarding efficacy and safety of idursulfase therapy in patients with mucopolysaccharidosis type II (MPS-II). A new tool for evidence-based medicine in rare diseases.

BACKGROUND: A preliminary exploratory study shows solid agreement between the results of case reports and clinical study meta-analyses in mucopolysaccharidosis Type I (MPS-I) adult patients. The aim of the present study is to confirm previous results in another patient population, suffering from mucopolysaccharidosis Type II (MPS-II). METHODS: A systematic review and meta-analysis of case reports published by April 2018 was conducted for MPS-II patients treated with enzyme replacement therapy (ERT). The study is reported in accordance with PRISMA and MOOSE guidelines (PROSPERO database code CRD42018093408). The assessed population and outcomes were the same as previously analyzed in a meta-analysis of MPS-II clinical studies. The primary endpoint was the percent of clinical cases showing improvement in efficacy outcome, or no harm in safety outcome after ERT initiation. A restrictive procedure to aggregate case reports, by selecting standardized and well-defined outcomes, was proposed. Different sensitivity analyses were able to evaluate the robustness of results. RESULTS: Every outcome classified as "acceptable evidence group" in our case report meta-analysis had been graded as "moderate strength of evidence" in the aforementioned meta-analysis of clinical studies. Sensitivity, specificity, and positive-negative predictive values for results of both meta-analyses reached 100%, and were deemed equivalent. CONCLUSIONS: Aggregating case reports quantitatively, rather than analyzing them qualitatively, may improve conclusions in rare diseases and personalized medicine. Additionally, we propose some methods to evaluate publication bias and heterogeneity of the included studies in a meta-analysis of case reports.

Presenting signs and patient co-variables in Gaucher disease: outcome of the Gaucher Earlier Diagnosis Consensus (GED-C) Delphi initiative.

BACKGROUND: Gaucher disease (GD) presents with a range of signs and symptoms. Physicians can fail to recognise the early stages of GD owing to a lack of disease awareness, which can lead to significant diagnostic delays and sometimes irreversible but avoidable morbidities. AIM: The Gaucher Earlier Diagnosis Consensus (GED-C) initiative aimed to identify signs and co-variables considered most indicative of early type 1 and type 3 GD, to help non-specialists identify 'at-risk' patients who may benefit from diagnostic testing. METHODS: An anonymous, three-round Delphi consensus process was deployed among a global panel of 22 specialists in GD (median experience 17.5 years, collectively managing almost 3000 patients). The rounds entailed data gathering, then importance ranking and establishment of consensus, using 5-point Likert scales and scoring thresholds defined a priori. RESULTS: For type 1 disease, seven major signs (splenomegaly, thrombocytopenia, bone-related manifestations, anaemia, hyperferritinaemia, hepatomegaly and gammopathy) and two major co-variables (family history of GD and Ashkenazi-Jewish ancestry) were identified. For type 3 disease, nine major signs (splenomegaly, oculomotor disturbances, thrombocytopenia, epilepsy, anaemia, hepatomegaly, bone pain, motor disturbances and kyphosis) and one major co-variable (family history of GD) were identified. Lack of disease awareness, overlooking mild early signs and failure to consider GD as a diagnostic differential were considered major barriers to early diagnosis. CONCLUSION: The signs and co-variables identified in the GED-C initiative as potentially indicative of early GD will help to guide non-specialists and raise their index of suspicion in identifying patients potentially suitable for diagnostic testing for GD.

Agreement between the results of meta-analyses from case reports and from clinical studies regarding the efficacy of laronidase therapy in patients with mucopolysaccharidosis type I who initiated enzyme replacement therapy in adult age: An example of case reports meta-analyses as an useful tool for evidence-based medicine in rare diseases.

BACKGROUND: Case reports might have a prominent role in the rare diseases field, due to the small number of patients affected by one such disease. A previous systematic review regarding the efficacy of laronidase therapy in patients with mucopolysaccharidosis type I (MPS-I) who initiated enzyme replacement therapy (ERT) in adult age has been published. The review included a meta-analysis of 19 clinical studies and the description of eleven case reports. It was of interest to perform a meta-analysis of those case reports to explore the role of such meta-analyses as a tool for evidence-based medicine in rare diseases. METHODS: The study included all case reports with standard treatment regimen. Primary analysis was the percentage of case reports showing an improvement in a specific outcome. Only when that percentage was statistically higher than 5%, the improvement was confirmed as such. The outcomes that accomplished this criterion were ranked and compared to the GRADE criteria obtained by those same outcomes in the previous meta-analysis of clinical studies. RESULTS: There were three outcomes that had a significant improvement: Urine glycosaminoglycans, liver volume and 6-minute walking test. Positive and negative predictive values, sensitivity and specificity for the results of the meta-analysis of case reports as compared to that of clinical studies were 100%, 88.9%, 75% and 100%, respectively. Accordingly, absolute (Rho=0.82, 95%CI: 0.47 to 0.95) and relative agreement (Kappa=0.79, 95%CI: 0.593 to 0.99) between the number of case reports with improvement in a specific outcome and the GRADE evidence score for that outcome were good. Sensitivity analysis showed that agreement between the meta-analysis of case reports and that of the clinical studies were good only when using a strong confirmatory strategy for outcome improvement in case reports. CONCLUSIONS: We found an agreement between the results of meta-analyses from case reports and from clinical studies in the efficacy of laronidase therapy in patients with MPS-I who initiated ERT in adult age. This agreement suggests that combining case reports quantitatively, rather than analyzing them separately or qualitatively, may improve conclusions in the field of rare diseases.

Diferencias entre agalsidasa alpha y agalsidasa Beta en el tratamiento de la enfermedad de Fabry / Differences between agalsidase alpha and agalsidase Beta in the treatment of Fabry disease

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Exploring the patient journey to diagnosis of Gaucher disease from the perspective of 212 patients with Gaucher disease and 16 Gaucher expert physicians.

Gaucher disease (GD) is a rare hereditary disorder caused by a deficiency of the lysosomal enzyme ß-glucocerebrosidase. Diagnosis is challenging owing to a wide variability in clinical manifestations and severity of symptoms. Many patients may experience marked delays in obtaining a definitive diagnosis. The two surveys reported herein aimed to explore the patient journey to diagnosis of GD from the perspectives of Gaucher expert physicians and patients. Findings from the surveys revealed that many patients experienced diagnostic delays and misdiagnoses, with nearly 1 in 6 patients stating that they were not diagnosed with GD for 7years or more after first consulting a doctor. Physicians and patients both reported multiple referrals to different specialties before a diagnosis of GD was obtained, with primary care, haematology/haematology-oncology and paediatrics the main specialties to which patients first presented. Splenomegaly, thrombocytopenia, anaemia and bone pain were reported as the most common medical problems at first presentation in both surveys. These findings support a clear need for straightforward and easy-to-follow guidance designed to assist non-specialists to identify earlier patients who are at risk of GD.

Efficacy of laronidase therapy in patients with mucopolysaccharidosis type I who initiated enzyme replacement therapy in adult age. A systematic review and meta-analysis.

BACKGROUND: The efficacy of starting enzyme replacement therapy (ERT) in adults with Muchopolysaccharidosis Type I (MPS-I) is controversial. Evaluating the benefits reported by patients initiating ERT with laronidase at adult age might help physicians decide whether the use of ERT in these patients is worthwhile from a clinical point of view. OBJECTIVE: To assess every effectiveness variable modified in MPS-I patients who initiated laronidase at adult age. METHODS: A systematic search of the literature, from inception to July 2016, was conducted using MEDLINE, EMBASE, CENTRAL and LILACS to identify randomized trials or observational studies including ≥1 MPS-I patients with ERT initiated in adult age (≥18years) and evaluating ERT efficacy. A meta-analysis of studies evaluating the same effectiveness outcome was performed and the evidence was rated according to GRADE criteria. Heterogeneity was assessed by the Chi-squared test and the I-squared statistic. Case reports were excluded from meta-analysis but their main outcomes were separately evaluated. The decrease in urine glycosaminoglycans (uGAGs) levels as patient percentage with reduction in uGAGs and with normalization was the primary outcome. RESULTS: Nineteen clinical studies and 12 case reports were selected. ERT decreased uGAG levels (high evidence) and liver volume (high), improved 6-min walking test (6MWT) (moderate) and increased blood anti-ERT antibody levels (high). There was no conclusive results (low or very low evidence) regarding improvement/stabilization of respiratory function, change in shoulder flexion, cardiac improvement/stabilization, improvement in symptoms of nocturnal hypoventilation and sleep apnea, improvement in quality of life, visual acuity, otolaryngologic function, bone mineral density or effectiveness of intrathecal therapy. LIMITATIONS: Excluding case reports, there was no study conducted specifically in the target population (ERT ≥18years). Data were from subgroup analyses of selected studies. There was a great heterogeneity between designs and clinical outcomes evaluated. CONCLUSIONS: ERT improves uGAGs and liver volume in MPS-I patients initiating therapy as adults, although the putative clinical benefit associated to these improvements is unclear. Moderate evidence was shown for improvement in 6MWT. Systematic review registration number (PROSPERO): 42,016,041,306.

Assessment of Bone Health in Patients With Type 1 Gaucher Disease Using Impact Microindentation.

Gaucher disease (GD), one of the most common lysosomal disorders (a global population incidence of 1:50,000), is characterized by beta-glucocerebrosidase deficiency. Some studies have demonstrated bone infiltration in up to 80% of patients, even if asymptomatic. Bone disorder remains the main cause of morbidity in these patients, along with osteoporosis, avascular necrosis, and bone infarcts. Enzyme replacement therapy (ERT) has been shown to improve these symptoms. This cross-sectional study included patients with type 1 Gaucher disease (GD1) selected from the Catalan Study Group on GD. Clinical data were collected and a general laboratory workup was performed. Bone mineral density (BMD) was measured at the lumbar spine and hip using dual-energy X-ray absorptiometry (DXA). Patients with bone infarcts or any other focal lesion in the area of indentation visible on imaging were excluded. Bone Material Strength index (BMSi) was measured by bone impact microindentation using an Osteoprobe instrument. Analysis of covariance (ANCOVA) models were fitted to adjust for age, sex, weight, and height. Sixteen patients with GD1 and 29 age- and sex-matched controls were included. GD1 was associated with significantly lower BMSi (adjusted beta -9.30; 95% CI, -15.18 to -3.42; p = 0.004) and reduced lumbar BMD (adjusted beta -0.14; 95% CI, -0.22 to -0.06; p = 0.002) and total hip BMD (adjusted beta -0.09; 95% CI, -0.15 to -0.03; p = 0.006), compared to GD1-free controls. Chitotriosidase levels were negatively correlated with BMSi (linear R2 = 51.6%, p = 0.004). Bone tissue mechanical characteristics were deteriorated in patients with GD1. BMSi was correlated with chitotriosidase, the marker of GD activity. Bone disorder requires special consideration in this group of patients, and microindentation could be an appropriate tool for assessing and managing their bone health. © 2017 American Society for Bone and Mineral Research.

Proceso de transición de la asistencia pediátrica a la adulta en pacientes con errores congénitos del metabolismo. Documento de consenso / Transition process from paediatric to adult care in patients with inborn errors of metabolism. Consensus statement

Antecedentes y objetivo: El proceso de transición de la asistencia pediátrica a la adulta es un tema de gran interés en los últimos años, especialmente en enfermedades crónicas de inicio en la infancia, como los errores congénitos del metabolismo (ECM). Los avances en el diagnóstico y el tratamiento de estas enfermedades han mejorado su pronóstico, encontrando en la actualidad un elevado número de pacientes con ECM que alcanzan la edad adulta y necesitan ser atendidos por profesionales no pediátricos. El objetivo de este trabajo es establecer unas pautas de actuación para que los especialistas involucrados garanticen una transición exitosa de la atención sanitaria de estos pacientes. Metodología: Tras realizar una revisión bibliográfica del tema, los autores, partiendo de su propia experiencia, elaboraron un documento inicial que fue sometido a sucesivos debates hasta obtener el documento definitivo. En caso de discrepancia de criterio, la recomendación de consenso se decidió por mayoría. Resultados: Se presentan una serie de recomendaciones para el mejor abordaje clínico de la transición asistencial de los pacientes con ECM desde el entorno pediátrico a la asistencia de adultos, con el objetivo de conseguir los mejores resultados en este proceso, dadas las características especiales de este subgrupo de pacientes, así como las principales dificultades que conlleva el proceso de transición Conclusiones: Se resalta el papel del médico internista en este proceso de transición y su correcta articulación con el entorno pediátrico y social. Asimismo, se recomiendan acciones y actitudes para mejorar la calidad de dicha transición (AU)

Background and objective: The transition process from paediatric to adult care is a subject of great interest in recent years, especially in chronic diseases with childhood onset, such as inborn errors of metabolism (IEM). Advances in diagnosis and treatment of these diseases have improved their prognosis, with a high number of patients with IEM who currently reach adult age and need to be attended to by non-paediatric professionals. The objective of this work is to establish action guidelines so that the specialists involved can guarantee a successful transition of these patients’ healthcare. Methodology: After carrying out a bibliographic review of the subject, the authors, beginning with their own experience, produced an initial document which was subjected to successive debates until the final document was obtained. The consensus recommendation was decided by the majority in case of criterion discrepancy. Results: A series of recommendations are presented for the best clinical management of the transitions of care of patients with IEM from the paediatric to adult care setting in order to achieve the best results in this process given the special characteristics of this patient subgroup and the main difficulties entailed in the transition process. Conclusions: The role of the internal medicine doctor in this transition process and correct interrelation with the paediatric and social setting is stressed. Furthermore, actions and attitudes are suggested to improve the quality of said transition (AU)

[Transition process from paediatric to adult care in patients with inborn errors of metabolism. Consensus statement]. / Proceso de transición de la asistencia pediátrica a la adulta en pacientes con errores congénitos del metabolismo. Documento de consenso.

BACKGROUND AND OBJECTIVE: The transition process from paediatric to adult care is a subject of great interest in recent years, especially in chronic diseases with childhood onset, such as inborn errors of metabolism (IEM). Advances in diagnosis and treatment of these diseases have improved their prognosis, with a high number of patients with IEM who currently reach adult age and need to be attended to by non-paediatric professionals. The objective of this work is to establish action guidelines so that the specialists involved can guarantee a successful transition of these patients' healthcare. METHODOLOGY: After carrying out a bibliographic review of the subject, the authors, beginning with their own experience, produced an initial document which was subjected to successive debates until the final document was obtained. The consensus recommendation was decided by the majority in case of criterion discrepancy. RESULTS: A series of recommendations are presented for the best clinical management of the transitions of care of patients with IEM from the paediatric to adult care setting in order to achieve the best results in this process given the special characteristics of this patient subgroup and the main difficulties entailed in the transition process. CONCLUSIONS: The role of the internal medicine doctor in this transition process and correct interrelation with the paediatric and social setting is stressed. Furthermore, actions and attitudes are suggested to improve the quality of said transition.

Patients with type 1 Gaucher disease in Spain: A cross-sectional evaluation of health status.

A multicentre, cross-sectional epidemiological survey was conducted to describe the health status of patients with type 1 Gaucher disease (GD1) in Spain. Patient data were collected retrospectively from clinical records. Therapeutic goals for seven clinical parameters were chosen as primary outcome measures. 108 GD1 patients (mean age 44.8 years; 53% male) were recruited from 28 hospitals. Ninety-five patients (88%) were receiving treatment for GD1. Hemoglobin concentration was the therapeutic goal with the highest level of achievement, being met by 105 of 108 patients (97%), followed by the goals for liver volume (86/98 patients; 88%), spleen volume (67/77 patients; 87%) and platelet count (81/108 patients; 75%). The goal for bone mineral density (BMD) was met by 48 of 75 patients (64%), and the goal for quality of life was met by 65 of 103 patients (63%). Bone pain was the parameter with the lowest level of achievement (goal met by 50/94 patients; 53%). The clinical information most often missing from patient records was the BMD Z-score (missing for 31% of patients). These data suggest that most Spanish GD1 patients have good control over hematological and visceral parameters, but there is a need to improve monitoring and treatment of GD-related bone disease.

Guía para el seguimiento de la enfermedad de Pompe de inicio tardío / Guidelines for monitoring late-onset Pompe disease

Aunque el tratamiento con alglucosidasa alfa ha contribuido a mejorar el pronóstico de los pacientes con enfermedad de Pompe de inicio tardío, es necesario hacer un seguimiento periódico de la evolución de la enfermedad y de la eficacia del tratamiento. Por este motivo, un comité de expertos españoles ha elaborado una guía para el seguimiento de estos pacientes. El comité propone un modelo de pruebas de seguimiento para la enfermedad de Pompe de inicio tardío. En primer lugar, ha de valorarse el estado nutricional y la función deglutoria. En segundo lugar, y debido a la variabilidad del cuadro clínico, el comité recomienda el uso simultáneo de varias escalas que midan distintas funciones y pará- metros. De este modo, la fuerza muscular se evalúa con la escala del Medical Research Council; la función motora, con la prueba de la marcha en seis minutos y pruebas cronometradas; la discapacidad, con la escala de actividad específica de la enfermedad de Pompe construida según el análisis de Rasch; la función respiratoria, con la medida de la capacidad vital forzada y la saturación de oxígeno; y la fatiga, con la escala de intensidad de la fatiga. Por último, la seguridad y la tolerabilidad del tratamiento enzimático sustitutivo se controlan con el registro y tratamiento de los potenciales efectos adversos y la medición de los anticuerpos antialglucosidasa alfa. Se incluyen también diversas recomendaciones generales (AU)

Although treatment with alglucosidase alfa has helped improve the prognosis of patients with late-onset Pompe disease, both the development of the disease and the effectiveness of the treatment need to be monitored on a regular basis. This is the reason that has led a committee of Spanish experts to draw up a series of guidelines on how to follow up these patients. The committee proposes a model of follow-up tests for late-onset Pompe disease. First of all, the nutritional status and swallowing function must be evaluated. Second, and due to the variability of the clinical features, the committee recommends the simultaneous use of several scales to measure different functions and parameters. Thus, muscular force is assessed with the Medical Research Council scale; motor functioning, with the six-minute walk test and timed tests; disability, with the Rasch-built Pompe-specific Activity scale; respiratory functioning, with measurement of the forced vital capacity and oxygen saturation; and fatigue, with the fatigue intensity scale. Lastly, the safety and tolerability of enzyme replacement therapy are controlled by registering and treating the potential side effects and measurement of the anti-alglucosidase alfa antibodies. A number of different general recommendations are also included (AU)

Delayed diagnosis of late-onset Pompe disease in patients with myopathies of unknown origin and/or hyperCKemia.

Pompe disease is a rare metabolic myopathy whose diagnosis is sometimes delayed despite being essential for improving clinical outcomes. We aimed to investigate the prevalence of late-onset Pompe disease among patients with a myopathy of unknown etiology, including polymyositis, or with idiopathic rise of creatine kinase (CK) levels, in a department of internal medicine. A cohort study was conducted in 241 subjects: 140 patients with myopathies of unknown origin or increased CK levels, 30 with polymyositis and 71 who constituted the control group of other myopathies. Acid α-glucosidase (GAA) activity was tested in dried blood spots. If a positive result was obtained, GAA activity in isolated lymphocytes and/or genetic testing was performed as a confirmatory diagnosis. Out of the 140 investigated patients, 2 patients with myopathies of unknown origin were confirmed to be positive for Pompe disease. Thus, late-onset Pompe disease should be considered among adult patients with myopathy of unknown origin.

[Guidelines for monitoring late-onset Pompe disease.Sociedad Española de Medicina Interna (SEMI), Sociedad Española de Neurología (SEN) y Sociedad Española de Neumología y CirugíaTorácica (SEPAR)]. / Guía para el seguimiento de la enfermedad de Pompe de inicio tardío.

Although treatment with alglucosidase alfa has helped improve the prognosis of patients with late-onset Pompe disease, both the development of the disease and the effectiveness of the treatment need to be monitored on a regular basis. This is the reason that has led a committee of Spanish experts to draw up a series of guidelines on how to follow up these patients. The committee proposes a model of follow-up tests for late-onset Pompe disease. First of all, the nutritional status and swallowing function must be evaluated. Second, and due to the variability of the clinical features, the committee recommends the simultaneous use of several scales to measure different functions and parameters. Thus, muscular force is assessed with the Medical Research Council scale; motor functioning, with the six-minute walk test and timed tests; disability, with the Rasch-built Pompe-specific Activity scale; respiratory functioning, with measurement of the forced vital capacity and oxygen saturation; and fatigue, with the fatigue intensity scale. Lastly, the safety and tolerability of enzyme replacement therapy are controlled by registering and treating the potential side effects and measurement of the anti-alglucosidase alfa antibodies. A number of different general recommendations are also included.

TITLE: Guia para el seguimiento de la enfermedad de Pompe de inicio tardio.Aunque el tratamiento con alglucosidasa alfa ha contribuido a mejorar el pronostico de los pacientes con enfermedad de Pompe de inicio tardio, es necesario hacer un seguimiento periodico de la evolucion de la enfermedad y de la eficacia del tratamiento. Por este motivo, un comite de expertos españoles ha elaborado una guia para el seguimiento de estos pacientes. El comite propone un modelo de pruebas de seguimiento para la enfermedad de Pompe de inicio tardio. En primer lugar, ha de valorarse el estado nutricional y la funcion deglutoria. En segundo lugar, y debido a la variabilidad del cuadro clinico, el comite recomienda el uso simultaneo de varias escalas que midan distintas funciones y parametros. De este modo, la fuerza muscular se evalua con la escala del Medical Research Council; la funcion motora, con la prueba de la marcha en seis minutos y pruebas cronometradas; la discapacidad, con la escala de actividad especifica de la enfermedad de Pompe construida segun el analisis de Rasch; la funcion respiratoria, con la medida de la capacidad vital forzada y la saturacion de oxigeno; y la fatiga, con la escala de intensidad de la fatiga. Por ultimo, la seguridad y la tolerabilidad del tratamiento enzimatico sustitutivo se controlan con el registro y tratamiento de los potenciales efectos adversos y la medicion de los anticuerpos antialglucosidasa alfa. Se incluyen tambien diversas recomendaciones generales.

"Pregnancy in adult-onset idiopathic inflammatory myopathy": report from a cohort of myositis patients from a single center.

BACKGROUND AND PURPOSE: Idiopathic inflammatory myopathies (IIM) are systemic diseases, characterized by the presence of an inflammatory muscle infiltrate. Although more frequent in women, its relationship with pregnancy has not been extensively studied. Our goal was to analyze the interaction between pregnancy and myositis in a cohort of IIM women from a single center. METHODS: A total of 51 patients from a historical cohort of IIM diagnosed between 1983 and 2013 were interviewed with a specific questionnaire. Comparisons between pregnancies occurring before and after the onset of the disease were performed using generalized mixed-effect models with normal and binomial distributions adjusted for confounding factors and clustering. RESULTS: A total of 102 pregnancies from 51 patients (41 with dermatomyositis and 10 with polymyositis) were analyzed. A total of 14 pregnancies from 8 patients occurred after disease onset; statistically significant (p = 0.02) clinical improvement during gestation was evident in 7 pregnancies (4 patients), 5 of them (from 2 patients) experienced a relapse of IIM symptoms afterwards, while in the rest, there was no influence of pregnancy on the disease. No disease flare associated with pregnancy was observed. Two patients were diagnosed within the first 6 months after delivery and none during pregnancy. No evidence was found to support pregnancy as a trigger for myopathy (p = 0.71). CONCLUSIONS: Pregnancy does not seem to carry a worse prognosis for the mother nor for the fetus in patients with IIM; on the contrary, nearly half of the patients in our series improved clinically when they became pregnant, a relapse of IIM symptoms being common afterwards. Pregnancy does not appear to be a trigger for IIM.

Terapia génica en el tratamiento de los errores congénitos del metabolismo / Gene therapy for the treatment of inborn errors of metabolism

En la mayoría de los errores congénitos del metabolismo existe un defecto enzimático que produce el bloqueo de una ruta metabólica y el acúmulo de metabolitos tóxicos. Para su tratamiento actualmente disponemos de la restricción dietética, la potenciación de otras vías metabólicas alternativas y la sustitución de la enzima deficitaria mediante el trasplante de células, el trasplante hepático o la administración de la enzima purificada. La terapia génica, mediante la trasferencia en el organismo de una copia correcta del gen alterado mediante un vector, se perfila como el futuro en el tratamiento de este tipo de enfermedades. Sin embargo, la dificultad de los vectores actualmente empleados en atravesar la barrera hematoencefálica, su respuesta inmunitaria, su toxicidad celular, así como su potencial oncogénesis limitan enormemente su aplicación clínica en humanos (AU)

Due to the enzymatic defect in inborn errors of metabolism, there is a blockage in the metabolic pathways and an accumulation of toxic metabolites. Currently available therapies include dietary restriction, empowering of alternative metabolic pathways, and the replacement of the deficient enzyme by cell transplantation, liver transplantation or administration of the purified enzyme. Gene therapy, using the transfer in the body of the correct copy of the altered gene by a vector, is emerging as a promising treatment. However, the difficulty of vectors currently used to cross the blood brain barrier, the immune response, the cellular toxicity and potential oncogenesis are some limitations that could greatly limit its potential clinical application in human beings (AU)