Estudio evolutivo de metabolitos porfirínicos de un caso de porfiria cutánea tardía / Porphyrins in a case of porphyria cutanea tarda: follow-up study

Resumen Las porfirias son errores congénitos poco frecuentes del metabolismo de las porfirinas. La porfiria cutánea tardía (PCT) es la más frecuente dentro de este grupo de enfermedades. Reportamos el estudio evolutivo de metabolitos porfirínicos de una paciente de 51 años con porfiria cutánea tardía, cuatro años después de su diagnóstico. Durante este período, se le indicó un esquema terapéutico de flebotomías en el Instituto de Hematología e Inmunología. Uno de los exámenes complementarios para su seguimiento fue la determinación de porfirinas totales en la orina, plasma y heces. Los resultados del estudio bioquímico de las porfirinas mostraron mejoría en todos los parámetros, lo que contribuyó a corroborar la utilidad del estudio de estos metabolitos como seguimiento de esta enfermedad y efectividad del tratamiento.

Abstract Porphyrias are rare congenital errors in the metabolism of porphyrins. Porphyria cutanea tarda is the most frequent among different types of porphyrias. We report the follow-up study of porphyrin metabolites of a 51-year-old patient with porphyria cutanea tarda four years later of her diagnosis. During this period, it was indicated a therapeutic scheme of phlebotomies in the Institute of Hematology and Immunology. One of the complementary examinations for its follow-up was the determination of total porphyrins in the urine, plasma and feces. Porphyrins in plasma decreased from 13 500 nmol/L at onset of disease to 250 nmol/L four years later. Although, porphyrins in feces and plasma could not quantify, we observed non-presence of peaks at 405 nm and 615.1 nm, respectively. These results contributed to corroborate the usefulness of the study of these metabolites for monitoring of this disease and effectiveness of the treatment.

Circulating autoantibodies against the NR2 peptide of the NMDA receptor are associated with subclinical brain damage in hypertensive patients with other pre-existing conditions for vascular risk.

Arterial hypertension (HT) and other vascular pre-existing conditions (PEC) generate asymptomatic brain damage which increases the occurrence of stroke and cognitive decline. The aim of this work was to explore if serum antibodies against the NR2 subunit of the NMDA receptor (NR2Ab) could predict subclinical brain damage (SBD) in hypertensive patients with PEC. Forty seven neurologically asymptomatic hypertensive subjects were classified according to the number of PEC (retinopathy, overweight/obesity, diabetes mellitus and dyslipidemia). NR2A/B Ab were measured in serum employing an ELISA method. 3.0-T Brain MRI imaging was performed, and visual ratings of white matter hyperintensities (WMH) and counts of dilated Virchow-Robin spaces (DVRS) and lacunes were obtained. Brain atrophy was evaluated with cortical thickness measurements and linear measures. Higher levels of NR2Ab were associated with more severe periventricular WMH (PWMH), more DVRS and more severe SBD; while greater frontal interhemispheric fissure width (IHFW), as a linear measure of frontal atrophy, was inversely related with NR2Ab. Overall and regional cortical thickness were not significantly associated with NR2 Ab. A multivariate analyses showed that IHFW and PWMH were the only variables independently associated with serum NR2Ab concentration. ROC analysis revealed that NR2Ab (cutoff: 1.7ng/ml) predicted PWMH with a sensitivity and specificity of 65% and 87% respectively. CONCLUSIONS: Serum NR2Ab levels may reflect SBD in HT subjects with PEC, especially in younger populations at risk, where age-related cortical atrophy has not yet been fully established.

Serum neuron-specific enolase and S100 calcium binding protein B biomarker levels do not improve diagnosis of acute stroke.

BACKGROUND: The high sensitivities and specificities reported for blood biomarkers as a supportive test in the diagnosis of acute stroke do not correspond with their performance for decision-making in emergency situations. METHODS: Seventy-two patients with suspected stroke were recruited: 44 with ischaemic stroke, 17 with haemorrhagic stroke and 11 stroke mimics, as well as a high-risk control group of 79 individuals. Serum neuron-specific enolase (NSE) and S100 calcium binding protein B (S100B) biomarker levels were determined on admission, using immunoassay kits. The sensitivities and specificities of NSE and S100B for distinguishing acute stroke from stroke mimics and high-risk controls were calculated. RESULTS: For cut-off values (NSE ≤ 14 micrograms per litre and S100B ≤130 nanograms per litre) the sensitivity was 53% and 55% respectively. Specificity was 64 for both versus the stroke mimic group. Specificity was higher (79% and 86% respectively) when calculated on the basis of the control group. CONCLUSIONS: This study supports the evidence indicating that serum levels of NSE and S100B do not improve the diagnosis of acute stroke.

High proportion of mannosidosis and fucosidosis among lysosomal storage diseases in Cuba.

Although lysosomal storage disorders (LSDs) are considered individually rare, as a group they present a non-negligible frequency. Few studies have been made of populational occurrence of LSDs; they have been conducted predominantly on Caucasian populations. We studied the occurrence of LSDs in Cuba. Data from individuals who had been referred to the Institute of Neurology and Neurosurgery in Havana from hospitals all over the country between January 1990 and December 2005 were analyzed. This institute was the only laboratory to provide enzyme-based diagnostic testing for 19 LSDs in Cuba during this period. Occurrence rates were calculated by dividing the number of postnatal diagnoses by the number of births during the study period. The combined occurrence of LSDs in Cuba was 5.6 per 100,000, lower than that reported in other studies conducted on Caucasian populations. The most frequent individual LSDs were: mucopolysaccharidosis type I (1.01 per 100,000) and, surprisingly, alpha-mannosidosis (0.72 per 100,000) and fucosidosis (0.62 per 100,000). These findings may be related to specific genetic characteristics and admixture of the Cuban population. This is the first comprehensive study of the occurrence of LSDs in Cuba. We conclude that the epidemiology of these diseases can vary regionally, and we stress the need for similar surveys in other Latin American countries.

Mucopolisacaridosis: diagnóstico enzimático de 20 años en Cuba / Mucopolysaccharidosis: 20-year enzymatic diagnosis in Cuba

Introduction. Mucopolysaccharidoses (MPS), which belong to the family of inborn errors of metabolism, are characterised by their severe clinical manifestations (skeletal, neurological and visceral) and a chronic, progressive course leading to death at early stages of life. Aim. To accomplish an enzymatic diagnosis and characterise MPS within the Cuban population. Subjects and methods. A total of 664 patients with a clinical suspicion of some type of MPS were referred to theInstitute of Neurology and Neurosurgery in Havana in order to determine a possible enzymatic deficiency and to classify the type of MPS involved in each case. Enzymatic determinations of alpha-L-iduronidasa, alpha-N- cetylglucosaminidase, betagalactosidase,arylsulphatase B and beta-glucuronidase were performed in leukocyte homogenate for MPS I, IIIB, IVB, VI andVII, respectively, in patients, parents and controls. Results. In all, 42 cases of MPS were diagnosed: MPS I (62%, n = 26), MPS VI (29%, n = 12), MPS IIIB (7%, n = 3) and MPS IVB (2%, n = 1). No patients with MPS VII were identified. The patients diagnosed with MPS were of both sexes and ages ranged between 4 months and 10 years. The specific activity of the enzymesthat were studied was deficient in patients with respect to parents and controls. The percentage of activity was lower in patients compared to parents. Conclusions. These studies made it possible to evaluate the enzymatic deficiencies and to establish thediagnosis of MPS I, MPS IIIB, MPS IVB, MPS VI and MPS VII in the Cuban population (AU)

Introducción. Las mucopolisacaridosis (MPS), dentro de los errores innatos del metabolismo, se caracterizan por sus manifestaciones clínicas graves (esqueléticas, neurológicas y viscerales), con un curso crónico y progresivo, que conducena la muerte en etapas tempranas de la vida. Objetivo. Diagnosticar enzimáticamente y caracterizar las MPS en la población cubana. Sujetos y métodos. Se remitió un total de 664 pacientes con sospecha clínica de algún tipo de MPS al Instituto de Neurología y Neurocirugía de La Habana para determinar la posible deficiencia enzimática y clasificar el tipo de MPS.Las determinaciones enzimáticas de alfa-L-iduronidasa, N-alfa- etilglucosaminidasa, beta-galactosidasa, arilsulfatasa B y beta-glucuronidasa se realizaron en homogenado de leucocitos para MPS I, IIIB, IVB, VI y VII, respectivamente, en pacientes,padres y controles. Resultados. Se diagnosticaron 42 casos de MPS: MPS I (62%, n = 26), MPS VI (29%, n = 12), MPS IIIB (7%, n = 3) y MPS IVB (2%, n = 1). No se identificó ningún paciente con MPS VII. Los pacientes con MPS diagnosticados fueron de ambos sexos, y el rango de edad osciló de 4 meses a 10 años. La actividad específica de las enzimas estudiadas fue deficitaria en pacientes respecto a padres y controles. El porcentaje de actividad resultó inferior en pacientes respecto apadres. Conclusión. Estos estudios permitieron valorar las deficiencias enzimáticas y establecer el diagnóstico de las MPS I, IIIB, IVB, VI y VII en la población cubana (AU)

[Mucopolysaccharidosis: 20-year enzymatic diagnosis in Cuba]. / Mucopolisacaridosis: diagnostico enzimatico de 20 anos en Cuba.

INTRODUCTION: Mucopolysaccharidoses (MPS), which belong to the family of inborn errors of metabolism, are characterised by their severe clinical manifestations (skeletal, neurological and visceral) and a chronic, progressive course leading to death at early stages of life. AIM. To accomplish an enzymatic diagnosis and characterise MPS within the Cuban population. SUBJECTS AND METHODS: A total of 664 patients with a clinical suspicion of some type of MPS were referred to the Institute of Neurology and Neurosurgery in Havana in order to determine a possible enzymatic deficiency and to classify the type of MPS involved in each case. Enzymatic determinations of alpha-L-iduronidasa, alpha-N-acetylglucosaminidase, beta-galactosidase, arylsulphatase B and beta-glucuronidase were performed in leukocyte homogenate for MPS I, IIIB, IVB, VI and VII, respectively, in patients, parents and controls. RESULTS. In all, 42 cases of MPS were diagnosed: MPS I (62%, n = 26), MPS VI (29%, n = 12), MPS IIIB (7%, n = 3) and MPS IVB (2%, n = 1). No patients with MPS VII were identified. The patients diagnosed with MPS were of both sexes and ages ranged between 4 months and 10 years. The specific activity of the enzymes that were studied was deficient in patients with respect to parents and controls. The percentage of activity was lower in patients compared to parents. CONCLUSIONS: These studies made it possible to evaluate the enzymatic deficiencies and to establish the diagnosis of MPS I, MPS IIIB, MPS IVB, MPS VI and MPS VII in the Cuban population.

Mucopolisacaridosis: diagnóstico enzimático de 20 años en Cuba / Mucopolysaccharidosis: 20-year enzymatic diagnosis in Cuba

Las mucopolisacaridosis (MPS), dentro de los errores innatos del metabolismo, se caracterizan por sus manifestaciones clínicas graves (esqueléticas, neurológicas y viscerales), con un curso crónico y progresivo, que conducen a la muerte en etapas tempranas de la vida. Objetivo. Diagnosticar enzimáticamente y caracterizar las MPS en la población cubana. Sujetos y métodos. Se remitió un total de 664 pacientes con sospecha clínica de algún tipo de MPS al Instituto de Neurología y Neurocirugía de La Habana para determinar la posible deficiencia enzimática y clasificar el tipo de MPS. Las determinaciones enzimáticas de alfa-L-iduronidasa, N-alfa-acetilglucosaminidasa, beta-galactosidasa, arilsulfatasa B y beta-glucuronidasa se realizaron en homogenado de leucocitos para MPS I, IIIB, IVB, VI y VII, respectivamente, en pacientes, padres y controles...(AU)