Vaccination strategies for people living with inborn errors of metabolism in Brazil.

OBJECTIVE: Through a literature review, make recommendations regarding immunizations in people living with Inborn Error of Metabolism (IEM) in Brazil, assess the possible impact on metabolic decompensations after immunization, and if this specific population may have an impaired immune response to vaccines. SOURCE OF DATA: The MeSH Terms vaccination OR vaccine OR immunization associated with the term inborn error of metabolism AND recommendation were used in combination with search databases. Only articles published after 1990, in the languages English, Spanish, French or Portuguese, human-related were included. SYNTHESIS OF DATA: A total of 44 articles were included to make the following recommendations. Individuals with IEMs need to be up to date with their immunizations. Regarding which vaccines should be offered, children and adults should follow the routine immunization schedules locally available, including the COVID-19 vaccines. The only exception is the rotavirus vaccine for hereditary fructose intolerance. The benefit of immunization outweighs the very low risk of metabolic decompensation. Since not all patients will have an adequate immune response, measuring antibody conversion and titers is recommended CONCLUSIONS: All patients should receive age-appropriate immunizations in their respective schedules without delays. The only situation when vaccination may be contraindicated is with oral rotavirus vaccine in hereditary fructose intolerance. Monitoring the levels of antibodies should be done to detect any immune dysfunction or the necessity for boosters. A personalized immunization schedule is ideal for patients with IEMs. The reference organizations could improve their recommendations to address all IEMs, not only some of them.

Epidemiological aspects of hereditary fructose intolerance: A database study.

Hereditary fructose intolerance (HFI) is an inborn error of fructose metabolism of autosomal recessive inheritance caused by pathogenic variants in the ALDOB gene that lead to aldolase B deficiency in the liver, kidneys, and intestine. Patients manifest symptoms, such as ketotic hypoglycemia, vomiting, nausea, in addition to hepatomegaly and other liver and kidney dysfunctions. The treatment consists of a fructose-restricted diet, which results in a good prognosis. To analyze the distribution of ALDOB variants described in patients and to estimate the prevalence of HFI based on carrier frequency in the gnomAD database, a systematic review was conducted to assess ALDOB gene variants among patients with HFI. The prevalence of HFI was estimated from the carrier frequency of variants described in patients, as well as rare variants predicted as pathogenic by in silico tools. The p.(Ala150Pro) and p.(Ala175Asp) variants are the most frequent and are distributed worldwide. However, these variants have particular distribution patterns in Europe. The analysis of the prevalence of HFI showed that the inclusion of rare alleles predicted as pathogenic is a more informative approach for populations with few patients. The data show that HFI has a wide distribution and an estimated prevalence of ~1:10,000.

Fructose Malabsorption in Chilean Children Undergoing Fructose Breath Test at a Tertiary Hospital.

ABSTRACT: Fructose is a highly abundant carbohydrate in western diet and may induce bowel symptoms in children as in adults. The main objective of this study is to describe the frequency of fructose malabsorption (FM) in symptomatic patients 18 years or younger undergoing fructose breath test in a single tertiary center between 2013 and 2018, and to evaluate whether certain symptoms are related to positivity of the test. Out of 273 tests 183 (67%) were compatible with FM. The most frequent pretest symptom in the overall study population was bloating (83%), followed by abdominal pain (73%). Patients with positive test were younger than those with a negative test (median 5 vs 8 years, P < 0.001). In multivariate analysis, which included age, sex, and symptoms (diarrhea, abdominal pain, bloating, nausea), only age <6 years (odds ratio 2.93, 95% confidence interval 1.64-5.23) and absence of nausea (odds ratio = 3.32, 95% confidence interval 1.56-7.05) were associated with FM.

Intestinal fructose malabsorption is associated with increased lactulose fermentation in the intestinal lumen / Má absorção intestinal de frutose associa-se com maior fermentação de lactulose na luz intestinal

Abstract Objective: To study fructose malabsorption in children and adolescents with abdominal pain associated with functional gastrointestinal disorders. As an additional objective, the association between intestinal fructose malabsorption and food intake, including the estimated fructose consumption, weight, height, and lactulose fermentability were also studied. Methods: The study included 31 patients with abdominal pain (11 with functional dyspepsia, 10 with irritable bowel syndrome, and 10 with functional abdominal pain). The hydrogen breath test was used to investigate fructose malabsorption and lactulose fermentation in the intestinal lumen. Food consumption was assessed by food registry. Weight and height were measured. Results: Fructose malabsorption was characterized in 21 (67.7%) patients (nine with irritable bowel syndrome, seven with functional abdominal pain, and five with functional dyspepsia). Intolerance after fructose administration was observed in six (28.6%) of the 21 patients with fructose malabsorption. Fructose malabsorption was associated with higher (p < 0.05) hydrogen production after lactulose ingestion, higher (p < 0.05) energy and carbohydrate consumption, and higher (p < 0.05) body mass index z-score value for age. Median estimates of daily fructose intake by patients with and without fructose malabsorption were, respectively, 16.1 and 10.5 g/day (p = 0.087). Conclusion: Fructose malabsorption is associated with increased lactulose fermentability in the intestinal lumen. Body mass index was higher in patients with fructose malabsorption.

Resumo Objetivo: Pesquisar a má absorção de frutose em crianças e adolescentes com dor abdominal associada com distúrbios funcionais gastrintestinais. Como objetivo adicional, estudou-se a relação entre a má absorção intestinal de frutose e a ingestão alimentar, inclusive a estimativa de consumo de frutose, o peso e a estatura dos pacientes e a capacidade de fermentação de lactulose. Métodos: Foram incluídos 31 pacientes com dor abdominal (11 com dispepsia funcional, 10 com síndrome do intestino irritável e 10 com dor abdominal funcional). O teste de hidrogênio no ar expirado foi usado para pesquisar a má absorção de frutose e a fermentação de lactulose na luz intestinal. O consumo alimentar foi avaliado por registro alimentar. Foram mensurados também o peso e a estatura dos pacientes. Resultados: Má absorção de frutose foi caracterizada em 21 (67,7%) pacientes (nove com síndrome do intestino irritável, sete com dor abdominal funcional e cinco com dispepsia funcional). Intolerância após administração de frutose foi observada em seis (28,6%) dos 21 pacientes com má absorção de frutose. Má absorção de frutose associou-se com maior produção de hidrogênio após ingestão de lactulose (p < 0,05), maior consumo de energia e carboidratos (p < 0,05) e maior valor de escore z de IMC para a idade (p < 0,05). As medianas da estimativa de ingestão diária de frutose pelos pacientes com e sem má absorção de frutose foram, respectivamente, 16,1 e 10,5 g/dia (p = 0,087). Conclusão: Má absorção de frutose associa-se com maior capacidade de fermentação de lactulose na luz intestinal. O índice de massa corporal foi maior nos pacientes com má absorção de frutose.

Intestinal fructose malabsorption is associated with increased lactulose fermentation in the intestinal lumen.

OBJECTIVE: To study fructose malabsorption in children and adolescents with abdominal pain associated with functional gastrointestinal disorders. As an additional objective, the association between intestinal fructose malabsorption and food intake, including the estimated fructose consumption, weight, height, and lactulose fermentability were also studied. METHODS: The study included 31 patients with abdominal pain (11 with functional dyspepsia, 10 with irritable bowel syndrome, and 10 with functional abdominal pain). The hydrogen breath test was used to investigate fructose malabsorption and lactulose fermentation in the intestinal lumen. Food consumption was assessed by food registry. Weight and height were measured. RESULTS: Fructose malabsorption was characterized in 21 (67.7%) patients (nine with irritable bowel syndrome, seven with functional abdominal pain, and five with functional dyspepsia). Intolerance after fructose administration was observed in six (28.6%) of the 21 patients with fructose malabsorption. Fructose malabsorption was associated with higher (p<0.05) hydrogen production after lactulose ingestion, higher (p<0.05) energy and carbohydrate consumption, and higher (p<0.05) body mass index z-score value for age. Median estimates of daily fructose intake by patients with and without fructose malabsorption were, respectively, 16.1 and 10.5g/day (p=0.087). CONCLUSION: Fructose malabsorption is associated with increased lactulose fermentability in the intestinal lumen. Body mass index was higher in patients with fructose malabsorption.

[Correlation between the presence and intensity of symptoms and the results of hydrogen breath tests in the diagnosis of carbohydrate intolerance]. / Correlación entre los síntomas digestivos y los resultados de una prueba de hidrógeno en aliento en el diagnóstico de intolerancia a carbohidratos.

BACKGROUND: Hydrogen breath tests (HBT) are used to confirm the diagnosis of carbohydrate intolerance or small intestinal bacterial overgrowth (SIBO). OBJECTIVE: Determine the existence of a correlation between the presence and intensity of symptoms experimented by the patient after the ingestion of a carbohydrate load and the test result. MATERIALS AND METHODS: This is an observational, retrospective and analytic study, in which all patients' files from year 2008 to 2014 containing a report of a HBT performed at Hospital San José TEC de Monterrey were revised. Using a visual analogue scale (VAS), the patient reported the intensity of gastrointestinal symptoms during the test. Descriptive statistics were obtained, and exclusively for lactose HBTs, Pearson's correlation coefficient (r) between maximum hydrogen concentration in breath and symptom intensity was calculated. RESULTS: A HBT was performed in 33 patients: 23 with lactose, 5 with fructose, and 5 with lactulose as substrate. Of these, 10, 2, and 5 tests were positive, respectively. For lactose HBTs, the symptom with most sensitivity was flatulence (80%), which also had the greatest likelihood ratio for a positive test (1.73). Diarrhea had the greatest specificity (84.6%). A tendency for positivity was observed when patients presented symptoms. A moderately positive correlation between hydrogen ppm and symptom intensity was found (r=0.427, p=0.023). CONCLUSIONS: A correlation between symptom intensity and test positivity was found in patients with lactose intolerance. The presence of flatulence after lactose loading may be indicative of a positive test.

Neutrotoxic effects of fructose administration in rat brain: implications for fructosemia.

Fructose accumulates in tissue and body fluids of patients affected by hereditary fructose intolerance (HFI), a disorder caused by the deficiency of aldolase B. We investigated the effect of acute fructose administration on the biochemical profile and on the activities of the Krebs cycle enzymes in the cerebral cortex of young rats. Rats received a subcutaneous injection of NaCl (0.9 %; control group) or fructose solution (5 µmol/g; treated group). Twelve or 24 h after the administration, the animals were euthanized and the cerebral cortices were isolated. Peripheral blood (to obtain the serum) and cerebral spinal fluid (CSF) from the animals were also collected. It was observed that albumin levels were decreased and cholesterol levels were increased in CSF of animals 12 h after the administration of fructose. In addition, serum lactate levels were increased 12 h after the administration, as compared to control group. Furthermore, malate dehydrogenase activity was increased in cerebral cortex from treated group 24 h after the administration of this carbohydrate. Herein we demonstrate that fructose administration alters biochemical parameters in CSF and serum and bioenergetics parameters in the cerebral cortex. These findings indicate a possible role of fructose on brain alterations found in HFI patients.

Evaluation of the In Vivo and In Vitro Effects of Fructose on Respiratory Chain Complexes in Tissues of Young Rats.

Hereditary fructose intolerance (HFI) is an autosomal-recessive disorder characterized by fructose and fructose-1-phosphate accumulation in tissues and biological fluids of patients. This disease results from a deficiency of aldolase B, which metabolizes fructose in the liver, kidney, and small intestine. We here investigated the effect of acute fructose administration on the activities of mitochondrial respiratory chain complexes, succinate dehydrogenase (SDH), and malate dehydrogenase (MDH) in cerebral cortex, liver, kidney, and skeletal muscle of male 30-day-old Wistar rats. The rats received subcutaneous injection of sodium chloride (0.9%; control group) or fructose solution (5 µmol/g; treated group). One hour later, the animals were euthanized and the cerebral cortex, liver, kidney, and skeletal muscle were isolated and homogenized for the investigations. Acute fructose administration increased complex I-III activity in liver. On the other hand, decreased complexes II and II-III activities in skeletal muscle and MDH in kidney were found. Interestingly, none of these parameters were affected in vitro. Our present data indicate that fructose administration elicits impairment of mitochondrial energy metabolism, which may contribute to the pathogenesis of the HFI patients.

[Fructose intolerance in patients with irritable bowel syndrome: a case-control study]. / Intolerancia a la fructosa en pacientes con síndrome de intestino irritable; un estudio de casos y controles.

INTRODUCTION: Recently it has been reported that prevalence of fructose intolerance (FI) in patients with functional gastrointestinal disorders range between 38% -75%. OBJECTIVE: To determine the prevalence of FI in subjects diagnosed with irritable bowel syndrome (IBS). METHODS: We studied 25 subjects (17 women, average age 36 years) with IBS (Rome II) and 25 healthy controls (14 women, mean age 37 years) who underwent a breath test after oral loading with fructose (Gastrolyzer ®, Bedfont Scientific Ltd., UK). The load consisted of 25 grams of fructose dissolved in 250 ml of water (10% solution). Breath test analysis of the particles per million (ppm) of hydrogen exhaled were performed every 15 minutes for 3 hours. The fructose breath test was considered positive when concentrations of hydrogen were higher than at 20 ppm or a raising greater than 5 ppm in 3 consecutive samples was detected. RESULTS: According to the Rome II criteria, 10 patients (40%) had IBS-C, 9 (36%) had IBS-D and 6 (24%) had IBS-M. Thirteen (52%) of IBS patients had IF, while only 4 (16%) of control subjects (p = 0.01). Patients with IBS and fructose intolerante tend to suffering from diarrhea predominant IBS (p = 0.053). CONCLUSIONS: Fructose intolerance may be responsible for gastrointestinal symptoms in at least half of IBS patients, especially in the group of patients with IBS-D.

Alteraciones del metabolismo de la fructosa / Fructose metabolism defects

Las alteraciones en el metabolismo de la fructosa se producen por 3 defectos enzimáticos. 1.- Por deficiencia de fructoquinasa, la que no genera ningún síntoma clínico y por tanto no requiere tratamiento. 2.- La deficiencia de la aldolasa B, que ocasiona la Intolerancia Hereditaria a la Fructosa, e impide la transformación de la fructosa-1-fosfato en fructosa 1,6 difosfato. El cuadro clínico se manifiesta cuando se introduce azúcar en la dieta, apareciendo náuseas, vómitos, palidez, sudoración, temblor, letargia, convulsiones, hipoglicemia, daño hepático, ictericia, edema y ascitis. El tratamiento consiste en eliminar la fructosa de la dieta, como sacarosa (glucosa y fructosa), fructosa libre, sorbitol. El tratamiento si se entrega precozmente tiene excelente resultado, desaparecen los vómitos y se normaliza la disfunción renal. 3.- La deficiencia de fructosa 1-6-difosfatasa que transforma la glucosa a partir de todos los sustratos neoglucogénicos, lactato, glicerol y alanina y también la fructosa de la dieta, se caracteriza por presentar acidosis láctica, hipoglicemia, disnea, taquicardia, apnea, irritabilidad, letargia, coma, convulsiones. El tratamiento consiste en prevenir las hipoglicemias y la neoglucogénesis, evitando el ayuno prolongado y proporcionando una dieta fraccionanda.

Tolerância hereditária à frutose: causa de vômitos recorrentes na infância / Hereditary fructose intolerance: cause of recurrent vomiting in childhood

A intolerância hereditária à frutose é uma doença metabólica infrequente que apresenta sintomas gastrointestinais acompanhados de hipoglicemia, devendo ser considerada na investigação de vomitos recorrentes de etiologia desconhecida em crianças e adultos jovens. Entretanto, por ser pouco comum, essa possibilidade é frequentemente esquecida na elaboração do diagnostico diferencial, o que pode fazer casos passarem despercebidos, pretelando o tratamento o aumentando o custo do diagnóstico. Com o objetivo de resaltar a importância de considerar a intolerância à frutose na elaboração do diagnóstico diferencial, relata-se um caso dessa doença diagnosticado em uma menina de nove anos de idade que aprentava vômitos recorrentes desde o período do desmame. Após o diagnóstico de intolerância hereditária à frutose, surgiram queixas ósseas que possivelmente estão ligadas a essa doença. A fisiopatologia e as medidas diagnósticas e terapêuticas são discutidas

Pruebas de laboratorio útiles para el control de la diabetes mellitus: hemoglobina glucosilada / Laboratory tests used in diabetes mellitus control: glycosilated hemoglobin

La diabetes mellitus es una enfermedad crónica que requiere del cuidado médico constante y de la educación tanto del paciente como de sus familiares. Para su control, el médico se apoya en unas serie de pruebas de laboratorio entre las cuales la hemoglobina glucosilada (HbA1C) juega un papel importante. Esta prueba tiene la ventaja de monitorear las condiciones metabólicas del paciente en las ocho semanas precedentes permitiendo así conocer con mayor certeza la calidad del control de la diabetes. La determinación de hemoglobina glucosilada se debe realizar cada tres o cuatro meses y los valores estimados como normales son de 3 a 6 por ciento

Determinación de substancias reductoras en la orina como método inicial para el diagnóstico temprano de galactosemia e intolerancia hereditaria a la fructuosa en niños con hepatitis / Determination of the reducing substances in the urine as a diagnostic method for galactosemia and fructose intolerance in children with neonatal hepatitis

La determinación de substancias reductoras en orina, se realizó en 40 niños con hepatitis neonatal utilizando, para ello, la prueba de Clinitest y Benedict. Sólo en dos niños se obtuvo como resultado una reacción falsa positiva. Se concluye que el clinitest es un método sencillo, práctico, económico y de gran utilidad para la detección temprana e inicial de galactosemia e intolerancia a la fructuosa. Las que deberán corroborarse en caso necesario posteriormente con un estudio metabólico completo