Correlation Between Capillary and Venous Blood Glucose in the Lactose Tolerance Test.

BACKGROUND: The lactose tolerance test is a classic method for the study of lactose malabsorption. However, the methodology used has not been standardized, and this leads to differences in results. AIM: The aim of this report was to analyze whether capillary blood glucose measurement is in agreement with venous blood glucose when performing lactose tolerance test. METHODS: This is a prospective study of consecutive patients with suspected lactose malabsorption who had lactose tolerance test performed in venous and capillary blood simultaneously, using a load of 50 g lactose. Agreement was measured using the concordance correlation coefficient of Lin (95 % CI) and Bland-Altman plots. The degree of agreement was measured using the Kappa index. A value of p < 0.05 was considered statistically significant. RESULTS: Eighty-four patients (68 % women) were included. The concordance correlation coefficient showed very poor agreement between the two techniques: 0.68 (0.58-0.77), 0.72 (0.62-0.8), and 0.77 (0.69-0.83) for baseline, 30, and 60 min, respectively. The Bland-Altman plots showed that capillary blood glucose measurements result in higher levels than venous blood glucose measurements, with mean differences of 0.39, 0.77, and 1.1 mmol/L at baseline, 30, and 60 min, respectively. The degree of agreement was low, with a Kappa index of 0.59 (p < 0.001). CONCLUSIONS: The test measured in venous blood is not in agreement with the measurement obtained from capillary blood. It is likely that the diagnostic accuracy attributed without distinction to lactose tolerance test in different studies for lactose malabsorption is incorrect, making it necessary to specify the analysis method.

Induction of tolerance by oral immunotherapy in patients with cow's milk allergy

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Kinetics of in vitro response to Beta-lactoglobulin in children allergic to and tolerant of cow´s milk protein

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Intolerancia a la lactosa / Lactose intolerance

La intolerancia a la lactosa (IL) es el síndrome de malabsorción más frecuente en la infancia y adolescencia. Se manifiesta con dolor, molestias abdominales, diarrea, flatulencia, distensión abdominal, náuseas e incluso vómitos. La lactosa es un disacárido presente en la leche que se hidroliza gracias a la acción de la lactasa-floricina-hidrolasa (LPH). Así, la IL se produce cuando, por diferentes circunstancias (transitorias como las infecciones o genéticas), la LPH disminuye/pierde su función induciendo una carencia en la digestión de la lactosa. Puesto que en esta situación se produce (en muchos casos) una retirada de lácteos, debe controlarse especialmente la ingestión de calcio y, por la particular dependencia de este, la densidad mineral ósea (DMO). La DMO es un factor relevante para prevenir la osteoporosis y, dado que una buena masa ósea en la etapa adulta dependerá del acopio efectuado durante la infancia, se debe prestar especial atención a los aspectos nutricionales. Para ello, existen diferentes opciones dietéticas como leche sin lactosa o de baja concentración además de bebidas vegetales o alimentos ricos en calcio; sin embargo, estas dos últimas opciones son inadecuadas nutricionalmente como sustitutivas de la leche (AU)

Lactose intolerance (LI) is the most common malabsorption syndrome in childhood and adolescence. It manifests itself as pain, abdominal trouble, diarrhoea, flatulence, abdominal distension, nausea and even vomiting. Lactose is a disaccharide present in milk which is hydrolysed through the action of lactase-phlorizin hydrolase (LPH). Thus, LI occurs when, for different reasons (transitory infections or genetic), the LPH diminishes/loses its function, inducing a deficiency in lactose digestion. As in this situation dairy products are often withdrawn, special care must be taken to monitor calcium intake and, due to its particular dependence on this, bone mineral density (BMD). BMD is an important factor in preventing osteoporosis and, as good bone mass in adulthood will depend on that built up in childhood, special attention must be paid to nutritional aspects. There are different dietary options for this purpose, such as lactose-free milk or milk with a low lactose content, as well as plant-based drinks or calcium-rich foods; however, the latter two options are nutritionally inadequate as milk substitutes (AU)

Lactose intolerance genetic testing: is it useful as routine screening? Results on 1426 south-central Italy patients.

Adult-type hypolactasia is a widespread condition throughout the world, causing lactose malabsorption. Several studies suggested that the identification of C/T-13910 and G/A-22018 mutations, located upstream the gene encoding the lactase-phlorizin hydrolase (LPH), is a useful tool for the differential diagnosis of hypolactasia. We evaluated the frequencies of C/T-13910 and G/A-22018 variants in a central-south Italian population and the usefulness of lactase deficiency genetic testing in the clinic practice. The genomic DNA of 1426 patients and 1000 healthy controls from central-south Italy was isolated from peripheral whole blood and genotyped for the C/T-13910 and G/A-22018 polymorphisms by high-resolution melting analysis (HRMA) and sequencing. The frequencies of genotypes in the 1426 patients analysed were as follows: 1077 CC/GG (75.5%), 287 CT/GA (20.1%), 24 TT/AA (1.7%), 38 CC/GA (2.7%). Only 64 out of 1426 (4.5%) performed also L-BHT test, 29 of which were negative for L-BHT also in presence of different genotypes. Among the 35 individuals with L-BHT positive, 34 were CC/GG and only one CT/GA. Although lactose genetic test is a good predictor of persistence/non-persistence lactase in specific population, its use in the central-south Italy population should be limited given the high prevalence of the CCGG diplotype in normal individuals.

Test de tolerancia a la lactosa reducido a 30 minutos: un estudio exploratorio de su factibilidad e impacto / Lactose tolerance test shortened to 30 minutes: an exploratory study of its feasibility and impact

Introducción: la malabsorción a la lactosa (ML) es una patología muy frecuente con alta prevalencia en nuestro medio. El test de tolerancia a la lactosa (TTL) es una prueba básica y económica que permite su diagnóstico sin precisar tecnología compleja. Recientemente se ha demostrado que este test puede reducirse a 3 determinaciones (basal, 30 y 60 min) sin afectar al resultado final. El propósito de nuestro estudio fue el valorar la factibilidad y ventajas de poder acortar y simplificar el TTL a 30 min, así como el impacto económico que conllevaría. Material y métodos: estudio multicéntrico y observacional de pacientes consecutivos a los que se les realiza un TTL ante la sospecha de ML. Los enfermos reciben 50 g de lactosa tras 12 h de ayuno y se les realiza extracción de sangre venosa en los 3 tiempos para la medición de la glucemia (mg/dl). La diferencia entre el test reducido y el completo se analizaron con el test de McNemar. La comparación de los niveles de glucemia entre los pacientes con test normal y patológico fue realizada usando el test t-Student para comparación de medias independientes. La concordancia fue evaluada con el índice Kappa. Se consideró p < 0,05 como estadísticamente significativo. Resultados: se incluyeron 270 pacientes (69,6 % mujeres) con edad media de 39,9 ± 16 años. El TTL fue patológico en 151 casos (55,9 %). No observamos diferencias estadísticamente significativas entre las glucemias basales de los pacientes con TTL normal o patológico (p = 0,13), sin embargo, como cabía esperar, estas diferencias fueron evidentes en los demás tiempos (p < 0,01). La eliminación de la determinación de glucemia a los 60 min tan solo sobrevaloró el diagnóstico de ML (falsos positivos) en 6 enfermos (2,22 %), con índice kappa de 0,95 (IC 95 %: 0,92- 0,99) (p < 0.001) respecto al test completo. Si se hubiera suprimido la determinación de los 60 min, se podría haber ahorrado al menos 7.726 euros. Conclusión: el reducir el TTL a 2 determinaciones (basal y 30 min) no implica apenas cambios en el resultado final del test, sin embargo conllevaría un ahorro de tiempo, material y personal (AU)

Introduction: Lactose malabsorption (LM) is a very common condition with a high prevalence in our setting. Lactose tolerance test (LTT) is a basic, affordable test for diagnosis that requires no complex technology. It has been recently shown that this test can be shortened to 3 measurements (baseline, 30 min, 60 min) with no impact on final results. The purpose of our study was to assess the feasibility and benefits of LTT simplification and shortening to 30 min, as well as the financial impact entailed. Material and methods: A multicenter, observational study of consecutive patients undergoing LTT for LM suspicion. Patients received 50 g of lactose following a fasting period of 12 h, and had blood collected from a vein at all 3 time points for the measurement of blood glucose (mg/dl). Differences between the shortened and complete test forms were analyzed using McNemar’s test. A comparison of blood glucose levels between patients with normal and abnormal results was performed using Student’s T-test for independent mean values. Consistency was assessed using the kappa index. A p < 0.05 was considered to be statistically significant. Results: A total of 270 patients (69.6 % females) were included, with a mean age of 39.9 ± 16 years. LTT was abnormal for 151 patients (55.9 %). We observed no statistically significant differences in baseline blood glucose levels between patients with normal and abnormal LTT results (p = 0.13); however, as was to be expected, such differences were obvious for the remaining time points (p < 0.01). Deleting blood glucose measurements at 60 minutes only led to overdiagnose LM (false positive results) in 6 patients (2.22 %), with a kappa index of 0.95 (95 % CI: 0.92-0.99) (p < 0.001) versus the complete test. Suppressing measurements at 60 min would have saved at least Euros 7,726. Conclusion: The shortening of LTT to only 2 measurements (baseline and 30-min) hardly leads to any differences in final results, and would entail savings in time, materials, and personnel (AU)

Can we shorten the lactose tolerance test?

BACKGROUND: Lactose malabsorption (LM) is a very common problem with high prevalence in Southern Europe. The lactose tolerance test (LTT) is a basic probe, which is widespread in local hospitals, because it requires non-complex and inexpensive infrastructure. The aims of our study are to determine that a reduction in the duration of LTT does not affect its diagnostic accuracy to detect LM and to calculate the savings that this reduction may represent. METHODS: A prospective study of consecutive patients who underwent LTT for suspected LM was conducted. We analyzed and compared the clinical results and costs (extraction, analytical measurement, time spent by nursing staff, technicians and patients) of suppressing LTT points at 30 and 120 min. RESULTS: The study included 201 patients. Pathological LTT was found in 119 cases. Eliminating the measurement of glucose at 120 min did not alter the LTT interpretation in any patient; however, up to 18.4% of patients had a LTT misinterpretation when the 30 min point was suppressed. If the LTT 120 min measurement would have been suppressed, 41,334 euros could have been saved. CONCLUSIONS: Suppressing the 120 min LTT point does not imply any changes in clinical results and reduces patient's waiting time; it also benefits the health system by saving time, manpower and materials.

Comparison of Quick Lactose Intolerance Test in duodenal biopsies of dyspeptic patients with single nucleotide polymorphism LCT-13910C>T associated with primary hypolactasia/lactase-persistence.

PURPOSE: To analyze the usefulness of Quick Lactose Intolerance Test in relation to the genetic test based on LCT-13910C>T genotypes, previously validated for clinical practice, for primary hypolactasia/lactase-persistence diagnosis. METHODS: Thirty-two dyspeptic patients that underwent upper gastrointestinal endoscopy entered the study. Two postbulbar duodenal biopsies were taken for the Quick test, and gastric antral biopsy for DNA extraction and LCT-13910C>T polymorphism analysis. DNA was also extracted from biopsies after being used in the Quick Test that was kept frozen until extraction. RESULTS: Nine patients with lactase-persistence genotype (LCT-13910CT or LCT-13910TT) had normolactasia, eleven patients with hypolactasia genotype (LCT-13910CC) had severe hypolactasia, and among twelve with mild hypolactasia, except for one that had LCT-13910CT genotype, all the others had hypolactasia genotype. The agreement between genetic test and quick test was high (p<0.0001; Kappa Index 0.92). Most of the patients that reported symptoms with lactose-containing food ingestion had severe hypolactasia (p<0.05). Amplification with good quality PCR product was also obtained with DNA extracted from biopsies previously used in the Quick Test; thus, for the future studies antral gastric biopsies for genetic test would be unnecessary. CONCLUSION: Quick test is highly sensitive and specific for hypolactasia diagnosis and indicated those patients with symptoms of lactose intolerance.

Influencia del tiempo de tránsito orocecal en la percepción de los síntomas de intolerancia a la lactosa / Impact of orocecal transit time on patient’s perception of lactose intolerance

Antecedentes: los síntomas atribuidos a la intolerancia a la lactosa son un importante problema de salud pública. El tiempo de tránsito es un factor implicado en la severidad de los síntomas asociados al consumo de lactosa. Objetivos: elucidar la relación entre el tiempo de tránsito orocecal (TTOC) y los síntomas de intolerancia a la lactosa. Métodos: estudio observacional en pacientes con un test del aliento de hidrógeno con lactosa patológico (excreción de hidrógeno superior a 25 ppm). El TTOC se midió mediante el test del aliento y los síntomas mediante una escala previamente validada. Los síntomas se determinaron dos veces: antes de recibir la lactosa, preguntando acerca de los síntomas en casa cuando se consumen lácteos (“síntomas en casa”), y de nuevo después de completar el test del aliento con lactosa (“síntomas test”). Resultados: se han incluido 161 pacientes. No se observa correlación entre el TTOC y los síntomas en casa (r = -0,1). Cuando el TTOC fue más rápido de 60 minutos, la intensidad de los “síntomas test” fue parecida a la de los “síntomas en casa”. Sin embargo, en los pacientes con TTOC normal o lento, los “síntomas en casa” fueron más intensos que los “síntomas test” (p < 0,05). En casa los síntomas fueron independientes del TTOC mientras que después de la sobrecarga de lactosa los síntomas fueron más intensos cuanto más rápido el TTOC. Conclusiones: los síntomas que refieren las personas con malabsorción de lactosa son más pronunciados en casa que tras una sobrecarga de lactosa. Los síntomas de intolerancia que los pacientes atribuyen al consumo de lactosa en casa no son debidos a un TTOC rápido(AU)

Background: symptoms attributed to the lactose intolerance are an important public health issue because of their prevalence and social relevance. Also because they may cause undue rejection of dairy products consume with potential health consequences. Transit time is a putative factor implied in the severity of symptoms associated with lactose. Objectives: to elucidate the relation between orocecal transit time (OCTT) and lactose intolerance symptoms. Methods: observational study in patients referred to a lactose hydrogen breath test who showed an increase in breath H2 excretion higher than 25 ppm. OCTT was measured with the breath test and symptoms of lactose tolerance with a validated scale. Symptoms were measured twice: before receiving the lactose, inquiring about self perceived symptoms when patients consumed dairy products at home (“home symptoms”), and again after completing the lactose breath test (“test symptoms”). Results: 161 patients were included. There was no correlation between OCTT and home symptoms (r = -0.1). When OCTT was faster than 60 minutes, intensity of “test symptoms” was similar to “home symptoms”. However, in patients with normal or slow OCTT, the “home symptoms” were more intense than the “test symptoms” (p < 0.05). At home, symptoms were independent of OCTT but with the lactose test load the symptoms were proportionately more intense with faster OCTT. Conclusions: in lactose maldigesters, selfreported symptoms of lactose intolerance are more pronounced at home than after a high lactose challenge. Intolerance symptoms that patients attributed to lactose consume at home are due to factors other than fast OCTT(AU)

Comparison of Quick Lactose Intolerance Test in duodenal biopsies of dyspeptic patients with single nucleotide polymorphism LCT-13910C>T associated with primary hypolactasia/lactase-persistence / Comparação do Teste Quick de Intolerância à Lactose em biópsias duodenais de pacientes dispépticos com polimorfismo de nucleotídeo único LCT-13910C>T associado com hipolactasia primária/lactase persistente

PURPOSE: To analyze the usefulness of Quick Lactose Intolerance Test in relation to the genetic test based on LCT-13910C>T genotypes, previously validated for clinical practice, for primary hypolactasia/lactase-persistence diagnosis. METHODS: Thirty-two dyspeptic patients that underwent upper gastrointestinal endoscopy entered the study. Two postbulbar duodenal biopsies were taken for the Quick test, and gastric antral biopsy for DNA extraction and LCT-13910C>T polymorphism analysis. DNA was also extracted from biopsies after being used in the Quick Test that was kept frozen until extraction. RESULTS: Nine patients with lactase-persistence genotype (LCT-13910CT or LCT-13910TT) had normolactasia, eleven patients with hypolactasia genotype (LCT-13910CC) had severe hypolactasia, and among twelve with mild hypolactasia, except for one that had LCT-13910CT genotype, all the others had hypolactasia genotype. The agreement between genetic test and quick test was high (p<0.0001; Kappa Index 0.92). Most of the patients that reported symptoms with lactose-containing food ingestion had severe hypolactasia (p<0.05). Amplification with good quality PCR product was also obtained with DNA extracted from biopsies previously used in the Quick Test; thus, for the future studies antral gastric biopsies for genetic test would be unnecessary. CONCLUSION: Quick test is highly sensitive and specific for hypolactasia diagnosis and indicated those patients with symptoms of lactose intolerance.

OBJETIVO: Analisar a aplicabilidade do Teste Quick de Intolerância à Lactose em relação ao teste genético baseado nos genótipos LCT-13910C>T, previamente validado para a prática clínica, para diagnóstico de má digestão primária de lactose/digestão de lactose. MÉTODOS: Trinta e dois pacientes dispépticos submetidos à endoscopia digestiva entraram no estudo. Duas biópsias duodenais pós-bulbares foram empregadas no Teste Quick, e biópsia do antro gástrico para extração de DNA e análise do polimorfismo LCT-13910C>T. DNA também foi extraído de biópsias depois de terem sido usadas no teste Quick, e conservadas congeladas. RESULTADOS: Nove pacientes com genótipo de lactase persistente (LCT-13910CT ou LCT-13910TT) tinham normolactasia, onze pacientes com genótipo de hipolactasia (LCT-13910CC) tinham hipolactasia severa, e entre doze com hipolactasia leve, com exceção de uma que tinha genótipo LCT-13910CT, todos os demais tinham genótipo de hipolactasia. A concordância entre o teste genético e o Quick Teste foi alta (p<0,0001; Índice Kappa=0,92). A maioria dos pacientes que relataram sintomas com ingestão de alimentos com lactose tinham hipolactasia severa (p<0,05). Amplificação com produto de PCR foi obtido com DNA extraído das biópsias usadas no teste Quick; portanto, nos trabalhos futuros seria desnecessário coletar biópsia do antro gástrico para o teste genético. CONCLUSÃO: O Teste Quick é altamente sensível e específico para diagnóstico de hipolactasia e indicou aqueles pacientes com sintomas de intolerância à lactose.

Diagnosis of adult-type hypolactasia/lactase persistence: genotyping of single nucleotide polymorphism (SNP C/T-13910) is not consistent with breath test in Colombian Caribbean population.

CONTEXT: Genotyping of single nucleotide polymorphism (SNP C/T(-13910)) located upstream of the lactase gene is used to determine adult-type hypolactasia/lactase persistence in North-European Caucasian subjects. The applicability of this polymorphism has been studied by comparing it with the standard diagnostic methods in different populations. OBJECTIVE: To compare the lactose hydrogen breath test with the genetic test in a sample of the Colombian Caribbean population. METHODS: Lactose hydrogen breath test and genotyping of SNP C/T(-13910) were applied to 128 healthy individuals (mean age 35 ± 1). A positive lactose hydrogen breath test was indicative of hypolactasia. Genotyping was done using polymerase chain reaction/restriction fragment length polymorphism. The kappa index was used to establish agreement between the two methods. RESULTS: Seventy-six subjects (59%) were lactose-maldigesters (hypolactasia) and 52 subjects (41%) were lactose-digesters (lactase persistence). The frequencies of the CC, CT and TT genotypes were 80%, 20% and 0%, respectively. Genotyping had 97% sensitivity and 46% specificity. The kappa index = 0.473 indicates moderate agreement between the genotyping of SNP C/T(-13910) and the lactose hydrogen breath test. CONCLUSION: The moderate agreement indicates that the genotyping of the SNP C/T(-13910) is not applicable to determine adult-type hypolactasia/lactase persistence in the population participating in this study.

Diagnosis of adult-type hypolactasia/lactase persistence: genotyping of single nucleotide polymorphism (SNP C/T-13910) is not consistent with breath test in Colombian Caribbean population / Diagnóstico de hipolactasia tipo adulto/persistência da lactase: a genotipagem do polimorfismo de um único nucleotídeo (SNP) C/T-13910 não é consistente com o teste de hidrogênio na população do Caribe Colombiano

CONTEXT: Genotyping of single nucleotide polymorphism (SNP C/T-13910) located upstream of the lactase gene is used to determine adult-type hypolactasia/lactase persistence in North-European Caucasian subjects. The applicability of this polymorphism has been studied by comparing it with the standard diagnostic methods in different populations. OBJECTIVE: To compare the lactose hydrogen breath test with the genetic test in a sample of the Colombian Caribbean population. METHODS: Lactose hydrogen breath test and genotyping of SNP C/T-13910 were applied to 128 healthy individuals (mean age 35 ± 1). A positive lactose hydrogen breath test was indicative of hypolactasia. Genotyping was done using polymerase chain reaction/restriction fragment length polymorphism. The kappa index was used to establish agreement between the two methods. RESULTS: Seventy-six subjects (59%) were lactose-maldigesters (hypolactasia) and 52 subjects (41%) were lactose-digesters (lactase persistence). The frequencies of the CC, CT and TT genotypes were 80%, 20% and 0%, respectively. Genotyping had 97% sensitivity and 46% specificity. The kappa index = 0.473 indicates moderate agreement between the genotyping of SNP C/T-13910 and the lactose hydrogen breath test. CONCLUSION: The moderate agreement indicates that the genotyping of the SNP C/T-13910 is not applicable to determine adult-type hypolactasia/lactase persistence in the population participating in this study.

CONTEXTO: A genotipagem do SNP C/T-13910 localizado corrente acima do gene da lactase é usada para determinar hipolactasia e persistência da lactase tipo adulto em indivíduos caucasianos do Norte da Europa. A aplicabilidade deste polimorfismo tem sido estudada em comparação com métodos padronizados de diagnóstico em diferentes populações. OBJETIVO: Comparar o teste de hidrogênio expirado após a ingestão de lactose com o teste genético em uma mostra da população do Caribe Colombiano. MÉTODOS: O teste de hidrogênio expirado após a ingestão de lactose e a genotipagem do SNP C/T-13910 foram aplicados em 128 sujeitos sadios (idade media 35 ± 1). O teste de hidrogênio positivo foi indicativo de hipolactasia. A genotipagem foi feita pelo método "polymerase chain reaction/restriction fragment length polymorphism". O índice Kappa foi utilizado para estabelecer a concordância entre os dois métodos. RESULTADOS: Setenta e seis indivíduos (59%) foram mau digestores da lactose (hipolactasia) e 52 outros (41%) foram digestores da lactose (persistência da lactase). As frequências dos genotipos CC, CT e TT foram 80%, 20% e 0%, respectivamente. A genotipagem mostrou 97% da sensibilidade e 46% da especificidade. O índice kappa: 0,473 indicou moderada concordância entre os dois métodos. CONCLUSÃO: A moderada concordância indica que a genotipagem do SNP C/T-13910 nao é aplicável para determinar hipolactasia tipo adulto/persistência da lactase na população estudada.

Epidemiología de la historia de alergia a proteínas de la leche de vaca en niños mayores de un año de edad y su tolerancia / Epidemiology of cow's milk allergy and its tolerance in children more than one year old

Introducción: la alergia a las proteínas de la leche de vaca (PLV) es una afección frecuente en el primer año de vida, cuya incidencia parece estar aumentando en los países desarrollados. Objetivos: estudiar, en el ámbito de la Atención Primaria, la prevalencia acumulada de alergia IgE-mediada a las PLV en niños mayores de un año de edad y la adquisición de tolerancia, y factores que pueden estar asociados a ella. Material y métodos: estudio retrospectivo de las historias clínicas de los pacientes menores de 14 años de un centro de salud en Palencia (2805 niños). Resultados: el 2,35% (66) presentó alergia a las PLV. El 57,6% consiguió tolerar las PLV, la edad media a la que se logró fue de 34,6 meses. No se encontró ningún factor asociado al hecho de alcanzar la tolerancia. Los niños que no presentaban manifestaciones respiratorias de atopia tendían a tolerar antes, pero no de forma estadísticamente significativa. Conclusiones: se encontró en el ámbito sanitario de la Atención Primaria, una prevalencia elevada de alergia a las PLV IgE-mediada. La probabilidad de alcanzar la tolerancia a las PLV disminuye con la edad y es máxima entre los dos y los tres años. Se necesita realizar un diagnóstico preciso, tanto para el bienestar de los pacientes y sus familias como para evitar gastos sanitarios innecesarios(AU)

Introduction: allergy to cow's milk (CM) proteins is a frequent condition in the first year of life and its incidence seems to be increasing in the developed countries. Objectives: to study the accumulated prevalence of IgE-mediated cow's milk allergy (CMA) in children more than one year old at primary care, and tolerance development and factors that can be associated to it. Material and methods: retrospective study of (2,805) clinical histories of patients under 14 years in a primary health centre. Results: we found cow's milk allergy in 2.35% (66); 57.6% were able to tolerate CM at an average age of 34.6 months. We did not find any factors associated to the development of tolerance. Children who did not suffer respiratory symptoms tended to reach tolerance earlier but there was not statistical significance. Conclusions: we found a high prevalence of IgE-mediated CMA in primary care. The probability to develop tolerance to CM falls with age being the maximum in the second and third years of life. Carrying out an appropriated diagnosis is needed for patient and family comfort and for avoiding unnecessary health care expenditure(AU)

Association of lactose sensitivity with inflammatory bowel disease--demonstrated by analysis of genetic polymorphism, breath gases and symptoms.

BACKGROUND: Sensitivity to lactose has been reported in Crohn's disease, but its true role in inflammatory bowel disease (IBD) is unclear. The genetic marker CC13910, on chromosome2, with measurement of breath hydrogen and methane, and gut and systemic symptoms, are now the most comprehensive tests for evaluating sensitivity to lactose. AIM: To investigate, for the first time, the prevalence of lactose sensitivity in IBD, using the most comprehensive tests for diagnosing this condition. METHODS: Prevalence of CC13910 genotype was investigated using RT-PCR in 165 patients (Crohn's disease = 70, ulcerative colitis = 95), and 30 healthy volunteers. Genotype was correlated with breath hydrogen and methane up to 6 h after 50 g of oral lactose, all symptoms being recorded for up to 48 h. Critically, Crohn's disease and ulcerative colitis patients were selected with no record of lactose sensitivity, in remission at the time of the test. RESULTS: Lactose sensitivity occurred in a much higher proportion of patients, (approximately 70%), with IBD than previously thought. Seventeen per cent had raised methane, without raised breath hydrogen; those with ulcerative colitis exhibiting most symptoms. All CC patients were lactose sensitive. There was no correlation between genetic phenotype and IBD. As substantial numbers of IBD patients were CT or TT, and were lactose sensitive, this polymorphism cannot explain full down-regulation of the lactase gene. CONCLUSIONS: Our results have implications for the clinical management of IBD. The high breath methane raised the possibility of a pathogenic role for methanogenic archaebacteria (Archaea) in IBD. This needs to be investigated.

Persistence of cow's milk allergy beyond two years of age

Background Cow's milk allergy (CMA) epidemiology seems to be changing over time, with an increase in prevalence and persistence. Our aim was to characterise a population of children with CMA beyond two years of age, followed up in a Paediatric Allergy Clinic at the tertiary care level. Methods Retrospective study of children with persistent CMA diagnosed from January 1997 to June 2006. Medical records were analysed regarding: clinical presentation, follow-up, treatment and acquisition of tolerance. Data analysis was performed using Excel 2007 for Windows. Results Seventy-nine children were included, with mean age at first symptoms of 3 months. The symptoms were immediate in 93%, with cutaneous (87.3%), gastrointestinal (55.7%) and respiratory (25.3%) manifestations. During the follow-up period, 30% developed atopic eczema, 52% asthma and 35% rhinoconjunctivitis. A family history of atopy was identified in 53%. The majority presented increased serum total IgE (376±723 KU/l) and positive skin prick test (SPT) to cow's milk (CM) (79%). SPT to goat's milk was positive in 2/3 of cases. Fifty-five percent had at least one accidental exposure to CM (severe reactions in 6%). During CM elimination diet, 35% were initially given an extensively hydrolysed formula, 17% a soy formula, and 48% both. By the age of 10 years, 44% of children persisted with CMA. Discussion Our population of CM allergic children presented immediate symptoms with cutaneous expression in the majority. Severe reactions were common on accidental exposure. By the age of 10years, 44% maintained CMA, highlighting the importance of a multidisciplinary follow-up

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Frequency of lactose malabsorption among healthy southern and northern Indian populations by genetic analysis and lactose hydrogen breath and tolerance tests.

BACKGROUND: Lactose malabsorption (LM), the inability to break down lactose into glucose and galactose, is due to a deficiency in the small intestinal lactase phlorizin hydrolase enzyme. Ethnic and geographic variations of LM are known. OBJECTIVE: The aim of this study was to compare the frequency of LM in healthy southern and northern Indian populations. DESIGN: A total of 153 healthy volunteers (76 from southern and 77 from northern India) were evaluated for LM by using a lactose tolerance test (LTT), a lactose hydrogen breath test (lactose HBT), and polymerase chain reaction-restriction fragment length polymorphism to identify the lactase gene C/T-13910 polymorphism (confirmed by sequencing). RESULTS: Volunteers from southern and northern India were comparable in age and sex. The LTT result was abnormal in 88.2% of southern Indians and in 66.2% of northern Indians (P = 0.001). The lactose HBT result was abnormal in 78.9% of southern Indians and in 57.1% of northern Indians (P = 0.003). The CC genotype was present in 86.8% and 67.5% (P = 0.002), the CT genotype was present in 13.2% and 26.0% (P = 0.036), and the TT genotype was present in 0% and 6.5% (P = 0.03) of southern and northern Indians, respectively. The frequency of symptoms after the lactose load (47.4% compared with 15.6%; P < 0.001) and peak concentrations of breath hydrogen (88.5 +/- 71.9 compared with 55.4 +/- 61.9 ppm; P = 0.003), both of which might indicate the degree of lactase deficiency, were higher in southern than in northern Indians. CONCLUSION: The frequency and degree of LM is higher in southern than in northern Indian healthy populations because of genetic differences in these populations.