Implantação de um método para determinação da atividade da transcetolase eritrocitária para avaliação indireta da tiamina / Implementation of a method for determining the erythrocyte transketolase activity for indirect evaluation of thiamin

O teste de ativação da transcetolase eritrocitária (TK-E) pelo pirofosfato de tiamina (TPP) exógeno é um método indireto para mensurar a tiamina (vitamina B1). A diminuição da atividade da transcetolase eritrocitária e o aumento da estimulação in vitro com o TPP maior do que 17% indicam deficiência de tiamina. Este é um método plausível, pois são nos eritrócitos que estão concentradas a maior parte desta vitamina. Em virtude de surtos de beribéri que tem ocorrido no Brasil desde 2006, o Instituto Adolfo Lutz (IAL), como Laboratório Central de Saúde Pública, propôs a implantação desse método para auxiliar na investigação de novos surtos ou de casos isolados. Foram avaliados o teste de precisão, a linearidade, a estabilidade do hemolisado e da amostra, e estimados os limites de detecção e de quantificação. A atividade da TK-E sem ativação pelo TPP foi de 0,732 UI/gHb e com ativação foi de 0,827 UI/gHb. Todos os resultados dos parâmetros avaliados neste estudo apresentaram-se dentro dos critérios de aceitabilidade garantindo-se a confiabilidade do método. Fica, assim, disponível mais um ensaio bioquímico para a Rede Pública de Saúde, mas ainda necessário definir os valores de referência para estabelecer os limites clínicos da deficiência de tiamina.

Erythrocyte transketolase activation test (TK-E) by exogenous thiamine pyrophosphate (TPP)is an indirect method to measure thiamine (vitamin B1). The decrease in the erythrocyte transketolase activity and the increase of in vitro stimulation with TPP greater than 17 % indicate thiamine deficiency. It is a reasonable method as the major portion of this vitamin are concentrated in erithrocytes. Due to the beriberi outbreaks that have occurred in Brazil since 2006, the Adolfo Lutz Institute (IAL), as a Central Public Health Laboratory, proposed the implementation of this method to give support to the investigation on the new outbreaks or isolated cases. The evaluated parameters were precision, linearity, hemolysate and sample stability, and the limits of detection and quantification were estimated. The TK-E activity without activation by TPP was 0.732 UI/gHb, and with activation was 0.827 UI/gHb. All of the results obtained from the evaluated parameters showed to be within the eligibility criteria, ensuring the reliability of the proposed methods.Thus, this method showed to be adequate as biochemical assay for the Public Health Network. However, there is a need to define the reference values to establish the clinical limits of thiamine deficiency.

Implantação de um método para determinação da atividade da transcetolase eritrocitária para avaliação indireta da tiamina / Implementation of a method for determining the erythrocyte transketolase activity for indirect evaluation of thiamin

O teste de ativação da transcetolase eritrocitária (TK-E) pelo pirofosfato de tiamina (TPP) exógeno é um método indireto para mensurar a tiamina (vitamina B1). A diminuição da atividade da transcetolase eritrocitária e o aumento da estimulação in vitro com o TPP maior do que 17 % indicam deficiência de tiamina. Este é um método plausível, pois são nos eritrócitos que estão concentradas a maior parte desta vitamina. Em virtude de surtos de beribéri que tem ocorrido no Brasil desde 2006, o Instituto Adolfo Lutz (IAL), como Laboratório Central de Saúde Pública, propôs a implantação desse método para auxiliar na investigação de novos surtos ou de casos isolados. Foram avaliados o teste de precisão, a linearidade, a estabilidade do hemolisado e da amostra, e estimados os limites de detecção e de quantificação. A atividade da TK-E sem ativação pelo TPP foi de 0,732 UI/gHb e com ativação foi de 0,827 UI/gHb. Todos os resultados dos parâmetros avaliados neste estudo apresentaram-se dentro dos critérios de aceitabilidade garantindo-se a confiabilidade do método. Fica, assim, disponível mais um ensaio bioquímico para a Rede Pública de Saúde, mas ainda necessário definir os valores de referência para estabelecer os limites clínicos da deficiência de tiamina.

Erythrocyte transketolase activation test (TK-E) by exogenous thiamine pyrophosphate (TPP) is an indirect method to measure thiamine (vitamin B1). The decrease in the erythrocyte transketolase activity and the increase of in vitro stimulation with TPP greater than 17 % indicate thiamine deficiency. It is a reasonable method as the major portion of this vitamin are concentrated in erithrocytes. Due to the beriberi outbreaks that have occurred in Brazil since 2006, the Adolfo Lutz Institute (IAL), as a Central Public Health Laboratory, proposed the implementation of this method to give support to the investigation on the new outbreaks or isolated cases. The evaluated parameters were precision, linearity, hemolysate and sample stability, and the limits of detection and quantification were estimated. The TK-E activity without activation by TPP was 0.732 UI/gHb, and with activation was 0.827 UI/gHb. All of the results obtained from the evaluated parameters showed to be within the eligibility criteria, ensuring the reliability of the proposed methods. Thus, this method showed to be adequate as biochemical assay for the Public Health Network. However, there is a need to define the reference values to establish the clinical limits of thiamine deficiency.

Pediatric cardiac beriberi: 3 different presentations.

The authors report 3 cases of pediatric cardiac beriberi at Queen Sirikit National Institute of Child Health during the last 10-year-period. The first two cases presented classically while the third case came with an unusual presentation. Cardiac beriberi is an old disease in modern Bangkok which can present in as several different clinical patterns. The diagnosis needs a high index of suspicion. Echocardiographic findings of right heart dysfunction and dramatic response to intravenous thiamine are diagnostic.

Beriberi outbreak among commercial fishermen, Thailand 2005.

In April 2005, The Tahi Bureau of Epidemiology investigated a reported outbreak of beriberi among commercial fishermen in Maha Chai, a port city in the Gulf of Thailand. The objective of this study was to verify the diagnosis of beriberi in affected individuals, describe the possible outbreak, ascertain risk factors, and provide prevention and control measures. We interviewed ill persons and treating doctors, and reviewed medical records to conduct a descriptive study. A probable case was defined as a crewmember of Ship A with one of the following: leg edema scrotal edema or ascites, dyspnea, chest discomfort, chest pain, extremity numbness, or extremity weakness. Confirmed cases were those with clinical criteria and laboratory findings consistent with thiamine deficiency. The outbreak started in early March, 2005 and continued until March 31, 2005. Ship A had 28 crewmembers (four Thai, 24 Myanmar). Overall, there were 15 probable cases (attack rate 53.6%, with three confirmed and 12 probable cases). Only three were tested for Vitamin B1 deficiency. All cases were male, with a median age of 28 years (range 20-45). Fourteen of the 15 cases were Myanmar and one Thai. Due to limited resources, the crew ate only seafood and polished rice for almost two months prior to symptoms. Symptoms included edema (60%), chest discomfort (54%), and dyspnea (27%). Two persons died while on board the ship (case fatality 13%). The total time at sea for Ship A was 18 months, including a five-month delay in docking due to licensing problems.

Mielinólise pontina e extra-pontina associada a Shoshin beribéri em paciente etilista / Central pontine and extra-pontine myelinosis in alcoholic patient with Shoshin beriberi

A mielinólise pontina está classicamente associada à rápida correção de hiponatremia crônica. Recentemente, fatores importantes adicionais tem sido descritos na patogênese dessa condição. Relatamos o caso de um paciente de 43 anos, etilista, desnutrido, que apresentou quadro agudo de insuficiência cardíaca por "Shoshin beribéri", insuficiência renal com tratamento por diálise. Evoluiu com tetraparesia e coma. Apresentou mielinólise pontina central e extra-pontina à ressonância magnética de crânio e anormalidades no potencial evocado auditivo.

Edema generalizado e circulação hiperdinâmica: um possível caso de beribéri / Generalized edema and hyperdynamic circulation: a possible case of beriberi

Paciente com insuficiência cardíaca causada pelo beribéri, apresentando regressão dos sinais e sintomas adquiridos após medicação com tiamina.

Beriberi heart disease in two thai laborers working in Saudi Arabia: recovery from shoshin beriberi

More than 200 cases of unexplained sudden death, in apparently healthy Thai workers, have been reported in the Far East during the last year. Described herein are two patients with beriberi heart disease. Both patients presented with a recent history of dyspnea, ankle edema, tachycardia and with physical signs of biventricular heart and clinical features of high cardiac output failure. The diet regimen was low in thiamine and both patients ate polished rice three times a day. Echocardiographic and Doppler studies revealed, in both cases, a left ventricle with a normal size and ejection fraction. The right atrium and ventricle were dilated. Despite conventional anti-failure therapy with digoxin, diuretics, and eventually intravenous inotropic support, one of the patients developed severe cardiogenic shock and metabolic acidosis. There was a dramatic hemodynamic response to intravenous thiamine and the patient recovered within hours. In both cases, the clinical features of high cardiac output status with biventricular heart failure subsided with thiamine therapy. These findings were corroborated by the normalization of the heart size and cardiac output in both cases