Abnormal transcranial Döppler ultrasonography in children with sickle cell disease

BACKGROUND: Stroke is a potentially fatal complication of sickle cell disease in children between 2-16 years and transcranial Döppler has been recommended as a screening method in these cases. OBJECTIVE: The main goal of this study was to correlate transcranial Döppler results to complications related to stroke in sickle cell disease and baseline characteristics of the population. METHODS: This was an observational study of children and adolescents with ages between 2-16 years with sickle cell disease who were followed in three centers. RESULTS: From January 2008 to July 2009, 902 patients were enrolled in this study. The median age was 6.5 years (range: 1.8-15.8), 52.3% were male, 74.4% had hemoglobin SS; 221 (28.6%) had at least one complication associated with sickle cell disease. A total of 773 patients performed transcranial Döppler; in 91.2% this was a method of screening. Conditional or abnormal transcranial Döppler results were more common in patients with sickle cell disease complications versus those without complications (ODDS ratio = 3.18; 95% Confidence interval = 1.92-5.27). There was a significant difference in the frequency of conditional or abnormal transcranial Döppler results in patients with abnormal laboratory results compared to those without abnormalities (OR=4.03); 95% confidence interval = 2.30-7.06. CONCLUSIONS: Conditional or abnormal transcranial Döppler results were significantly more frequent in patients with complications of sickle cell disease confirming the increased risk of stroke in this subgroup of patients. This observation reinforces the recommendation of transcranial Döppler as a screening test for all patients with sickle cell disease with ages between 2 and 16 years.

Sickle cell disease: acute clinical manifestations in early childhood and molecular characteristics in a group of children in Rio de Janeiro

OBJECTIVE: To describe clinical events of sickle cell disease and the correlation with β-globin haplotypes and α-thalassemia in under 6-year-old children. METHODS: A retrospective study was conducted of under 6-year-old children from the neonatal screening program in Rio de Janeiro. Forty-eight male and 48 female children were enrolled in this study, 79 with sickle cell anemia and 17 with hemoglobin SC. The mean age was 29.9 (standard deviation = 20.9) months, 62 (16.2 ± 8.6) were aged between 0-3 years old and 34 (54.9 ± 11.3) were from 3-6 years old. Painful events, acute splenic sequestration, hemolytic crises, hand-foot and acute chest syndromes and infections were evaluated. RESULTS: The events were more frequent in under 3-year-old children, 94% of children had at least one episode. Infection was the most common event affecting 88.5% of children. Acute splenic sequestration took place earlier, while painful crises and acute chest syndromes in under 6-year-old children. Thal-α 3.7 was observed in 20.9% of cases. Bantu was the most frequent haplotype found, followed by Benin. No correlation was observed between clinical events and β-globin haplotypes. Children with sickle cell anemia and α-thalassemia have less infectious events. No correlation was found among these polymorphisms and clinical events, however, the majority of children with Bantu/Bantu and without α-thalassemia had more clinical events.

Genetic polymorphisms and cerebrovascular disease in children with sickle cell anemia from Rio de Janeiro, Brazil / Polimorfismos genéticos e doença cerebrovascular em crianças com anemia falciforme do Rio do Janeiro, Brasil

The aim of the present work was to examine possible genetic risk factors related to the occurrence of cerebrovascular disease (CVD) in Brazilian population, the frequency of βS-globin gene haplotypes and co-inheritance with α-thalassemia (-α3.7kb) and single nucleotide polymorphism of methylenetetrahydrofolate reductase (MTHFR-C677T), Factor V Leiden (FV-G1691A) and prothrombin (PT-G20210A) genes in children from Rio de Janeiro. Ninety four children with sickle cell anemia (SCA) were included, 24 patients with cerebrovascular involvement and 70 patients without CVD as control group. The mean age of children at the time of the cerebrovascular event was similar to the control group. The frequency of -α3.7kb thalassemia was similar in both groups (p=0.751). Children with Bantu/Atypical βS-globin gene haplotype presented 15 times more chance (OR=15.4 CI 95 percent 2.9-81.6) of CVD than the other βS-globin gene haplotypes. The C677T polymorphism of MTHFR gene was similar in both groups (p=0.085). No mutation in the FV Leiden or PT genes was found. A large study seems necessary to establish the role of these genetic polymorphisms in Brazilian miscegenated population.

Avaliar o papel da talassemia alfa (-α3.7kb), dos haplótipos da globina βS, e mutações nos genes da metileno-tetrahidrofolato redutase (MTHFR-C677T), fator V de Leiden (FV-G1691A) e protrombina (PT-G20210A) como fatores de risco para a doença cerebrovascular em pacientes com anemia falciforme. Foi realizado um estudo de caso controle com 94 crianças portadoras de anemia falciforme, 24 com doença cerebrovascular (DCV) e 70 sem DCV como grupo controle. A frequência de talassemia -α3.7kb foi semelhante em ambos os grupos (p=0,751). Crianças portadoras do haplótipo Bantu/Atípico da globina βS apresentam 15 vezes mais chances de desenvolverem DCV (OR=15,4 IC 95 por cento 2,9-81,6) do que os outros haplótipos. A frequência do polimorfismo MTHFR-C677T foi semelhante em ambos os grupos (p=0,085) e não foi observada mutação nos genes fator V e protrombina. Estudos com maior número de casos são necessários para esclarecer o papel desses polimorfismos genéticos na nossa população.

Brazilian Guidelines for transcranial doppler in children and adolescents with sickle cell disease

BACKGROUND: Sickle cell disease is the most common monogenic hereditary disease in Brazil. Although strokes are one of the main causes of morbidity and mortality in these patients, the use of transcranial Doppler to identify children at risk is not universally used. OBJECTIVE: To develop Brazilian guidelines for the use of transcranial Doppler in sickle cell disease children and adolescents, so that related health policies can be expanded, and thus contribute to reduce morbidity and mortality. METHODS: The guidelines were formulated in a consensus meeting of experts in transcranial Doppler and sickle cell disease. The issues discussed were previously formulated and scientific articles in databases (MEDLINE, SciELO and Cochrane) were carefully analyzed. The consensus for each question was obtained by a vote of experts on the specific theme. RESULTS: Recommendations were made, including indications for the use of transcranial Doppler according to the sickle cell disease genotype and patients age; the necessary conditions to perform the exam and its periodicity depending on exam results; the criteria for the indication of blood transfusions and iron chelation therapy; the indication of hydroxyurea; and the therapeutic approach in cases of conditional transcranial Doppler. CONCLUSION: The Brazilian guidelines on the use of transcranial doppler in sickle cell disease patients may reduce the risk of strokes, and thus reduce the morbidity and mortality and improve the quality of life of sickle cell disease patients.

Avaliação da concentração de flúor e do consumo de água mineral / Evaluation of the fluoride concentration and consumption of mineral water

OBJETIVO: Considerando a água como importante fonte de ingestão de flúor, o aumento da prevalência de fluorose dentária e do consumo de água mineral, o estudo realizado teve como objetivo avaliar o consumo de água mineral e sua concentração de flúor. MÉTODOS: A pesquisa foi realizada nos bairros do município de Bauru, SP. Foram visitadas mil residências que compunham uma amostra estratificada, obtida por conglomerados. Cada conglomerado correspondia a um quarteirão. Para efeito de sorteio os quarteirões foram numerados dentro das 17 regiões estabelecidas no plano diretor do município. Para coleta das amostras de água mineral foram usados frascos plásticos de 50 ml, previamente identificados. Na análise de flúor utilizou-se eletrodo íon sensível (Orion 9609) após tamponamento com TISAB II. Informações a respeito do consumo de água mineral foram obtidas com a aplicação de um questionário. RESULTADOS: Constatou-se que cerca de 29,7 por cento da população do município consome água mineral. Nas 260 amostras analisadas, das 29 diferentes águas, a concentração de flúor variou de 0,045 a 1,515 mg/l. Em uma das águas, constava no rótulo o valor de 0,220 mg/l, mas na análise constatou-se 1,515 mg/l de flúor. Além disso, algumas águas não traziam especificado a concentração de flúor; e, na análise constataram-se valores variando entre 0,049 e 0,924 mg/l. CONCLUSÕES: Os resultados mostraram uma grande variação na concentração de flúor e reforçam a importância do controle dessas águas por parte da vigilância sanitária.