BACKGROUND: In sickle cell disease, the quantification of Hb A2 is important for the differential diagnosis between sickle cell anemia (Hb SS) and Hb S/ß0-thalassemia.OBJECTIVE: To determine Hb A2 levels as quantified by high performance liquid chromatography in patients with sickle cell anemia (Hb SS) and with the SC hemoglobinopathy, with or without concomitant alpha thalassemia.METHODS: This is a retrospective study of 242 children aged between two and six years with diagnoses of Hb SS or Hb SC. The hemoglobin was evaluated using high performance liquid chromatography and alpha thalassemia [3.7 kb deletion (-a3.7)] was detected by polymerase chain reaction. Patients were classified as homozygous (-a3.7/-a3.7), heterozygous (-a3.7/a), or homozygous wild-type. Analysis of variance was used to compare the mean Hb A2 values between the alpha thalassemia groups.RESULTS: The mean (± standard deviation) Hb A2 concentrations in the Hb SS group (n = 135) was 3.68 ± 0.65%. The mean values for individuals with Hb SS and heterozygous (n = 28) or homozygous for alpha thalassemia (n = 3) were 3.98 ± 0.64% and 4.73 ± 0.25%, respectively. The mean Hb A2 of all the Hb SC patients (n = 107) was 4.01 ± 0.507 with 4.29 ± 0.41% and 4.91 ± 0.22% in individuals heterozygous (n = 23) and homozygous for alpha thalassemia (n = 7), respectively. All patients homozygous for alpha thalassemia had Hb A2 levels above 3.5%. However, Hb A2 values above 5.2% were seen in patients with Hb SS and Hb SC, independently of alpha thalassemia.CONCLUSION: Hb A2 levels are elevated in patients with Hb S or Hb C, and are directly influenced by the alpha thalassemia genotypes.

OBJETIVO: Descrever a história de aleitamento materno (AM) e estado antropométrico de crianças com doença falciforme (DF). MÉTODOS: Estudo transversal com 357 crianças com hemoglobinopatias SS e SC de dois e seis anos, acompanhadas regularmente num Serviço de Referência em Triagem Neonatal (SRTN) entre novembro de 2007 e janeiro de 2009. O desfecho correspondeu ao estado antropométrico e as exposições foram: padrão do AM, tipo de hemoglobinopatia, faixa etária e sexo da criança. RESULTADOS: A média (DP) de idade observada foi de 3,7 (1,1) anos, 52,9% meninos e 53,5% com hemoglobinopatia SS. A prevalência de aleitamento materno exclusivo (AME) até o sexto mês foi de 31,5%, a mediana (p25-p75) do tempo de AME foi de 90 (24-180) dias e a mediana (p25-p75) da idade de desmame foi de 360 (90-720) dias. Crianças eutróficas em relação ao P/A tiveram o tempo de AME, em média, quase quatro vezes maior do que os desnutridos (p < 0,01), bem como foram desmamadas mais tarde (p < 0,05). O déficit de altura foi encontrado em 5% das crianças e todas as crianças com baixa estatura grave tinham hemoglobinopatia SS e mais de quatro anos. CONCLUSÕES: O tempo de AME e a idade de desmame foram superiores aos encontrados na literatura, possível efeito do acompanhamento multidisciplinar. A duração do AME e a idade mais tardia de desmame foram associadas a melhores indicadores antropométricos.

OBJECTIVE: To study the breastfeeding history (BF) and the anthropometric status of children with Sickle Cell Disease (SCD). METHODS: A cross-sectional study of 357 children with SCD aged between 2 and 6 years, regularly followed at a Newborn Screening Reference Service (NSRS) between November 2007 and January 2009. The outcome was anthropometric status and the exposures were: BF pattern, type of hemoglobinopathy and child's age and gender. RESULTS: The mean (SD) age was 3.7 (1.1) years, 52.9% were boys and 53.5% had SCA (hemoglobin SS). The prevalence of exclusive breastfeeding (EBR) up to six months of age was 31.5%, the median EBR times (p25-p75) was 90.0 (24.0-180.0) days and the median weaning ages (p25-p75) was 360.0 (90.0-720.0) days respectively. Normal W/H children experienced EBR for a mean duration almost four times longer than malnourished children (p=0.01), and were weaned later (p<0.05). Height deficit was found in 5.0% of children, while all the children with severe short stature had had SCA (hemoglobin SS) and were older than 4 years of age. CONCLUSIONS: EBF time and weaning age were greater than that found in the literature, which is a possible effect of the multidisciplinary follow-up. Duration of EBF and later weaning were associated with improved anthropometric indicators.

CONTEXTO: Compressão medular, secundária à hematopoese extramedular, é uma manifestação bastante descrita mas rara, encontrada em várias doenças hematológicas, incluindo a <FONT FACE="Symbol">b</font>-talassemia. RELATO DE CASO: Nós relatamos o caso de uma paciente com <FONT FACE="Symbol">b</font>-talassemia intermediária que apresentou paraparesia crural devido a compressão medular por uma massa extramedular paravertebral. Ela foi tratada com baixas doses de radioterapia e transfusões, com sucesso. Após esplenectomia, a paciente tem sido acompanhada por mais de quatro anos, sem apresentar necessidade de transfusão ou recurrência do quadro de compressão medular. DISCUSSÃO: Hematopoese extramedular deve ser investigada em pacientes com doenças hematológicas e sintomas de compressão medular. O pronto reconhecimento e tratamento radioterápico pode aliviar a sintomatologia rapidamente.

CONTEXT: Spinal cord compression due to extramedullary hematopoiesis is a well-described but rare syndrome encountered in several clinical hematologic disorders, including <FONT FACE="Symbol">b</font>-thalassemia. CASE REPORT: We report the case of a patient with intermediate <FONT FACE="Symbol">b</font>-thalassemia and crural paraparesis due to spinal cord compression by a paravertebral extramedullary mass. She was successfully treated with low-dose radiotherapy and transfusions. After splenectomy, she was regularly followed up for over four years without transfusion or recurrence of spinal cord compression. DISCUSSION: Extramedullary hematopoiesis should be investigated in patients with hematologic disorders and spinal cord symptoms. The rapid recognition and treatment with radiotherapy can dramatically alleviate symptoms.