Consensus statement for diagnosis and treatment of paroxysmal nocturnal haemoglobinuria

Paroxysmal nocturnal hemoglobinuria is a chronic, multi-systemic, progressive and lifethreatening disease characterized by intravascular hemolysis, thrombotic events, serious infections and bone marrow failure. Paroxysmal nocturnal hemoglobinuria results from the expansion of a clone of hematopoietic cells that due to an inactivating mutation of the X-linked gene PIG-A are deficient in glycosylphosphatidylinositol-linked proteins. Early diagnosis, using flow cytometry performed on peripheral blood, the gold standard test to confirm the diagnosis of paroxysmal nocturnal hemoglobinuria, is essential for improved patient management and prognosis. The traditional therapy for paroxysmal nocturnal hemoglobinuria includes blood transfusion, anti-thrombosis prophylaxis or allogeneic bone marrow transplantation. The treatment that has recently become available is the complement blockade by the anti-C5 monoclonal antibody eculizumab. In this consensus, we are aiming to review the diagnosis and treatment of the paroxysmal nocturnal hemoglobinuria patients, as well as the early recognition of its systemic complications. These procedures express the opinions of experts and have been based on the best available evidence and international guidelines, with the purpose of increasing benefits and reducing harm to patients.

Mortality in children, adolescents and adults with sickle cell anemia in Rio de Janeiro, Brazil

Abstract Objective: To determine the mortality rate of children, adolescents and adults with sickle cell anemia in Rio de Janeiro, Brazil. Methods: The number of deaths, the mortality rate and the causes of deaths in patients with sickle cell anemia who were treated and followed up at our institution for 15 years were determined and compared to data available for the Brazilian population. Results: The overall number of deaths was 281 patients with a mortality rate of 16.77%. Survival probability was significantly higher in females. The number of deaths and the mortality rate were age-specific with a significant increase in the 19- to 29-year-old age group. The remaining life expectancy of the patients with sickle cell anemia was less than that of Brazilians at large. The gap between the two was about 20 years for ages between one and five years with this gap decreasing to ten years after the age of 65 years. The most common causes of death were infection, acute chest syndrome, overt stroke, organ damage and sudden death during painful crises. Conclusion: To the best of our knowledge, this is the first Brazilian study in a single institution in Rio de Janeiro; the mortality rate was 18.87% among adult patients with sickle cell anemia. The mortality rates in children and adults are higher than those reported in developed countries of the northern hemisphere.

Brazilian Thalassemia Association protocol for iron chelation therapy in patients under regular transfusion

In the absence of an iron chelating agent, patients with beta-thalassemia on regular transfusions present complications of transfusion-related iron overload. Without iron chelation therapy, heart disease is the major cause of death; however, hepatic and endocrine complications also occur. Currently there are three iron chelating agents available for continuous use in patients with thalassemia on regular transfusions (desferrioxamine, deferiprone, and deferasirox) providing good results in reducing cardiac, hepatic and endocrine toxicity. These practice guidelines, prepared by the Scientific Committee of Associação Brasileira de Thalassemia (ABRASTA), presents a review of the literature regarding iron overload assessment (by imaging and laboratory exams) and the role of T2* magnetic resonance imaging (MRI) to control iron overload and iron chelation therapy, with evidence-based recommendations for each clinical situation. Based on this review, the authors propose an iron chelation protocol for patients with thalassemia under regular transfusions.

The influence of hydroxyurea on oxidative stress in sickle cell anemia

OBJECTIVE: The oxidative stress in 20 sickle cell anemia patients taking hydroxyurea and 13 sickle cell anemia patients who did not take hydroxyurea was compared with a control group of 96 individuals without any hemoglobinopathy. METHODS: Oxidative stress was assessed by thiobarbituric acid reactive species production, the Trolox-equivalent antioxidant capacity and plasma glutathione levels. RESULTS: Thiobarbituric acid reactive species values were higher in patients without specific medication, followed by patients taking hydroxyurea and the Control Group (p < 0.0001). The antioxidant capacity was higher in patients taking hydroxyurea and lower in the Control Group (p = 0.0002 for Trolox-equivalent antioxidant capacity and p < 0.0292 for plasma glutathione). Thiobarbituric acid reactive species levels were correlated with higher hemoglobin S levels (r = 0.55; p = 0.0040) and lower hemoglobin F concentrations(r = -0.52; p = 0.0067). On the other hand, plasma glutathione levels were negatively correlated with hemoglobin S levels (r = -0.49; p = 0.0111) and positively associated with hemoglobin F values (r = 0.56; p = 0.0031). CONCLUSION: Sickle cell anemia patients have high oxidative stress and, conversely, increased antioxidant activity. The increase in hemoglobin F levels provided by hydroxyurea and its antioxidant action may explain the reduction in lipid peroxidation and increased antioxidant defenses in these individuals.

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.

Triagem neonatal para hemoglobinopatias no Rio de Janeiro, Brasil / Neonatal screening for hemoglobinopathies in Rio de Janeiro, Brazil

OBJETIVO: Descrever os principais resultados do programa de triagem neonatal para a doença falciforme do Estado do Rio de Janeiro em 15 meses de funcionamento (agosto de 2000 a novembro de 2001). MÉTODOS: A partir de agosto de 2000, amostras de sangue passaram a ser coletadas de todos os recém-nascidos atendidos em postos de atençäo básica à saúde no Estado para triagem neonatal da doença falciforme. Essas amostras säo submetidas a cromatografia líquida de alta resoluçäo. Se o cromatograma resultante for compatível com a doença falciforme, a criança e seus pais säo encaminhados para confirmaçäo diagnóstica e tratamento. RESULTADOS: De agosto de 2000 a novembro de 2001, 99 260 recém nascidos participaram da triagem. Houve um caso de homozigose para Hb C. Um em cada 27 recém-nascidos triados pelo programa apresentou o traço falciforme (Hb AS). A doença falciforme foi constatada em 83 casos (um caso novo para cada 1 196 nascimentos): 62 Hb S, 18 Hb SC, 3 Hb SD. Uma criança näo compareceu para confirmaçäo diagnóstica. As 82 crianças acompanhadas apresentaram 15 intercorrências (infecçöes de vias aéreas superiores, febre, seqüestro esplênico, síndrome mäo-pé e crises de vaso-oclusäo), motivando sete internaçöes. Houve necessidade de transfusäo sangüínea em 15 crianças, mas nenhuma tornou-se alo-imunizada. Os demais bebês estäo evoluindo satisfatoriamente com o uso de penicilina profilática. CONCLUSÖES: Nossos dados evidenciam a importância do diagnóstico precoce da doença falciforme, de forma a prevenir e evitar as freqüentes complicaçöes infecciosas enfrentadas por esses pacientes