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.

Consensus statement for diagnosis and treatment of paroxysmal nocturnal haemoglobinuria.

Paroxysmal nocturnal hemoglobinuria is a chronic, multi-systemic, progressive and life-threatening 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.

Deep venous thrombosis in children with sickle cell disease.

BACKGROUND: Deep venous thrombosis (DVT) is rare in children compared to adults. Its incidence and risk factors in children are not well known. This study determined these aspects of DVT in children with sickle cell disease (SCD). PROCEDURE: A retrospective, observational and descriptive study was performed. Patients born between October 2000 and October 2012 with SCD and registered in HEMORIO, including those who died in HEMORIO, were included in this study. Patients whose medical records were inaccessible, who died in institutions other than HEMORIO, who died with implanted deep venous catheters, and those who were not monitored in HEMORIO for a period of 1 year or more were excluded from the study. Of a total of 1,519 patients, 456 were excluded and 1,063 patients were included in the study. Data were obtained from the computer system and the medical records at HEMORIO. RESULTS: Of the 1,063 patients, 2 (0.2%) developed DVT with both cases being related to central venous catheters (CVCs) (P-value <0.001). Of the patients who required CVCs, the prevalence of DVT was 10%. No other variable was clinically or statistically significant with respect to DVT. CONCLUSION: The establishment of CVCs in children with SCD poses a high risk for DVT. If this procedure is necessary, the internal jugular vein should be utilized instead of the subclavian and femoral veins. The identification of associated risk factors may justify antithrombotic prophylaxis.

Newborn screening program for hemoglobinopathies in Rio de Janeiro, Brazil.

BACKGROUND: Newborn screening for hemoglobinopathy in Brazil has been decentralized until 2001 when the Health Ministry of Brazil established the National Newborn Hemoglobinopathy Screening Program. The State of Rio de Janeiro started a program in collaboration with the State Health Department and the Institute of Hematology in Rio (HEMORIO). The goal of this study was to evaluate the effectiveness of the first 10 years of the Newborn Hemoglobinopathy Screening Program in identifying and managing infants with Sickle cell disease (SCD) in the State of Rio de Janeiro. PROCEDURE: Blood samples from 1,217,833 neonates were analyzed by High Performance Liquid Chromatography. Infants with SCD were enrolled in comprehensive treatment programs. RESULTS: Data showed that 4.87% of the newborns were heterozygous for a hemoglobin variant, 0.08% were homozygous or doubly heterozygous for abnormal hemoglobins and 95.02% had normal hemoglobin. All the 912 newborns with SCD were referred for treatment at HEMORIO, 34 (3.7%) of these died due to acute chest syndrome, sepsis or splenic sequestration. Four more children died of unknown causes. The implementation of the Rio de Janeiro Newborn Screening Program gradually increased the area of the State covered by the program. CONCLUSION: Data collected during the 10 years of the program showed reduction in mortality of patients with SCD in comparison to available historical statistical data before the implementation of the national screening program. This 10-year study showed that early diagnosis and treatment of newborns was associated with improved survival and quality of life of Brazilian children with SCD.

Genetic and biochemical markers of hydroxyurea therapeutic response in sickle cell anemia.

BACKGROUND: Sickle cell anemia (SCA) presents a complex pathophysiology which can be affected by a number of modifying factors, including genetic and biochemical ones. In Brazil, there have been no studies verifying ßS-haplotypes effect on oxidative stress parameters. This study evaluated ßS-haplotypes and Hb F levels effects on oxidative stress markers and their relationship with hydroxyurea (HU) treatment in SCA patients. METHODS: The studied group was composed by 28 SCA patients. Thirteen of these patients were treated with HU and 15 of them were not. We used molecular methodology (PCR-RFLP) for hemoglobin S genotype confirmation and haplotypes identification. Biochemical parameters were measured using spectrophotometric methods (Thiobarbituric-acid-reactive substances and Trolox equivalent antioxidant capacity levels, catalase and GST activities) and plasma glutathione levels by High-performance liquid chromatography coupled to electrochemical detection. RESULTS: We found the highest frequency of Bantu haplotype (48.2%) which was followed by Benin (32.1%). We observed also the presence of Cameroon haplotype, rare in Brazilian population and 19.7% of atypical haplotypes. The protective Hb F effect was confirmed in SCA patients because these patients showed an increase in Hb F levels that resulted in a 41.3% decrease on the lipid peroxidation levels (r =-0.74, p=0.01). Other biochemical parameters have not shown differential expression according to patient's haplotypes. Bantu haplotype presence was related to the highest lipid peroxidation levels in patients (p < 0,01), but it also conferred a differential response to HU treatment, raising Hb F levels in 52.6% (p = 0.03) when compared with the group with the same molecular profile without HU usage. CONCLUSIONS: SCA patients with Bantu haplotype showed the worst oxidative status. However these patients also demonstrated a better response to the treatment with HU. Such treatment seems to have presented a "haplotype-dependent" pharmacological effect.

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.

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.

Transfusion and chelation practices in sickle cell disease: a regional perspective.

Although most common in tropical regions, population migration has meant that sickle cell disease is now one of the most prevalent genetic diseases worldwide. The issues and challenges faced by physicians and patients have been discussed by an international group of experts representing 4 key regions: the USA, Europe, Latin America, and the Middle East/Africa. Conclusive evidence to support the use of transfusion therapy for the prevention of stroke has resulted in key changes to patient management in all regions, and increasing numbers of patients are benefiting from this management approach. However, it is apparent that transfusion therapy is still under-utilized, largely due to concerns over iron overload, alloimmunization, limited blood supplies, and, sometimes, due to parental refusal. Once transfused, assessment and management of body iron levels can be poor, particularly in patients who are intermittently transfused. Compliance with chelation therapy regimens is a significant challenge, but new therapeutic options are likely to overcome some of the current barriers. Key requirements in all regions were considered to be the following: to provide greater physician, patient, and family education; to ensure effective transition from pediatric to adult care; and to establish national guidelines in order to ensure best practice is consistently applied.

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