Treatment and Management of Late Complications in Hereditary Hemolytic Anemia / 임상소아혈액종양

Hereditary hemolytic anemia is a very heterogeneous disorder in which abnormalities of red blood cell structural protein, globin protein, or enzyme defect lead to shortened life span. There has been much progress in revealing its pathophysiology and genetic backgrounds, but the lifelong plans for caring these patients are not well established yet. All patients with hereditary hemolytic anemic have three common problems: transfusion dependency, iron overload and iron chelation therapy. Patients with hereditary spherocytosis (HS) usually manifest severe anemia in neonatal period and infancy, but transfusion requirements may decrease in adulthood. But patients with thalassemia or sickle cell disease usually transfusion-dependent throughout life. Maintaining the optimal hemoglobin (Hb) levels in these patients is crucial because correction of anemia and dilution of abnormal Hb helps prevent certain complications that frequently occur in these patients. Frequent transfusion leads to transfusion-mediated infection and hemochromatosis. Iron chelation therapy should be started early to prevent permanent organ damage. Folate therapy can be helpful in patients with hereditary spherocytosis. Regular evaluations for cholestasis should be started at age 5, and splenectomy with concurrent cholecystectomy can be considered if the patient has cholecystitis. Hydroxyurea can be used to reduce transfusion requirements and prevent complications in patients with β-thalassemia and sickle cell disease. Consensus on long-term management of patients with hereditary hemolytic anemia is lacking, especially for adult patients. But further efforts to build guidelines for long-term follow-up and management of the patients with hereditary hemolytic anemia in the context of Korean society are needed.

Treatment and Management of Late Complications in Hereditary Hemolytic Anemia / 임상소아혈액종양

Hereditary hemolytic anemia is a very heterogeneous disorder in which abnormalities of red blood cell structural protein, globin protein, or enzyme defect lead to shortened life span. There has been much progress in revealing its pathophysiology and genetic backgrounds, but the lifelong plans for caring these patients are not well established yet. All patients with hereditary hemolytic anemic have three common problems: transfusion dependency, iron overload and iron chelation therapy. Patients with hereditary spherocytosis (HS) usually manifest severe anemia in neonatal period and infancy, but transfusion requirements may decrease in adulthood. But patients with thalassemia or sickle cell disease usually transfusion-dependent throughout life. Maintaining the optimal hemoglobin (Hb) levels in these patients is crucial because correction of anemia and dilution of abnormal Hb helps prevent certain complications that frequently occur in these patients. Frequent transfusion leads to transfusion-mediated infection and hemochromatosis. Iron chelation therapy should be started early to prevent permanent organ damage. Folate therapy can be helpful in patients with hereditary spherocytosis. Regular evaluations for cholestasis should be started at age 5, and splenectomy with concurrent cholecystectomy can be considered if the patient has cholecystitis. Hydroxyurea can be used to reduce transfusion requirements and prevent complications in patients with β-thalassemia and sickle cell disease. Consensus on long-term management of patients with hereditary hemolytic anemia is lacking, especially for adult patients. But further efforts to build guidelines for long-term follow-up and management of the patients with hereditary hemolytic anemia in the context of Korean society are needed.

Deficiencia de glucosa-6-fosfatodeshidrogenasa: De lo clínico a lo bioquímico / Glucose-6-phosphate dehydrogenase: From the clinical to the biochemical aspects / Deficiência de glicose-6-fosfato desidrogenase: Aspectos clínicos e bioquímicos

La deficiencia de Glucosa-6-fosfato deshidrogenasa (G6PD) es la enzimopatíamás frecuente, con una prevalencia global del 4,9% y con alrededor de 330 a 400 millones de personas afectadas en el mundo. La G6PD desempeña un papel fundamental en el equilibrio redox intracelular, especialmente en los eritrocitos; en condiciones de estrés oxidativo inducido (por ejemplo,por exposición a agentes externos como fármacos, alimentos o infecciones),los hematíes portadores de la variante enzimática y con deficiencia de la actividad enzimática, sufren daños irreversibles que condicionan su destrucción acelerada. La hemólisis explica el espectro de manifestaciones clínicas de esta enfermedad, que incluyen ictericia neonatal, episodios de hemólisis aguda inducida por agentes externos o anemia hemolítica crónica. El presente trabajo hace una reseña de los aspectos epidemiológicos y clínicos de esta enfermedad y revisa los aspectos fisiopatológicos a nivel bioquímico-molecular, con particular énfasis en la caracterización genética,estructural y funcional de las variantes asociadas a la deficiencia de G6PD.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most frequent enzymopathy in humans with a global prevalence of 4.9 % and around 330 to 400 million patients affected worldwide. G6PD plays a fundamental role in the intracellular redox equilibrium, especially in red blood cells (RBC). Under oxidative stress (induced by exposure to external agents like drugs, infections or diet) RBC carrying the deficient variant suffer irreversible damage resulting in their accelerated destruction. This hemolysis explains the clinical manifestations of the disease that include neonatal jaundice, inducedacute hemolysis or chronic hemolytic anemia. This work summarizes the epidemiologic and clinical features of G6PD deficiency, and reviews the molecular pathophysiology of this disease with special emphasis on the genetical, structural and functional characterization of variants causing this pathology.

A deficiência da Glicose-6-FosFato desidrogenase (G6PD) é a enzimopatia mais Frequente, com uma prevalência global do 4,9%, e com aproximadamente 330 a 400 milhões de pessoas afetadas no mundo. A G6PD tem um importante papel no equilíbrio celular redox intracelular, especialmente nos eritrócitos; em condições de estresse oxidativo induzido, (por exemplo, pela exposição a agentes externos como Fármacos, alimentos, ou infecções) as hemácias portadoras da variante enzimática e com defciência da atividade enzimática, sofrem danos irreversíveis que condicionam a sua destruição acelerada. A hemólise explica o espectro de manifestações clínicas desta doença, que incluem icterícia neonatal, episódios de hemólise aguda induzida por agentes externos ou anemia hemolítica crônica. Este trabalho faz uma resenha dos aspectos epidemiológicos e clínicos desta doença, e revisa os aspectos fsiopatológicos no nível bioquímico-molecular, com ênfase especial na caracterização genética, estrutural e funcional das variantes associadas à defciência de G6PD.

RBC Enzyme Analysis / 임상소아혈액종양

Among ~20 RBC enzyme deficiencies causing hereditary hemolytic anemia (HRA), deficiencies involving three RBC enzymes such as glucose-6-phosphatase, pyruvate kinase and pyrimidine 5'-nucleodiase were known to be relatively common. The methods that have been used for RBC enzyme analysis are based on the kinetic spectrophotometry. This method, however, usually requires multiple step reactions and manual manipulations which are labor-intensive and time-consuming, and carry a greater risk of error due to their complexity. To solve this problem, we had successfully developed the multiplex enzyme analysis for galactose using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). We are now trying to adopt this method to other RBC enzymes associated with HRA. The devised method will allow simple, rapid, sensitive and reproducible quantification of RBC enzymes and should be helpful for the confirmatory diagnosis of HRA caused by RBC enzyme deficiencies.

RBC Enzyme Analysis / 임상소아혈액종양

Among ~20 RBC enzyme deficiencies causing hereditary hemolytic anemia (HRA), deficiencies involving three RBC enzymes such as glucose-6-phosphatase, pyruvate kinase and pyrimidine 5'-nucleodiase were known to be relatively common. The methods that have been used for RBC enzyme analysis are based on the kinetic spectrophotometry. This method, however, usually requires multiple step reactions and manual manipulations which are labor-intensive and time-consuming, and carry a greater risk of error due to their complexity. To solve this problem, we had successfully developed the multiplex enzyme analysis for galactose using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). We are now trying to adopt this method to other RBC enzymes associated with HRA. The devised method will allow simple, rapid, sensitive and reproducible quantification of RBC enzymes and should be helpful for the confirmatory diagnosis of HRA caused by RBC enzyme deficiencies.

Red Blood Cell Enzymopathies Causing Hereditary Hemolytic Anemia / 임상소아혈액종양

The RBC enzyme deficiencies causing hereditary hemolytic anemia (HHA) can be divided into three groups: those participating in the glycolytic (E-M) pathway; those involved with the maintenance of a high ratio of reduced to oxidized glutathione; one enzyme in the nucleotide degradation and salvage pathway. Although RBC enzyme deficiencies causing HHA are rare, 3 of the 15 kinds of important and relatively frequently reported enzyme deficiencies such as pyruvate kinase, glucose-6-phosphate-dehydrogenase and pyrimidine-5'-nucleotidase deficiencies are briefly reviewed. The molecular genetics, clinical symptoms, diagnosis and therapeutic approaches of each enzyme deficiencies are summerized. As these enzyme deficiencies are reported throughout the world as well as in Korea with the identification of the mutations, considering a broad spectrum of etiologies for the diagnosis of HHA seems to be warranted.

Red Blood Cell Enzymopathies Causing Hereditary Hemolytic Anemia / 임상소아혈액종양

The RBC enzyme deficiencies causing hereditary hemolytic anemia (HHA) can be divided into three groups: those participating in the glycolytic (E-M) pathway; those involved with the maintenance of a high ratio of reduced to oxidized glutathione; one enzyme in the nucleotide degradation and salvage pathway. Although RBC enzyme deficiencies causing HHA are rare, 3 of the 15 kinds of important and relatively frequently reported enzyme deficiencies such as pyruvate kinase, glucose-6-phosphate-dehydrogenase and pyrimidine-5'-nucleotidase deficiencies are briefly reviewed. The molecular genetics, clinical symptoms, diagnosis and therapeutic approaches of each enzyme deficiencies are summerized. As these enzyme deficiencies are reported throughout the world as well as in Korea with the identification of the mutations, considering a broad spectrum of etiologies for the diagnosis of HHA seems to be warranted.

Hereditary Hemolytic Anemia in Korea: a Retrospective Study from 1997 to 2006 / 대한혈액학회지

BACKGROUND: The aim of this study was to investigate the prevalence, clinical and laboratory findings of hereditary hemolytic anemia (HHA) in Korea from 1997 to 2006 and to develop the appropriate diagnostic approach for HHA. METHODS: By the use of questionnaires, information on the clinical and laboratory findings ofHHA diagnosed from 1997 to 2006 in Korea was collected and analyzed retrospectively. A total of 431 cases were enrolled in this study from 46 departments of 35 hospitals. RESULTS: The overall frequency of HHA did not change through the 10-year period for pediatrics but did show an increasing tendency for internal medicine. The overall male to female sex ratio did not show sex predominance (1.17:1), but a significant male predominance with a ratio of 1.49:1 was seen for pediatrics while a significant female predominance with a ratio of 1:1.97 was seen forinternal medicine. Of the total cases, 74.2% (282/431) were diagnosed before the age of 15 years. The etiologies of HHA were classified as red cell membrane defects, hemoglobinopathies, red cell enzyme deficiencies and unknown causes. There were 382 cases (88.6%) of red cell membrane defects with 376 cases (87.2%) of hereditary spherocytosis and 6 cases (1.4%) of hereditary elliptocytosis, 20 cases (4.6%) of hemoglobinopathies with 18 cases (4.2%) of beta-thalassemia, a case (0.2%) of alpha-thalassemia and a case (0.2%) of Hemoglobin Madrid, 7 cases (1.6%) of red cell enzyme deficiencies with 5 cases (1.2%) of glucose-6- phosphate dehydrogenase (G-6-PD) deficiency, a case (0.2%) of pyruvate kinase (PK) deficiency and a case (0.2%) of enolase deficiency, and 22 cases (5.1%) of unknown causes. The most common chief complaint in pediatric patients was pallor and that in adult patients was jaundice. In the red cell membrane defect group of patients, the level of hemoglobin was significantly higher than in adult patients. The mean corpuscular volume, mean corpuscular hemoglobin, corrected reticulocyte count, total and indirect bilirubin level and lactate dehydrogenase levels in the hemoglobinopathy group of patients were significantly lower than the values in the red cell membrane defect group of patients. The mean concentration of G-6-PD was 0.8+/-0.7U/1012RBC in the G-6-PD deficient patients, PK was 1.7U/1010 RBC in the PK deficient patient, and the level of enolase was 0.04U/g of Hb in the enolase deficient patient. CONCLUSION: The most prevalent cause of HHA in Korea during 1997 to 2006 was hereditary spherocytosis, but HHA by other causes such as hemoglobinopathy and red cell enzyme deficiency gradually increased with the development of molecular diagnostic methods and increasing general interest. However, the etiologies of HHA need to be pursued further in 5.1% of the patients. An systematic standard diagnostic approach is needed in a nationwide prospective study for correct diagnoses and appropriate management of HHA.

Hemolytic anemia in pediatrics / 소아과

To understand the hemolytic anemia (HA) in children, the diagnostic approach and management of hereditary and acquired HA are described. The hereditary hemolytic anemia (HHA) can be classified according to the pathogenesis into three types:RBC membrane defects, hemoglobinopathies, and RBC enzymopathies. Clinical characteristics, laboratory findings and molecular defects of these three types are presented briefly. In Korea, HHA due to the RBC membrane defect, hereditary spherocytosis had been reported often but HHA due to hemoglobinopathies and RBC enzymopathies had been thought to be relatively rare. With recent development in the molecular diagnosis, beta thalassemia, mostly heterozygote, G6PD and pyruvate kinase deficiency have been reported with gene characterization. If the patients with microcytic hypochromic anemia show unproportionally low MCV or MCH or refractory to the iron therapy, hemoglobin electrophoresis and gene analysis for thalassemia or other unstable hemoglobinopathies need to be done accordingly. The global movement of the population especially from the region prevalent of hemoglobinopathies or enzymopathies to Korea warrants considering broad spectrum of etiology for the diagnosis of HHA. Aquired HA resulting from extracellular factors such as autoimmune HA from warm antibody, cold agglutinin and paroxysmal cold hemoglobinuria as well as nonimmune HA are described briefly.

Hereditary Hemolytic Anemia

The hereditary hemolytic anemia (HHA) can be classified into three types according to the pathogenesis: RBC membrane defects, hemoglobinopathies, and RBC enzymopathies. Clinical characteristics of these three types of HHA are presented briefly in this paper. In Korea, HHA due to RBC membrane defect such as hereditary spherocytosis had been relatively well recognized, while HHA due to hemoglobinopathies and RBC enzymopathies had been considered rare. However, with the recent development of molecular testing, beta thalassemia, G6PD and pyruvate kinase deficiency have been reported with identification of disease-causing mutations. If a patient with microcytic hypochromic anemia shows unproportionally low MCV or MCH or refractory to iron therapy, hemoglobin electrophoresis and gene study for thalassemia or other unstable hemoglobinopathies are needed. It should be noted that the recent population migration to Korea from the regions where hemoglobinopathies or enzymopathies are prevalent warrants considering a broad spectrum of etiologies for the diagnosis of HHA.