Characteristics of Silent Alpha Thalassemia Gene in Child-Bearing Adults in Guangdong / 中国实验血液学杂志

OBJECTIVE@#To investigate characteristics of silent alpha thalassemia genes in child-bearing adults in Guangdong, in order to provide data for the prevention and control of hemoglobin H disease.@*METHODS@#A total of 8 752 cases were collected from January 2016 to December 2020. Gap-PCR was used to detect the deletional of α-thalassemia mutations (-α3.7, -α4.2), while PCR reverse dot blot hybridization assay (RDB) was used to detect the non-deletional α-thalassemia mutations (Hb CS, Hb QS and Hb Westmead).@*RESULTS@#Among 8 752 subjects, 717 cases of silent α-thalassemia were detected, the detection rate was 8.19%, including 555 cases of deletional α-thalassemia (77.41%) and 162 cases of non-deletional α-thalassemia 22.59%. The mean corpuscular volume (MCV) of deletional silent α-thalassemia was (82.09±4.10) fl, and mean corpuscular hemoglobin (MCH) was (27.03±1.37) pg, which both were over the diagnostic cut-off value for thalassemia. The MCV of non-deletional silent α-thalassemia was (81.07±4.93) fl, and MCH was (26.77±2.20) pg. According to the diagnostic criteria, if using MCV<82 fl or (and) MCH<27 pg as a positive criteria for screening thalassemia in the childbearing age, the screening sensitivity was 53.14% and different in different genotype, among which ααQS/αα was 100%, -α3.7/αα, -α4.2/αα, ααCS/αα and ααWS/αα was 62.15%, 63.41%, 44.83% and 39.62%, respectively. Namely, nearly half the carriers of such mutations might have escaped detection as a result of their screening strategy.@*CONCLUSION@#When a couple is preparing for pregnancy, if one of them has been determined to be mild α-thalassemia or hemoglobin H disease, other half is necessary to carry out silent α thalassemia detection to prevent the birth of children with hemoglobin H disease even if MCV>82 fl and MCH>27 pg.

Analysis of clinical features and ATRX gene variants in a Chinese pedigree affected with X-linked alpha thalassemia mental retardation (ATR-X) syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic basis of two brothers featuring X-linked alpha thalassemia mental retardation (ATR-X) syndrome.@*METHODS@#An infant who had presented at the Qilu Children's Hospital in 2020 for unstable upright head and inability to roll over and his family were selected as the study subjects. The clinical features of the child and one of his brothers were summarized, and their genomic DNA was subjected to targeted capture and next generation sequencing (NGS).@*RESULTS@#The brothers had presented with mental retardation and facial dysmorphisms. NGS revealed that they had both harbored a hemizygous c.5275C>A variant of the ATRX gene located on the X chromosome, which was inherited from their mother.@*CONCLUSION@#The siblings were diagnosed with ATR-X syndrome. The discovery of the c.5275C>A variant has enriched the mutational spectrum of the ATRX gene.

The Value of Umbilical Cord Blood Erythrocyte Index in the Screening of Neonatal Thalassemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the relationship between umbilical cord blood erythrocyte index and thalasse-mia, and reveal its clinical value in the screening of thalassemia in neonates.@*METHODS@#2 919 cases of umbilical cord blood from neonatal who were born in Boai Hospital of Zhongshan Affiliated with Southern Medical University from July 2017 to December 2018 were collected, the routine blood tests were preformed to detect the umbilical cord blood. Thalassemia gene in peripheral blood of neonates was collected. The cut-off values of cord blood indexes were determined, and the sensitivity, specificity and other evaluation indexs were calculated.@*RESULTS@#Among the cord blood in 2 919 neonates, 314 cases were detected out as thalassemia(positive rate: 10.76%). The average level of RBC and RDW in 2 605 children with non-thalassemia was lower than those with 314 children with thalassemia. The levels of Hb, MCV, MCH, MCHC, HCT, Hb/RBC and MCV/RBC in children with non-thalassemia were higher than those with thalassemia, and there were significant differences in the neonates between the two groups. The RBC and RDW levels of neonates in the α-thalassemia group were higher than those in the non-thalassemia group, while the levels of Hb, MCV, MCH, MCHC, HCT, Hb/RBC and MCV/RBC of neonates were lower than those in the non-thalassemia group. The levels of MCV, MCH and Hb/RBC of neonates in the β-thalassaemia group were lower than those in the non-thalassaemia group. The levels of MCV, MCH, Hb/RBC, and MCV/RBC of neonates in the complex thalassemia group were lower than those in the non-thalassemia group. When the cut-off value of MCV was set to 106.05 fl, the sensitivity was 0.548, and the specificity was 0.907, the specificity was the highest among all indexes. The area under the ROC curve of the combined diagnosis of MCH+MCV/RBC was the largest(0.807), the sensitivity was 0.710, the specificity was 0.841, the positive predictive value was 0.348, and the negative predictive value was 0.960.@*CONCLUSION@#The single indicator of umbilical cord blood red blood cells has advantages and disadvantages for the screening of thalassemia, but the combination of MCH+MCV/RBC can improve the accuracy of the screening or diagnosis of thalassemia, it also has a positive effect to the reduction of the birth rate of children with thalassemia major, which showed a high popularization value in primary hospitals.

Alfa-Talassemias: aspectos moleculares e diagnóstico / Alpha-Thalassemias: molecular aspects and diagnosis

A α-talassemia é um dos distúrbios da síntese de hemoglobina mais comuns no mundo, sendo causada, principalmente,por mutações delecionais nos genes α-globínicos. De acordo com o número degenes mutados que varia de um a quatro, a α-talassemia pode ser divididaem quatro fenótipos: α-talassemia silenciosa, traço α-talassêmico, Doençade HbH e hidropsia fetal, espectivamente. Segundo a literatura, afrequência de α-talassemia no Brasil também é considerável, sendo de grande importância o diagnósticocorreto deste distúrbio, que pode ser realizado com auxílio de exames convencionais que apresentam vantagens e desvantagens. Contudo, em alguns casos, principalmente nas formas menores da α-talassemia, a confirmação diagnóstica só pode ser realizada através dos exames moleculares que, apesar de confirmatórios, não estão disponíveisem grande parte dos laboratórios de análises clínicas e, devido ao custo, não são acessíveis à população em geral..

Clinical Characteristics of Pediatric Thalassemia in Korea: A Single Institute Experience

Few literatures have elaborated on the clinical characteristics of children with thalassemia from low-prevalence areas. A retrospective analysis was conducted on children genetically confirmed with thalassemia at Seoul National University Children's Hospital in Korea. Nine children (1alpha thalassemia trait, 6beta thalassemia minor, 2beta thalassemia intermedia) were diagnosed with thalassemia at median age of 4.3 yr old with median hemoglobin of 9.7 g/dL. Seven (78%) children were incidentally found to be anemic and only 2 with beta thalassemia intermedia had presenting symptoms. Five children (56%) were initially misdiagnosed with iron deficiency anemia. Despite the comorbidities due to alpha thalassemia mental retardation syndrome, the child with alpha thalassemia trait had mild hematologic profile. Children with beta thalassemia intermedia had the worst phenotypes due to dominantly inherited mutations. None of the children was transfusion dependent and most of them had no complications associated with thalassemia. Only 1 child (11%) with codon 60 (T-->A) mutation of the HBB gene needed red blood cell transfusions. He also had splenomegaly, cholelithiasis, and calvarial vault thickening. Pediatricians in Korea must acknowledge thalassemia as a possible diagnosis in children with microcytic hypochromic hemolytic anemia. High level of suspicion will allow timely diagnosis and managements.

Haemoglobinopathies in Southeast Asia.

In Southeast Asia α-thalassaemia, β-thalassaemia, haemoglobin (Hb) E and Hb Constant Spring (CS) are prevalent. The abnormal genes in different combinations lead to over 60 different thalassaemia syndromes, making Southeast Asia the locality with the most complex thalassaemia genotypes. The four major thalassaemic diseases are Hb Bart's hydrops fetalis (homozygous α-thalassaemia 1), homozygous β-thalassaemia, β-thalassaemia/Hb E and Hb H diseases. α-Thalassaemia, most often, occurs from gene deletions whereas point mutations and small deletions or insertions in the β-globin gene sequence are the major molecular defects responsible for most β-thalassaemias. Clinical manifestations of α-thalassaemia range from asymptomatic cases with normal findings to the totally lethal Hb Bart's hydrops fetalis syndrome. Homozygosity of β-thalassaemia results in a severe thalassaemic disease while the patients with compound heterozygosity, β-thalassaemia/Hb E, present variable severity of anaemia, and some can be as severe as homozygous β-thalassaemia. Concomitant inheritance of α-thalassaemia and increased production of Hb F are responsible for mild clinical phenotypes in some patients. However, there are still some unknown factors that can modulate disease severity in both α- and β-thalassaemias. Therefore, it is possible to set a strategy for prevention and control of thalassaemia, which includes population screening for heterozygotes, genetic counselling and foetal diagnosis with selective abortion of affected pregnancies.

Characterization of alpha thalassemic genotypes by multiplex ligation-dependent probe amplification in the Brazilian population

Alpha-thalassemia is the most common inherited disorder of hemoglobin synthesis. Genomic deletions involving the alpha-globin gene cluster on chromosome 16p13.3 are the most frequent molecular causes of the disease. Although common deletions can be detected by a single multiplex gap-PCR, the rare and novel deletions depend on more laborious techniques for their identification. The multiplex ligation-dependent probe amplification (MLPA) technique has recently been used for this purpose and was successfully used in the present study to detect the molecular alterations responsible for the alpha-thalassemic phenotypes in 8 unrelated individuals (3 males and 5 females; age, 4 months to 30 years) in whom the molecular basis of the disease could not be determined by conventional methods. A total of 44 probe pairs were used for MLPA, covering approximately 800 kb from the telomere to the MSLN gene in the 16p13.3 region. Eight deletions were detected. Four of these varied in size from 240 to 720 kb and affected a large region including the entire alpha-globin gene cluster and its upstream regulatory element (alpha-MRE), while the other four varied in size from 0.4 to 100 kb and were limited to a region containing this element. This study is the first in Brazil to use the MLPA method to determine the molecular basis of alpha-thalassemia. The variety of rearrangements identified highlights the need to investigate all cases presenting microcytosis and hypochromia, but without iron deficiency or elevated hemoglobin A2 levels and suggests that these rearrangements may be more frequent in our population than previously estimated.

Detection of alpha-thalassemia-1 Southeast Asian and Thai Type Deletions and beta-thalassemia 3.5-kb Deletion by Single-tube Multiplex Real-time PCR with SYBR Green1 and High-resolution Melting Analysis / 대한진단검사의학회지

BACKGROUND: Prevention and control of thalassemia requires simple, rapid, and accurate screening tests for carrier couples who are at risk of conceiving fetuses with severe thalassemia. METHODS: Single-tube multiplex real-time PCR with SYBR Green1 and high-resolution melting (HRM) analysis were used for the identification of alpha-thalassemia-1 Southeast Asian (SEA) and Thai type deletions and beta-thalassemia 3.5-kb gene deletion. The results were compared with those obtained using conventional gap-PCR. DNA samples were derived from 28 normal individuals, 11 individuals with alpha-thalassemia-1 SEA type deletion, 2 with alpha-thalassemia-1 Thai type deletion, and 2 with heterozygous beta-thalassemia 3.5-kb gene deletion. RESULTS: HRM analysis indicated that the amplified fragments from alpha-thalassemia-1 SEA type deletion, alpha-thalassemia-1 Thai type deletion, beta-thalassemia 3.5-kb gene deletion, and the wild-type beta-globin gene had specific peak heights at mean melting temperature (Tm) values of 86.89degrees C, 85.66degrees C, 77.24degrees C, and 74.92degrees C, respectively. The results obtained using single-tube multiplex real-time PCR with SYBR Green1 and HRM analysis showed 100% consistency with those obtained using conventional gap-PCR. CONCLUSIONS: Single-tube multiplex real-time PCR with SYBR Green1 and HRM analysis is a potential alternative for routine clinical screening of the common types of alpha- and beta-thalassemia large gene deletions, since it is simple, cost-effective, and highly accurate.

Detection of alpha-thalassemia-1 Southeast Asian and Thai Type Deletions and beta-thalassemia 3.5-kb Deletion by Single-tube Multiplex Real-time PCR with SYBR Green1 and High-resolution Melting Analysis / 대한진단검사의학회지

BACKGROUND: Prevention and control of thalassemia requires simple, rapid, and accurate screening tests for carrier couples who are at risk of conceiving fetuses with severe thalassemia. METHODS: Single-tube multiplex real-time PCR with SYBR Green1 and high-resolution melting (HRM) analysis were used for the identification of alpha-thalassemia-1 Southeast Asian (SEA) and Thai type deletions and beta-thalassemia 3.5-kb gene deletion. The results were compared with those obtained using conventional gap-PCR. DNA samples were derived from 28 normal individuals, 11 individuals with alpha-thalassemia-1 SEA type deletion, 2 with alpha-thalassemia-1 Thai type deletion, and 2 with heterozygous beta-thalassemia 3.5-kb gene deletion. RESULTS: HRM analysis indicated that the amplified fragments from alpha-thalassemia-1 SEA type deletion, alpha-thalassemia-1 Thai type deletion, beta-thalassemia 3.5-kb gene deletion, and the wild-type beta-globin gene had specific peak heights at mean melting temperature (Tm) values of 86.89degrees C, 85.66degrees C, 77.24degrees C, and 74.92degrees C, respectively. The results obtained using single-tube multiplex real-time PCR with SYBR Green1 and HRM analysis showed 100% consistency with those obtained using conventional gap-PCR. CONCLUSIONS: Single-tube multiplex real-time PCR with SYBR Green1 and HRM analysis is a potential alternative for routine clinical screening of the common types of alpha- and beta-thalassemia large gene deletions, since it is simple, cost-effective, and highly accurate.

Enfermedad por hemoglobina H: primer caso de la variante de hemoglobina H tipo, menos alfa elevado a potencia 3.7 / SEA, en Costa Rica / Hemoglobin H disease: first case of hemoglobin H variant type (-a 3.7 / SEA) in Costa Rica

La enfermedad por Hemoglobina H es la forma más común de talasemia intermedia y posee muchas características que requieren cuidadosa consideración en su manejo clínico. En lamayoría de los casos, la enfermedad por Hemoglobina H resulta de un estado doble heterocigoto producido por unadeleción tipo α0 que remueve ambos genes de α-globina en uno de los cromosoma 16 y de una deleción tipo α+ en uno de los genes de α-globina en el otro cromosoma 16, resultando enuna condición tipo (--/-α). El exceso de cadenas β de globina precipita y forma una hemoglobina anormal característica; la hemoglobina H (Hb H), un tetrámero de β globina (β4). Lospacientes con hemoglobina H que se encuentran en estado compensado pueden tener niveles de hemoglobina entre 9 y 10 g/dL, sin embargo durante las crisis hemolíticas, que se desarrollan durante o después de infecciones agudas con fiebres altas, la hemoglobina puede llegar a disminuirsignificativamente y los pacientes pueden desarrollar shock y fallo renal. Aún cuando la esplenectomía eleva la hemoglobina significativamente, no se recomienda porque la mayoría delos pacientes tienen un nivel aceptable de hemoglobina mientras se encuentren compensados. Se presenta el primercaso descrito en Costa Rica de enfermedad por hemoglobina H variante del sudeste asiático (-α3.7/ --SEA).

Hemoglobin H (Hb H) disease is the most common form of thalassemia intermedia and has many features that require careful consideration in its management. In the majority of cases, the disease results from double heterozygosity for α0- thalassemia due to deletions that remove both linked α-globin genes on one chromosome 16, and deletional α+ from single α-globin gene deletions on the other chromosome 16 resulting in a (--/-α) condition. The excess β globin chainprecipitates and forms a characteristic abnormal hemoglobin: hemoglobin H a β globin tetramer (β4). In a steady state,patients with Hb H disease have hemoglobin levels around 9 to 10 g/dL however, during a hemolytic crisis, which frequently occur in or after acute infections causing high fever, the hemoglobin may drop significantly and the patients can develop shock or renal shutdown. Even though splenectomy leads to significant elevation of hemoglobin levels, it is not recommended because the majority of patients do well with said steady-state hemoglobin levels. We present here the first case of hemoglobin H (-α3.7/ --SEA) southeast Asia variant described in Costa Rica.

Dificuldades na identificação laboratorial da talassemia alfa / Difficulty on laboratory identification of alpha thalassemia

Introdução: Talassemia alfa é uma síndrome associada à redução da síntese de cadeias de globina do tipo alfa. A gravidade das manifestações clínicas está relacionada com a quantidade de globinas produzida e a estabilidade das cadeias beta presentes em excesso. A talassemia alfa mínima resulta da deleção de apenas um dos quatro genes a (-α/αα). Clinicamente apresenta anemia leve com microcitose ou ausência de anemia, sendo o diagnóstico realizado por meio de visualização da hemoglobina (Hb) H por eletroforese alcalina em acetato de celulose ou por identificação de inclusões celulares de Hb H coradas pelo azul de crezil brilhante. Objetivo: Avaliar portadores de talassemia alfa e seus respectivos progenitores, correlacionando perfil hematológico e presença de Hb H, utilizando procedimentos laboratoriais clássicos em três diferentes amostragens. Discussão e conclusão: Os dados obtidos mostram que a presença de Hb H, indicativo de talassemia alfa, pode não ser confirmada em uma análise posterior. Entre os fatores que podem influenciar no não aparecimento de Hb H em pessoa comprovadamente com talassemia alfa está a deficiência de ferro. A talassemia alfa está associada a defeitos envolvendo os genes codificadores da cadeia alfa, mas também pode estar relacionada com desbalanciamento temporário na expressão dos genes globina, diminuição de alfa ou aumento de beta, o que poderia explicar o aparecimento de tetrâmeros de cadeia beta (Hb H), sugerindo diagnóstico de talassemia alfa mínima.

Introduction: Alpha thalassemia is a syndrome with associated with the reduction of alpha globin chain synthesis. The severity of clinical manifestations is related to the amount of globins produced and the stability of beta chains that are present in excess. Alpha thalassemia minor is caused by the deletion of one of the four genes a (-α/αα). Clinically, it presents mild anemia with microcytosis or absence of anemia. The diagnosis is made by the visualization of Hb H through alkaline electrophoresis on cellulose acetate or by the identification of inclusion bodies stained with brilliant cresyl blue. Objective: Evaluate alpha thalassemia carriers and their respective progenitors, correlating their hematology profile and the presence of Hb H by means of standard laboratory procedures in three different samplings. Discussion and conclusion: The results show that the presence of Hb H, which is indicative of alpha thalassemia, may not be confirmed in a subsequent analysis. Iron deficiency in Hb H carriers is among the factors that may influence on the absence of Hb H in alpha thalassemia proven patients. Alpha thalassemia is associated with genetic defects involving alpha chain encoding genes, but may be also associated with a temporary imbalance of globin gene expression, alpha chain reduction or beta increase, which could explain the presence of beta chain tetramer (Hb H) leading to the diagnosis of alpha thalassemia minor.

Comparison of erythrocyte indices to differentiate between iron deficiency and alpha-thalassaemias in children with microcytosis and/or hypochromia

Erythrocyte indices used to differentiate between iron deficiency anaemia [IDA] and thalassaemias have been studied mainly in countries with a high prevalence of IDA or beta-thalassaemias. This study was carried out in the United Arab Emirates where alpha-thalassaemias are prevalent. We studied the predictive value and Youden index of several indices in 85 children aged 6 months to 12 years with microcytosis and/or hypochromia, with or without anaemia [determined by serum measurement of iron or therapeutic iron trial]. The best discriminatory indices for detecting IDA versus alpha-thalassaemias were a Green -King index > 65 [correctly identified 75.3% of children, Youden index 44.3] and red cell distribution width > 14% [correctly identified 57.8%, Youden index 38.1]

Homozygosity for the Mediterranean alpha-thalassemic deletion [hemoglobin Baits hydrops fetalis]

Hemoglobin Barts hydrops fetalis syndrome is the most severe and generally fatal clinical phenotype of alpha-thalassemia. We diagnosed a fetus at 23-weeks gestation with having hydrops fetalis, by ultrasound. At 32 weeks, intrauterine death was detected. Molecular studies revealed that the fetus had the hemoglobin Barts hydrops fetalis syndrome due to homozygosity for the Mediterranean alpha-thalassemia deletion. This clinical phenotype is generally rare in the Eastern Mediterranean, and this is the first report of this syndrome from Iraq. Techniques for molecular characterization became available only very recently in this country, in a diagnostic setting. Thus, the detection of further cases might be expected in future

Microcytic hypochromic anemia patients with thalassemia: genotyping approach.

BACKGROUND: Microcytic hypochromic anemia is a common condition in clinical practice, and alpha-thalassemia has to be considered as a differential diagnosis. AIMS: This study was conducted to evaluate the frequency of alpha-gene, beta-gene and hemoglobin variant numbers in subjects with microcytic hypochromic anemia. SETTING AND DESIGNS: Population-based case-control study in the Iranian population. MATERIALS AND METHODS: A total of 340 subjects from southwest part of Iran were studied in the Research Center of Thalassemia and Hemoglobinopathies (RCTH), Iran. Genotyping for known alpha- and beta-gene mutations was done with gap-PCR and ARMS. In cases of some rare mutations, the genotyping was done with the help of other techniques such as RFLP and ARMS-PCR. STATISTICAL ANALYSIS: Statistical analysis was carried out by SPSS 11.5 and an independent-sample t test. RESULTS: Out of the total 340 individuals, 325 individuals were evaluated to have microcytic hypochromic anemia based on initial hematological parameters such as MCV<80 fl; MCH<27 pg; the remaining 15 patients were diagnosed with no definite etiology. The overall frequency of -alpha3.7 deletion in 325 individuals was 20.3%. The most frequent mutations were IVS II-I, CD 36/37 and IVS I-110 with frequencies of 6.31%, 5.27% and 1.64%, respectively. Only, there was a significant difference between beta-thalassemia trait and beta-thalassemia major with regard to MCV (P<0.05) and MCH (P<0.05) indices, and also MCH index between beta-thalassemia trait and Hb variants (P<0.05). CONCLUSION: Molecular genotyping provides a rapid and reliable method for identification of common, rare and unknown alpha- and beta-gene mutations, which help to diagnose unexplained microcytosis and thus prevent unnecessary iron supplementation.

Haematological and molecular aspects of hemoglobinosis H: about three Tunisian cases

Hemoglobinosis H is the severest alpha-thalassemia compatible with life. The clinical manifestation seems to be different regarding to the genotype. The present paper aims to provide to hematological and molecular data related to three patients suffering from hemoglobinosis H alpha thalassemia and their family. The clinical and biological profiles appear to be similar to those observed in thalassemia intermedia with mild hemolytic microcytic anemia. The diagnosis was based on decreased Hb A2 level [< 2%] and the presence of Hb H at an amount ranging from 10 to 30%. Two different molecular defects were observed. The genotypes were an association of two types of deletion [--MEDI an alpha [3.7]] and two point mutations [alpha[snt] and alpha t], The correlation phenotype / genotype showed that non-deletional Hb H is more severe than deletional forms. Detection of athalassemia trait remains difficult, it's detection is yet a matter of exclusion diagnosis based on the observation of isolated microcytosis with normal or limited Hb A2 levels with a normal iron state. Molecular study is a powerful tool for the diagnosis of such alpha cases

Patrón clínico y hematológico de pacientes con drepanocitosis o diagnóstico presuntivo de talasemia / Hematological and clinical profile in sickle cell or thalassemic patients

Clinical and hematological characteristics of 14 patients with sickle cell anemia; one heterozygous AS, and 7, with diagnostic of microcytic hypochromic anemia were analyzed. Hemoglobin phenotypes were identified by electrophoresis, fetal hemoglobin was quantificated for alkaline denaturation and the HbA2 for ionic exchange chromatography; -α3,7-thalassemia was detected by mutation identification using polymerase chain reaction (PCR). SS phenotype was confirmed in 10 patients, two were SSF, one was SSFA2, and one was ASF (HbF - 2%). The patient diagnosed as AS was SSF (HbF = 21%). AD-patients presented a moderate clinical course of the illness. Five microcytic hypochromic anemia patients were HbAA, one was HbAAA2 and another HbAAF; those patients present a high hematological and clinical variation, β-thalassemia was 19%. -α3,7 -thalassemia was not detected. Infection was most frequent clinical manifestation (respiratory tract infection and intestinal parasitism). These results shows that -α3,7 -thalassemia are not modulator genetic factors of clinical and hematological manifestations of patients with microcytic hypochromic anemia and sickle cell anemia. We suggest that environmental factors such as respiratory tract infection and intestinal parasitism may be affect the course of illness.

Se analizaron las características clínicas y hematológicas de 14 pacientes con diagnóstico clínico de anemia drepanocítica (AD), un heterocigoto AS con manifestaciones clínicas, y siete pacientes con diagnóstico de anemia microcítica hipocrómica resistente a tratamiento con hierro y ácido fólico. Los fenotipos hemoglobínicos fueron determinados mediante electroforesis, la cuantificación de hemoglobina fetal se realizó por desnaturalización alcalina y la hemoglobina A2 por cromatografía de intercambio iónico. La detección de -α3,7 talasemia se realizó mediante la técnica de reacción en cadena de polimerasa (PCR). Se confirmó el fenotipo SS para 10 pacientes; de los cuatro restantes, dos fueron SSF, uno SSFA2, y uno fue heterocigoto ASF (HbF = 2%). El paciente diagnosticado como heterocigoto AS resultó ser SSF (HbF = 21%). Los pacientes con AD presentaron un curso clínico moderado de la enfermedad. De los siete pacientes con anemia microcítica hipocrómica, cinco fueron HbAA, uno fue HbAAA2 y otro HbAAF; todos presentaron una alta variación hematológica y clínica. Se detectó la presencia de β-talasemia en 19% de los pacientes. No se detectó la presencia de -α3,7 -talasemia. La manifestación clínica más frecuente fue la infección (respiratoria o parasitismo intestinal). De acuerdo con estos resultados, en estos pacientes se descarta la presencia de -α3,7 -talasemia, como atenuante de las manifestaciones clínicas de la anemia drepanocítica y como factor modulador de la variabilidad clínica observada en los pacientes con anemia microcítica-hipocrómica; se sugiere que factores ambientales tales como parasitosis intestinales y enfermedades respiratorias pueden afectar el curso de la enfermedad.

Bronquite plástica em criança com talassemia alfa / Plastic bronchitis in a child with thalassemia alpha

OBJETIVO: A bronquite plástica é uma doença infreqüente na criança, sendo caracterizada por moldes ou cilindros mucofibrinosos na árvore traqueobrônquica. Faz parte do diagnóstico diferencial de crianças com insuficiência respiratória de início agudo, e o tratamento precoce é importante para a resolução do quadro. O objetivo deste relato é descrever um caso de bronquite plástica tratado com sucesso por endoscopia, em paciente portador de talassemia alfa. DESCRIÇÃO: Criança do sexo masculino, 3 anos de idade, sem antecedentes mórbidos significativos, apresentou quadro de insuficiência respiratória aguda, com achados radiológicos de atelectasia pulmonar sugestivos de aspiração de corpo estranho. Não havia sintomas respiratórios ou antecedentes de alergia ou infecções respiratórias de repetição. A realização de broncoscopia flexível, complementada por endoscopia rígida e exame anatomopatológico, evidenciou a presença de bronquite plástica. Após a realização da endoscopia, a criança evoluiu satisfatoriamente, com curva térmica afebril e extubação em 72 horas. Foram utilizadas medicações sintomáticas, sem necessidade de antimicrobianos. Dez dias após a alta, a radiografia de tórax encontrava-se normal. A talassemia alfa foi diagnosticada através da eletroforese de hemoglobina. COMENTARIOS: A importância clínica da bronquite plástica reside no fato de apresentar um quadro semelhante ao de outras doenças mais prevalentes, como a aspiração de corpo estranho e a asma brônquica. A suspeita do quadro recomenda a realização de endoscopia para diagnóstico e tratamento. É reconhecida a ocorrência de bronquite plástica em crianças com fibrose cística, pós-operatório de cirurgia cardíaca e anemia falciforme. No presente artigo, foi observada uma associação com talassemia alfa.