Polimorfismo XmnI está associado com os níveis de hemoglobina fetal em hipoplasias medulares

CONTEXT AND OBJECTIVE: Acquired fetal hemoglobin (HbF) elevation has been implicated as a prognostic factor in dyserythropoietic disorders. Our objectives were to examine acquired HbF increases in aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH) patients, and to evaluate whether there is an association between the presence of XmnI and 5' hypersensitive site locus control region (LCR-HS2) polymorphisms and the HbF levels. DESIGN AND SETTING: Cross-sectional study at the Hematology and Blood Transfusion Service of Universidade Federal de São Paulo (UNIFESP) - Escola Paulista de Medicina. METHODS: We studied a group of 37 patients with AA and/or PNH. Polymerase chain reaction (PCR) and enzymatic digestion were utilized to analyze XmnI polymorphisms; and PCR, cloning and automated sequencing for the HS2 polymorphisms. RESULTS: The mean HbF level was 2.32%, but there was no significant difference in HbF level between the AA and PNH groups (p = 0.46). HbF levels of less than 1.0% showed a significant correlation with absence of the XmnI (+) polymorphism (p = 0.02). The presence of the XmnI allele was greater in the AA group (p = 0.007). CONCLUSIONS: XmnI polymorphism absence reduction is associated with acquired HbF elevation. Further studies are required to confirm these observations and make treatment, prognosis and survival comparisons.CONTEXTO E OBJETIVO: O aumento adquirido da hemoglobina fetal (HbF) já foi implicado como fator prognóstico em distúrbios diseritropoiéticos. Nossos objetivos foram de examinar elevações adquiridas na HbF em pacientes com anemia aplástica (AA) e hemoglobinúria paroxística noturna (PNH), e de avaliar se há associação entre a presença de polimorfismos XmnI e de região de controle de locus gênico 5' (LCR-HS2) e os níveis de HbF. TIPO DE ESTUDO E LOCAL: Estudo longitudinal no Serviço de Hematologia e Transfusão de Sangue da Universidade Federal de São Paulo (UNIFESP) - Escola Paulista de Medicina. MÉTODOS: Estudamos um grupo de 37 pacientes com AA e/ou PNH. Reação de polimerase em cadeia (PCR) e digestão enzimática foram usadas para analisar polimorfismos XmnI; e PCR para clonagem e sequenciamento automático dos polimorfismos HS2. RESULTADOS: O nível médio de HbF foi de 2,32%, mas não houve diferença significativa entre o nível de HbF dos pacientes AA e PNH (p = 0.46). Os níveis de HbF menores que 1,0% mostraram correlação estatisticamente significativa com ausência do polimorfismo XmnI (+) (p = 0.007). CONCLUSÕES: Ausência de polimorfismo XmnI está associado com diminuição de HbF. Mais estudos são necessários para confirmar estas observações e fazer comparações sobre tratamento, prognóstico e sobrevida.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Hematology and Blood Transfusion ServiceUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPM, Hematology and Blood Transfusion ServiceUNIFESP, EPMSciEL

XmnI polymorphism is associated with fetal hemoglobin levels in hypoplastic syndromes

CONTEXT AND OBJECTIVE: Acquired fetal hemoglobin (HbF) elevation has been implicated as a prognostic factor in dyserythropoietic disorders. Our objectives were to examine acquired HbF increases in aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH) patients, and to evaluate whether there is an association between the presence of XmnI and 5' hypersensitive site locus control region (LCR-HS2) polymorphisms and the HbF levels. DESIGN AND SETTING: Cross-sectional study at the Hematology and Blood Transfusion Service of Universidade Federal de São Paulo - Escola Paulista de Medicina. METHODS: We studied a group of 37 patients with AA and/or PNH. Polymerase chain reaction (PCR) and enzymatic digestion were utilized to analyze XmnI polymorphisms; and PCR, cloning and automated sequencing for the HS2 polymorphisms. RESULTS: The mean HbF level was 2.32%, but there was no significant difference in HbF level between the AA and PNH groups (p = 0.46). HbF levels of less than 1.0% showed a significant correlation with absence of the XmnI (+) polymorphism (p = 0.02). The presence of the XmnI allele was greater in the AA group (p = 0.007). CONCLUSIONS: XmnI polymorphism absence reduction is associated with acquired HbF elevation. Further studies are required to confirm these observations and make treatment, prognosis and survival comparisons

Duffy-negative is associated with hemolytic phenotype of sickle cell anemia

Universidade Federal de São Paulo, Disciplina Hematol & Hemoterapia, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Disciplina Hematol & Hemoterapia, BR-04023900 São Paulo, BrazilWeb of Scienc