Dificuldades na identificação laboratorial da talassemia alfa

Resumo

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 α (-α/α α). 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.

Descrição

Palavras-chave

Hemoglobinopatias, Hemoglobina H, Talassemia alfa

Citação

DIAS-PENNA, Karlla Greick Batista et al. Dificuldades na identificação laboratorial da talassemia alfa. Jornal Brasileiro de Patologia e Medicina Laboratorial, Rio de Janeiro, v. 46, n. 4, p. 91-97, 2010.