Spectrin interactions with globin chains in the presence of phosphate metabolites and hydrogen peroxide: implications for thalassaemia.

We have shown the differential interactions of the erythroid skeletal protein spectrin with the globin subunits of adult haemoglobin (HbA); these indicate a preference for alpha-globin over that for beta-globin and intact HbA in an adenosine 5'-triphosphate (ATP)-dependent manner. The presence of Mg/ATP led to an appreciable decrease in the binding affinity of the alpha-globin chain to spectrin and the overall yield of globin-spectrin cross-linked complexes formed in the presence of hydrogen peroxide. Similar effects were also seen in the presence of 2-,3-diphosphoglycerate (2,3 DPG), the other important phosphate metabolite of erythrocytes. The binding affinity and yield of cross-linked high molecular weight complexes (HMWCs) formed under oxidative conditions were significantly higher in alpha-globin compared with intact haemoglobin, HbA and the beta-globin chain. The results of this study indicate a possible correlation of the preferential spectrin binding of the alpha-globin chain over that of the beta-globin in the haemoglobin disorder beta-thalassaemia.

Microesferocitosis familiar: estudio en 10 familias / Familial microspherocytosis: a study in 10 families

A raíz de 10 casos índices, se estudiaron 10 familias con un total de 20 pacientes que sufrían microesferocitosis hereditaria. El diagnóstico fue tardío, en la mayoría de los casos en edad escolar. En sólo 2 niños la enfermedad fue identificada en el período de RN porque sus madres estaban en estudio por anemia y sufrieron crisis hemolíticas durante el embarazo. De un total de 20 episodios de complicación, las crisis hemolíticas constituyeron el 80%, las crisis aplásticas el 15% y la colelitiasis el 5%. Las crisis aplásticas fueron más severas porque fueron acompañadas por anemia importante