Haemoglobin H disease (HbH) is an alpha thalassemic disorder characterized by a marked depression of alpha chain production. This defect leads to the formation of large amounts of beta tetramers. Recently Wickramasinghe et al. described by the electron microscope typical intracytoplasmic inclusions in the more mature erythroid cells of a patient affected by a genetically determined (HbH) disease. We report here a case of probably acquired HbH disease, in which electron microscopy revealed similar findings. The patient was a 56 year old Italian male admitted to the hospital for severe anemia. All the ultrastructural findings have been already described in beta-thalassemia and in other dyserythropoietic syndromes. In addition, in our case, roughly 20% of late erythroblasts and 40% of non-nucleated erythroid profiles showed intracytoplasmic inclusions characterized by an irregular elongated shape and sometimes arranged in a branched pattern. Their matrix consisted of an electrodense material with a fine granular structure without any evident limiting membrane. These latter inclusions are very similar to those described by Wickramasinghe et al in HbH disease, and might consist of beta chain tetramers which precipitate during electron microscopy fixation procedures as they do in red blood cells supravitally stained with brilliant cresyl blue. Nevertheless in our case, the absence of a past haematological history, the presence of a normal alpha-genes complement and the extremely high beta-alpha ratio (3/1) which is observed only in the severe forms of alpha-thalassemia, strongly suggested the diagnosis of acquired, non-genetically determined HbH disease. The inclusions observed are however submicroscopically different from those seen in homozigous beta-thalassemia and, whenever confirmed by other authors, they could be considered a typical ultrastructural feature of HbH disease, either genetically determined or acquired.
|Number of pages||4|
|Publication status||Published - 1982|
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