Clinical Picture of b- Thalassemia Major

Clinical Picture of b- Thalassemia Major

T

he clinical picture of β-thalassemia major includes features that are due to the disease itself, as well as others that represent the consequences of therapy and are, in a sense, iatrogenic (Caterina and Renzo, 2004).

1.     Anemia

Hypochromic microcytic anemia becomes apparent 3-6 months after birth when the switch from gamma to beta chain production should take place (Honig, 2000).

2.     Iron overload

The primary long-term complication of chronic RBCs transfusions for thalassemia is iron loading and the resultant parenchymal toxicity. As iron levels build up in the body, transferrin becomes saturated. Iron begins to accumulate in the tissues, bound to protein storage molecules ferritin and haemosiderin. In iron overload, the capacity to bind iron is exceeded both within the cells and in the plasma compartment. Unbound iron or "free iron" begins to circulate. This is highly reactive and alternates between the ferrous (Fe²) and ferric (Fe³) forms. This results in gain and loss of electrons which can generate harmful free radicals (Borgana-Pignatti, 2005).

3.     Skeletal changes:

Un-transfused or poorly transfused patients develop typical bone abnormalities that are due to extremely increased erythropoiesis with consequent expansion of the bone marrow to 15-30 times normal. The most striking skeletal changes are seen in the skull and facial bones. There is bossing of the skull and overgrowth of the maxillary region, the whole face gradually assumes a mongloid appearance (Honig, 2000).  The outer and inner tables are thin, and the trabeculae are arranged in vertical striations, resulting in a "hair-on-end" appearance. A peculiar, stratified appearance of the skull has been reported. Ear impairment due to extramedullary marrow growing in the middle ear and progressive visual loss caused by compressive optic neuropathy have been reported (Aarabi et al., 1998).

Osteoporosis in thalassemia has been found to affect 51% of the patients, with an additional 45% affected by osteopenia. Fractures and bone pain of varying severity are common complaints among adult patients and they have been attributed to expanded bone marrow with consequent pressure on the cortical bone (Angastiniotis et al., 1998).