Thalassemia is a chronic , congenital hemolytic anemia in which the chief
defect seems to be an inability to produce cells capable of normal
incorporation of hemoglobin. (MAROLW, 1980). The term thalassemia ,
which is derived from the Greek word thalassa, meaning sea and mia
blood is applied to a variety of inherited blood disorders characterized
by deficiencies in the rate of production of specific globin chains in Hgb,
the name appropriately refers to descendants of or those people living
near the Mediterranean Sea , who have the highest incidence of the
disease , namely Italians , Greeks and Syrians. (Wong's,2009).
B- Thalassemia is the most common of the thalassemia and occurs in
four forms. Two heterozygous forms, thalassemia minor , an
asymptomatic silent carrier , and thalassemia trait, which produces a
mild microcytic anemia . Thalassemia intermediate , which is manifested
as splenomegaly and moderate to sever anemia. A homozygous forms ,
thalassemia major( also known a cooley anemia), which results in
anemia that would lead to cardiac failure and death in early childhood
without transfusion support. (Wong's, 2009). The objective of supportive
therapy is to maintain sufficient Hgh levels to prevent bone marrow
expansion and the resulting bony deformities, and to provide sufficient
RBCs to support normal growth and normal physical activity.
Transfusions are the foundation of medical management. One of the
potential complications of frequent blood transfusions is iron overload ,
because the body has no effective means of elimination the excess iron ,
the mineral is deposited in body tissues . To minimize the development
of hemosiderosis , the new oral iron chelator deferasiorx has been
shown to be equivalent to deferoxamine ( Deferral ) , a parenteral iron –
chelating agent, and families( Wong's, 2009)
The goal of iron chelation therapy in multiply transfused patients is to
prevent morbidity and
early mortality from the toxic effects of transfusional iron overload, in
particular cardiac deaths.
At the same time treatment should be associated with as few drug-related
side effects as possible.
Desferrioxamine (Desferral), given parenterally, and the oral chelator,
Deferiprone (Ferriprox),
given as monotherapy or in combination are effective in clinical practice
and have improved
survival although both agents have disadvantages in routine use. A new
oral drug, deferasirox
(Exjade) has recently been licensed and clinical trial data suggests that it
is effective at
maintaining iron or achieving negative iron balance and its once-daily
formulation may
encourage adherence to treatment. Data on long term efficacy is not yet
available. Thus clinicans
and patients are faced with a choice of treatment. The following
guidelines were based on
consensus views of practising clinicians taking into account clinical
experience and available
clinical data and, as such, may change when new information becomes
available.
General considerations
Consensus view is important to ensure consistency between patients
and centres
Decisions about chelation should be made by a consultant
haematologist experienced in the
use of chelation regimes
The goal of chelation therapy is prevention rather than rescue; trends in
ferritin levels need
regular review with view to increasing dose or changing to an alternative
drug(s).
Management decisions should ideally be directed