Clinical
Picture of b- Thalassemia Major
8. Pulmonary Complications:
Iron deposition in the lungs leads to elevation of pulmonary
vascular resistance causing pulmonary hypertension and hypoxaemia, so chelation
therapy reduces iron deposition and its contribution to the elevation of
pulmonary vascular resistance (Atichartakan et al., 2003). Some
studies showed mild to moderate small airway obstruction and air trapping by
thin-section CT (Khong et al., 2003).
9. Pseudoxanthoma Elasticum:
The
development of clinical and histopathologic manifestations of a diffuse elastic
tissue defect, resembling inherited pseudoxanthoma elasticum, has been
encountered with a notable frequency in patients with β-thalassemia. This
clinical syndrome consisting of skin, ocular, and vascular manifestations, has
a variable severity and is age dependent, with an onset usually after the
second decade of life (Aessopos et al., 2002). The defect is
believed to be acquired, but its progression seems to be similar to that of the
inherited form (Cianciulli et al., 2002).
10. Secondary Gout:
Hyperuricemia is not unusual
in thalassemia patients, but gouty arthritis has been rarely reported (Paik
et al. 1970).
11.
Cardiac
complications:
Cardiac iron overload is the
most frequent cause of death from chronic transfusion therapy. The cardiac
complications related to excessive iron may result from long term iron
deposition in vulnerable areas or due to more immediate effects of
non-transferrin bound iron. (Cohen et al, 2004).
12. Bacterial infections:
It has been suggested that the relatively high serum iron level
may favor bacterial growth. Another possible mechanism is the blockage of the
monocyte-macrophage system due to the increased rate of red cell destruction (Wetherall
et al., 1994).
In 1996 El Alfy et al., reported that the corrected
total leucocytic count was higher in thalassemic patients with splenectomy than
the non-splenectomized patients. This could be attributed to the continuous
antigenic stimulation of thalassemic patients provoked by frequent blood
transfusion and repeated infections.
13.
Endocrinopathies:
Endocrine dysfunction is
well recognized in transfusion dependent thalassemic patients, and is thought
to reflect the consequence of iron overload. The ability of desferroxamine to
prevent endocrine damage is less clear (Grundy et al., 1994).
a.
Thyroid:
Even though iron deposition
in thyroid parenchymal tissue is often extensive, dysfunction is usually
limited to primary subclinical hypothyroidism (David and Stuart, 1998).
Thyroid dysfunction has been reported in thalassemic patients, but severity is
variable in different series. Some studies report high prevalence reaching
17-18% (Magro et al., 1990). Others report low incidence of 0.9% (Pantelakis,
1994). It is thought to be also due to iron overload (Khalifa et
al., 1982).
b.
Diabetes mellitus:
It is a well documented
complication of thalassemia major particularly among polytransfuscd patients.
Iron deposition in the liver may produce insulin resistance by interfering with
the ability of insulin to suppress hepatic glucose production. It was found
that the incidence of DM was lower in those receiving good chelation (Low,
1997).
c.
Adrenal:
Adrenal pathologic process
in patients with thalassemia are historically characterized by iron deposition
limited primarily to the zona glomerulosa, the site of mineralocorticoid
production (Low, 1997). Iron deposition in zona fasciculata may
also occur (Modell 1984).
d.
Delayed growth:
The most common endocrinal
problem. The etiology of impaired growth includes the lack of pubertal spurt
due to delayed or absent puberty (Soliman et al. 1999).
e.
Delayed puberty and hypogonadism:
It is due to iron overload
which leads to damage at pituitary-hypothalamic or gonadal level (Low,
1997).
f.
Hypoparathyrodism:
The least common endocrinal
problem, it is thought to be due to tissue fibrosis secondary to hemosidrosis
and iron overload (Low, 1997).
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