Beta-
thalassemia major is considered to be one of the most common inherited
hemolytic anemia in Egypt. Our study showed that the patients were underweight
as their BMI was significantly lower compared to that of controls, this
underweight is in accordance with previous reports and can be explained by
disorder in the endocrine system as a result of iron overload and prolonged use
of iron chelating therapy (23, 24). The present significant reduction in Hb,
and red blood indices as HCT, MCV, and MCH in our patients compared to controls
may be attributed to defect in the erythropoiesis associated with beta-
thalassemia, similar data was also reported by Filiz Simsek and his colleagues
(25). The higher the serum level of iron and ferritin, and the lower serum
level of TIBC that are found here and in other studies (25, 26) are
consequences of the absence of beta globin chains and accumulation of unpaired
alpha globin that causes iron overload and hence cellular oxidative damage.
(26)
For trace
elements, although some studies showed the increased serum Cu levels in
patients with beta-thalassemia major (27-29). Others found, reverse results
(30-32). We and those who found hypercupraemia in patients with
beta-thalassemia major related that finding to hemochromatosis associate with
beta-thalassemia major.
Regarding serum
zinc, their levels were found to be significantly lower than controls, that may
be either due to an excessive release from hemolyzed red cells, desferrioxamine
therapy or as of a result of undernutrition in those patients (33, 34).
Although several studies revealed lower serum zinc in thalassemia patients (33,
34), others revealed higher serum zinc in the thalassemia patients with no
relation to ferritin level (35). Our patients also showed a significantly lower
serum Ca and significantly higher phosphorous levels that are in agreement with
previous studies (8,9,10), we think that the reason for this might be
delay in starting iron chelating therapy and poor compliance with the therapy
in some of our patients and this further explains the underweight in those
patients. However other reports reported no changes in mean calcium and
phosphorous levels (36, 37). Furthermore, serum Mg levels were significantly
reduced in beta-thalassemia patients than in controls this finding was in
agreement with Md Fazlul Karim, et al.
who explained the presence of hypomagnesemia as a result of lower
thyroid hormones resulted from iron overload (38). On the other hand, opposite
result described in Al-Samarrai AH et al study, (28) Herein, the
majority of the patients had a high ferritin levels (mean 1087 ± 519.6
ug/l) with more than 50% of patients more than 1000 ug/l, as a result of
repeated blood transfusion, that is the main feature of beta-thalassemia
patients (39-42). So, we tried to correlate our findings in patients after
dividing them into 2 groups depending on the clinical cut of (1000 ug/l), No,
the results didn’t differ significantly with ferritin level ?1000 ug/l. This
new finding may be either due to the cut of (1000 ug/l) is very high so the
pathology is present in both groups equally.
The present work
found T cells but not B cells or NK cells are raised in beta-thalassemia
patients, this indicate activation of the cell-mediated immune cells in those
patients, furthermore, this increase in the total T lymphocyte pool is mainly
related to increase in the cytotoxic T lymphocytes and not in T helper
lymphocytes, that in fact were reduced in our patients. This is in accordance
with the concept described by many other researchers (43- 45). Whether this
specific increase in CD8 T cells and the decrease CD4 is due to continuous
alloantigenic stimulation of the immune system with autoimmune hemolysis as a
result of iron overload remain to be elusive. The different finding by others
who found either increase in the proportion of both CD8 positive cells and CD4
positive cell or no change in T lymphocyte population (12, 46). The discrepancy between our results and
theirs may be related to the changes in the immune system is time-related and
depending on the disease duration and iron overload amount. The absence of
changes in the other immune arms (humoral and innate) reported here came in
agreement with Ahmadiafshar’ s finding who found no abnormalities in cellular
and humeral system (47) and unlike those who found alteration of
immunoglobulins (48). Further analysis of the effect of ferritin on immune
markers depending on the cut off 1000 ?g/L could reveal significant difference between patients with
ferritin level ?1000 and patients with ferritin <1000 when compared with the
controls, as the level of T cells and CD8 positive cells is higher in patients
with ferritin level ?1000 but not in patients with ferritin <1000, in
agreement with this a recent work of Hagag and others (44,45) found significant
a negative correlation between serum ferritin and CD3 and CD4, and positive
correlation with CD8. Our results were in contrast with. Noulsri et al (49) who
reported insignificant differences in T-cell subsets CD3, CD4 and CD8 between
patients and controls and they concluded that high iron levels in
beta-thalassemic patients have a more significant effect on the function and activity
of T cells rather than on their number. (46,49). Variation among results can be
contributed to several factors as, the clinical heterogeneity among beta
-thalassemia patients, frequency of blood transfusion, spelenctomy, serum iron
status, iron chelation therapy In
conclusion, although the alteration in the level of trace elements and cell
mediated immunity did not significantly differ among beta- thalassemia patients
with high ferritin level (?1000) and
those with low ferritin level (<1000), the impaired levels of these
molecules and cells in the whole patients indicates oxidative stress and
damage even in patients with ferritin
level (<1000), initiating chelation therapy regardless of the level of
ferritin can be a more realistic approach in beta-thalassemia major, in addition,
further large scale studies are recommended.
