FUNCTIONAL
STUDIES OF CIRCULATING EOSINOPHILS AND SERUM IMMUNOGLOBULIN E CONCENTRATION
IN THALASSAEMIC CHILDREN
Leung TF, Li CK,
Li K, Chik KW, Wong RPO, Shing MMK, Yuen PMP
Division of
Haematology and Oncology, Department of Paediatrics, The Chinese University
of Hong Kong, Hong Kong SAR, China
Objective:
Homozygous thalassaemia is associated with immunomodulation in the lymphoid
system. We investigate the in vitro
eosinophil functions in these patients upon IL-13 stimulation.
Methods:
Priming of circulating eosinophils was detected by their surface CD69
expression whereas eosinophil survival was studied using
7-amino-actinomycin D. These eosinophil functions were analyzed with
respect to history of blood transfusion and severity of iron overload.
Results:
Eighteen patients and 18 control subjects were enrolled. The median (range)
serum ferritin concentration in patients was 7036 (3305 – 24636) pmol/l.
Two thalassaemic patients had elevated serum IgE level. IL-13-primed
eosinophils from thalassaemics expressed significantly higher CD69 (p = 0.027). Unstimulated eosinophils
from patients survived longer (p
= 0.049) whereas those following IL-13 stimulation died earlier (p = 0.019). Serum ferritin level or
blood transfusion parameters did not correlate with eosinophil functions in
our patients.
Conclusion:
Circulating eosinophils from thalassaemic patients have abnormal patterns
of in vitro priming and survival.
However, these changes do not correlate with blood transfusion or body iron
status.