Abstract
The aim of the study was to assess glucocorticoid sensitivity in survivors of
childhood acute lymphoblastic leukemia using in vivo and in vitro tests. Thirty
leukemia survivors of both sexes aged ≥18 years participated in the study and at
least two years after therapy withdrawal. In vivo tests comprised: a) a very low
dose intravenous dexamethasone suppression test for measurement of serum
cortisol before, after, and % suppression, compared with 32 age-matched
controls; and b) 0.25 mg overnight oral dexamethasone suppression test for
assessment of salivary cortisol before, after, and % suppression. In vitro
methods comprised: c) glucocorticoid receptor polymorphisms: BcI1-NR3C1 and
A3669G; and d) splicing variant of glucocorticoid receptor GR-α mRNA by
real-time quantitative polymerase chain reaction, compared with 32 controls.
There was a reduction in salivary cortisol, and 73.3% of leukemia survivors
showed high sensitivity according to % suppression after oral dexamethasone
(p<0.05). Serum cortisol at baseline, after the test, % suppression after
intravenous dexamethasone, and the percentage of high sensitivity were reduced
in the leukemia group (%F=36.7; p<0.05). The BcI1-NR3C1 and A3669G
polymorphisms were present in 11/30 (36.7%) and 5/30 (16.7%) patients,
respectively. GR-α mRNA levels were lower in the leukemia group than in the
controls (p<0.05). Survivors of acute lymphoblastic leukemia presented with
reduced glucocorticoid sensitivity. Glucocorticoid sensitivity allows
individualized treatment to avoid adverse effects and may be involved in
cardiovascular disease risk among this particular group of cancer survivors.
Keywords
glucocorticoid effect - adrenal - glucocorticoid receptor - dexamethasone - real-time polymerase chain reaction - saliva