Summary
Often long-term low-dosage glucocorticoid therapy cannot be terminated. This is due
to the fact that even low doses which are within the physiological replacement range
can cause a detectable, though clinically insignificant suppression of the adrenal
gland function, resulting in “corticosteroid withdrawal syndrome”. Another reason
is the fact that it is necessary to be able to suppress undesirable inflammatory reactions
caused by the underlying disease. ACTH testing of the adrenal capacity is widespread,
but repeated testing may lead to undesirable side effects, such as allergic reactions.
This study investigates the usefulness of testing the function of the pituitary-adrenal
axis in predicting withdrawal problems. In 21 patients with chronic inflammatory disease
who were treated with glucocorticoid doses of 5 to 10 mg prednisolone equivalent daily
for a period of 2 to 131 months, stimulation with lOOp.g hCRH (human corticotrophin-releasing
hormone) was performed prior to the gradual withdrawal of medication. Blood samples
were taken at baseline and after 45 minutes to measure ACTH and cortisol levels. Four
weeks after steroid withdrawal the patients were reevaluated for signs of a relapse
of the underlying disease in order to establish the necessity of reintroducing steroid
therapy. This reevalution comprised clinical criteria, laboratory tests and the patients'
own assessment of his/her well-being.
In sixteen patients who later successfully withdrew from glucocorticoid therapy, a
significant increase in cortisal levels was noticed after stimulation with CRH (p
< 0.05). In five patients, with whom steroid withdrawal was not successful, baseline
levels of cortisol were significantly lower than in the others (p < 0.05) and no sufficient
increase was achieved after stimulation with CRH.
These results show that successful withdrawal of a long-term lowdosage glucocorticoid
therapy depends on the integrity of the pituitary- adrenal axis. Therefore CRH testing
for evaluation of the pituitary-adrenal axis can be helpful in identifying patients
in whom glucocorticoid withdrawal would be troublesome.
Key-Word
CRH test - glucocorticoid therapy - Crohn's disease - ulcerative colitis - systemic
lupus erythematosus
