Difference in GC-induced Adrenal Insufficiency in RA Related to Polymorphisms in the Glucocorticoid Receptor Gene

Observational Cohort Study on Difference in Glucocorticoid-induced Adrenal Insufficiency in Patients With Rheumatoid Arthritis Related to Different Sensitivity Polymorphisms in the Glucocorticoid Receptor Gene

Development of glucocorticoid (GC)-induced adrenal insufficiency is a serious adverse effect of GC treatment. It is today not possible to predict this adverse effect. The project aims at investigating a possible individual aspect, which may render subjects more or less sensitive to glucocorticoids, and thereby influence development of GC induced adrenal insufficiency. The hypothesis is that subjects with one or another of the polymorphisms in the GC receptor gene will either have increased or diminished GC sensitivity. This may be responsible for differences in development of GC induced adrenal insufficiency.

Blood is sampled from patients with rheumatoid arthritis (RA), fulfilling the inclusion criteria and patients are genotyped for the SNPs N363S, BclI, ER22/23EK and 9β and grouped according to haplotypes. SNPs will be determined by polymerase chain reaction (PCR). Patients will be included for a Synacthen test, to evaluate their adrenal function. Information from the results of the study will be able to assist clinicians to identify patients at risk and thus individualize GC therapy in a tailored fashion. Results of the study will be important for all patient groups worldwide on GC therapy.

Inclusion Criteria:

• Adult patients > 18 years)
• Caucasian classified with rheumatoid arthritis.
• 1987 ACR-classification criteria.
• Prednisolone min 5mg/day for at least 6 months.
• Presence of either BclI (high GC sensitivity) or 9β (low GC sensitivity)polymorphisms, or wildtype for for all 4 SNPs studied. Patients with or without these polymorphisms were invited to a Synacthen® test, but patients with a mixed hetero- and homozygote genotype were not

Exclusion Criteria:

• Other major organ disease
• Females pregnant
• Females not willing to pause estrogen-containing medications 6 weeks prior to Synacthen® test
• unable to give a written informed content