Objective: To determine the relationship between inflammation and glucocorticoid metabolism in vivo, in a clinical study of patients with inflammatory arthritis treated with anti-TNFα therapy.
Methods: Urine samples were collected from patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA) as part of a multicentre study assessing responses to infliximab and etanercept. Systemic measures of glucocorticoid metabolism were assessed by gas chromatography/mass spectrometry at weeks 0 (baseline), 4 and 12 after anti-TNFα therapy. Clinical data including DAS28 and C-reactive protein were also collected.
Results: Systemic measures of 11β-HSD1 activity in patients with inflammatory arthritis decreased significantly following anti-TNFα therapy in patients with RA and PsA. Additionally, the activity of the glucocorticoid inactivating enzyme 5α-reductase appeared to increase significantly.
Conclusions: This study demonstrates, for the first time, that the increased 11β-HSD1 activity seen in patients with inflammatory arthritis is mediated through TNFα. Furthermore, the changes in related glucocorticoid metabolising enzymes suggest that there is a coordinated change in glucocorticoid metabolism which promotes higher tissue glucocorticoid levels.
Keywords: Anti-TNF; Corticosteroids; Psoriatic Arthritis; Rheumatoid Arthritis.
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