Membrane glucocorticoid receptor expression on peripheral blood mononuclear cells in patients with ankylosing spondylitis.

Abstract

To investigate the expression of membrane glucocorticoid receptors (mGCR) on peripheral blood mononuclear cells (PBMC) in patients with ankylosing spondylitis (AS). We used high sensitivity immunofluorescence with magnetofluorescent liposomes for the detection of mGCR on PBMC from patients with AS (n = 26) and healthy controls (n = 11). The frequency of mGCR+ monocytes and B lymphocytes was significantly higher in patients with AS than in controls (monocytes 12.5 +/- 9.9% vs 4.8 +/- 1.4%, B lymphocytes 8.7 +/- 6.3% vs 4.4 +/- 3.6%). We did not find mGCR on T lymphocytes. The frequency of mGCR+ cells did not correlate with variables of AS disease activity [C-reactive protein, erythrocyte sedimentation rate, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), BASDAI 6, or numerical rating scales]. mGCR are upregulated in monocytes and B lymphocytes of patients with AS. This upregulation does not correlate with the humoral or overall disease activity. mGCR are not present on T lymphocytes. Our findings may be related to the limited benefit of low-dose and the efficacy of high-dose (intravenous pulse or intraarticular) glucocorticoid treatment in AS. Drugs binding selectively to mGCR may be a new therapeutic option for AS.