Abstract
Purpose :
In a recent clinical trial of IFNα in Behçet’s Disease (BD), disease control on lower doses of corticosteroids was associated with an increase in peripheral blood regulatory T cells (Treg) and a decrease in CD4+IL-17+ (Th17) levels. At baseline, most BD with ocular involvement patients were receiving corticosteroids, and in this study we determined whether there was a correlation between corticosteroid dose, Treg and Th17 cells.
Methods :
21 BD patients with ocular involvement who required systemic treatment with steroids were recruited to the trial at one centre. Peripheral blood samples were stained with fluorochrome-conjugated antibodies for flow cytometry. Whole blood was cultured overnight, either unstimulated, or stimulated with anti-CD3/CD28 mAb, or PMA/ionomycin with brefeldin A, then stained for surface and intracellular markers. Statistical analyses were performed using SPSS with Spearman rank correlation test to compare the dose of corticosteroid with CD4+CD25+FoxP3+, CD4+CD25+FoxP3+IL-10+, and CD4+IL-17+ expression. A P value of <0.05 was significant.
Results :
There was a positive correlation (correlation coefficient=0.816, P=0.001) between corticosteroid dose (10mg/d, IQR 7.5-15) and IL10+FoxP3+CD4+CD25+ (0.01%, IQR 0-0.10%). IL10+FoxP3+ expression within CD4+T cells in response to anti-CD3/28 stimulation had a significant positive correlation with corticosteroid dose (correlation coefficient=0.774, P=0.003). However, the level of FoxP3 expression within the CD4+ or CD4+CD25+ populations did not correlate with corticosteroid dose. IL-17+CD4+cell levels (0.50%, IQR 0.37%-1.02%) were not significantly decreased by increasing corticosteroid dose (11mg/d, IQR 5-25), although there was a trend towards a negative correlation.
Conclusions :
Corticosteroid dose positively correlated with IL-10 and FoxP3 co-expression within CD4+CD25+ and CD4+ T cells, but did not change the frequency of Th17 cells. FoxP3 expression alone or percentages of Treg did not correlate with corticosteroid dose.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.