Upregulated Cellular Expression of IL-17 by CD4+T-Cells in Osteoporotic Postmenopausal Women

Aim: The study aimed to investigate cellular expression of IL-17 by CD4+ T-cells in osteoporotic postmenopausal women. Methods: We enrolled 25 postmenopausal women with osteoporosis (PostMO) and 25 postmenopausal women with normal bone mineral density measurements (PostM) to examine the production of IL-17, tumor necrosis factor alpha (TNF alpha) and receptor activator of nuclear factor K-B ligand (RANKL) by CD4+ T-cells and IL-17, ROR gamma t, TNF alpha and RANKL mRNA levels in CD4+ T-cells. Circulating concentrations of IL-17 along with IL-6, TNF alpha, RANKL and osteoprotegerin (OPG) were also determined. Results: Osteoporotic postmenopausal women had higher serum concentrations of IL-17 (3.7 +/- 1.3 vs. 2.5 +/- 1.1 ng/ml, p = 0.042), IL-6 (158 +/- 56 vs. 105 +/- 39 pg/ml, p = 0.044), TNF alpha (138 +/- 41 vs. 74 +/- 11 pg/ml, p < 0.001) and OPG (1.7 +/- 0.4 vs. 1.3 +/- 0.4 ng/ml, p = 0.039) than healthy controls. The IL-17-producing CD4+ T-cells were higher in the PostMO group than in the PostM group (7.1 +/- 2.4 vs. 4.9 +/- 1.4%, p = 0.0015). Additionally, osteoporotic postmenopausal women had greater mRNA levels of IL-17 (3.5 +/- 2.9 vs. 1.2 +/- 1.0%, p = 0.019) and ROR gamma t (5.7 +/- 2.5 vs. 2.2 +/- 1.0%, p < 0.001) in CD4+ T-cells than in healthy controll. Conclusions: Our findings implied that the upregulated production of IL-17 may play an important role in regulating bone loss in osteoporotic postmenopausal women. (C) 2016 S. Karger AG, Basel