Endocrine Abstracts

IL17 proinflammatory cytokine through T cell activation has prominent bone-wasting effect. Our previous results highlighted the role of IL17 in postmenopausal osteoporosis. To demonstrate the HLA allele association with the increased IL17 levels in postmenopausal osteoporosis was the object of the study.

HLA class I and II alleles were measured in 64 postmenopausal women (in four subgroups: with low IL17 (1, 3) and high (>3.04 pmol/l) IL17 levels (2, 4) with osteopenia and osteoporosis) by PCR technique. IL17 levels and bone mineral density (BMD) with T-score values in lumbar region (osteopenia: >−1 and <−2.5; osteoporosis: <−2.5) were detected with ELISA and dual energy X-ray absorptio-metry (DXA) using Hologic Discovery Wi, respectively. Allele frequencies on five loci were calculated with Arlequin software and 2×2 crosstabs for χ², and Fischer’s exact tests were performed with SPSS Software.

The IL17 levels were as follows in osteopenic subgroups (1 and 2): 2.91±0.12 ng/ml, n=8 and 3.48±0.38 ng/ml, n=15; in osteoporotic subgroups (3 and 4): 2.85±0.12 ng/ml, n=6 and 3.79±0.55 ng/ml, n=35). The results gave significant difference in Cw*01 and Cw*15 HLA class I allele frequencies (AF%) between osteoporotic women with high (4) and low (3) IL17 levels (AF% 1.4 vs 25%, P<0.009 for Cw*01 and AF% 0 vs 16.67%, P<0.02 for Cw*15 by Fischer exact test).

In conclusion, our findings suggested that increased IL17 levels can accelerate the bone-wasting in postmenopausal osteoporosis. Postmenopausal osteoporotic women with increased frequency of Cw*01 and Cw*15 HLA alleles showed significant lower IL17 levels compared with those who had these alles in decreased frequency on C locus. The presence of Cw*01 and Cw*15 HLA class I alleles played preventing role in the increase of IL17 in hungarian osteoporotic women.