Abstract
Background. Bone loss in ankylosing spondylitis may be related to inflammation. Data from previous studies on circulating levels of sRANKL, OPG, MMP3, and TIMP is inconsistent; thus this study is planned to look at this aspect in Asian Indian patients. Methods. Cross-sectional study included patients with ankylosing spondylitis and age- and gender-similar controls. Serum levels of sRANKL, OPG, MMP-3, and TIMP-1 were measured by ELISA. Results. Included 85 patients (M : F = 82 : 3) having mean age (±SD) 33.0 ± 10.0 years and disease duration 11.3 ± 7.3 years. BASDAI, BASFI, BASMI, and ESR were 4.0 ± 2.2, 3.9 ± 2.8, 3.0 ± 2.8, and 59.2 ± 31.2, respectively. Patients had higher mean (±SD) OPG level (649.7 ± 286.8, 389.3 ± 244.8 pg/mL, P < 0.001). However, there was no difference in sRANKL (349.2 ± 872.0, 554.7 ± 1850.1, P = ns). Serum MMP-3 (91.4 ± 84.7, 55.9 ± 37.1 ng/mL, P < 0.01) and TIMP-1 (520.6 ± 450.7, 296.5 ± 114.2 ng/mL, P < 0.001) levels were higher in patients; however, there was no difference in MMP-3/TIMP-1 ratio. Conclusion. Circulating levels of OPG were higher; however, there was no difference in sRANKL in Asian Indian ankylosing spondylitis patients. Although both MMP-3 and TIMP-1 were raised, their ratio was not different from that of controls.