The effect of tumor necrosis factor-α inhibitor on bone mineral density of active rheumatoid arthritis patients with low bone mass / 中华风湿病学杂志

ABSTRACT

Objective To explore the effect of tumor necrosis factor (TNF)-α inhibitors therapy on bone mineral density (BMD) in active rheumatoid arthritis (RA) patients with low bone mass.Methods Sixtytwo active RA patients with low bone mass were treated with a standard treatment of calcium carbonate 0.5 g/d and alfacalcidol 0.25 μg/d,and were divided into two groups.Patients of the control group were treated with methotrexate 10 mg per week,while patients of the experimental group were treated with combined recombinant human type Ⅱ tumor necrosis factor receptor-antibody fusion protein 50 mg per week or adalimumab 40 mg/2 week subcutaneously for 12 months with methotrexate.BMD of lumbar spine (L2-4),femoral neck,trochanter and Ward's triangle region by dual energy X-ray absorptiometry (DEXA),as well as the bone turnover markers serum C telopeptide of type-Ⅰ collagen (CTX-Ⅰ) and serum procollagen type-Ⅰ N propeptide (PINP) were measured by enzyme-linkedimmunosorbent assay (ELISA) in both groups at the baseline,treatment for six-month and twelve-month.T test and Chi-square test was used to process the data.Results ① After 6 months of treatment,the BMD of lumbar spine,femoral neck and trochanter in the group with TNF-α inhibitors were higher than the control group [(0.68±0.08) g/cm2 vs (0.65±0.06) g/cm2,t=2.269,P=0.027; (0.63±0.08) g/cm2 vs (0.58±0.09) g/cm2,t=2.111,P=0.040; (0.61±0.10) g/cm2 vs (0.56±0.07) g/cm2,t=2.203,P=0.032; respectively].And after 12 months,the BMD of all regions were significantly higher thanthe control group [spine,(0.68±0.07) g/cm2 vs (0.62±0.08) g/cm2,t=5.115,P=0.000; femoral neck,(0.63±0.08)g/cm2 vs (0.56±0.08) g/cm2,t=3.475,P=0.001; Ward's triangle region (0.60±0.08) g/cm2 vs (0.56±0.08) g/cm2,t=2.309,P=0.025; trochanter,(0.61±0.10) g/cm2 vs (0.53±0.08) g/cm2,t=3.254,P=0.002; respectively].② Compared to the baseline,BMD of lumbar spine was significantly decreased in the control group after 12 months.While in the group of TNF-α inhibitors,BMD of lumbar spine was increased[(0.66±0.08) g/cm2 vs (0.68±0.07)g/cm2,t=3.411,P=0.001].③ Compared to the baseline,CTX-Ⅰ,a marker of bone resorption was significantly decreased at 6 months and 12 months in the group with TNF-αinhibitors [6 months,(0.33±0.2) ng/ml vs (0.46±0.22) ng/ml,t=5.548,P＜0.01; 12 months,(0.31±0.21) ng/ml vs (0.46±0.22) ng/ml,t=5.974,P＜0.01],while this decline was not found in the control group.PINP,a marker of bone formation was stable in both 2 groups during the study.Conclusion In active RA patients with low bone mass,loss of BMD in the spine and hip can be arrested by the treatmentof TNF-α inhibitors.