Background Treatment for rheumatoid arthritis has become to obtain remission as biologics are widely used. Nonetheless, the main target of the treatment is synovitis and evaluation and treatment for osteoporosis with RA are not enough even though these patients have got remission.
Objectives Our purpose is to investigate effects on bone metabolism of anti-TNF-α Biologics and bisphosphonates (BPs) among patients with rheumatoid arthritis (RA).
Methods We selected 18 cases of patients with RA who received BPs for the first time and investigated effects on bone metabolism of BPs after 6 months. Moreover, 40 cases of patients with RA who already took BPs more than 6 months (BPs group) and 40 cases of those who received BPs and anti-TNF-α Biologics (BPs+anti-TNF-α group) were subjected to this study as well. We investigated bone resorption markers (N-telopeptide of type 1 collage (NTX), tartrate-resistant acid phosphatase (TRACP) 5b), bone formation markers (bone specific alkaline phosphatase (BAP), osteocalcin), cartilage metabolic markers (matrix metalloproteinase (MMP)-3, cartilage oligometric matrix protein (COMP)), bone mineral density (BMD) and inflammatory situation with ESR, CRP, DAS28 (ESR) and DAS28 (CRP).
Results BPs significantly decreased bone resorption marker such as NTX (22% decrease change, P<0.01) and TRACP 5b (50% decrease change, P<0.001). BPs also significantly suppressed bone formation markers such as BAP (52% decrease change, P<0.01) and osteocalcin (33% decrease change, P<0.01). These data indicate BPs led to low bone turn over. Additionally, BPs significantly increased lumbar BMD (3% increase change, P<0.05). Between the BPs and BPs+anti-TNF-α group, COMP is significantly lower in BPs+anti-TNF-α groups than BPs group (BPs group: 915.5±298.0, BPs+anti-TNF-α groups: 804.2±357.9, P<0.05) at the baseline data. Moreover, CRP of BPs+anti-TNF-α group is significantly lower than that of BPs group (BPs group 0.8±0.9, BPs+anti-TNF-α groups: 0.64±1.0, P<0.05). Percent change of MMP-3 during 6 months was significantly reduced among BPs+anti-TNF-α group compare to BPs group (BPs group: 10.7±41.3, BPs+anti-TNF-α groups: -28.6±39.4,P<0.001).Other biomarkers such as NTX, TRACP5b, BAP, osteocalcin and BMD did not change significantly during 6months among these 2 groups.
Conclusions We confirmed administration of BPs led to low turnover in patients with RA. Several papers showed anti-TNF-α Biologics decrease bone resorption markers such as NTX and CTX and that do not change or decrease bone formation markers and BMD1,2. Nevertheless, there is no report to investigate BPs group and BPs+anti-TNF-α group while lots of patients with RA take BPs due to osteoporosis. There was no further suppression of osteoclast activity when we administered both BPs and anti-TNF-α Biologics compared to BPs alone. In addition, our data suggested that anti-TNF-α Biologics treatment for patients with RA has a posibility of indirect suppression of cartilage destruction.
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Yasunori K et al. Reduction of urinary levels of pyridinoline and deoxypyridinoline and serum levels of soluble receptor activator of NF-kappa B ligand by etanercept in patients with rheumatoid arthritis. Clin Rheumatol. 27(9):1093-101. 2008
Disclosure of Interest None declared