[Effect of tumour necrosis factor α blockade on bone metabolism in chronic inflammatory joint diseases]

To evaluate the effect of anti-TNF treatments on bone mineral density (BMD), bone remodelling markers (BRM) and receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) in patients with chronic inflammatory joint diseases.

A longitudinal prospective study was performed under clinical practice conditions on 31 patients diagnosed of rheumatoid arthritis, psoriatic arthropathy and ankylosing spondylitis who had received treatment with anti-TNF alpha drugs for one year. BMD, OPG and RANKL soluble form (sRANKL) were studied at the onset and end of the study. During the study (0, 3, 6, 9 and 12 month), disease activity (SDAI, BASDAI and CRP), functional capacity (HAQ, BASFI), BRM and vitamin D were studied.

BMD was not modified after one year of treatment. The patients who took corticosteroids had a mean bone mass loss of 3% in the lumbar spine (±1.6, P=.02). In regards to the BRM, did not experience significant changes over the course of the study. Disease activity, both SDAI (P=.002) and BASDAI (P=.002), decreased. OPG was maintained without changes during the year of treatment while both the sRANKL (0.28±0.22, P=.013) and sRANKL/OPG ratio significantly decreased (0.04±0.03, P=.031).

The patients being treated with anti-TNF did not present with a significant loss of DMO during the study (one year), at the same time experiencing an improvement in disease activity. This protection has been clearer in the responding patients.