Bone Abstracts

Background: The activity of rheumatoid arthritis (RA) is the one of the significant reasons of the increase of bone resorption and decrease of bone mineral density (BMD). The control of activity of inflammatory process with biologics (including rituximab – anti-CD20 antibodies) can be considered as possibility of decrease in bone resorption and BMD stabilization.

Objectives: To access the dynamics of BMD after 24 months of treatment with rituximab in RA patients RA.

Methods: Retrospective study of a cohort of RA patients (33 women and four men), mean (S.D.) age at the beginning of rituximab treatment 48.8±14.2 years, mean duration of disease 9.1±7.1 years. The high activity of RA (DAS-28) was in 34 (92%), moderate – 3 (8%) patients. BMD was assessed in all patients at the beginning of therapy with rituximab and 24 months after by dual energy X-ray absorptiometry (DXA) on one Hologic «DiscoveryA» at least in one of following sites: lumbar spine(L1-L4) (n=26), hip neck (n=19) and left forearm (n=7).

Results: Mean BMD L1-L4 before\after the treatment with rituximab was 0.947±0.164 and 0.971±0.133 g/cm², at hip neck 0.759±0.110 and 0.725±0.119 g/cm², at forearm 0.493±0.084 and 0.449±0.090 g/cm² respectively. Distinctions are not revealed. The analysis of BMD loss/increase in 24 months showed that the increase of BMD was occurred respectively: at L1-L4 in 15 patients (0.947±0.164 and 0.971±0.133 g/cm²), at hip neck – in eight (0.765±0.098 and 0.787±0.096 g/cm²). The loss of BMD respectively at L1-L4 was occurred in 11 patients (1.027±0.150 and 0.986±0.141 g/cm²), at hip neck – in 11 patients (0.755±0.122 and 0.680±0.117 g/cm²), at forearm in seven patients (0.493±0.084 and 0.449±0.090 g/cm²) – with not significant results.

Conclusions: It was obtained no significant evidence of BMD loss or increase in patients with high activity of RA, taking rituximab within 24 months, nevertheless the BMD remained stable. Studying of a contribution of other factors, which influence on BMD change, requires more careful analysis.