The Effect of TNF Blockade on Bone Loss in Early Rheumatoid Arthritis

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The Effect of TNF Blockade on Bone Loss in Early Rheumatoid Arthritis

Category:  17 RA‹treatment

Mark Quinn

University of Leeds, Leeds, United Kingdom

Presentation Number: 1387

Poster Board Number: 342

Keywords: TNF, Bone, Loss

Background: Osteoporosis is a known complication in rheumatoid arthritis

(RA) and occurs early in the disease process. Treatment with the TNFalpha

inhibitor infliximab is effective in controlling inflammation in RA. The aim

of this double blind randomised controlled study was to evaluate the effect

of infliximab suppression of inflammation on the bone mineral density (BMD)

of patients with new onset RA.

Methods: 20 patients (7 males, 13 females) with early RA (disease < 12

months) were commenced on methotrexate (MTX) and randomised to infliximab 3

mg/kg body weight (n=10) or placebo (n=10). Demographic and clinical date

were collected at baseline and after 54 weeks. Total hand, hip (femoral

neck, total hip) and spine (L2-L4) bone mineral density (BMD) were assessed

at baseline and week 54 using by dual x-ray absorptiometry (DXA). Short-term

in-vivo precision was 1.07% for total hand, 1.43% for total hip, 2.89% for

femoral neck and 2.42% for spine L2-4. The long-term spine phantom precision

for the whole study period was 0.80%. We used paired and independent

Students t-test for continuous variables and McNemars test for categorical

variables where appropriate.

Results: There were no significant baseline differences between treatment

groups for clinical (age, gender, weight, height, physician and patient

global assessments, TJC, SJC, HAQ, ESR, CRP) and all BMD outcomes. In the

infliximab treated group BMD loss was less than in the placebo treated group

as shown in the table below displaying mean (95% CI) percentage BMD

reductions. A statistically significant difference between the treatment and

the placebo group was found only at the hip (*p <0.05).

    Hand Fem. neck* Total hip* Spine L2-4

TNF ɢ% BMɢ (ɥI) -2.2%

(-4.6, +0.1) -0.3%

(-1.4, +0.7) -0.2%

(-1.4, +0.9) -0.8%

(-5.2, +3.5)

Placebo ɢ% BMɢ (ɥI) -2.8%

(-7.8, +2.2) -3.4%

(-5.6, -1.3) -2.6%

(-4.5, -0.8) -1.8

(-6.7, +3.2)

Conclusions: Treatment with TNF blockade in early RA patients protects

against bone loss at the hip but not at the hand. This may reflect different

osteoclast-related mechanisms for bone loss at different sites.