Bone Abstracts

The problem of early diagnosis of rheumatoid arthritis remains an important area of research in rheumatology. We investigated changes in bone metabolism, bone mineral density in early rheumatoid arthritis (ERA; up to 12 months). Data were compared with changes in the MRI study of the dominant hand.

We observed 24 patients with ERA, the average age – 33.6±5.7 years. The men were 6 (25%), women – 18 (75%). Bone mineral density (BMD) was determined by DXA «Challenger» (DMS, France). Measurements of urinary pyridinoline (PYD) and deoxypyridinoline (DPD) and osteocalcin (OC) were performed. MRI of the dominant hand was performed in 24 patients, fulfilling the American College of Rheumatology criteria for RA. The MRI protocol consisted of fat – suppressed T2, and plain and contrast enhanced T1-weighted sequences. Assessment of bone marrow edema, synovitis and bone erosions was performed by the OMERACT RA MRI scoring system. Clinical assessment was evaluated using the disease activity score for 28 joint indices (DAS-28).

We found a significant increase in PYD and DPD and no changes of the OC level in the ERA patient’s. The severity of inflammation and the number of inflamed joints by DAS28 score was associated with increased excretion of PYD and DPD, but not to the level of OC. Decrease BMD in the wrist and radius was observed in all patients. BMD correlated with markers of formation and resorption, as well as high rates of disease activity on DAS28. MRI of the dominant hand in patients with ERA in scoring (quantitative) assessment identified by OMERACT synovitis (all patients), bone marrow edema (all patients) and erosions (16 patients – 66.7%). Identification of synovitis and erosions on MRI correlated with high disease activity, decreased BMD. The appearance of bone erosions was associated with a slight decrease in OC and increased excretion of PYD and DPD.

These data emphasize the early increase in the activity of bone resorption markers with the absence of reducing the activity of bone formation markers in early rheumatoid arthritis. Changes in bone metabolism with an increased resorption correlate with disease activity and detection of erosions on MRI.