Background/Purpose: Progressive bone destruction occurs in rheumatoid arthritis (RA) due to imbalance of osteoblast/osteoclast activity. Bone morphogenetic proteins (BMPs) regenerate bone damage by stimulating the differentiation of osteoblasts. Effects of BMPs and their inhibitors in the mechanism of bone destruction have not been identified yet. The aim of this 1 year follow-up prospective study which preliminary results were presented as poster in 2015 ACR Congress is to compare plasma levels of BMP 2, 3, 4, 5, 6, 7, 9, 14, noggin, sclerostin in RA patients and healthy volunteers and to assess correlations of these proteins with disease activity, clinical and radiographic progression in RA.

Methods: 138 RA patients (Group 1=85 using DMARDs, Group 2=53 using anti-TNFα) fulfilling the 1987 ACR criteria and 80 healthy volunteers aged 18-65 years were recruited. All groups were matched by age and sex. 125 RA patients (Group1=77, Group2=48) reached to the end of study. Tender/swollen joint, ESR, CRP, DAS28-ESR, DAS28-CRP, pain and HAQ were evaluated. Structural damage was measured by modified total Sharp scoring method (mTSS). Plasma levels of BMPs, noggin and sclerostin were measured by ELISA method. Measurement of BMPs and their inhibitors, HAQ, mTSS and clinical assessment were repeated 1 year later in patient groups. Differences between group 1 and 2 were compared by Mann-Whitney U test. Baseline and 1-year datas were compared by Wilcoxon test. P value of 0.05 was considered statistically significant.

Results: Disease duration was statistically longer in anti-TNFα group (p=0.005). In our preliminary results plasma levels of BMP 2, 4, 5, 6, 7, 9, 14 were decreased; however, BMP subgroup inhibitors which are BMP 3, noggin and sclerostin were increased in RA patients. Also, the correlation between BMP 2,5, 14, sclerostin and disease activity scores were statistically significant in DMARD group. In 1 year follow-up datas BMP 2, 3, 4, 5, 7, 9, 14 were statistically significant in DMARD group and BMP2, 3, 7 and 9 were statistically significant also in anti-TNFα group when compared with the plasma levels of healthy volunteers. The comparison of basal and 1 year follow-up BMPs are shown in table 1. There was no correlation between BMP subgroups and HAQ, erosion scores, DAS28-ESR, DAS28-CRP in both of the patient groups in 1 year follow-up datas.

Conclusion: These results imply the relevance of BMPs and their inhibitors mainly with early diagnosis of RA rather than follow-up and prognosis.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/plasma-levels-of-bone-morphogenetic-protein-bmp-subgroups-and-their-inhibitors-noggin-sclerostin-in-rheumatoid-arthritis-patients-and-correlation-with-disease-activity-clinical-and-radiographic-2/