Background The TCZ treatment for RA is known that there is a discrepancy within DAS remission and SDAI remission rate cause by the weight of gravity of acute phase reactants.
Especially TCZ strongly inhibits CRP which produced by the liver through the IL-6. Therefore even if we meet to the DAS remission; we come across the cases occasionally who have not been sufficiently suppressed clinically. Considering this, we examined the difference of background factors which to meet the SDAI remission in addition to the DAS remission.
Objectives To compare the patients with TCZ who showed only DAS28-ESR remission and both DAS28 (ESR) and SDAI remissions.
Methods Subjects were patients who met DAS28-ESR remission criteria after 6 months of TCZ therapy. Patients who showed only DAS28 (ESR) remission were compared with those with both DAS28 (ESR) and SDAI remission. Age, sex, disease duration, disease stage, anti- cyclic citrullinated peptide (CCP) antibody, quantitative rheumatoid factor(RF), Matrix Metalloproteinase (MMP)-3, tender joints, swollen joints, Visual analogue scale(VAS), Erythrocyte Sedimentation Rate (ESR), C-reactive protein (CRP), Disease activity score (DAS), Simplified disease activity index(SDAI), Modified health assessment questionnaire (mHAQ), Prednisolone(PSL) and Methotrexate(MTX) dosage were compared. Statistical analysis was by Fisher’s exact test and Wilcoxon rank test.
Results After 6 months, 31 patients met DAS remission criteria. Of these, 8 showed DAS remission only, and 23 also showed SDAI remission. At the start there were no statistically significant differences between groups in sex ratio, age, disease duration, MMP-3, tender joints, swollen joints, VAS, ESR, CRP, mHAQ, PSL and MTX use (respectively 50% vs. 39.1%, 37.5% vs. 60.9%) and dosage (respectively 5.50±3.11mg vs. 3.95±2.01mg, 6.83±3.33mg vs. 7.00±1.04mg). Statistically significant differences at start were seen in anti-CCP antibody, quantitative RF and DAS (p=0.005, p=0.02, p=0.006, respectively). After multivariate analysis of these three for DAS/SDAI remissions, only anti-CCP antibody remained (p=0.005). Anti-CCP antibody in DAS remission and DAS/SDAI remissions was 8.30±8.65 and 84.3±72.9, and patients with high value of anti-CCP antibody tended to achieve SDAI remission.
Conclusions There have been reported that the ACPA itself would become the factor to enhance the inflammation of RA recently.(1) The possibility of relation between citrullination and the occurrence of ACPA positive RA. ACPA itself promotes the activation of complement system and furthermore, it causes the proinflammatory cytokine production, and this cause the inflammatory cycle which is called the RA cycle. Take into account the above information, the high ACPA case have strong proinflammatory cytokine production and it suggests that there are high IL-6 value. In this regards we can infer that TCZ might have stronger effect for high ACPA case. Anti-CCP antibody is likely a factor related to DAS/SDAI remissions in TCZ therapy.
Walther J van Venrooji et al. Anti-CCP antibodies: the past, the present and the future. Nat. Rev. Rheumatol. 7, 391-398: 2011.
Disclosure of Interest None Declared