Background/Purpose:

Recent reports have shown that positivity for rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) can influence the efficacy of rheumatoid arthritis (RA) treatment. Additionally, RF⁺ and ACPA⁺ statuses were emphasized in the revised ACR–EULAR Classification Criteria for Rheumatoid Arthritis. This study examined whether RF⁺ and ACPA⁺ statuses in patients with RA impacted the clinical efficacy of anti-TNF-α or anti-IL-6 therapy.

Methods:

We retrospectively evaluated 235 patients with RA who were observed through 52 weeks of follow-up after infliximab (IFX) or tocilizumab (TCZ) treatment at our hospital and related facilities (IFX, n = 142; TCZ, n = 93). Clinical efficacy was assessed based on a 28-joint disease activity score using erythrocyte sedimentation rate (DAS28-ESR) remission and achievement of Boolean-based remission criteria and its components (≤1) at 52 weeks after initiating treatment.

Results:

Before treatment, DAS28-ESR score in IFX and TCZ groups was 6.6 ± 1.5 and 6.5 ± 1.3, respectively. The proportion of RF⁺ and ACPA⁺ patients was 79.6% and 81.7% in the IFX group and 79.6%, and 87.1% in the TCZ group, respectively. The proportion of patients concomitantly treated with MTX was 100% in the IFX group and 55% in the TCZ group (p < 0.0001); the proportion of patients previously treated with biological products was 0% in the IFX group and 56% in the TCZ group (p < 0.0001). Among patients who achieved remission at 52 weeks in the IFX group, DAS28-ESR remission was seen in 36% and 59% RF⁺ and RF⁻ patients (p = 0.02), respectively, and in 36% and 62% ACPA⁺ and ACPA⁻ patients, respectively (p = 0.01). TJC ≤1 was seen in 60% and 89% ACPA⁺ and ACPA⁻ patients, respectively (p = 0.005) and SJC ≤1 was seen in 60% and 85% ACPA⁺ and ACPA⁻ patients, respectively (p = 0.01). The proportion of patients who achieved remission was significantly lower in RF⁺ and ACPA⁺ patients. In the TCZ group, no efficacy index between RF⁺ and RF⁻ patients or between ACPA⁺ and ACPA⁻ patients significantly correlated with remission. Correlations between pretreatment patient demographics and achievement of DAS28 remission at 52 weeks were evaluated. In the IFX group, patients who achieved no remission had higher CRP levels (3.0 vs. 1.9 mg/dL; p = 0.0007), higher disease activity by DAS28-ESR (6.8 vs. 6.2; p = 0.01), and a significantly higher RF⁺ (86% vs. 71%; p = 0.02) and ACPA⁺ rates (88% vs. 72%; p = 0.01) than those who achieved remission. However, similar differences were not observed in the TCZ group. A multivariate logistic regression analysis was performed to identify factors related to non-remission at 52 weeks after initiating treatment. DAS28-ESR (OR, 2.24; 95% CI, 1.52–3.47; p = 0.0001) and ACPA⁺ (OR, 2.82; 95% CI, 1.19–6.97; p = 0.04) were identified as related factors in the IFX group; however, no factors were identified for the TCZ group.

Conclusion:

RF⁺ and ACPA⁺ statuses are likely to be risk factors that affect the clinical efficacy of IFX treatment but not TCZ treatment.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/positivity-of-rheumatoid-factor-and-anti-cyclic-citrullinated-peptide-is-associated-with-the-response-rate-of-infliximab-but-not-tocilizumab-in-treatment-of-rheumatoid-arthritis/