Background: The availability of rituximab (RTX) for the treatment of rheumatoid arthritis (RA) as rescue approach after DMARDs or TNF-α blockers failure, makes important to single out clinical and biologic features that could distinguish patients with a better chance of responding to B cell depletion. Objectives: To examine baseline clinical and biological characteristics that could better predict the efficacy of RTX in a cohort of RA patients after 12 months follow-up (FU). Methods: 51 RA patients not responders to DMARDs and/or TNF-α blockers underwent RTX treatment. Each patient received at baseline two infusions, two weeks apart (1g at day 1 and 15). Re-treatment was considered after at least 24 weeks in those patients who presented clinical relapse or residual disease activity. Clinical, immunological and laboratory data were recorded at baseline and every 3 months. The EULAR response criteria based on DAS were used to assess disease activity (DAS<2.4: low disease activity). At the time of analysis 34 patients had reached the 12 months FU(T12). Results: The mean patients age at baseline was 58±12 years, and the mean disease duration was 13±10 years. 31 patients (60.8%) had received previous treatment with TNF-α blockers, 22 of them (71%) had withdrawn because of lack of efficacy. 34 (66.7%) received concomitant MTX and 30 (58.8%) were in daily oral steroid therapy. 27 (52.9%) and 37 (72.5%) of patients were positive for anti-CCP and rheumatoid factor (RF), respectively. 13 (25,5%) were IgA RF positive and 23 (45,1%) were IgM RF positive. Seronegative patients were 7 (13.7%). Mean basal DAS was 4.2±1.4, while mean basal HAQ was 1,57±0,92. At T12 analysis, 16/34 patients (47%) reached a DAS≤2.4(good responders), while 18 (53%) had a DAS>2.4(poor responders). Baseline characteristics that could distinguish the two subgroups of patients were represented by different levels of RF (961.3±794.2 vs 189.7±303.1 in poor responders, p=0.005) and CRP (13.4±11.8 vs 26.4±17.9, p=0.03). Furthermore, among good responders, a higher percentage of patients positive for IgA RF (50.0% vs 11.1%, p=0.01) and/or IgM RF (68.8% vs 33.3%, p=0.04) was found. Logistic regression analysis revealed as baseline factors predictive of efficacy the following:IgA RF>20 U/ml (OR: 35.7-95%CI: 1.51-843.70), IgM RF>20 U/ml (OR: 13.8, 95%CI: 1.0-199.9), CRP>5mg/l (OR: 0.05-95%CI: 0.03-0.70) and HAQ>1.5 (OR:0.06-95%CI: 0.01-0.77). Using as cut-off level for IgM RF 30U/ml its predictivity increased (OR: 47.7, 95%CI: 2.1-1089.0). Moreover, RF revealed to be predictive when the 40U/ml cut-off was considered (OR=38.5-95% CI:2.1-711). Conclusion: In our cohort of RTX treated RA patients the best predictor of long term efficacy was represented by the positivity for IgA RF along with a low level of CRP and a low disability at baseline.
B-cell depletion in rheumatoid arthritis: searching for serologic and clinical baseline factors that could predict long-term efficacy
Gremese E;
2010-01-01
Abstract
Background: The availability of rituximab (RTX) for the treatment of rheumatoid arthritis (RA) as rescue approach after DMARDs or TNF-α blockers failure, makes important to single out clinical and biologic features that could distinguish patients with a better chance of responding to B cell depletion. Objectives: To examine baseline clinical and biological characteristics that could better predict the efficacy of RTX in a cohort of RA patients after 12 months follow-up (FU). Methods: 51 RA patients not responders to DMARDs and/or TNF-α blockers underwent RTX treatment. Each patient received at baseline two infusions, two weeks apart (1g at day 1 and 15). Re-treatment was considered after at least 24 weeks in those patients who presented clinical relapse or residual disease activity. Clinical, immunological and laboratory data were recorded at baseline and every 3 months. The EULAR response criteria based on DAS were used to assess disease activity (DAS<2.4: low disease activity). At the time of analysis 34 patients had reached the 12 months FU(T12). Results: The mean patients age at baseline was 58±12 years, and the mean disease duration was 13±10 years. 31 patients (60.8%) had received previous treatment with TNF-α blockers, 22 of them (71%) had withdrawn because of lack of efficacy. 34 (66.7%) received concomitant MTX and 30 (58.8%) were in daily oral steroid therapy. 27 (52.9%) and 37 (72.5%) of patients were positive for anti-CCP and rheumatoid factor (RF), respectively. 13 (25,5%) were IgA RF positive and 23 (45,1%) were IgM RF positive. Seronegative patients were 7 (13.7%). Mean basal DAS was 4.2±1.4, while mean basal HAQ was 1,57±0,92. At T12 analysis, 16/34 patients (47%) reached a DAS≤2.4(good responders), while 18 (53%) had a DAS>2.4(poor responders). Baseline characteristics that could distinguish the two subgroups of patients were represented by different levels of RF (961.3±794.2 vs 189.7±303.1 in poor responders, p=0.005) and CRP (13.4±11.8 vs 26.4±17.9, p=0.03). Furthermore, among good responders, a higher percentage of patients positive for IgA RF (50.0% vs 11.1%, p=0.01) and/or IgM RF (68.8% vs 33.3%, p=0.04) was found. Logistic regression analysis revealed as baseline factors predictive of efficacy the following:IgA RF>20 U/ml (OR: 35.7-95%CI: 1.51-843.70), IgM RF>20 U/ml (OR: 13.8, 95%CI: 1.0-199.9), CRP>5mg/l (OR: 0.05-95%CI: 0.03-0.70) and HAQ>1.5 (OR:0.06-95%CI: 0.01-0.77). Using as cut-off level for IgM RF 30U/ml its predictivity increased (OR: 47.7, 95%CI: 2.1-1089.0). Moreover, RF revealed to be predictive when the 40U/ml cut-off was considered (OR=38.5-95% CI:2.1-711). Conclusion: In our cohort of RTX treated RA patients the best predictor of long term efficacy was represented by the positivity for IgA RF along with a low level of CRP and a low disability at baseline.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
