Table 2 Baseline and follow-up characteristics of rheumatoid factor and antibodies against CCP isotypes for responders and non-responders to RTX, respecting baseline seropositivity, mean titers and their relative changes upon RTX treatment
50 RA patients upon RTX treatment | RRs (n = 37) | NRRs (n = 13) | ||
|---|---|---|---|---|
| Â | RF IgG | |||
Positive at baseline (n, %) | 2 | 5 % | 1 | 8 % |
Negative at baseline (n, %) | 35 | 95 % | 12 | 92 % |
Mean baseline titer (v ± SD in IU/ml) | 11.99 | 15.99 | 13.69 | 12.30 |
Titer decrease (n, %) | 37 | 100 % | 13 | 100 % |
Titer increase (n, %) | 0 | 0 % | 0 | 0 % |
Mean titer at 24 weeks (v ± SD in IU/ml) | 3.07 | 0.97 | 4.47 | 3.48 |
Percentage decline/Wilcoxon P value | 74.38 % | P <0.0001 | 67.32 % | P = 0.002 |
Mann–Whitney U P value (24 weeks) | P = 0.224 | |||
Seronormalization (n, %) | 2 | 100 % | 1 | 100 % |
Seroconversion (n, %) | 0 | 0 % | 0 | 0 % |
| Â | RF IgM | |||
Positive at baseline (n, %) | 21 | 57 % | 8 | 62 % |
Negative at baseline (n, %) | 16 | 43 % | 5 | 38 % |
Mean baseline titer (v ± SD in IU/ml) | 44.48 | 69.40 | 86.22 | 102.8 |
Titer decrease (n, %) | 36 | 97 % | 11 | 85 % |
Titer increase (n, %) | 0 | 0 % | 2 | 15 % |
Mean titer at 24 weeks (v ± SD in IU/ml) | 16.54 | 20.85 | 58.67 | 81.14 |
Percentage decline/Wilcoxon P value | 62.82 % | P <0.0001 | 31.95 % | P = 0.011 |
Mann–Whitney U P value (24 weeks) | P = 0.170 | |||
Seronormalization (n, %) | 8 | 38 % | 1 | 13 % |
Seroconversion (n, %) | 0 | 0 % | 0 | 0 % |
| Â | RF IgA | |||
Positive at baseline (n, %) | 20 | 54 % | 9 | 69 % |
Negative at baseline (n, %) | 17 | 46 % | 4 | 31 % |
Mean baseline titer (v ± SD in IU/ml) | 102.35 | 124.7 | 167.6 | 144.7 |
Titer decrease (n, %) | 30 | 81 % | 10 | 77 % |
Titer increase (n, %) | 5 | 14 % | 2 | 15 % |
Mean titer at 24 weeks (v ± SD in IU/ml) | 60.77 | 94.57 | 124.0 | 128.4 |
Percentage decline/Wilcoxon P value | 40.62 % | P <0.0001 | 26.05 % | P = 0.014 |
Mann–Whitney U P value (24 weeks) | P = 0.147 | |||
Seronormalization (n, %) | 7 | 35 % | 1 | 11 % |
Seroconversion (n, %) | 1 | 6 % | 0 | 0 % |
| Â | ACCP IgG | |||
Positive at baseline (n, %) | 34 | 92 % | 12 | 92 % |
Negative at baseline (n, %) | 3 | 8 % | 1 | 8 % |
Mean baseline titer (v ± SD in U/ml) | 1125.71 | 700.0 | 1044.35 | 775.6 |
Titer decrease (n, %) | 29 | 78 % | 8 | 62 % |
Titer increase (n, %) | 5 | 14 % | 4 | 31 % |
Mean titer at 24 weeks (v ± SD in U/ml) | 841.11 | 667.2 | 861.55 | 682.1 |
Percentage decline/Wilcoxon P value | 25.28 % | P <0.0001 | 17.50 % | P = 0.129 |
Mann–Whitney U P value (24 weeks) | P = 0.982 | |||
Seronormalization (n, %) | 0 | 0 % | 0 | 0 % |
Seroconversion (n, %) | 0 | 0 % | 0 | 0 % |