Table 2.
Factors associated with time to relapse to first cycle rituximab.
| Risk factors | Univariable analysis | Multivariable analysis (MVA) |
|---|---|---|
| HR (95% CI); p-values (with multiple imputation) | HR (95% CI); p-values (with multiple imputation) | |
| Baseline clinical/serological characteristics | ||
| Age at rituximab initiation (per 10 years) | 1.01 (0.86–1.17); p = 0.954 | Not included in MVA |
| Female | 1.15 (0.65–2.02); p = 0.629 | Not included in MVA |
| Disease duration at rituximab initiation (years) | 1.06 (0.98–1.15); p = 0.160 | Included in MVA but removed from final model as p < 0.20 |
| Concomitant immunosuppressant | 0.69 (0.39–1.22); p = 0.205 | 0.48 (0.24–0.94); p = 0.034 |
| Positive ANCA immunofluorescence | 0.89 (0.46–1.71); p = 0.725 | Not included in MVA |
| Positive anti-PR3/anti-MPO at rituximab initiation | 0.57 (0.31–1.06); p = 0.077 | Included in MVA but removed from final model as p < 0.20 |
| CRP at ri initiation (mg/L) | 1.00 (0.99–1.01); p = 0.456 | Not included in MVA |
| BVAS 3.0 per point score | 0.99 (0.94–1.05); p = 0.763 | Included in MVA but removed from final model as p < 0.20 |
| VDI per point score | 1.14 (0.87–1.50); p = 0.353 | Not included in MVA |
| Clinical and serological characteristics at 26 weeks | ||
| Complete response | 0.34 (0.19–0.61); p<0.001 | 0.24 (0.12–0.50); p<0.001 |
| Positive ANCA immunofluorescence | 0.99 (0.56–1.75); p = 0.962 | Not included in MVA |
| Positive anti-PR3/anti-MPO | 0.79 (0.44–1.42); p = 0.426 | Not included in MVA |
| CRP (mg/L) | 0.99 (0.97–1.02); p = 0.618 | Not included in MVA |
| B-cell subsets, depletion, and repopulation | ||
| Naïve B cells at rituximab initiation (×109/L) a | 1.00 (1.00–1.01); p = 0.797 | Not included in MVA |
| Memory B cells at rituximab initiation (×109/L) a | 1.01 (1.00–1.02); p = 0.040 | 1.01 (1.00–1.02); p = 0.045 |
| Plasmablasts at rituximab initiation (×109/L) a | 1.04 (0.94–1.16); p = 0.459 | Not included in MVA |
| Complete depletion at 6 weeks postrituximab | 0.90 (0.50–1.61); p = 0.721 | Not included in MVA |
| Naïve B-cell repopulation at 26 weeks | 0.38 (0.19–0.76); p = 0.006 | 0.43 (0.22–0.84); p = 0.013 |
| Memory B-cell repopulation at 26 weeks | 0.45 (0.20–0.99); p = 0.046 | Included in MVA but removed from final model as p < 0.20 |
| Plasmablast cell repopulation at 26 weeks | 1.14 (0.61–2.13); p = 0.675 | Not included in MVA |
a
(Count ×109 cells/L) for each subset multiplied by 1,000 prior to analysis.
The bold values denote variables which are statistically significant in the analyses.