Table III. Percentage of IgG anti-phiX174 antibody after phiX174 immunization (least-squares mean with 95% mean confidence limits).
Time point | Rituximab group | Control group | P value |
---|---|---|---|
2 wk after secondary | 1.3 (−6.1 to 8.7), n = 20 | 46.6 (38.3 to 55.0), n = 16 | <.0001 |
2 wk after tertiary | 0.00 (−8.0 to 8.0), n = 17 | 88.3 (79.9 to 96.6), n = 16 | <.0001 |
2 wk after quaternary | 29.6 (20.5 to 38.8), n = 13 | 90.3 (81.9 to 98.6), n = 16 | <.0001 |
The ratio of IgM/IgG activities against phiX174 was determined by using the in vitro treatment of serum with 2-mercaptoethanol (to eliminate IgM) for 30 minutes before the phage neutralization assay and is expressed as a percentage of IgG.9,10 Analysis used a repeated-measures model with a treatment group-by-time interaction adjusting for age and sex.