Anti–human factor IX IgG levels following injection of human factor IX protein
Group . | No. . | Mean IgG anti—human factor IX, ng/mL . | SD . |
|---|---|---|---|
| A/J males | 10 | 5300 | 4721 |
| A/J females | 9 | 1727 | 1716 |
| C57BL/6J males | 10 | 0 | 0 |
| C57BL/6J females | 10 | 15 | 48 |
Group . | No. . | Mean IgG anti—human factor IX, ng/mL . | SD . |
|---|---|---|---|
| A/J males | 10 | 5300 | 4721 |
| A/J females | 9 | 1727 | 1716 |
| C57BL/6J males | 10 | 0 | 0 |
| C57BL/6J females | 10 | 15 | 48 |
On days 1, 3, 5, 7, 9, 11, and 13, 50 U/kg was given intravenously; antibody levels were measured 1 month after first protein injection. Values are means of anti—human factor IX levels, calculated using a standard curve of monoclonal anti—human factor IX antibody at defined concentrations. P = .002 for A/J male versus C57BL/6J male; P = .0037 for A/J female versus C57BL/6J female.