Estimated prevalence of FVIII-binding antibodies in healthy individuals and in different patient cohorts
| Patient type . | Sample size . | Prevalence of positive individuals, % (95% CI) . | Prevalence of antibodies with titers ≥ 1:80, % (95% CI) . | Prevalence of antibodies with titers < 1:80, % (95% CI) . |
|---|---|---|---|---|
| Healthy | 600 | 19 (16-22) | 2 (1-4) | 17 (14-20) |
| Severe hemophilia A without inhibitor (HA-no/INH) | 77 | 34 (24-45) | 5 (2-13) | 31 (22-42) |
| Severe hemophilia A after successful ITI (HA-ITI) | 23 | 39 (22-59) | 4 (1-21) | 35 (19-55) |
| Severe hemophilia A with inhibitor (HA-INH) | 20 | 100 (84-100) | 100 (84-100) | 0 (0-16) |
| Acquired hemophilia A (Acqu-HA) | 9 | 100 (70-100) | 100 (70-100) | 0 (0-30) |
| Patient type . | Sample size . | Prevalence of positive individuals, % (95% CI) . | Prevalence of antibodies with titers ≥ 1:80, % (95% CI) . | Prevalence of antibodies with titers < 1:80, % (95% CI) . |
|---|---|---|---|---|
| Healthy | 600 | 19 (16-22) | 2 (1-4) | 17 (14-20) |
| Severe hemophilia A without inhibitor (HA-no/INH) | 77 | 34 (24-45) | 5 (2-13) | 31 (22-42) |
| Severe hemophilia A after successful ITI (HA-ITI) | 23 | 39 (22-59) | 4 (1-21) | 35 (19-55) |
| Severe hemophilia A with inhibitor (HA-INH) | 20 | 100 (84-100) | 100 (84-100) | 0 (0-16) |
| Acquired hemophilia A (Acqu-HA) | 9 | 100 (70-100) | 100 (70-100) | 0 (0-30) |
Estimated prevalence of FVIII-binding antibodies in healthy individuals, in patients with hemophilia A without inhibitors, and in patients with hemophilia A after successful immune tolerance induction therapy (ITI). Some samples contained more than one population of antibodies of different Ig isotypes and IgG subclasses which were individually assessed for antibody titers ≥ 1:80 and antibody titers < 1:80, respectively. Therefore, the prevalence of antibody titers ≥ 1:80 and antibody titers < 1:80 does not necessarily add up to the total prevalence of positive individuals.
FVIII indicates factor VIII; and CI, confidence interval.