Titers of FVIII-binding antibodies assessed for individual Ig isotypes and IgG subclasses. Shown are the detected titers of Ig isotypes and IgG subclasses of FVIII-binding antibodies for patients with hemophilia A and inhibitors (HA-INH; A), for patients with hemophilia A without inhibitors (HA-noINH; B), and for healthy individuals (C). Plasma samples were diluted at least 1:20. Samples that did not give a positive signal at this minimum dilution were considered as negative (not detectable, ND). The dotted line at a titer of 1:80 indicates the minimum titer required for proof of specificity. Titers of <1:80 were too low to be confirmed for specificity. (Figure and legend reprinted with permission from Whelan et al.¹² )