Inhibition of patient antibodies (left) and antibodies from 13 healthy subjects (right) by soluble Fab fragments derived from pooled normal human IgG.

Seven of the 9 patient antibodies were inhibited by less than 50%, and 2 (from patient nos. 4 and 7) were inhibited by more than 80%. Antibodies from the 13 healthy subjects were inhibited by 68% to 98% (average 85%). Brackets depict mean ± 1 SD.