Exchange of light chains among platelet autoantibody clones.

Heavy and light chains for 3 platelet-binding clones (H44L4, H47L64, and H36L76) were interchanged to generate 9 possible combinations (6 novel and 3 reconstituted originals). (A) Flow cytograms comparing the fluorescent intensities of the 3 index antibodies. (B) Matrix showing that only reconstituted original heavy-chain–light-chain pairs conferred platelet binding. Numbers in boxes represent mean fluorescent intensities.