Effect of GPIIIa49-66 and wild-type HIV-1 peptides on Ab-induced platelet fragmentation. CAPE and ESIEF refer to positive control samples in which Ab was preincubated with peptide GPIIIa49-66 (CAPESIEFPVSEARVLED) or GPIIIa52-60 (SIEFPVSE). First set of bars refer to control, patient IgG, irrelevant peptide, or positive control inhibitory peptide (CAPE) prior to incubation with gel-filtered platelets. Second set of bars refers to positive control inhibitory peptide (ESIEF). The remaining bar panels refer to preincubation with various wild-type 10-mer HIV-1 peptides. □ indicates control IgG; ▪, patient Ig; ▦, irrelevant peptide. The horizontal line, dark gray, white, and black bars refer to molecular Ab/peptide ratios of 1:100, 1:10, 1:5, and 1:2, respectively. Numbers refer to PHC or H clones of Table 1. HR1 refers to H20R1; HR3 refers to H19R3.