Role of heparin-dependent antigens in immune heparin-induced thrombocytopenia

Occasionally, other antigens can be involved in HIT pathogenesis, such as interleukin-8 (IL-8) or neutrophil-activating peptide-2 (NAP-2), two CXC chemokines of the PF4 superfamily that exhibit affi nity for heparin (Amiral et al., 1996a; Regnault et al., 2003). More recently, antibodies to protamine sulfate complexed to heparin have been identifi ed in patients clinically suspected to have HIT but who do not have antibodies against PF4/H complexes (Amiral and Vissac, 2009).