对于接受肝素治疗的患者来说,根据个体及药物相关的危险因素不同,HIT的发病率不同,平均介于0.1%至5.0%。外伤和术后接受肝素治疗的患者的HIT发病率最高(1%至5%),而HIT在内科预防性使用肝素的患者(发病率小于1%)及产科患者中极为罕见(发病率小于0.1%)。[7]Warkentin TE, Sheppard JA, Moore JC, et al. Laboratory testing for the antibodies that cause heparin-induced thrombocytopenia: how much class do we need? J Lab Clin Med. 2005;146:341-346.http://www.ncbi.nlm.nih.gov/pubmed/16310517?tool=bestpractice.com[8]Warkentin T, Sheppard J, Horsewood P, et al. Impact of the patient population on the risk for heparin-induced thrombocytopenia. Blood. 2000;96:1703-1708.http://www.bloodjournal.org/content/96/5/1703.longhttp://www.ncbi.nlm.nih.gov/pubmed/10961867?tool=bestpractice.com[9]Prandoni P, Siragusa S, Girolami B, et al. The incidence of heparin-induced thrombocytopenia in medical patients treated with low-molecular-weight heparin: a prospective cohort study. Blood. 2005;106:3049-3054.http://www.bloodjournal.org/content/106/9/3049.longhttp://www.ncbi.nlm.nih.gov/pubmed/16030191?tool=bestpractice.com[10]Lubenow N, Hinz P, Thomaschewski S, et al. The severity of trauma determines the immune response to PF4/heparin and the frequency of heparin-induced thrombocytopenia. Blood. 2010;115:1797-1803.http://www.bloodjournal.org/content/115/9/1797.longhttp://www.ncbi.nlm.nih.gov/pubmed/19965682?tool=bestpractice.com[11]Lindhoff-Last E, Nakov R, Misselwitz F, et al. Incidence and clinical relevance of heparin-induced antibodies in patients with deep vein thrombosis treated with unfractionated heparin or low-molecular-weight heparin. Br J Haematol. 2002;118:1137-1142.http://www.ncbi.nlm.nih.gov/pubmed/12199798?tool=bestpractice.com相比于低分子量肝素(LMWH),普通肝素的肝素诱导性血小板减少症风险显著升高。[12]Martel N, Lee J, Wells PS. Risk for heparin-induced thrombocytopenia with unfractionated and low-molecular-weight heparin thromboprophylaxis: a meta-analysis. Blood. 2005;106:2710-2715.http://www.bloodjournal.org/content/106/8/2710.longhttp://www.ncbi.nlm.nih.gov/pubmed/15985543?tool=bestpractice.com女性的肝素诱导性血小板减少症风险比男性高1.5至2倍。[13]Warkentin TE, Sheppard JA, Sigouin CS, et al. Gender imbalance and risk factor interactions in heparin-induced thrombocytopenia. Blood. 2006;108:2937-2941.http://www.bloodjournal.org/content/108/9/2937.longhttp://www.ncbi.nlm.nih.gov/pubmed/16857993?tool=bestpractice.com