Heparin antibodies

I am sorry about your dad. I found info on the internet, perhaps some you have already read. I hope this helps.

I found a discussion here regarding Heparin-Induced Thrombocytopenia: Pathophysiology and Management http://www.medscape.com/viewarticle/569661

Summary

Immune HIT is a rare but serious consequence of heparin administration. Different patient populations are at variable risk for HIT, although the grounds for these discrepancies are not clear. The "4T" system of clinical diagnosis gives a framework for accurate diagnosis as well as acute treatment recommendations. Accurate diagnosis of HIT, however, depends on laboratory confirmation of the presence of antibodies to the heparin-PF4 complex.

Removal of heparin is a critical but insufficient management practice, and alternative anticoagulants should be carefully used to prevent thrombosis. The renal and hepatic health of the patient should be considered when choosing a therapy because different drugs are cleared by these organs. Small molecule anticoagulation drugs are in development for prevention of thrombosis and may be of use in HIT after evaluation in clinical trials.
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From http://www.sciencedaily.com/releases/2005/12/051203122633.htm (discussing surgery in HIT patients::
"... there is no simple solution to the problem. Several anti-clotting medications may provide an alternative to heparin, but they are not approved by the Food and Drug Administration for use during heart surgery. The safety of these alternative medications in the setting of complex heart surgery remains to be determined.

Another option may be for patients with the antibodies to delay surgery until the antibody levels subside. However, in some cases this might require months -- and, in many cases, the severity of a patient's disease may not allow for safe delay of surgery."

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From http://bloodjournal.hematologylibrary.org/cgi/content/full/101/1/31:

"Patients should be told that they have developed antibodies induced by heparin, which places them at increased risk for thrombosis if heparin is needed again in the next 120 days and that alternative agents should be considered or they should be tested for antibodies before receiving heparin again. If they have a more remote history of HIT, they could probably receive heparin again if needed but other agents may be preferred. These recommendations are in evolution as more is learned about HIT. "

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Treatment

From http://en.wikipedia.org/wiki/Heparin-induced_thrombocytopenia:

Treatment is by prompt withdrawal of heparin and replacement with a suitable alternative anticoagulant. To block the thrombotic state, lepirudin, fondaparinux, bivalirudin, argatroban, danaparoid or other direct thrombin inhibitors are used. Low molecular weight heparin is contraindicated in HIT.

According to systematic review, patients treated with lepirudin for heparin-induced thrombocytopenia showed a relative risk reduction of clinical outcome (death, amputation, etc.) to be 0.52 and 0.42 when compared to patient controls. In addition, patients treated with argatroban for HIT showed a relative risk reduction of the above clinical outcomes to be 0.20 and 0.18. [3]

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