HIT

[EmetyreUSMLEStep1Tutor1]

Guys, can anyone please explain me why in heparin induced thrombocytopenia thrombosis occurs?

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[Captain Sisko]

according to first aid, you develop IgG against heparin bound platelet factor 4. The complex of PF4, IgG, and heparin activates platelets which causes thrombosis and depletion of platelets (thrombocytopenia). I originally thought it was some sort of AI reaction against platelets but it's an activation and depletion instead. You can get around this with LMWH or fondaparinux which (I think, because they're smaller and don't have the binding site) don't bind PF4.

 

[EmetyreUSMLEStep1Tutor1]

>PF4, IgG, and heparin activates platelets which causes thrombosis and depletion of platelets
Okay, I get it now Thanks very much!

 

[worldbeater]

Also, other solutions if the platelet count is dropping is to stop the drug (which is a given) or add agatroban (direct thrombin inhibitor)