• Uremia
• Liver disease
• Paraproteinemia (multiple myeloma, Waldenström's macroglobulinemia, monoclonal gammopathy, or polyclonal hypergammaglobulinemia)
• Myeloproliferative disease
• Myelodysplastic syndrome
• Disseminated intravascular coagulopathy
• Extracorporeal circulation (dialysis, CPB, plasmapheresis)
• Medications (aspirin, NSAIDS, thienopyridines, GP IIb/IIa antagonists, beta-lactam antibiotics, antidepressants, phenothiazines)
• Herbal remedies (fish oil, flaxseed oil, ginger seed extract, Gingko biloba, garlic, tumeric)

CPB = cardiopulmonary bypass; GP = glycoprotein; NSAIDS = nonsteroidal anti-inflammatory drug.