Taken together, our data strongly suggest that although the occurrence of leprosum clot represents a rare phenomenon associated with procoagulant exacerbation and vascular abnormalities, all leprosy MB patients enrolled in the present work develop a procoagulant status, presenting exacerbation of in vitro clot formation in some acute cases due to high levels of fibrinogen, anti-cardiolipin antibodies, von Willebrand factor and soluble tissue factor. The gene discussed is VWF; the disease is leprosy.