Ihe kpatara ya bụ ihe na-eme ka ọbara ghara ịba n'ime mmadụ ruo mgbe ọ nwụrụ n'ihi ọrịa AIDS metụtara mmịnye ọbara mgbe ọ dị afọ 46. Aha ọzọ maka ihe kpatara ya bụ plasma thromboplastin, nke otu ìgwè nọọrọ onwe ha na California nyere. Ihe kpatara ya bụ ihe na-eme ka ọbara ghara ịba n'ime mmadụ, nke otu onye America na-akpọ Stephen Christmas (1947<unk>1993) chọpụtara na 1952 na onye ọrịa na-arịa ọrịa hemophilia B aha ya bụ Stephen Christmas (1947<unk>1993). Ihe kpatara ya bụ Dr. Rosemary Biggs na Prọfesọ R.G. MacFarlane na Oxford, UK. Ihe kpatara ya bụ, ya mere, a na-akpọ Christmas Factor.
Ihe E Ji Mara Krismas