[Sudden fainting in a young woman].

A 37-year old woman (without personal medical records) is admitted in hospital for a sudden syncope (duration 15 minutes) with postcritical condition. Her family records show the sudden death of the mother (at 39). Complementary exams do not indicate anything abnormal except a hypercholesterolemia and the electrocardiogram reveals a lengthening of the QT interval.

Recombinant staphylokinase variants with reduced antigenicity due to elimination of B-lymphocyte epitopes.

Site directed mutagenesis (350 variants) of recombinant staphylokinase (SakSTAR), a potent fibrin-selective thrombolytic agent, was undertaken in order to reduce its antigenicity while maintaining its potency. Variants with K35A, (ie, Lys[K] in position 35 substituted with Ala[A]), E65D or E65Q, K74R or K74Q, E80A+D82A, K130T, and K135R displayed increased enzymatic activity or reduced binding of human staphylokinase-specific antibodies. Additive mutagenesis identified 8 variants with intact thrombolytic potencies, which absorbed down to less than a third of SakSTAR-specific antibodies.