Transmission of multiple sclerosis by blood transfusion?

A survey of 14,000 multiple sclerosis patients revealed 289 blood donors; 65 of them had already shown clinical manifestations at the time of blood donation. In view of current immunological and virological hypotheses on multiple sclerosis, such patients should not be accepted as blood donors. An effort is being made to determine whether multiple sclerosis has been transmitted to the recipients of this blood.