Studies on Diphtheria Immune Globulin Prepared from Outdated Human Blood

Summary. Approximately one per cent of 8,481 units of outdated plasma tested had 4 or more units of diphtheria antitoxin per ml. Two lots of diphtheria immune globulin (human) were prepared from outdated plasma rich in diphtheria antitoxin. Plasma of this potency was satisfactory to prepare diphtheria immune globulin having 80 or 90 units of antitoxin per ml. When diphtheria immune globulin (human) containing 250 units of antitoxin was injected into human volunteers, serum antitoxin levels of at least 0.01 units per ml were reached in two to seven days and lasted for 21 to 36 days.