Effect of fragmentation of tetanus immune globulin (human) on neutralization of tetanus toxin.

The effect of fragmentation produced by plasmin digestion of tetanus immune globulin (human) on the neutralization of tetanus toxin was determined. Based on a mouse test, there was a significant reduction in neutralizing potency when fragmentation to 3.5 S material reached or exceeded 20% suggesting a threshold for antibody fragmentation beyond which the resulting decrease in antibody potency would result in serious disease. Because this threshold is not known for man, the use of fragmented globulin for the prevention or treatment of tetanus should be avoided until additional data are available on its neutralizing potency and efficacy.