High-titer protamine-specific IgG antibody associated with anaphylaxis: report of a case and quantitative analysis of antibody in vasectomized men.

A vasectomized man reacted to intravenous protamine with shock; IgG and IgE antibodies against protamine were then measured in a group of 55 vasectomized men and compared to 55 age-matched controls. The index case was a 63-year old vasectomized man who while having mitral valve repair and cardiopulmonary bypass reacted to intravenous protamine with severe hypotension and pulmonary hypertension. protamine is the standard drug given to reverse the anticoagulatory effects of heparin used in cardiac procedures. He had another episode of bradycardia and hypotension 2 weeks later during heparin and protamine infusion as part of a follow-up studies. To document the presence of antibodies against protamine a solid phase radioimmunoassay of protamine-IgG and -IgE was developed and performed on the subjects serum. This test was also applied to vasectomized men aged 21-45 years and 50 age-matched controls. The subject had a protamine-specific IgG level of 53 mcg/ml at the time of the 1st reaction 667 at the 2nd and 79 mcg/ml 3 months later. 16 (29%) of the vasectomized men also had protamine-specific IgG. None of the controls had protamine IgG. None of the men studies showed protamine-specific IgE in their sera. Before this case diabetics receiving protamine-insulin were considered at risk for reactions to iv protamine but only one other case of a vasectomized man succumbing to shock after protamine infusion has been reported.