Allergic reaction to protamine: a late complication of elective vasectomy?

Nucleoprotamines are a normal component of human sperm cells. Antibodies against these protamines develop in 22 to 33 per cent of patients undergoing elective vasectomy. These antibodies, in turn, have been shown to cross-react with medicinal protamines, which are extracted commercially from the testes of salmon and certain other fish. This cross-reactivity against protamines raises the possibility that patients who have undergone elective vasectomy may be at increased risk of an allergic reaction developing if they are later exposed to protamine as a medication. Since medicinal protamines currently enjoy widespread clinical use, this information should be borne in mind by those clinician using protamine and by urologists when counselling patients concerning elective vasectomy for sterilization.