Heart valves from pigs and the porcine endogenous retrovirus: experimental and clinical data to assess the probability of porcine endogenous retrovirus infection in human subjects.

OBJECTIVE: Replacement of heart valves in human subjects has become a routine procedure in cardiac operations. We sought to investigate whether commercially available glutaraldehyde-fixed porcine heart valve prostheses cause porcine endogenous retrovirus infection in human subjects because recent studies revealed that human cells can be infected with porcine endogenous retrovirus.
METHODS: Blood samples of 18 patients who underwent aortic or mitral valve replacement with porcine heart valves were collected 6 months to 3 years after operation and tested for porcine endogenous retrovirus by means of polymerase chain reaction and reverse transcriptase-polymerase chain reaction. In addition, we tried to trace porcine endogenous retrovirus in 3 commercially available, glutaraldehyde-fixed, porcine heart valves.
RESULTS: Porcine endogenous retrovirus can be easily detected in native porcine heart valves and degrades completely within 1 week of fixation in glutaraldehyde. In all 3 commercially available porcine heart valves, no traces of porcine endogenous retrovirus were found. All blood samples showed negative test results for the porcine endogenous retrovirus genome.
CONCLUSION: Our results indicate that glutaraldehyde fixation of porcine heart valves reliably prevents cross-species transmission of porcine endogenous retrovirus.