Mason-Pfizer like virus in kidney grafted patients.

Lymphocytes from a kidney grafted patient were specifically stimulated to incorporated thymidine in vitro by mitomycin C treated Hela cells infected with a Mason-Pfizer like virus (MPV). The thermolabile mutant of vesicular stomatitis virus (VSV tl) grown in leukocytes of this patient produced pseudotypes which were neutralized by the patient's sera and boy rabbit anti-MPV sera. Coculture of the patients leukocytes with SIRC cells yielded virus populations with dual properties; those of MPV plus those of another virus which was not typed serologically but possessed the biological properties of typical C particles. The patient also had neutralizing antibodies to MPV, which were detected by inhibition of syncytium formation on KC cells and by neutralization of VSV tl (MPV) pseudotypes. Preliminary results on the frequency of similar findings in other kidney grafted patients are presented.