[1] Acad Med Ctr, Renal Transplant Unit, NL-1100 DE Amsterdam, Netherlands
[2] Acad Med Ctr, Lab Expt & Clin Immunol, NL-1100 DE Amsterdam, Netherlands
[3] Acad Med Ctr, Dept Clin Virol, NL-1100 DE Amsterdam, Netherlands
[4] Netherlands Canc Inst, Dept Immunol, Amsterdam, Netherlands