Search for latent cytomegalovirus in renal allografts

Cytomegalovirus (CMV) infection is common after renal transplantation, and cytomegaloviruria occurs in about two-thirds of the recipients. These observations suggest that the allografts may be a site of latent infection with CMV and its reactivation may be the source of viruria. To investigate this possibility, 130 kidney specimens from 85 persons were cultured, and simultaneous explants were made of 63 of them from 50 people. No CMV was received from 33 normal kidney or cadaver donors or from 19 allograft recipients who had no evidence of posttransplantation infection with CMV. The experiment included 37 primary organ explants that yielded no evidence of latent virus. Among 33 allograft recipients with posttransplantation CMV infection, overt infectious virus was isolated from 6 of 57 allograft biopsies. All six positive specimens were from four patients, all of whom had viruria simultaneously. Organ explants from 20 of the recipients with demonstrated postoperative CMV infection, including 13 viruric patients, failed to unmask any latent CMV. Thus, allograft kidneys were infrequently infected with CMV (6%), even in patients with viruria (24%). The kidney parenchyma appears to be an uncommon site of latent CMV infection and may not be the usual source of virus in patients with viruria.