Activation of human polyomavirus infection-detection by cytologic technics.

Human polyomaviruses produce characteristic large basophilic nuclear inclusions in urothelial cells. Cytologic screening of urinary sediment for inclusion-bearing cells permits the identification of persons who are actively excreting these viruses. The human polyomavirus-induced changes may be differentiated from changes induced by other viruses and from cancer by transmission electron microscopy of infected cells. Cytologic evidence of virus infection was detected in five of 37 cancer patients receiving various treatments, two of whom were also diabetic, and in two of 84 adult patients who had diabetes mellitus. The monitoring of 3,648 urine samples sent for routine cytologic examination revealed 12 additional patients to have cytologic changes of human polyomavirus infection. Electron microscopy confirmed the presence of polyomavirus particles in seven of the 19 cytologically positive specimens. Previous reports of human polyomavirus excretion have been confined to describing patients whose immunity may have been impaired by drug therapy, congenital disease, or pregnancy. This study indicates that cytologic evidence of active human polyomavirus infection may be found among patients receiving various treatments for a number of medical disorders not usually associated with immunologic defects. Further studies to identify factors concerned in the reactivation of human polyomavirus are indicated.