Occurrence of BK virus and BK virus-specific antibodies in the urine of patients receiving chemotherapy for malignancy.

Urine specimens from 23 children and 9 adults who were undergoing treatment for malignancy as well as urines from 40 normal individuals were concentrated and examined for evidence of papovavirus infection. Papovavirus particles were detected in 6 of 64 urines examined by electron microscopy. Three of the particle-positive urines induced BK virus-specific immunofluorescence after inoculation of WI38 cells, and three isolations of BK virus were made by inoculation of urines from virus-excreting patients into Vero cells. BK virus-specific hemagglutination-inhibiting and immunofluorescence neutralizing antibodies were found in a majority of urines from adult patients, in about a fifth of pediatric patients, and less often in normal urines. Urines of virus-excreting patients generally had antibodies. In indirect fluorescent antibody tests, BK virus-specific antibodies of the immunoglobulin G class were found in five urine specimens from patients; immunoglobulin A antibodies were not detected in any urine. These data suggest that activation of BK virus is related to immunosuppression and not to transplantation itself and that the occurrence of virus-specific antibodies in urine may be indicative of virus multiplication in the urinary tract.