The human polyomaviruses BKPyV and JCPyV are members of Polyomaviridae family and
after primary infections they persist as latent infection especially in the kidneys.
BKVPy reactivation is mainly related to a renal nephropathy and JCV reactivation can
induce the progressive multifocal leukoencephalopathy. The aim of this study was to
investigate and to compare the presence of BKPyV and JCPyV in urine and plasma samples
from immunocompromised and immunocompetent groups. The viral detection and quantification
was done by a real time PCR from 100 healthy individuals and from 72 kidney transplanted
patients (KTx) enrolled in a prospective study. Polyomavirus DNA urinary shedding
was identified in 19% of healthy person, BKPyV in 6%; JCPyV more frequent in 13%.
No individuals in this group developed polyomavirus viremia. BKPyV and JCPyV viruria
was seen in 36% and 28% of KTx respectively, and 11% had a concomitant BKPyV and JCPyV
viruria. Only BKPy viremia was detected in 5.5% of the KTx. In healthy persons, JCPyV
shedding was associated with older individuals. However, in KTx, BKPyV was associated
with younger age and male gender. No significant association was found between the
patient's origin and BKPyV or JCPyV infection. In conclusion and consisting with previous
reports, BKPyV and JCPyV prevalence and urinary loads were significantly higher in
immunosuppressed compared to non-immunosuppressed individuals. In Addition and by
contrast to KTx, JCPyV was more frequent than BKPyV in healthy individuals. Furthermore,
the shedding of both polyomaviruses was differently associated with the age and the
sex according to each population.