Antibodies to dsDNA are produced during primary BK virus infection in man, indicating that anti-dsDNA antibodies may be related to virus replication in vivo.

Experimental immunizations with both the Polyomavirus BK and with the isolated viral genomic dsDNA regularly induce antibodies with a relative affinity for BK virus dsDNA. In the present study we demonstrate that the anti-dsDNA responses to BK virus in experimental animals also appear during natural BK virus infection in man. Fifty-nine children were examined over time for serological signs of primary BK virus infection. Of eight children found to undergo primary infection with BK virus, anti-BK dsDNA antibodies appeared in all. In 4 of the 8 patients the antibodies cross-reacted significantly with mammalian dsDNA, and weak cross-reactions were also noted in at least three other patients. The antibodies resembled those induced in the experimental model with regard to their relative affinity for BK dsDNA. In contrast, most, but not all, anti-dsDNA antibodies from 10 SLE patients cross-reacted extensively with dsDNA from viral and mammalian origin. Thus, a dsDNA virus like BK virus may provoke immunological intolerance to dsDNA, but, with qualities different from those produced during SLE. The present observations demonstrate that induction of anti-dsDNA antibodies is not restricted to experimental immunization of animals, but does also take place in humans during naturally acquired BK virus infection. The relevance of this model for the spontaneous production of anti-dsDNA antibodies is discussed.