Detection by PCR of human polyomaviruses BK and JC in immunocompromised individuals and partial sequencing of control regions

Abstract Immunocompromised individuals were tested for the presence of the human polyomaviruses JC (JCV) and BK (BKV) by the polymerase chain reaction (PCR). The use of appropriate primers in a nested PCR allowed the detection of both viruses simultaneously. Viruses were differentiated by restriction fragment length analysis of amplified DNA fragments. Both BKV and JCV DNA were detected in the urine of an AIDS patient with progressive multifocal leukencepha‐lopathy. In autopsy materials from this patient, JCV‐ but not BKV‐DNA was found in brain and kidney tissue, whereas lung tissue was negative for both virus DNAs. To evaluate the methology further, hybridization‐positive urines from three recipients of bone marrow transplants and a positive urine of an acute myeloid leukemia patient were analyzed by this PCR method. One case was positive both for BKV and JCV, two cases were positive only for BKV, and one was negative for both. Parts of the control regions of JCV and BKV were sequenced directly from PCR‐derived fragments. The JCV sequence from urine of the AIDS patient compared to sequences from a bone marrow transplant recipient and to archetypical reference strains showed two nucleotide (nt) exchanges out of 250 nt. The BKV sequences from the AML and the AIDS patients showed five nt exchanges out of 265 nt in the control region and were identified as BKV WW or WWT3 strains. In the agnogene region five exchanges were detected, two of them resulting in non‐conservative amino acid exchanges. The possibility of testing clinical specimens of different origins by this PCR method is important for elucidating often unclear clinical courses in immunocompromised patients. Furthermore, our results show the versatility of PCR for diagnosis and for molecular characterization of human polyomaviruses.