Detection, distribution, and pathologic significance of BK virus strains isolated from patients with kidney transplants, with and without polyomavirus-associated nephropathy.
BACKGROUND
BK virus strains or regulatory region sequence variations may play a role in the pathogenesis of polyomavirus-associated nephropathy (PVAN), although no definite relationship has yet been demonstrated.


OBJECTIVE
To investigate the pathologic significance of BK virus strains and regulatory region sequence variations.


METHODS
Eight (3.5%) of 226 patients with renal transplants developed PVAN; the remaining 218 cases were used as controls. From the patients who developed PVAN, 70 urine samples, 63 blood samples, and 17 renal biopsy samples were taken, and 682 urine samples, 677 blood samples, and 101 renal biopsy samples were taken from the control cases. Amplification and sequence analyses of regulatory region were obtained, and the sequences were analyzed using the Basic Local Alignment Search Tool program.


RESULTS
The WWT strain was more frequently detected in PVAN cases than in the control cases (urine: 88.5% vs 22.1%; blood: 85.2% vs 40%; renal biopsies: 77.8% vs 0%), and the AS and WW strains were only isolated from controls. Strain 128-1 was frequently associated with JC virus coinfection in both groups (PVAN: 78.3%; controls: 98%). Major WWT rearrangements were detected in 29.6% of the urine samples, 30.4% of the blood samples, and one renal biopsy from the PVAN cases, but in only one urine sample from the controls. Insertion of 8 base pairs (P block) was found in all 128-1 strains; WW and AS were archetypal in 78.9% and 57.7% of the samples, respectively.


CONCLUSIONS
Although the study included only 8 PVAN cases, regulatory region sequence variations seem to be frequent and independent of the development of the disease, and the WWT strain seems more frequently related to the development of nephropathy than other strains.
Department of Medical Science, University School of Medicine "Amedeo Avogadro" of Eastern Piedmont, Novara, Italy. renzo.boldorini@med.unipmn.it
Renzo
R
Boldorini
Sara
S
Allegrini
Umberto
U
Miglio
Alessia
A
Paganotti
Claudia
C
Veggiani
D000328:Adult; D000368:Aged; D001739:BK Virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology / Q000821:virology; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000473:pathology / Q000821:virology*; D027601:Polyomavirus Infections / Q000473:pathology / Q000821:virology*; D011183:Postoperative Complications / Q000473:pathology / Q000821:virology*; D017422:Sequence Analysis, DNA; D014412:Tumor Virus Infections / Q000473:pathology / Q000821:virology*; D014556:Urine / Q000821:virology; D014779:Virus Replication
D004279:DNA, Viral