BK virus nephropathy in renal transplant patients in London.
BACKGROUND
BK nephropathy (BKN) is an important cause of renal transplant dysfunction, believed to be associated with higher levels of immunosuppression. We assessed the experience of BKN in renal transplant patients in the London region.


METHODS
All six London transplant centers participated and case notes of patients with BKN in 2004 to 2005 were reviewed.


RESULTS
There were 17 cases of BKN, giving an incidence of 2.1%. Median time to diagnosis was 9 months. Median baseline creatinine rose from 150 to 196 mumol/L. At diagnosis, 16 patients were on tacrolimus, 15 on mycophenolate mofetil, and 10 on triple therapy with tacrolimus, mycophenolate mofetil, and prednisolone. Management of BKN involved reducing immunosuppression; cidofovir was used in two patients and methylprednisolone in five for acute rejection. Median follow-up time was 29.2 months. Creatinine returned to baseline in four patients, remained elevated in 12 and one patient lost his graft. The new median baseline creatinine was 216 mumol/L. Eight patients underwent repeat biopsies of which four became negative for BKV and three subsequently cleared the virus on blood and urine polymerase chain reaction and urine decoy cells. Overall, eight patients cleared the virus. None of age, sex, viral load, or biopsy characteristics (Banff ct score, Drachenberg grade, and number of BKV positive cells) were associated with poorer outcome when patients with increase in creatinine of less than 30% (n=7) or more than 30% (n=10) from baseline were compared.


CONCLUSIONS
The incidence of BKN in this study is comparable with previous studies, with more favorable outcomes. It supports the association of BKN with potent immunosuppression.
White
Laura H
LH
1 West London Renal and Transplant Centre, Hammersmith Hospital, Du Cane Road, London.
Casian
Alina
A
Hilton
Rachel
R
Macphee
Iain A M
IA
Marsh
James
J
Sweny
Paul
P
Trevitt
Ray
R
Frankel
Andrew H
AH
Warrens
Anthony N
AN
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000627:therapeutic use; D001739:BK Virus / Q000235:genetics / Q000302:isolation & purification; D001706:Biopsy; D006801:Humans; D007674:Kidney Diseases / Q000188:drug therapy / Q000821:virology*; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000473:pathology; D008131:London / Q000453:epidemiology; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D027601:Polyomavirus Infections / Q000188:drug therapy / Q000453:epidemiology*; D011183:Postoperative Complications / Q000821:virology*; D012189:Retrospective Studies; D012307:Risk Factors; D014412:Tumor Virus Infections / Q000188:drug therapy / Q000453:epidemiology*; D019562:Viral Load
D000998:Antiviral Agents