title: BK virus replication in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis.
abstract: BACKGROUND
  BK virus (BKV) is an important cause of renal dysfunction in kidney transplant (KTX) recipients. Immunosuppression intensity is a major risk factor for BKV replication in these patients. The prevalence of BKV replication in immunosuppressed patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) without transplant is not known.
  
  
  METHODS
  Consecutive patients (n = 37) with a diagnosis of GPA (n = 25) or MPA (n = 12) without history of KTX were evaluated for plasma BKV replication by quantitative PCR (group A). Descriptive data were collected. BKV replication in this nontransplant immunosuppressed vasculitis cohort was compared with a historical cohort of vasculitis KTX recipients (group B).
  
  
  RESULTS
  Group A patients had mean disease duration of 75 months. Mean age was 57 years and 54% were female. Mean time from vasculitis onset to BKV testing was 36 months, and 19/37 patients were tested within 24 months of induction therapy. At the time of BKV testing, 73% were on prednisone (P) with azathioprine, mycophenolate mofetil (MMF), methotrexate or leflunomide. None of the nontransplanted vasculitis patients had detectable plasma BKV. Among 35 patients in group B, 16 were tested for BKV; 5/16 (31%) had detectable virus in plasma at a mean of 6 months after TX (p = 0.002). Most (94%) were on maintenance therapy with MMF, P and tacrolimus.
  
  
  CONCLUSIONS
  Immunosuppressed patients with GPA/MPA without KTX had no evidence of plasma BKV. However, BKV was common in GPA/MPA patients after KTX, suggesting that replication may be related to differences in immunosuppression, alloimmune activation or differences in host defense mechanisms.
authors.affiliation: Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md., USA.
authors.forename: D
authors.initials: D
authors.lastname: Geetha
authors.forename: S M
authors.initials: SM
authors.lastname: Levine
authors.forename: R L
authors.initials: RL
authors.lastname: Manno
authors.forename: A
authors.initials: A
authors.lastname: Valsamakis
authors.forename: S
authors.initials: S
authors.lastname: Ghazarian
authors.forename: P
authors.initials: P
authors.lastname: Seo
mesh_terms: D000328:Adult; D000368:Aged; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000097:blood* / Q000821:virology*; D001739:BK Virus / Q000502:physiology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D027601:Polyomavirus Infections / Q000175:diagnosis*; D012189:Retrospective Studies; D012307:Risk Factors; D014779:Virus Replication
chemical_list: D007166:Immunosuppressive Agents