BK virus nephropathy- Current diagnosis and management

Author(s): Dr. Amit Kumar

The human polyomaviruses, BK virus (BKV) was first reported in 1971. BK polyoma Virus infection (BKPyV) of the general population occurs during early childhood yielding seroprevalence rates increasing to >90% by ap‐proximately 4 years of age. BK virus Nephropathy is important cause of graft damage and loss. The prevalence of BK virus nephropathy  is increasing in the current era of  potent immunosupression and more high risk HLA incompatible and ABO incompatible transplant being done. BKV affects upto 8% - 10% of recipients, and many a time results in allograftloss or permanent dysfunction.

It presents as an asymptomatic gradual rise in creatinine. Screening of transplant recipient for BKPyV‐DNAemia monthly until month 9, and then every 3 months until 2 years posttransplant is recommended. Stepwise reduction in immunosupression is recommended for KT pa‐

tients with plasma BKPyV‐DNAemia of >1000 copies/mL sustained for 3 weeks or increasing to >10 000 copies/mL. Reducing immunosuppression is also the primary intervention for biopsy‐proven BKPyV‐associated nephropathy. Despite improvement in understanding of disease, still many allograft are lost and some patients develop rejection following immunosiupression reduction. Thus managing BKPyV infection remains challanging for transplant physicians.