BK Virus‐Specific Antibodies and BKV DNA in Renal Transplant Recipients with BKV Nephritis

Abstract

We evaluated twenty renal transplant subjects at various stages of BKV nephritis (BKVN) for BKV-specific IgG and IgM antibodies using ELISA technique and BKV-DNA using PCR. They were divided as early onset (n = 7), stabilizing (n = 3), resolved (n = 8) and late onset (n = 2) BKVN. BKV-specific antibodies and BKV-DNA were simultaneously determined. The mean BKV-specific IgG level in early onset and stabilizing BKVN were 64 and 39 EIA units, and were significantly lower than 138 EIA units seen in resolved BKVN, P = 0.007, P = 0.008. The mean BKV-specific IgM levels in stabilizing BKVN was higher than resolved BKVN (130 vs 51 EIA units), P = 0.006. Mean plasma BKV loads for each group were 955 925, 5642 and 42 copies/mL of plasma, respectively. Prospective study in six BKVN cases revealed mean IgG, IgM levels and BKV-DNA at the time of diagnosis of BKVN as 39, 110 EIA units and 586 758 copies/mL of plasma, respectively. After a mean period of 5.2 months, IgG level increased to 120 EIA units (p = 0.0058) and had no detectable viral copies in circulation.Recovery from BKVN and elimination of BKV is associated with the development of BKV-specific IgG antibodies and this provides insight into the role of humoral immunity to BKV in the pathogenesis of BKVN.

BK Virus Infection in Transplant Recipients: An Overview and Update

“…An increasing anti-BK antibody titer has been seen to develop with a decrease of immunosuppression and treatment of BKVN (17). However, high-titer anti-BK antibody in the donor has been associated with an increased likelihood of development of BK viruria and viremia in the recipient (18).…”

Effects of Rituximab on the Development of Viral and Fungal Infections in Renal Transplant Recipients

“…While IgG monitoring was not routinely performed in our cohorts it is plausible that depletion of BK or other viral-specific IgG, may have occurred. Previous data demonstrated that low BK virus IgG levels correlated with a higher degree of BK replication [27]. BK and other non-CMV viral infections seen in our cohort either lacked prophylactic strategies (i.e., JC virus, RSV) or occurred late (>6 months) after RTX exposure, making prevention and/or monitoring for these infections difficult.…”

Reply: Antibody levels against BK virus and prostate, kidney and bladder cancers in the EPIC-Oxford cohort

“…Hariharan et al (2005) found that mean BK virus-specific IgG levels in patients with early onset and stabilizing BK virus nephropathy were significantly lower than those seen after the disease had resolved. Mean plasma BK virus load declined over the same period.…”