A case‐control study to assess the role of polyomavirus in transplant complications: Where do we stand?

Abstract

Purpose: The study's aim was to assess whether polyomavirus DNAemia screening was associated with different outcomes in patients with positive viremia compared with negative viremia. Methods: Case-control retrospective study of patients with polyomavirus DNAemia (viremia > 1000 copies/mL) matched 1:1 with controls. Control group consists of the patient who received a transplant immediately before or after each identified case and did have nil viremia. Finding: Ultimately, 120 cases of BK polyomavirus (BKPyV) were detected and matched with 130 controls. Of these, 54 were adult kidney transplant recipients (KTRs), 43 were pediatric KTRs, and 23 were undergoing hemato-oncologic therapy, of which 20 were undergoing hematopoietic stem cell transplantation. The odds ratio (OR) for overall risk of poorer outcomes in cases versus controls was 16.07 (95% CI: 5.55-46.54). The unfavorable outcome of switching the immunosuppressive drug (ISD) (14/40,35%) was no different from that of those treated with reduced ISD doses (31/71, 43.6%, P = .250). Acute rejection or graft-versus-host disease, previous transplant, and intensity of immunosuppression (4 ISDs plus induction or conditioning)

Risk factors for progression from low level BK dnaemia to unfavorable outcomes after BK management via immunosuppressive reduction

“…Our findings describing risk factors associated with progression to rejection after BKPyV-DNAemia corroborate previously published data describing risk factors for rejection in the absence of BKPyV-DNAemia, including non-depleting induction immunosuppression, a higher degree of HLA mismatch, and DGF. [31][32][33] This suggests the development of BKPyV-DNAemia and resultant management do not significantly modify risk factors for rejection that are identified at transplant. As these risk factors are well known, this information reinforces our current practice of evaluating rejection risk when modifying immunosuppression in the setting of BKPyV-DNAemia.…”

“…Recent literature suggests that the accepted practice of screening and immunosuppressive management does not improve outcomes in patients with BKPyV-DNAemia when compared to those who do not develop BKPyV-DNAemia. 33 Assays that measure immune response to BK infection and laboratory markers for BK progression could guide immunosuppressive modification and allow titration to response. In a study by Manzetti et al, BKPyV agnoprotein was identified as an important factor for immune escape and urinary shedding along with the rapid cellto-cell spread inside the renal tubules leading to the progression to BKPyVAN in KTRs.…”