The impact of FDA-cleared molecular solutions for BK polyomavirus quantitation

Accurate detection and monitoring of BK polyomavirus (BKV) infection is of critical importance in the post-transplant period, guiding treatment decisions that balance the anti-rejection effects of immune suppression with host-protective effects of immune defense. Historically, test methods for BKV have been independently developed by laboratories to address this unmet need. However, these assays can suffer from inconsistencies in analytical variability, which in turn have hindered the establishment of commutable and clinically actionable viral load thresholds for clinical management. As a result, the interpretation of viral load quantitation has not been standardized across transplant centers for the purpose of monitoring patients at highest risk for infection-related complications. In this review, we describe challenges that have historically limited widespread adoption of BKV quantitative testing. We then detail how developments in the field, including optimized amplicon selection, the introduction of an international standard, and the availability of Food and Drug Administration (FDA)-cleared methods, have played a role in harmonization of quantitative BKV measurements in the clinical management of transplant recipients.