WHO/BS/2015.2270 Collaborative Study to establish the 1st WHO IS for BKV DNA for nucleic acid amplification technique (NAT)-based assays
Overview
An international collaborative study was conducted to establish the 1 st WHO International Standard for use in the standardisation of Polyoma virus BKV nucleic acid amplification (NAT) technology assays. Two candidate samples of freeze-dried whole BKV virus preparations (subtype 1b-1 and 1b-2), formulated in 10mM Tris-HCl pH 7.4, 0.5% Human serum albumin (HSA), 0.1% D-(+)-Trehalose dehydrate, were analysed by 33 laboratories from 15 countries, each using their routine NAT-based assays for BKV detection. Of the two candidate samples 14/202 and 14/212 the latter was found to be most suitable for use as an international standard.
The results from the accelerated thermal degradation stability studies performed at 3 months have demonstrated that the candidate material is stable at temperatures used for storage (- 20°C) and laboratory manipulation (4°C to 20°C), as well 37°C to 45°C reflecting ambient temperature fluctuations encountered during global shipment. Further real-time stability studies will ensue to assess the long-term stability of the candidate.
Based upon the conclusion from the dataset received, it is proposed that the candidate sample (14/212; 4092 vials) be established as the 1st WHO International Standard for BKV DNA for nucleic acid amplification technique (NAT)-based assays with an assigned potency of 7.0 log10 IU/ mL per ampoule.