Development of the 1st International Reference Panel for HIV-1 RNA genotypes for use in nucleic acid-based techniques.

Twenty-eight laboratories from 16 countries participated in a collaborative study to evaluate an HIV-1 RNA Genotype Reference Panel for use with nucleic acid-based tests (NAT). The Reference Panel consisted of 11 coded samples representing different HIV-1 genotypes (subtypes A-D, AE, F, G, AA-GH, groups N and O) as well as a negative diluent control. Each laboratory assayed the eleven panel members concurrently with the 1st International Standard for HIV-1 RNA (NIBSC Code 97/656) on at least three separate occasions and the data collated and analysed at NIBSC. Twenty-nine sets of data from NAT were received, 19 from quantitative and 10 from qualitative assays, with six different commercial assays and five "in-house" assays represented. The results showed that viruses from subtypes A-D and recombinant virus AE [CRF01_AE] were detected consistently, but that some assays had difficulty with the detection and quantification of viruses from subtypes F and G, a mixed recombinant virus AA-GH and a representative of group N. Furthermore, most assays failed to detect the group O representative. The study illustrated the limitations of some molecular assays particularly in detection of certain non-B genotypes which are important viruses in the global AIDS pandemic and illustrated the value of a well-characterised genotype panel. The panel has been established by the World Health Organisation's Expert Committee on Biological Standardisation as the 1st International Reference Panel HIV-1 RNA Genotypes (code 01/466).