Blinded, multicenter quality control study for the quantification of human immunodeficiency virus type 1 RNA in plasma by the Belgian AIDS reference laboratories

Objective In order to evaluate the interlaboratory variation of HIV-1 RNA measurements in plasma, the Belgian AIDS reference laboratories organized a blinded multicenter quality control study. Methods A test panel of coded spiked HIV-1 plasma samples reflecting the dynamic range of the assay was composed and distributed. The HIV-1 RNA concentration of these samples was determined by the right Belgian AIDS reference laboratories by means of the Amplicor HIV-1 Monitor Version 1.5 assay. Results Analysis of the results demonstrated that there was little interlaboratory variation for the high concentration range (4.0-5.7 log(10) copies/mL), never exceeding 0.2 log(10) copies/mL. However the standard deviation for the low concentration range (2.6-3.9 log(10) copies/mL) reached up to 0.22 log(10) copies/mL. Conclusions Since interlaboratory variability never reached 0.5 log(10) copies/mL and each of the laboratories was able co detect four-fold differences in plasma HIV-1 RNA levels, the Amplicor assay can be used in multicenter studies without a centralized analysis of samples. Furthermore, this well-characterized proficiency panel of spiked plasma samples could be used as a standard in the study of interassay comparisons.