Discordance for HIV-1 RNA levels at <200 copies/mla

Assay (at <200 copies/ml)% discordant results of ≥200 copies/ml (no. of discordant samples/total no. of samples)
AmplicorRealTimeTaqMan v1TaqMan v2
AmplicorNA5 (58/1,161)3 (7/204)
RealTimeNA10 (37/356)7 (49/728)
TaqMan v17 (85/1,188)16 (59/378)7 (25/236)
TaqMan v23 (7/204)3 (22/701)1 (3/314)
  • a Shown are the percentages of results that were discordant between the assays at a threshold of 200 copies/ml. The percentage of discordant samples decreased for all comparisons when a threshold of 200 copies/ml was used, compared to a 50-copies/ml threshold. NA, not available.