Table 1.
Cytomegalovirus (CMV) DNA load values in plasma obtained with three different QRT-PCR assays coupled to three distinct automated extraction systems
| QRT-PCR assay and extraction system | CMV DNA load, log10 copies/ml, for groupa: |
||
|---|---|---|---|
| <3 (n = 10) | 3–4 (n = 22) | >4 (n = 10) | |
| Abbottb | |||
| m24 | 2.55 (0.19) | 3.61 (0.31) | 4.33 (0.18) |
| AmpliPrep | 2.14 (0.77) | 3.43 (0.38) | 4.20 (0.23) |
| EZ1 | 2.80 (0.17) | 3.80 (0.41) | 4.48 (0.26) |
| Rochec | |||
| m24 | ND | 3.79 (0.37) | 4.38 (0.23) |
| AmpliPrep | ND | 3.63 (0.31) | 4.17 (0.23) |
| EZ1 | ND | 4.04 (0.31) | 4.47 (0.25) |
| Nanogend | |||
| m24 | 3.22 (0.15) | 4.03 (0.26) | 4.81 (0.20) |
| AmpliPrep | 3.05 (0.11) | 3.80 (0.26) | 4.47 (0.28) |
| EZ1 | 3.32 (0.18) | 4.13 (0.30) | 4.82 (0.21) |
Specimens were subgrouped into three categories according to CMV DNA loads measured by using the Abbott real-time PCR assay (coupled with the Abbott mSample preparation system DNA kit on the m24 SP instrument). Data are reported as mean values (standard deviation) of CMV DNA loads quantitated in specimens testing positive by a given QRT-PCR assay. ND, not detected.
One of 10 specimens extracted with the AmpliPrep method tested negative by the Abbott QRT-PCR.
Only one out of 10 specimens with <3 log10 copies/ml extracted with the m24 SP and AmpliPrep systems and two extracted with the EZ1 system tested positive by the Roche QRT-PCR. Two specimens with CMV DNA loads between 3 and 4 log10 copies/ml extracted with the m24 SP, AmpliPrep, and EZ1 methods tested negative by the Roche QRT-PCR.
Three specimens (<3 log10 copies/ml) extracted with the AmpliPrep system and one (<3 log10 copies/ml) extracted with the EZ1 system tested negative by the Nanogen QRT-PCR.