Table 3.
Performance of TRF assay in detecting PA as PA83, PA63, and toxin complex in clinical samples. Results of testing 100 μl sera from ten confirmed clinical cases (cutaneous, inhalation, and gastrointestinal) and ten healthy persons. Concentration was determined using a PA83 standard curve.a
Clinical Form | Time from Onset to Sera Collection (Days) |
Lethal Factorb
(ng/ml) |
anti-PA IgGc
(μg/ml) |
TRF PA detection | |
---|---|---|---|---|---|
Concenetration (ng/ml)d |
Coefficient of Variation (CV) (%) |
||||
Cutaneouse | 8 | 0.996 | <LLOQ | 1.97 | 15.7 |
Cutaneouse | 8 | 1.264 | <LLOQ | 1.02 | 14.8 |
Cutaneouse | 7 | 0.310 | <LLOQ | 1.12 | 2.2 |
Cutaneouse | 6 | 0.675 | <LLOQ | 1.70 | 17.3 |
Cutaneouse | 1 | <LOD | <LLOQ | 4.03 | 5.3 |
Cutaneouse | 3 | 1.105 | <LLOQ | 1.89 | 1.3 |
Cutaneouse | 5 | 0.035 | 4.0 | <LLOQ | NA |
Inhalation | 8 | 0.705 | 7.5 | 1.81 | 8.2 |
Inhalation | 2 | 57.985 | <LLOQ | 68.73 | 2.2 |
Gastrointestinal | 11 | 0.314 | 6.9 | 1.80 | 8.8 |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
Healthy control | NA | NA | <LLOQ | <LLOQ | NA |
NA = not applicable
Measured using mass spectrometry with a limit of detection (LOD) for lethal factor of <0.005 ng/ml (Boyer et al.,2007; Boyer et al., 2011a).
Measured using ELISA with a lower limit of quantification (LLOQ) for anti-PA IgG of ≤3.7 μg/ml (Semenova, 2012).
The limit of quantification (LOQ), based on the RDL, for PA is ≤0.551 ng/ml.
Lethal factor and anti-PA IgG data from Boyer et al., 2011b.
f 37.5 μl per well instead of 50 μl of sera was tested, result was divided by 0.75 to adjust for this volume difference.