Table 2. Sensitivity and specificity of RT-QuIC assay for CJD skin samples.
NA, not available.
| Diagnosis | Lower back | Apex | Area near ear | Overall |
|---|---|---|---|---|
| sCJDVV1 | NA | + | NA | + |
| sCJDMM1 | NA | + | NA | + |
| sCJDVV1-2 | NA | + | NA | + |
| sCJDMM2 | NA | + | NA | + |
| sCJDMV2 | NA | + | NA | + |
| sCJDMM1 | NA | + | + | + |
| sCJDMM1 | +/−* | + | + | + |
| sCJDMM1 | +† | + | + | + |
| sCJDMM1 | −‡ | + | + | + |
| sCJDMM1 | + | +/− | + | + |
| sCJDVV2 | NA | + | + | + |
| sCJDVV2 | + | + | + | + |
| sCJDVV2 | NA | + | + | + |
| sCJDVV2 | + | + | + | + |
| sCJDMM2 | +/− | − | + | + |
| sCJDMM2 | NA | + | + | + |
| sCJDMM1-2 | + | + | + | + |
| sCJDMM1-2 | + | − | − | + |
| sCJDMV1-2 | + | + | + | + |
| sCJDMV1-2 | + | + | + | + |
| sCJDMV1 | + | + | + | + |
| Sensitivity (%) | 92 | 88 | 94 | 100§ |
| Non-CJD | − | − | − | − |
| Non-CJD | − | − | − | − |
| Non-CJD | NA | − | − | − |
| Non-CJD | − | − | − | − |
| Non-CJD | − | − | − | − |
| Non-CJD | − | − | − | − |
| Non-CJD | − | − | − | − |
| Specificity (%) | 100 | 100 | 100 | 100¶ |
*
Weak positive (+/−) means one of four or two of eight wells on two or more independent experiments.
†
Positive (+) RT-QuIC prion seeding activity.
‡
Negative (−) RT-QuIC prion seeding activity.
§
RT-QuIC analysis of skin samples from the torso or forearm of the UK vCJD and US vCJD patients, respectively, was RT-QuIC–positive and was included in the overall sensitivity and confidence interval calculations.
¶
RT-QuIC analysis of skin samples from the torso or forearm of eight non-CJD patients was RT-QuIC–negative and was included in the overall specificity and confidence interval calculations.