(328 days)
The Technozvm ADAMTS13 Activity assay is an enzyme-linked immunosorbent assay (ELISA) intended for the qualitative determination of ADAMTS13 activity in platelet poor human citrated plasma. The assay is intended to be used in conjunction with other clinical and laboratory findings as an aid in the diagnosis of thrombotic thrombocytopenic purpura (TTP) in adult and pediatric patients being evaluated for thrombotic microangiopathy (TMA).
The Technozym ADAMTS13 Activity assay is an enzyme linked immunosorbent assay (ELISA) used for detection of ADAMTS13 activity in citrated human plasma. The assay contains: ADAMTS13 Activity anti-GST coated test plate microplate coated with anti-GST antibody, ADAMTS13 Activity GST-VWF73 reagent that contains GST tagged peptide of 73 amino acids from the A2 domain of VWF with specific cleavage site for ADAMTS13 and serves as the in vitro substrate for ADAMTS13, ADAMTS13 Activity Calibrators-consists of six vials containing lyophilized plasma, each with a different level of ADAMTS13 activity, ADAMTS13 Activity Controls consists of two vials of lyophilized plasma, each with high or low levels of ADAMTS13 activity, ADAMTS13 Activity Conjugate - reagent that contains horseradish peroxidase (HRP) conjugated monoclonal antibody directed against the neoepitope exposed due to cleavage of GST-VWF73 by ADAMTS13 present in plasma, ADAMTS13 TMB substrate reagent contains tetramethylbenzidine (TMB) substrate for HRP, ADAMTS13 Activity Stop Solution reagent contains 2.5% sulfuric acid for stopping the conversion of TMB substrate.
The Technozym ADAMTS13 Activity assay is a manual enzyme-linked immunosorbent assay (ELISA) intended for the qualitative determination of ADAMTS13 activity in platelet-poor human citrated plasma. It is used in conjunction with other clinical and laboratory findings as an aid in the diagnosis of thrombotic thrombocytopenic purpura (TTP) in adult and pediatric patients being evaluated for thrombotic microangiopathy (TMA). The assay's clinical cutoff for TTP diagnosis is 0.1 IU/mL ADAMTS13 activity.
Acceptance Criteria and Device Performance
The primary acceptance criteria for this device appear to be related to its analytical performance (precision, specificity), and its clinical performance (sensitivity and specificity for TTP diagnosis).
Here's a table summarizing the reported device performance, which implicitly serves as the acceptance criteria based on the successful De Novo grant:
| Performance Metric | Acceptance Criteria (Effectively Met) | Reported Device Performance (Mean %CV / % Correct Call / Sensitivity/Specificity) | Study Type |
|---|---|---|---|
| Within-laboratory Precision | Quantitative: Low %CV | S1-S9: 4.52% - 9.26% Within-laboratory %CV | Within-laboratory Precision Study |
| Qualitative: High % Correct Call | S1-S9: 100% correct call (at cutoff) | Within-laboratory Precision Study | |
| Operator-to-operator Precision | Quantitative: Low %CV | S1-S9: 5.59% - 10.08% Within-laboratory %CV | Operator-to-operator Precision Study |
| Qualitative: High % Correct Call | S1-S9: 100% correct call (at cutoff) | Operator-to-operator Precision Study | |
| Site-to-site Reproducibility | Quantitative: Low %CV | S1-S9: 8.01% - 10.45% Reproducibility %CV | Site-to-site Reproducibility Study |
| Qualitative: High % Correct Call | S1-S9: 100% correct call (at cutoff) | Site-to-site Reproducibility Study | |
| Analytical Specificity/Interference | No clinically significant interference | None of 25 tested substances led to clinically significant interference | Interference Study |
| Clinical Sensitivity (TTP) | High Sensitivity | 84.8% (95% CI: 69.1% to 93.3%) | Clinical Performance Study |
| Clinical Specificity (TTP) | High Specificity | 97.1% (95% CI: 91.9% to 99%) | Clinical Performance Study |
| Positive Predictive Value (TTP) | High PPV | 90.2% (95% CI: 75.2% to 96.6%) | Clinical Performance Study |
| Negative Predictive Value (TTP) | High NPV | 95.3% (95% CI: 90.0% to 97.8%) | Clinical Performance Study |
| Prozone Effect (Hook Effect) | No significant hook effect | No significant hook effect up to 8 IU/mL | Prozone Effect Study |
| Cross-contamination | No cross-contamination | No cross-contamination observed | Cross-contamination Study |
| Reagent Shelf-life | Adequate Shelf-life | 24 months at 2-8°C | Real-time Shelf-life Stability Study |
| Frozen Sample Stability | Adequate Stability | 12 months at |
N/A