(266 days)
Alinity m BKV is an in vitro nucleic acid amplification test for the quantitation of BK virus (BKV) DNA in human EDTA plasma (K2 EDTA, K3 EDTA, and PPT) and urine stabilized using the Alinity m Urine Transport Kit on the automated Alinity m System.
In EDTA plasma (K2 EDTA, K3 EDTA, and PPT) and urine stabilized using the Alinity m Urine Transport Kit, Alinity m BKV is intended for use as an aid in the diagnosis and management of BKV in transplant patients.
In patients undergoing monitoring of BKV in EDTA plasma, serial DNA measurements can be used to indicate the need for potential treatment changes and to assess viral response to treatment.
The results from Alinity m BKV must be interpreted in conjunction with clinical signs and other relevant laboratory findings. Alinity m BKV is not cleared as a screening test for blood or blood products or human cells, tissues, and cellular and tissue-based products.
The Alinity m BKV assay utilizes real-time polymerase chain reaction (PCR) to amplify and detect BKV genomic DNA sequences that have been extracted from human EDTA plasma or urine specimens. The steps of the Alinity m BKV assay consist of sample preparation, real-time PCR assembly, amplification/detection, result calculation, and reporting. One transfer step of urine specimens into the Alinity m Urine Transport Kit by the user is required prior to placing urine specimens on the Alinity m System. Remaining steps of the Alinity m BKV assay procedure are executed automatically by the Alinity m System. Manual dilutions may be performed for low-volume plasma specimens to meet the minimum volume requirement. The Alinity m System is designed to be a randomaccess analyzer that can perform the Alinity m BKV assay in parallel with other Alinity m assays on the same instrument.
Alinity m BKV requires three separate assay specific kits as follows:
- . Alinity m BKV AMP Kit (List No. 09N85-095), consisting of 2 types of multi-well assay trays. The amplification tray (AMP TRAY 1) contains liquid, unit-dose PCR amplification/detection reagents and liquid, unit-dose Internal Control (IC) in separate wells; and the activation tray (ACT TRAY 2) contains liquid, unit-dose activation reagent. The intended storage condition for the Alinity m BKV AMP Kit is -25°C to -15°C.
- . Alinity m BKV CTRL Kit (List No. 09N85-085), consisting of negative controls, low positive controls, and high positive controls, each supplied as liquid in single-use tubes. The intended storage condition for the Alinity m BKV CTRL Kit is -25°C to -15°C.
- Alinity m BKV CAL Kit (List No. 09N85-075), consisting of 2 calibrator levels, . each supplied as liquid in single-use tubes. The intended storage condition for the Alinity m BKV CAL Kit is -25°C to -15°C.
The Alinity m BKV assay requires a transport kit for testing all urine specimens:
- Alinity m Urine Transport Kit (List No. 09N85-001) consisting of a transport tube . and transfer pipette. The transport tube contains transport buffer. The intended storage condition for the Alinity m Urine Transport Kit is 15℃ to 30℃.
BKV DNA from human plasma or urine is extracted automatically on board the Alinity m System using the Alinity m Sample Prep Kit 2, Alinity m Lysis Solution, and Alinity m Diluent Solution. The Alinity m System employs magnetic microparticle technology to facilitate nucleic acid capture, wash, and elution. The resulting purified DNA is then combined with liquid unit-dose Alinity m BKV activation reagent and liquid unit-dose Alinity m BKV amplification/detection reagents and transferred into a reaction vessel. Alinity m Vapor Barrier Solution is then added to the reaction vessel which is then transferred to an amplification/detection unit for PCR amplification and real-time fluorescence detection of BKV DNA.
At the beginning of the Alinity m BKV sample preparation process, a liquid unit-dose IC on the AMP Tray is transferred by the Alinity m System and delivered into each sample preparation reaction. The IC is then processed through the entire sample preparation and real-time PCR procedure along with the specimens, calibrators, and controls to demonstrate proper sample processing and validity.
The Alinity m BKV amplification/detection reagents consist of enzymes, primers, probes, and activation reagents that enable amplification and detection of dual targets in the BKV genome. Amplification and detection of the two BKV targets ensures sensitive detection of the viral genome even at low levels. In addition to the BKV primers and probes, the assay utilizes an IC primer/probe set for amplification and detection of the IC target sequence, which is not related to BKV. The IC probe is labeled with a different fluorophore than the BKV probes. This allows for simultaneous detection and discrimination of both the BKV and IC amplified products within the same reaction vessel.
A BKV calibration curve is required for determination of BKV DNA concentration. Two levels of calibrators are processed through sample preparation and PCR to generate the calibration curve. The concentration of BKV DNA in specimens and controls is then calculated from the stored calibration curve.
Assay controls are tested at or above an established minimum frequency to help ensure that instrument and reagent performance remains satisfactory. During each control event, a negative control, a low-positive control, and a high positive control are processed through sample preparation and PCR procedures that are identical to those used for specimens.
The Alinity m BKV assay also utilizes the following:
- Alinity m BKV Application Specification File (List No. 09N85-05A) .
- Alinity m System and System Software (List No. 08N53-002)
- Alinity m Sample Prep Kit 2 (List No. 09N12-001)
- . Alinity m Specimen Dilution Kit I (List No. 09N50-001)
- . Alinity m System Solutions, (List No. 09N20):
- o Alinity m Lysis Solution (List No. 09N20-001)
- o Alinity m Diluent Solution (List No. 09N20-003)
- o Alinity m Vapor Barrier Solution, (List No. 09N20-004)
- Alinity m Tubes and Caps (List No. 09N49): •
- Alinity m LRV Tube (List No. 09N49-001) o
- o Alinity m Transport Tubes Pierceable Capped (List No. 09N49-010)
- o Alinity m Transport Tube (List No. 09N49-011)
- o Alinity m Pierceable Cap (List No. 09N49-012)
- o Alinity m Aliquot Tube (List No. 09N49-013)
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Plasma Performance | Urine Performance |
|---|---|---|
| Limit of Detection (LoD) (95% detection probability) | Claimed LoD: 50 IU/mL (1.70 Log IU/mL) | Claimed LoD: 50 IU/mL (1.70 Log IU/mL) |
| (Genotypes Ia, Ic, II, III, IV detection at ≥95%) | All genotypes detected at ≥95% at 30 IU/mL (1.48 Log IU/mL) | All genotypes detected at ≥95% at 45 IU/mL (1.65 Log IU/mL) |
| Linear Range (Quantitation Range) | 50 IU/mL (1.70 Log IU/mL) to 1,000,000,000 IU/mL (9.00 Log IU/mL) (r=1.000) | 50 IU/mL (1.70 Log IU/mL) to 1,000,000,000 IU/mL (9.00 Log IU/mL) (r=1.000) |
| (Linearity for Genotypes) | Established for Ia, Ic, II, III, IV across the quantitation range | Established for Ia, Ic, II, III, IV across the quantitation range |
| Precision (Within-laboratory SD for Log IU/mL) | ≤ 0.25 Log IU/mL for 2.70-9.00 Log IU/mL; ≤ 0.50 Log IU/mL for 1.70-0.4% w/v) and PBMCs (>1 × 10^5 cells/mL). | |
| Carryover | 0.0% (95% CI: 0.0% to 1.1%) | 0.0% (95% CI: 0.0% to 1.1%) |
| Clinical Agreement (Plasma) | High agreement with comparator across viral load ranges: 100% for TND, 100% for |
§ 866.3183 Quantitative viral nucleic acid test for transplant patient management.
(a)
Identification. A quantitative viral nucleic acid test for transplant patient management is identified as a device intended for prescription use in the detection of viral pathogens by measurement of viral DNA or RNA using specified specimen processing, amplification, and detection instrumentation. The test is intended for use as an aid in the management of transplant patients with active viral infection or at risk for developing viral infections. The test results are intended to be interpreted by qualified healthcare professionals in conjunction with other relevant clinical and laboratory findings.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The labeling required under § 809.10(b) of this chapter must include:
(i) A prominent statement that the device is not intended for use as a donor screening test for the presence of viral nucleic acid in blood or blood products.
(ii) Limitations which must be updated to reflect current clinical practice. These limitations must include, but are not limited to, statements that indicate:
(A) Test results are to be interpreted by qualified licensed healthcare professionals in conjunction with clinical signs and symptoms and other relevant laboratory results; and
(B) Negative test results do not preclude viral infection or tissue invasive viral disease and that test results must not be the sole basis for patient management decisions.
(iii) A detailed explanation of the interpretation of results and acceptance criteria must be provided and include specific warnings regarding the potential for variability in viral load measurement when samples are measured by different devices. Warnings must include the following statement, where applicable: “Due to the potential for variability in [analyte] measurements across different [analyte] assays, it is recommended that the same device be used for the quantitation of [analyte] when managing individual patients.”
(iv) A detailed explanation of the principles of operation and procedures for assay performance.
(2) Design verification and validation must include the following:
(i) Detailed documentation of the device description, including all parts that make up the device, ancillary reagents required for use with the assay but not provided, an explanation of the methodology, design of the primer/probe sequences, rationale for the selected gene target, and specifications for amplicon size, guanine-cytosine content, and degree of nucleic acid sequence conservation. The design and nature of all primary, secondary and tertiary quantitation standards used for calibration must also be described.
(ii) A detailed description of the impact of any software, including software applications and hardware-based devices that incorporate software, on the device's functions;
(iii) Documentation and characterization (
e.g., determination of the identity, supplier, purity, and stability) of all critical reagents and protocols for maintaining product integrity throughout its labeled shelf-life.(iv) Stability data for reagents provided with the device and indicated specimen types, in addition to the basis for the stability acceptance criteria at all time points chosen across the spectrum of the device's indicated life cycle, which must include a time point at the end of shelf life.
(v) All stability protocols, including acceptance criteria.
(vi) Final lot release criteria along with documentation of an appropriate justification that lots released at the extremes of the specifications will meet the claimed analytical and clinical performance characteristics as well as the stability claims.
(vii) Risk analysis and documentation demonstrating how risk control measures are implemented to address device system hazards, such as Failure Mode Effects Analysis and/or Hazard Analysis. This documentation must include a detailed description of a protocol (including all procedures and methods) for the continuous monitoring, identification, and handling of genetic mutations and/or novel viral stains (
e.g., regular review of published literature and annual in silico analysis of target sequences to detect possible primer or probe mismatches). All results of this protocol, including any findings, must be documented.(viii) Analytical performance testing that includes:
(A) Detailed documentation of the following analytical performance studies: limit of detection, upper and lower limits of quantitation, inclusivity, precision, reproducibility, interference, cross reactivity, carry-over, quality control, specimen stability studies, and additional studies as applicable to specimen type and intended use for the device;
(B) Identification of the viral strains selected for use in analytical studies, which must be representative of clinically relevant circulating strains;
(C) Inclusivity study results obtained with a variety of viral genotypes as applicable to the specific assay target and supplemented by in silico analysis;
(D) Reproducibility studies that include the testing of three independent production lots;
(E) Documentation of calibration to a reference standard that FDA has determined is appropriate for the quantification of viral DNA or RNA (
e.g., a recognized consensus standard); and(F) Documentation of traceability performed each time a new lot of the standardized reference material to which the device is traceable is released, or when the field transitions to a new standardized reference material.
(ix) Clinical performance testing that includes:
(A) Detailed documentation from either a method comparison study with a comparator that FDA has determined is appropriate, or results from a prospective clinical study demonstrating clinical validity of the device;
(B) Data from patient samples, with an acceptable number of the virus-positive samples containing an analyte concentration near the lower limit of quantitation and any clinically relevant decision points. If an acceptable number of virus-positive samples containing an analyte concentration near the lower limit of quantitation and any clinically relevant decision cannot be obtained, contrived samples may be used to supplement sample numbers when appropriate, as determined by FDA;
(C) The method comparison study must include predefined maximum acceptable differences between the test and comparator method across all primary outcome measures in the clinical study protocol; and
(D) The final release test results for each lot used in the clinical study.