(123 days)
The Alethia CMV Assay Test System includes separately provided test kits for the Alethia CMV DNA Amplification Assay and the Alethia CMV External Control Reagents.
The Alethia CMV DNA Amplification Assay, performed on the Alethia instrument, is a qualitative, in vitro diagnostic test system for the direct detection of Cytomegalovirus (CMV) DNA in saliva samples from neonates younger than 21 days of age. The test is used as an aid in the diagnosis of congenital CMV infection. The results of this test should be used in conjunction with the results of other clinical findings.
Flocked swabs should be used to collect saliva from neonates. The swab can be collected dry, without viral transport media (VTM), or placed in no more than 1 mL VTM.
The Alethia CMV External Control Reagents are used as part of a routine quality control program to aid the user in detection of unexpected conditions that may lead to test errors. The external controls are intended for use with the Alethia CMV DNA Amplification Assay; the controls are not intended for use with other assays or systems.
The Alethia CMV Assay Test System, including the Alethia CMV DNA Amplification Assay and the Alethia CMV External Controls, is based on loopmediated amplification (LAMP) technology. The assay targets a region of the Cytomegalovirus genome that is conserved across multiple CMV strains. The Alethia CMV target is a 194 base pair (bp) sequence of the Human herpesvirus 5 genome.
LAMP uses specially designed primers to provide for specific and continuous isothermal DNA amplification. A bv-product of amplification is magnesium pyrophosphate, which forms a white precipitate leading to a turbid solution. Reaction solution absorbance characteristics are monitored by the Alethia™ instrument.
Changes in reaction solution turbidity created by precipitation of magnesium pyrophosphate indicate the presence of target DNA. The absence of target DNA results in no significant change in sample absorbance.
The Alethia CMV DNA Amplification Assay is a qualitative in vitro diagnostic test for the direct detection of Cytomegalovirus (CMV) DNA in saliva samples from neonates younger than 21 days of age. It aids in the diagnosis of congenital CMV infection.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Implicit from study results and regulatory requirements) | Reported Device Performance (from "Clinical studies" section) |
|---|---|
| Clinical Performance: | |
| Positive Percent Agreement (PPA) with Composite Reference Method | 100% (39/39) [95% CI: 91.0%; 100%] |
| Negative Percent Agreement (NPA) with Composite Reference Method | 99.8% (1,472/1,475) [95% CI: 99.4%; 99.9%] |
| Invalid Rate (Initial) | 1.7% (27/1,548) |
| Invalid Rate (Final, after re-testing) | 0.06% (1/1,548) [95% CI: 0.01%; 0.37%] |
| Analytical Performance: | |
| Limit of Detection (LoD) - Dry Swab | 1,025 copies/mL |
| Limit of Detection (LoD) - Swab in VTM | 15,686 copies/mL |
| Inclusivity (tested for 3 additional CMV strains) | 100% positive for AD-169, Toledo, and Towne strains at 2-3X LoD. |
| Cross-Reactivity (panel of 40 microorganisms and human genomic DNA) | No cross-reactivity observed. |
| Microbial Interference (panel of 40 microorganisms and human genomic DNA) | No microbial interference observed (all CMV positive samples remained positive). |
| Chemical/Biological Interfering Substances | No interference observed with specified substances at tested concentrations (except for mucin at 50 mg/mL, mitigated by labeling). |
| Sample Stability (room temp, refrigerated, frozen, freeze-thaw) | Supports storage for up to 48 hours at 19-30°C, 7 days at 2-8°C, or **frozen at |
§ 866.3181 Cytomegalovirus nucleic acid detection device for congenital cytomegalovirus infection.
(a)
Identification. A cytomegalovirus nucleic acid detection device for congenital cytomegalovirus infection is an in vitro diagnostic device intended for the qualitative detection of cytomegalovirus DNA in clinical samples from newborn babies to aid in the diagnosis of congenital cytomegalovirus infection. Negative results do not preclude infection and should not be used as the sole basis for diagnosis, treatment, or other patient management decisions. Positive results should be interpreted with consideration of other clinical information and laboratory findings and should not be used as the sole basis for treatment or other patient management decisions.(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) An intended use with a detailed description of what the device detects, the type of results provided to the user, the clinical indications appropriate for test use, and the specific population(s) to be tested.
(ii) A detailed device description, including all device components, instrument requirements, ancillary reagents required but not provided, and an explanation of the methodology, including all pre-analytical methods for specimen processing.
(iii) Performance characteristics from analytical and clinical studies required under paragraphs (b)(2)(ii) and (iii) of this section.
(iv) A detailed explanation of the interpretation of results and criteria for validity of results.
(v) A limiting statement that device results are not intended to be used as the sole basis for diagnosis, treatment, or other patient management decisions.
(vi) As applicable, a limiting statement and specific sample collection recommendations to indicate that breast milk can result in false positive results for saliva samples if samples are collected less than 1 hour after breastfeeding. Sample collection a minimum of 1 hour from breastfeeding must be recommended.
(vii) Detailed instructions for use that minimize the risk of generating a false result.
(2) Design verification and validation must include:
(i) Detailed device description documentation, including methodology from obtaining sample to result, design of primer/probe sequences, rationale for sequence selection, and computational path from collected raw data to reported result (
e.g., how collected raw signals are converted into a reported result).(ii) Detailed documentation of analytical studies including characterization of the cutoff, analytical sensitivity (limit of detection), inclusivity, reproducibility, interference, cross reactivity, instrument and method carryover/cross contamination, and sample stability and handling.
(iii) Detailed documentation from a clinical study documenting sensitivity and specificity of the device; if the number of positive samples in the clinical study is insufficient to properly estimate device sensitivity, additional pre-selected positive samples must be evaluated to supplement the study. Clinical study subjects must be consistent with the intended use population (
i.e., infants younger than 21 days of age), and device results must be compared to FDA-accepted comparator methods. Documentation from the clinical study must include the clinical study protocol, the clinical study report, testing results, and results of all statistical analyses.(iv) Detailed documentation for device software, including software applications and hardware-based devices that incorporate software.