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An evaluation is in process.A follow-up report will be submitted when the evaluation is complete.All available patient information was included.Additional patient details are not available.This report is being filed on an international product, list number 06r87-22, that has a similar product distributed in the us, list number 06r87-20.
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The customer observed a false positive sars-cov-2 igm result for one patient on an architect i1000sr analyzer.The following data was provided (<1.00 index (s/c) is negative, >/= 1.00 index (s/c) is positive): result, on (b)(6) 2021, was 19.11 index (s/c), repeated on (b)(6) 2021 was the same result.The sars-cov-2 igg quant result was 3.7 bau/ml, which is negative.The rna swab result was also negative.The patient was retested at another laboratory on (b)(6) 2021 with a different testing platform and the sars-cov-2 igm s1,s2,n result was 0.24 au/ml, which is negative.The sars-cov-2 igg rbd result was 3.37 bau/ml, which is negative.There was no impact to patient management reported.
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The complaint investigation for false positive architect sars-cov-2 igm results included a search for similar complaints, the review of complaint text, trending data, labeling, scientific literature, and device history records.Return testing was not complete as returns were not available.Specificity and sensitivity testing were done using an in-house retained kit of lot 27104fn00, stored at the recommended storage conditions.All validity and acceptance criteria were met indicating that the lot is performing acceptably.Device history record review on lot 27104fn00 did not show any potential non-conformances or deviations.Labeling was reviewed and found to adequately address the issue under review.The customer obtained a positive igm result of 19.11 index on 25may2021 for one patient sample when testing was performed with architect sars-cov-2 igm, lot 27104fn00.The patient sample returned a negative result of 3.7 bau/ml/26 au/ml (cutoff 7.1 bau/ml/50au/ml) for architect sars-cov-2 igg ii.The sample was repeated on 28may2021 with similar results obtained.The rna swab was also negative.A new sample collected approximately 2 days after the first sample was tested on an alternate platform (clia) which returned a negative result of 0.24 au/ml (cutoff 1.0 au/ml) for igm s1,s2,n and a negative result of 3.37 bau/ml (cutoff 4.33 bau/ml) for igg rbd.The additional sample was not re-tested on architect and it is not possible to obtain a further sample from the patient.In this case, the sample was positive for igm with a negative but elevated result obtained for igg ii indicating that antibody is present in the sample.Although the sample was negative on the alternate method for igm and igg, an elevated igg result was also generated with some signal also observed for igm.A direct comparison should not be made between the abbott assay and the alternate method as the abbott assay utilizes cmia technology and the alternate method is a different test methodology (clia technique).Per igm product labeling, the host immune system reacts to the infection by sars-cov-2 by producing specific antibodies.These antibodies have been reported to appear in serum or plasma of infected individuals after the detection of viral ribonucleic acid (rna) in swabs and a few days to 2 weeks after the onset of symptoms.Specific igm antibodies to sars-cov-2 may be detectable in covid-19 patients during the symptomatic phase of the disease after rna is no longer detectable.At this time, duration and strength of the igm antibody response continue to be characterized; the kinetics of this response are unknown.Per the clinical performance section of the package insert, a study was performed to estimate the negative percent agreement (npa), 2965 serum and plasma specimens from subjects assumed to be negative for sars-cov-2 were tested using the sars-cov-2 igm assay.All of the specimens were collected prior to september 2019 (pre-covid-19 outbreak).The npa is 99.56% (95% ci: 99.25, 99.74).The publication ¿longitudinal characterization of the igm and igg humoral response in symptomatic covid-19 patients using the abbott architect¿, g.N.Maine et al., https://doi.Org/10.1016/j.Jcv.2020.104663, evaluated the clinical performance of abbott sars-cov-2 igm and igg assays, as well as the longitudinal dynamics of the antibody response in symptomatic covid-19 patients.Clinical test sensitivity of the sars-cov-2 igm assay demonstrated that peak test sensitivity was reached at 4 to 5 weeks (96%) post symptom onset.A study of the longitudinal dynamics of igm in sars-cov-2 infected patients shows that igm levels declined steadily 4 to 5 weeks after symptom onset, and the positive rate dropped to 30.8 % at >3 months.The publication further documents that igm can persist in a small proportion of individuals beyond 3 months.The publication ¿characterization of antibody responses to sars-cov-2 in convalescent covid-19 patients¿, liu c, yu x, gao c, et al, https://doi.Org/10.1002/jmv.26646 , does not involve use of the abbott assay but demonstrated that igm reached its highest positivity rate (90.4%) in the first month after symptom onset.The positivity rate for igm declined over time however some individuals remained positive 6 months after symptom onset.Results should be used in conjunction with other data, e.G., symptoms, results of other tests, and clinical impressions.Results from antibody testing should not be used as the sole basis to diagnose or exclude sars-cov-2 infection or to inform infection status.Based on the investigation architect sars-cov-2 igm reagent lot 27104fn00 is performing as intended, no systemic issue or deficiency was identified.
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