A customer in (b)(6) notified biomérieux of obtaining false positive results for five (5) patient samples while using the vidas® sars-cov-2 igm (9com) 60t (ref 423833, lot 1008206950).The customer reported that the results obtained for the five (5) samples were > 2.Index interpretation i < 1.00 negative: no detection of igm anti-sars-cov-2.I = 1.00 positive: detection of igm anti-sars-cov-2.Repeat analysis was performed with the vidas® sars-cov-2 igm kit and also obtained positive results.These same samples were then analyzed with an alternate chemiluminescence method and the results were negative.There is no indication or report from the customer that this event led to a delay in reporting results or any adverse event related to any patient's state of health.A biomérieux internal investigation has been initiated.Note: reference 423833 is not sold or distributed in the united states.However, u.S-only product reference, 423833-01, has the same formulation and physical properties as reference 423833.
|
A customer in italy notified biomérieux of obtaining a false positive in association with the vidas sars-cov-2 igm (ref.423833; lot# 1008206950).The customer had five patient samples with positive results.They repeated the tests, and again obtained positive results.They then performed chemiluminescence testing on the samples to confirm the result and results were negative for sars-cov-2.Investigation: biomérieux created an internal investigation for this customer issue.First the investigator reviewed the production history records for the lot in question.No anomalies were noted during the manufacturing, control, or packaging processes.The laboratory requested the customer send in the samples in question, but they indicated they did not have them available to submit.Biomérieux investigator then conducted specificity testing using 30 stored samples collected before the pandemic (expected to be negative) using retained samples from three lots (including the customer¿s lot) of vidas sars cov-2 igm (1008093230 / 210514-0, 1008125220 / 210605-0 and 1008206950/210715 -0).All tests produced a negative result.The investigation was unable to reproduce the positive results internally.Conclusion: without submission of the customer¿s sample, the laboratory is unable to investigate further.The nonspecific result could be due to interferences such as (but not limited to) autoimmune disorder (antinuclear antibodies) or rheumatoid factor.Possible cross-reactivity is described in the vidas sars cov-2 igm package insert (¿cross-reactivity¿ section).Package insert also details (in its own section) limitations of the method, noting: interference may be encountered with certain sera containing antibodies directed against reagent components.For this reason, assay results should be interpreted taking into consideration the patient's clinical history and the results of any other tests performed.Results obtained using samples from sars-cov-2 infected patients must be interpreted with caution.This assay is intended for qualitative detection only.Test value itself cannot be used to determine the quantity of sars cov 2 igm antibodies.The magnitude of the measured result above the threshold is not indicative of the total amount of antibody present in the sample.The individual immune response following sars-cov-2 infection varies considerably and might give different results with assays from different manufacturers.Results of assays from different manufacturers should not be used interchangeably.According to the investigation, vidas sars-cov-2 igm ref.423833 lot 1008206950 / 210715-0 is still within expected performance.
|