A customer in (b)(6) notified biomérieux of obtaining false negative results for a patient sample when using vidas® sars-cov-2 igg (9cog) 60t (ref.423834, lot 1008364310 expiry 12oct2021) on their vidas® instrument (serial number (b)(4)).The customer reported bad correlation when using vidas sars cov2 igg compared to other systems as described below.The concerned patient was a woman ((b)(6) years old) who was infected and treated for covid in (b)(6) 2020 (pcr was positive).The customer tested a sample from this patient on (b)(6) 2021 with vidas sars cov 2 igg (lot 1008364310) and obtained a negative result (tv 0.48).The patient went to another lab on (b)(6) 2021, this laboratory tested a new sample from this patient with roche cobas 411 and obtained a positive result (index 51.95 - interpretation: >/=1 positive; <1 negative).The customer tested a third sample from the same patient with vidas sars cov 2 igg (lot 1008364310) on (b)(6) 2021 and obtained a negative result (tv 0.40).The last sample was also sent to a third laboratory and was tested with abbott igg test , the result was positive (index 1.60 ( interpretation >1.4 result positive).This sample was also tested with igm test (abbott) and the result was negative.There is no indication or report from the laboratory or physician that the discrepant results led to any adverse event related to the patient's state of health.A biomérieux internal investigation has been initiated.Note: reference 423834 is not sold or distributed in the united states.However, u.S.-only product reference, 423834-01, has the same formulation and physical properties as reference 423834.
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An investigation was initiated in response to a customer complaint of obtaining a suspected false negative result when testing a patient's samples on vidas® sars cov-2 igg lot 1008364310/211012-1.The customer¿s sample was no longer available to be submitted for the investigation.The analysis of the batch history record of vidas sars cov-2 igg batch 1008364310/211012-1 did not highlight any issue during control and packaging processes.During control chart analysis, analysis carried out for five (5) internal samples (two with a negative target and three with a positive one) on seven (7) batches of vidas sars cov-2 igm assay including the lot mentioned by customer (211012-0/211012-1).The analysis showed that the samples comply with the expectations, and vidas sars cov-2 igg batch 1008364310/211012-1 is in the trend compared to the other lots.The complaints laboratory tested three (3) internal samples with a positive target on vidas sars cov-2 igg lot 1008364310/211012-1.All the samples gave results in accordance with the expectations and similar to those obtained before the batch release.No evolution of the activity of vidas sars cov-2 igg lot 1008364310/211012-1 was observed over time.The negative result observed by the customer was not reproduced when testing internal samples on vidas sars cov-2 igg lot 1008364310/211012-1.Unfortunately, without any concerned sample available, it was not possible to pursue further the investigation, so no root cause could be identified.Regarding the possible explanation, a particular serological profile with a specific antibodies distribution (against either nucleocapsid antigen, spike protein or rbd sub domain) might explain the discrepant results observed by the customer.For information, roche anti sars cov-2 method detects all the ig antibodies (iga, igm and igg) against nucleocapsid antigen while vidas sars cov-2 assays give a separate answer about ig antibodies against a subdomain of spike protein (receptor binding protein = rbd).Regarding abbott anti-sars cov-2 igg method (1st generation), it allows the detection of igg antibodies against nucleocapsid protein.It is mentioned in the package insert of vidas sars cov-2 igg ref.423834 at the section limitations of the method.Results obtained using samples from sars-cov-2 infected patients must be interpreted with caution.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 investigation outcomes, there is no reconsideration of the performance of vidas sars cov-2 igg batch vidas sars cov-2 igg lot 1008364310/211012-1 to its expectations.
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