This report was initially submitted following notification from a customer in croatia regarding false negative results in association with the vidas® measles igg 60tests (ref.30219, lot 1007322860).The customer stated seventeen (17) patients were tested using vidas® measles igg 60tests lot 1007322860 and using the virotech test method.Seven (7) patients had no interpretation change in their results.Ten (10) patients obtained a negative result with the vidas® vidas® measles igg 60tests and a positive result using virotech.A biomérieux internal investigation has been completed with the following results: customer's material: five (5) patients' samples with id (b)(6) were received.Complaint trending analysis: complaint analysis found one complaint for sensitivity issues and two complaints for discrepant results on vidas measles igg batch 1007322860/200325-0.There is neither capa nor non conformity linked to the object of this issue.Analysis of control charts: analysis of five (5) internal samples from activity panel was carried out on eight (8) lots of vidas measles igg including the customer lot 1007322860/200325-0.Vidas measles igg lot 1007322860/200325-0 had a trend to give results slightly lower compared to other lots but remained compliant to the release criteria of this vidas assay.Tests performed internally: on internal samples.Five (5) positive samples with a positive target were selected according to their weak indexes and two (2) of them had a target just above the positive threshold.They were tested on retain kits of the vidas measles igg batch mentioned by the customer 1007322860/200325-0.The five (5) samples were within their acceptable range.There was no global evolution observed over time.On customer's samples: five (5) patients' samples were tested on four (4) different vidas measles igg batches including the batch mentioned by the customer.The negative results observed by the customer for samples (b)(6) were reproduced on all vidas measles igg batches including the one mentioned by the customer.For sample (b)(6), there was a distribution of results in both side of the thresholds depending on the vidas measles igg batch used.According to the investigation conducted by the industrialization and support team, including tests performed on additional samples from internal biobank, there is no reconsideration of the between-lot variability of vidas measles igg assay ref.30219 which still be in accordance with the precision profile of vidas measles parameter.It is mentioned in the vidas measles igg assay ref.30219 in the results and interpretation section: the imprecision inherent in any method implies a lack of confidence in samples with test values very close to the thresholds.Consequently, an equivocal zone is established between the thresholds based on a statistical understanding of this imprecision.Conclusion: although negative results were reproduced on some samples (e.G customer's samples) and some differences of test values were observed, there is no reconsideration of vidas measles igg assay performances.The results observed on one patient's sample is due to its activity close to the threshold leading a distribution on both sides.According to all the data issued during the both investigations, there is no reconsideration of the vidas measles igg lot.There is no uprising trend of complaints on the lot mentioned by the customer.The vidas measles igg lot 1007322860/200325-0 was still within specifications.
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