Diasorin (b)(4) received a complaint from a customer stating that a patient sample, previously graded as positive, resulted as negative after integral lot change.Data provided were reviewed: the sample tested on kit lots 358005, 358007 and 358008 resulted positive with kit lot 358005 and negative with kit lots 358007 and 358008.The sample was run on the first assay lot and a positive result was reported; weekly maintenance was performed, the new integral lot was calibrated, qc was run, and patient sample from the same tube was run again for lot comparison and graded negative.Each complained lot was internally tested for specificity and sensitivity.500 blood donor samples were tested for specificity obtaining the following results: kit lot 358005: 99%; kit lot 358007: 99,8%; kit lot 358008: 99,8% (ifu claim: 99,3% ic 95%: 98,6-99.6%).92 samples from commercial performance panel (pcr positive at least 11 days before) were tested for sensitivity obtaining the following results: kit lot 358005: 98,9%; kit lot 358007: 100%; kit lot 358008: 100% (ifu claim: 97,56% ic 95%: 87,4-99,57% - days from diagnosis >15).These results confirmed the absence of deviation in the assay performance.Customer added a re-run rule for sars-cov-2 assays: any sample resulting between 12-18 au/ml needed to be retested in duplicate.Results were shared: original result was 14.8 and, after repetition, the sample scored 16.5 and 16.4 au/ml.The resulting cv was 5.9% which is considered a good result.Samples were received from offsite already spun, but they were not poured off before transport.They were centrifuged once on-site.Complaint was classified as confirmed due to the occurrence of the event.Review of release data about reproducibility showed expected performance for all involved batches: no clear root cause could be identified and probable causes could be to be instrument- or handling-related.The performances of the liaison sars-cov-2 s1/s2 igg assay was verified and confirmed to be coherent with the claimed one.
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In light of the covid-19 pandemic and the subsequent authorizations (euas) for sars-cov-2 diagnostics tests and per the conditions of the emergency use authorization, suspected false negatives, false positives and significant changes in expected performance characteristics will be reported under 21 cfr 803.The alleged false test results in this event have not caused patient injury or death; however, this event is being reported conservatively because if the alleged malfunction were to recur there is a non-remote potential for serious injury or death.Diasorin (b)(4).Received a complaint from a customer stating that a patient sample, previously graded as positive, resulted as negative after a lot change.
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