Siemens filed mdr 1219913-2019-00270 reporting discordant positive advia centaur xpt anti-hbs2 (ahbs2) patient results (initial and repeat testing from one sample) compared to the clinical picture, other clinical diagnostic test results as well as to the atellica im ahbs2 assay.Additional information - january 3, 2020.Based on the information received, no product problem has been identified.Siemens cannot rule out preanalytical factors or a sample issue or normal assay performance for the false positive results seen by the customer.Siemens reviewed the calibration and control data provided and there is no evidence of a problem.The patient has hbv but the customer was not able to provide a list of medications/supplements the patient is taking.There is no sample that can be sent to siemens for evaluation.The clinical sensitivity and specificity section of the advia centaur xp/xpt anti-hbs2.Instructions for use (ifu) lists the 95% confidence interval (ci) for resolved relative specificity as 98.34% - 99.88% so a certain number of false positive results can be expected for this assay.This 1 false positive sample does not indicate a product problem with advia centaur xpt ahbs2 lot 116.The cause of the false positive results seen by the customer with this one sample when using advia centaur xpt ahbs2 lot 116 could not be determined but siemens cannot rule out pre-analytical factors, a sample issue, or normal assay performance.Based on the investigation, no product problem was identified.
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