Siemens filed initial mdr 1219913-2019-00248 on 11/18/2019.Additional information 12/06/2019: there is no sample that can be sent to siemens for further evaluation.Searches of the complaint database found no other complaints about false negative results with advia centaur xp hbsagii (hbsii) lot 192.As stated in the clinical sensitivity and specificity section of the advia centaur xp hbsii instruction for use (ifu) (10995358 revision 02, 2017-12) the clinical sensitivity is 100% with a 95% confidence interval (ci) of 99.09% - 100.00%.As stated in the limitations section of the advia centaur xp hbsii ifu "it is recognized that the current methods for the detection of hepatitis b surface antigen may not detect all potentially infected individuals.A nonreactive test result does not exclude the possibility of exposure to or infection with hepatitis b.A nonreactive test result in individuals with prior exposure to hepatitis b may be due to antigen levels below the detection limit of this assay or lack of antigen reactivity to the antibodies in this assay." although siemens has tested many different mutations (as outlined in the mutant hbsag detection section of the ifu), it is possible this sample has mutation(s) not yet evaluated.In addition to biotin, heterophilic antibodies can also interfere with advia centaur xp hbsii results.Patient samples with high levels of hbsag can cause a paradoxical decrease in the rlus (highdose hook effect).In the advia centaur xp hbsii assay, patient samples with levels of hbsag as high as 3.36 mg/ml are reactive.The cause of the false negative result seen by the customer with this one patient sample when using advia centaur xp hbsii lot 192 could not be determined, but hsc cannot rule out pre-analytical factors, a sample issue, or normal assay performance.Based on the investigation, no product problem was identified.No further evaluation of the device is required.Mdr 1219913-2019-00247 supplemental report 1 was filed for the same event for the initial result.
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