Mdr was filed on september 4, 2018 reporting an elevated advia centaur xp rubella igg (rubg) result compared to an alternate method.September 5, 2018, additional information.The customer provided the following information: the following results are all from the same patient.The sample from the first collection, sid: (b)(6) was re-run on july 26 2018 and resulted as 51.5 iu/ml and rerun again on july 27, 2018 and resulted as 58 iu/ml.A recollected sample from same patient, sid: (b)(6) was run on august 09, 2018.The first result was 59.1 iu/ml and repeated as 54.6 iu/ml.Sid: (b)(6), which was from the 2nd collection from the same patient was repeated on august 10 and resulted as 57 iu/ml.All the above 3 samples were tested on an alternate method on the same day and all results were <10 iu/ml.The patient did not receive a booster before the blood was tested on the advia centaur.The patient's immune status to rubella was in question as a result of the discrepancy between the different vendors.Following the second round of sample testing, the requesting doctor began to suspect that something in the patient serum was interacting with the advia centaur assay.The third sample tested by the customer and a competitor provided the same consistent results to the prior two collections (reactive on advia centaur, "immune" and non-reactive, "non-immune" on the other method).Following the third collection, the patient has been administered a rubella booster vaccine as suspected non-immune/non-responder to their original vaccine.The patient had her blood drawn a second time because of the original incorrect result.The sample was collected in a sst bd vacutainer.The samples are spun for 10 minutes at 3000 rpm at 25 degrees.The customer used advia centaur rubg lot: 202 during the repeat runs in may.The patient is on no known medications.275 test results from period of usage 26/3/18 to end of use 04/04/18 were available.13 results were non reactive (1 equivocal, 261 reactive).Lot: 202 was in use 04/04/18- 25/06/18.Out of 3043 total tests, 95 were non reactive (40 equivocal, 2908 reactive).Lot: 204 is in use 25/06/18- current; out of 2957 total tests, 71 non reactive (47 equivocal, 2839 reactive).Siemens continues to investigate.Mdr 1219913-2018-00213 supplemental report 1 was filed for the same event.
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Mdr 1219913-2018-00212 was filed on september 4, 2018 reporting an elevated advia centaur xp rubella igg (rubg) result compared to an alternate method.Mdr 1219913-2018-00212 supplemental 1 was filed on september 25, 2018 with additional information.December 3, 2018: siemens received the sample from (b)(6) 2018, sample id (b)(4) and tested it on two lots of advia centaur xp rubella g reagents, reagent lots 204 and 206 and on the immulite 2000xpi.The advia centaur xp rubella g results were 91.4 and 54.35 iu/ml(reactive results) respectively.The immulite 2000xpi result was 8.18 u/ml (indeterminate result).The sample was treated with a heterophilic blocking tube and tested with advia centaur xp rubella g reagent lots 204 and 206 and the results were 92.07 and 53 iu/ml respectively.These results indicate a non specific interferent in the sample.The elevated results is observed on multiple reagent lots and indicate that the issue is not a specific lot or a specific system issue.Three different methods have produced three different results of the august patient sample.The assays have different standardizations because different antibodies are used to create the assays.Per the warning in the advia centaur rubg instructions for use (ifu) "the calculated values for rubella igg in a given specimen, as determined by assays from different manufacturers, can vary due to differences in assay methods and reagent specificity.The results reported by the laboratory to the physician must include the identity of the rubella igg assay used.Values obtained with different assay methods cannot be used interchangeably.The reported igg level cannot be correlated to an endpoint titer." the calculated specificity on this account for advia centaur rubella g lot 202 from 2018/04-04 to end 2018/05-18 was 95/96= 0.9895 x100 = 99.0% and the calculated specificity on this account for advia centaur rubella g lot 204 from 2018/06-18 to end of august 2018 was 71/(71+1)= 71/72= 0.986 x 100= 98.6.The assay is performing as intended.No further investigation is required.Mdr 1219913-2018-00213, mdr 1219913-2018-00213 supplemental report 1and mdr 1219913-2018-00213 supplemental report 2 were filed for a different sample from the same patient.
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