| Catalog Number |
08828610190 |
| Medical Device Problem Code |
Incorrect Measurement (1383)
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| Health Effect - Clinical Code |
No Clinical Signs, Symptoms or Conditions (4582)
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| Date of Event |
02/13/2023
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Type of Reportable Event
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Malfunction
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Event or Problem Description
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The initial reporter stated they received questionable results for one patient tested with the elecsys free psa and the elecsys total psa assay on a cobas e 801 analytical unit.The free psa values were greater than the total psa values.The questionable results were reported outside of the laboratory.This medwatch will apply to the free psa assay.Please refer to the medwatch with patient identifier.Patient identifier (b)(6) for information related to the total psa assay.A first sample of the patient was tested on (b)(6) 2023: the first sample initially resulted in a free psa value of 2.88 ng/ml.The first sample initially resulted in a total psa value of 0.180 ng/ml.A second sample of the patient was tested on an unknown date: the second sample initially resulted in a free psa value of 2.79 ng/ml and repeated in a different laboratory on a cobas pure analyzer as 2.74 ng/ml.The second sample initially resulted in a total psa value of 0.174 ng/ml and repeated in a different laboratory on a cobas pure analyzer as 0.19 ng/ml.The patient went to another laboratory and received a free psa value of 0.068 ng/ml and a total psa value of 0.415 ng/ml.The method used and the date of measurement is unknown.The serial number of the e801 analyzer is (b)(4).
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Additional Manufacturer Narrative
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The last preventive maintenance was performed on 27-oct-2022 including a measuring cell change.The customer does not run quality controls daily.
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Additional Manufacturer Narrative
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Calibration signals were within the expected range.No quality control results for level 1 were provided.Quality control results of level 2 were acceptable for free psa.Upon review of the alarm trace, no relevant alarms were observed.The customer stores calibrators and controls in the freezer without temperature control.The customer thaws the aliquots, runs the quality control or calibrators, and freeze them again.The samples were requested but were not available for investigation.The investigation could not identify a product problem.The cause of the event could not be determined.The issue is consistent with an interference and/or a seldom psa isoform present in the sample that leads to the free psa values being greater than the total psa values.Per product labeling: "in rare cases, interference due to extremely high titers of antibodies to analytes specific antibodies, streptavidin or ruthenium can occur.These effects are minimized by suitable test design.".
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Search Alerts/Recalls
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