A united states customer contacted the siemens healthcare diagnostics remote services center (rsc) regarding a falsely elevated total prostate specific antigen (tpsa) result obtained on a patient sample on a dimension vista 500 instrument.The quality control (qc) was acceptable at the time of the event.The customer performed precision studies and the results were acceptable.The dimension vista and advia centaur methods use different technology to determine the antigen.The dimension vista method uses a homogeneous sandwich chemiluminescent immunoassay based on loci technology.The advia centaur method uses a two-site sandwich immunoassay using direct chemiluminometric technology.Per the dimension vista tpsa instructions for use (ifu, 2019-08-05 h pn 10867753 ¿ us, ref: k6451) in the warning section, the following is stated: "the concentration of tpsa in a given specimen determined with 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 psa assay used.Values obtained with different assay methods cannot be used interchangeably.If, in the course of monitoring a patient, the assay method used for determining psa levels serially is changed, additional sequential testing should be carried out.Prior to changing assays, the laboratory must confirm baseline values for patients being serially monitored".The results obtained from a redraw of the affected patient correlated with initial results and precision study is acceptable.The customer has been advised that results obtained from different assay methods must not be correlated due to differing technology and reagent composition.There is no evidence of a potential product issue.No further evaluation of the device is required.
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A falsely elevated total prostate specific antigen (tpsa) result was obtained on a patient sample on a dimension vista 500 instrument.The erroneous result was reported to the physician(s), who questioned the result.The sample was repeated on an alternate instrument (advia centaur method) at an alternate site.The repeat result was lower than the erroneous result.The repeat result was reported, as the correct result, to the physician(s).The repeat result matched the patient¿s clinical picture.A redraw sample was tested as part of troubleshooting and the results were similar to both platforms.It is unknown if patient treatment was given or delayed.There are no known reports of adverse health consequences due to the falsely elevated tpsa result.
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