VITROS IMMUNODIAGNOSTIC PRODUCTS PSA REAGENT PACK 6801756

[129584790] The investigation determined that lower than expected vitros psa results were attained from two different patient samples using vitros immunodiagnostics products psa (psa) reagent in combination with a vitros 5600 integrated system. The results were lower then expected when compared to the results obtained from the same samples freshly drawn. A definitive assignable cause for the low results could not be determined. Based on historical quality control results, a vitros psa lot 3620 and 3640 performance issue is not a likely contributor to the event. Continual tracking and trending of complaints has not shown any existing signals that would point to a potential systemic issue with vitros immunodiagnostics products psa (psa) reagent lot 3620 or 3640. In addition, there is no indication of an instrument malfunction. However, a within run precision test was not run at the time of the event and therefore, an instrument issue cannot be definitively ruled out. Furthermore, pre-analytical sample processing cannot be ruled out as a contributing factor, as it was not possible to establish if the customer was following the sample collection device manufacturer? S recommendation for sample centrifugation. It is possible that cellular debris, due to poor sample preparation, was present in the affected samples, although this could not be confirmed. Additionally, when samples are tested concurrently, reproducible results are obtained for both fresh and stored samples using both reagent lots. Only when fresh samples are compared to stored samples are biased results observed. Consequently, sample preparation and the handling and storage of the samples cannot be ruled out as a contributing factor to the event.
Patient Sequence No: 1, Text Type: N, H10

[129584791] A customer reported lower than expected patient sample results attained using vitros immunodiagnostics products psa (psa) reagent on a vitros 5600 integrated system. Patient sample 1 results of 29. 5 and 28. 3 ng/ml versus the expected result of 53. 3 ng/ml. Patient sample 3 result of 2. 27 ng/ml versus the expected result of 3. 11 ng/ml. Biased results of the magnitude and direction observed may lead to inappropriate physician action if they were to occur undetected on patient samples. The lower than expected vitros psa results were not reported from the laboratory. There have been no allegations of patient harm as a result of this event. This report is number 2 of 2 mdr? S for this event. Two (2) 3500a forms are being submitted for this event as 2 devices were involved. (b)(4).
Patient Sequence No: 1, Text Type: D, B5