MAUDE Adverse Event Report: SIEMENS HEALTHCARE DIAGNOSTICS, INC. ADVIA CENTAUR XPT TOXOPLASMA G (TOXO G); TOXOPLASMA GONDII IMMUNOASSAY, PRODUCT CODE: LGD

Model Number	N/A
Medical Device Problem Code	False Positive Result (1227)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	02/07/2020
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
Siemens healthcare diagnostics is investigating.It was noted that troubleshooting investigation, involving testing the patient using both an alternate sample and an alternate reagent lot, produced positive results that reproduced those initially observed.Additionally, positive results were obtained when this patient's sample was tested using a heterophilic antibody blocking tube and a non-specific antibody blocking tube.The toxo g instructions for use (ifu) states in the limitations section: "in geographic regions that have an apparent low prevalence of toxoplasma igg in asymptomatic populations, the positive predictive value of any assay is reduced due to the increased possibility that a positive result is actually falsely positive.As with all in vitro diagnostic assays, each laboratory should determine its own reference range(s) for the diagnostic evaluation of patient results.".
Event or Problem Description
On (b)(6) 2020, a discordant positive (reactive) advia centaur xpt toxoplasma g (toxo g) result was observed for one patient.The result was considered discordant relative to negative results obtained using two alternate testing methods.These negative results were accepted as correct.The patient in question had recently given birth when the discordant result was obtained.The same patient had tested negative for toxo g, while pregnant, in (b)(6) 2019.There is no indication that patient treatment was prescribed, delayed or altered.There was no report of adverse health consequences due to the false positive toxo g results.
Additional Manufacturer Narrative
Mdr 1219913-2020-00588 was filed on (b)(6) 2020 to report a discordant positive (reactive) advia centaur xpt toxoplasma g (toxo g) result was observed for one patient.Additional information, 19-jan-2021: siemens has completed the investigation.In (b)(6) 2020, the customer observed a false-reactive result when testing a patient post-delivery using advia centaur toxoplasma igg (toxo g), reagent lot 250.The patient had given birth in january.During pregnancy, the patient had non-reactive results , but for up to 6 months following delivery the patient produced reactive toxo g results.A historical sample from december 2019 was repeat-tested using advia centaur toxo g lot 250 and reproduced the original non-reactive result for that sample.The december sample and the (b)(6) sample were also repeated using an alternate method (unknown) and both results were non-reactive with that method.(b)(6) results for this patient were reactive for toxo g lot 250 and non-reactive for toxoplasma igm.The sample was tested with pcr and western blot and found non-reactive by both methods.This sample was treated with a heterophilic blocking tube (hbt) and a non-specific antibody blocking tube (nabt) and still produced a reactive result with the advia centaur toxo g assay.Samples from (b)(6) and (b)(6) were reactive with toxo g lot 263, but the quantitative values were lower.Instrument calibrations have been valid and qc acceptable when results were produced for this patient.Analysis of general customer data from february 2019 to june 2020 for toxo g lots 250 and 263 showed interpretation rates which were similar to those of previous reagent lots.The calculated specificity for this customer with toxo g lot 250 is 99.8%.The relative specificity results from the 3 studies described in the advia centaur toxoplasma g instructions for use range from 99.3% - 99.8%.The investigation indicates that the repeatedly false-reactive post-delivery results of this patient do not represent a lot-specific performance issue, but rather an isolated patient-specific event.Based on the available information advia centaur toxoplasma igg lots 250 and 263 are performing as intended and a product performance issue has not been identified.The customer is operational, and no further evaluation of the device is required.Note: in section h6, the investigation findings and investigation conclusion codes were added.

• Brand Name: ADVIA CENTAUR XPT TOXOPLASMA G (TOXO G)
• Common Device Name: TOXOPLASMA GONDII IMMUNOASSAY, PRODUCT CODE: LGD
• Manufacturer (Section D): SIEMENS HEALTHCARE DIAGNOSTICS, INC.; 511 benedict avenue; tarrytown NY 10591 5097
• MDR Report Key: 10944323
• Report Number: 1219913-2020-00588
• Device Sequence Number: 3190081
• Product Code: LGD
• UDI-Device Identifier: 00630414208459
• UDI-Public: 00630414208459
• Combination Product (Y/N): N
• Initial Reporter Country: FR
• PMA/510(K) Number: K102681
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: foreign,health professional,u
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 01/22/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: No Information
• Device Model Number: N/A
• Device Catalogue Number: 10310321
• Device Lot Number: 250
• Was Device Available for Evaluation?: No
• Initial Date Received by Manufacturer: 11/12/2020
• Supplement Date Received by Manufacturer: 01/19/2021
• Initial Report FDA Received Date: 12/04/2020
• Supplement Report FDA Received Date: 01/21/2021
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Patient Age: 30 YR