MAUDE Adverse Event Report: SIEMENS HEALTHCARE DIAGNOSTICS, INC. ADVIA CENTAUR TOXOPLASMA IGG (TOXO G); ENZYME LINKED IMMUNOABSORBENT ASSAY, TOXOPLASMA GONDII

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	04/07/2023
Type of Reportable Event	Malfunction
Event or Problem Description
The customer reports observation of reproducible false positive advia centaur xpt toxoplasma igg (toxo g) results for one patient.Elevated toxo g results were observed for two samples from one 34-year-old pregnant patient.An initial positive toxo g result was reported and questioned as discordant by the physician.Repeat testing using another method at another site produced a negative result, which was reported and accepted as correct.The same patient was tested three weeks later, and again produced a positive toxo g result, which was questioned.Repeat testing (using the same alternate method) again produced a negative result, which was accepted as correct.There are no allegations of patient harm, changes in treatment, or delays of diagnosis in association with the observed discordance.
Additional Manufacturer Narrative
A customer from outside the united states contacted siemens to report observation of falsely-elevated (false positive) advia centaur toxoplasma igg (toxo g) results for one patient, which were discordant relative to alternate-method testing.Quality control (qc) results were within acceptable ranges.No additional sample is available for testing/investigation.Siemens is investigating.
Additional Manufacturer Narrative
Mdr 2432235-2023-00088 was initially submitted on 2023-05-02.Update, 2023-06-26: siemens has concluded the investigation.A customer from outside the united states reported observation of reproducible false positive advia centaur xpt toxoplasma igg (toxo g) results for one patient when using toxo g kit lot 283.Siemens reviewed available data to investigate.Calibration data were not available, but quality control (qc) results were within expected ranges.Siemens reviewed internal quality control and medical decision pool test data, and determined that performance of toxo g lot 283 was comparable to other reagent lots.Analysis of field data from march of 2022 through april of 2023 demonstrated a similar result profile for lot 283 as compared to other reagent lots.The customer did not perform any investigative testing using heterophilic blocking tubes (hbt) and /or with non-specific antibody blocking tubes (nabt).There was not sufficient sample available to permit testing by siemens.The customer did not provide information regarding their total number of negative samples tested using this particular kit lot, so local specificity could not be evaluated.Based on the available information a patient-specific issue cannot be excluded as a potential cause of the observed false reactive toxo g results.The advia centaur xpt toxoplasma g (toxo g) instructions for use (ifu) notes that an initial relative specificity of 98.6% was observed across three studies.The customer is operational, and no further action required.Notes: 1) in section h6, the codes for investigation findings and investigation conclusion have been updated.2) mdr 2432235-2023-00087 supplemental 1 has been filed in association with the related observation of 2023-03-16.

• Brand Name: ADVIA CENTAUR TOXOPLASMA IGG (TOXO G)
• Common Device Name: ENZYME LINKED IMMUNOABSORBENT ASSAY, TOXOPLASMA GONDII
• Manufacturer (Section D): SIEMENS HEALTHCARE DIAGNOSTICS, INC.; 511 benedict avenue; tarrytown NY 10591
• Manufacturer (Section G): SIEMENS HEALTHCARE DIAGNOSTICS, INC.; 333 coney street; east walpole MA 02032
• Manufacturer Contact: barry memishian ; 511 benedict ave.; tarrytown 10591 ; 5082985306
• MDR Report Key: 16856096
• Report Number: 2432235-2023-00088
• Device Sequence Number: 6771241
• Product Code: LGD
• UDI-Device Identifier: 00630414208459
• UDI-Public: 00630414208459
• Combination Product (Y/N): N
• Initial Reporter Country: FR
• PMA/510(K) Number: K012183
• 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,User Facility
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 07/10/2023

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: Health Professional
• Device Expiration Date: 07/27/2023
• Device Model Number: N/A
• Device Catalogue Number: 10310321
• Device Lot Number: 283
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Initial
• Initial Date Received by Manufacturer: 04/28/2023
• Supplement Date Received by Manufacturer: 06/26/2023
• Initial Report FDA Received Date: 05/02/2023
• Supplement Report FDA Received Date: 07/10/2023
• Was Device Evaluated by Manufacturer? (Y/N): Device Not Returned to Manufacturer
• Date Device Manufactured: 07/27/2023
• Is the Device Labeled for Single Use? (Y/N): No
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Patient Age: 34 YR
• Patient Sex: Female