MAUDE Adverse Event Report: SIEMENS HEALTHCARE DIAGNOSTICS, INC. ATELLICA IM TOXOPLASMA IGG (TOXO G); TOXOPLASMA GONDII IMMUNOASSAY

Model Number N/A

Device Problem False Positive Result (1227)

Patient Problems No Known Impact Or Consequence To Patient (2692); No Clinical Signs, Symptoms or Conditions (4582)

Event Date 12/18/2019

Event Type  malfunction  

Manufacturer Narrative

The customer contacted the siemens customer care center (ccc) to report discordant, false positive atellica im toxoplasma igg (toxo g) patient results.Siemens has reviewed 13 months of patient data.The data included 338,073 results from (b)(6) 2019 to (b)(6) 2020 and toxo g reagent lots 235, 239, 243, 245, 247, 249, 251, 252 and 258.The rate of result interpretations for reagent lot 258 recover similar and comparable with the other reagent lots reviewed.Siemens is investigating.The instruction for use (ifu) states in the interpretation of results section: "results of this assay should always be interpreted in conjunction with the patient's medical history, clinical presentation, and other findings." the instruction for use (ifu) states in the limitations section: "specimens collected in the early stages of infection may have igg levels that are classified as negative.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." mdr 1219913-2020-00159 was filed for the same event.

Event Description

False positive atellica im toxoplasma igg (toxo g) results were obtained on samples from the same patient and questioned by the physician(s).The positive results were considered discordant compared to negative alternate toxoplasma igg test method results.The negative toxoplasma igg (toxo g) results were reported to the physician(s) as corrected results.There are no reports that treatment was altered or prescribed or adverse health consequences due to the discordant, false positive atellica im toxoplasma igg (toxo g) results.

Manufacturer Narrative

Siemens filed the initial mdr 1219913-2020-00160 report on 25-jun-2020 for false positive atellica im toxoplasma igg (toxo g) results from the same patient.03-jul-2020 additional information: siemens has reviewed additional toxoplasma igg (toxo g) patient data through (b)(6) 2020.The rate of result interpretations for reagent lot 258, including reagent lot 260 recover similar and comparable with the other reagent lots reviewed.The instruction for use (ifu) under the interpretation of results section states the following: "the magnitude of the measured result above the cut-off value is not indicative of the total amount of antibody present in the sample.The detection of toxoplasma igg in a given specimen, as determined by assays from different manufacturers, can vary due to differences in assay methods and reagent specificity." siemens continues to investigate.Mdr 1219913-2020-00159 supplemental report 1 was filed for the same event.

Manufacturer Narrative

Siemens filed the initial mdr 1219913-2020-00160 report on 25-jun-2020 for false positive atellica im toxoplasma igg (toxo g) results from the same patient and mdr 1219913-2020-00160 supplemental report 1 was filed on 27-jul-2020 for additional information.26-sep-2020 - additional information: siemens completed an internal study on atellica im system for toxoplasma igg (toxo g) assay.During the study toxo g reagent lots 258, 260 and 262 were used.Toxo g reagent lot 252 expired on august 9th, 2020 and was relabeled to reagent lot 997.Results generated with lot 997 were solely for informational purposes.Fifty (50) normal patient samples from siemens and fifty (50) patient samples from france were tested in replicates of 3 (n=3).The final interpretation was the same for all 50 samples from france and for 49/50 patient samples from siemens.The one siemens normal patient sample was reactive with reagent lots 997, 258 and 260 and equivocal with reagent lot 262.This is a cut off sample (10.0 iu/ml) and recovery was within acceptable precision at that level.Siemens continues to investigate and has requested heterophilic blocking tube (hbt) and non-specific antibody blocking tube (nabt) information.In section h6, the health effect - clinical code, clinical impact code and the component code were added.Mdr 1219913-2020-00159 supplemental report 2 was filed for the same event.

Manufacturer Narrative

Siemens filed the initial mdr 1219913-2020-00160 report on 25-jun-2020 for false positive atellica im toxoplasma igg (toxo g) results from the same patient.Mdr 1219913-2020-00160 supplemental report 1 (filed on 27-jul-2020) and mdr 1219913-2020-00160 supplemental report 2 (filed on 13-oct-2020) for additional information.05-nov-2020 - additional information: the customer provided seventeen samples of different patients, including samples from this patient to be tested with an alternate method.The result interpretation from four samples did not agree with the alternate toxo g test method, however three of these samples were different draws from this patient that were consistently reactive (positive) on the atellica im with multiple reagent lots.The fourth patient sample was considered to be a false nonreactive (negative) on the alternate method.Siemens has concluded the investigation.The customer initially reported false reactive (positive) atellica im toxoplasma igg (toxo g) results from a patient with reagent lot 258 and reagent lot 260 versus alternate methods.The customer's sample handling and calibration data were reviewed and observed to be acceptable.The calibration data was comparable to release specifications.The customer is using siemens quality control (qc) that recovered within acceptable ranges and similarly with peer, siemens analytics service (sas) and release data.The atellica im toxoplasma igg (toxo g) siemens analytics service (sas) patient data was reviewed from march 2019 to june 2020.Reagent lot 258 recovered similarly with interpretation rates of previous reagent lots.A review of internal data for mean control recovery comparing reagent lots 252 to 258, and reagent lots 258 to 260, showed the same trend; reagent lot 258 elevated compared to reagent lots 252 and 260.Further analysis of the siemens (sas) internal data (global and france only) for mean patient recovery across several reagent lots, verified that reagent lot 258 was elevated compared to reagent lots 252 and 260 globally and in france.The atellica im toxoplasma igg (toxo g) instructions for use (ifu) 10995430_en rev.02, 2019-08 interpretation of results section states the following: "the magnitude of the measured result above the cut-off value is not indicative of the total amount of antibody present in the sample." siemens initiated an internal study that included toxo g reagent lots 258, 260 and 262, fifty (50) normal patient samples from siemens and fifty (50) patient samples from france.The patient samples from france for the internal study were purchased by siemens from an approved supplier and french acquisition company (inospecimens niobank).All samples were tested in replicates of 3 (n=3).The final interpretation was the same for the patient samples across the reagent lots, except for one siemens' sample that was near the cutoff of 10 iu/ml.The recovery for this sample was within acceptable precision at that level.Based on the information provided, the false reactive (positive) atellica im toxo g results for this patient may potentially be attributed to an interferent specific in the patient samples.An interferent may not necessarily be due to an interfering antibody but may be due to other exogenous interferences such as drugs, nutritional supplements and/or herbal medicine in the blood.Siemens was unable to obtain the total number of negative samples the customer has tested with toxo g reagent lot 258 in order to calculate relative specificity.There was not sufficient sample volume available for further evaluation and the patient samples were not tested for the presence of heterophilic antibodies.In summary, atellica im toxoplasma igg reagent lot 258 is performing as intended.A product performance issue has not been identified.The customer is operational.The assay is performing within specifications.No further evaluation of the device is required.In section h6, the investigation finding, and investigation conclusion codes were updated.Mdr 1219913-2020-00159 supplemental report 2 was filed for the same event.

• Brand Name: ATELLICA IM TOXOPLASMA IGG (TOXO G)
• Type of Device: TOXOPLASMA GONDII IMMUNOASSAY
• Manufacturer (Section D): SIEMENS HEALTHCARE DIAGNOSTICS, INC.; 511 benedict avenue; tarrytown, ny
• MDR Report Key: 10195985
• MDR Text Key: 238809247
• Report Number: 1219913-2020-00160
• Device Sequence Number: 1
• Product Code: LGD
• UDI-Device Identifier: 00630414600123
• UDI-Public: 00630414600123
• Combination Product (y/n): N
• PMA/PMN Number: K012183
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: foreign,health professional,u
• Type of Report: Initial,Followup,Followup,Followup
• Report Date: 11/24/2020

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
• Device Operator: Health Professional
• Device Expiration Date: 11/01/2020
• Device Model Number: N/A
• Device Catalogue Number: 10995699
• Device Lot Number: 258
• Was Device Available for Evaluation?: No
• Initial Date Manufacturer Received: 06/09/2020
• Initial Date FDA Received: 06/25/2020
• Supplement Dates Manufacturer Received: 07/03/2020; 09/26/2020; 11/05/2020
• Supplement Dates FDA Received: 07/27/2020; 10/13/2020; 11/25/2020
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Age: 30 YR