MAUDE Adverse Event Report: VENTANA MEDICAL SYSTEMS INC VENTANA ANTI-MLH1 (M1) MOUSE MONOCLONAL PRIMARY ANTIBODY; IMMUNOHISTOCHEMISTRY TEST, DNA MISMATCH REPAIR (MMR) PROTEIN ASSAY

Catalog Number 08033668001

Device Problems False Positive Result (1227); Non Reproducible Results (4029)

Patient Problem No Clinical Signs, Symptoms or Conditions (4582)

Event Date 01/09/2023

Event Type  malfunction  

Event Description

A customer from ireland alleged discrepant results for 4 patient samples using the ventana anti-mlh1 (m1) mouse monoclonal primary antibody.The first two samples were run the week of (b)(6) 2023: two alleged samples initially produced positive staining results which were reported to medical personnel.The next two samples were run the week of (b)(6) 2023: the staining results for the other two alleged samples were reported to medical personnel as "uninterpretable." the hypermethylation testing results for all 4 patient samples indicated that the mlh-1 staining should have been negative.The customer stated the on-slide controls stained as expected.To date, no harm or injury is alleged.

Manufacturer Narrative

The investigation is ongoing.A supplemental mdr will be filed upon completion of the investigation.The customer issue has been alleged on the mlh1 (m1) mm pab-us export (catalog no: 08033668001; udi: (b)(4)) which is equivalent to the us kit; mlh1 (m1) mouse monoclonal pab us (catalog no: 07862237001; udi: (b)(4)).

Manufacturer Narrative

The device code was updated.The customer's slide images were requested for review but were not provided.A review of the mlh1 protocol report from the customer¿s host computer indicates that the customer was not using the package insert recommended protocol when the affected slides were stained.The customer decreased the antigen retrieval time and decreased the primary antibody incubation time.Product labeling states: "this antibody has been optimized for specific incubation times, but the user must validate results obtained with this reagent.The effect of varying time and temperature of the antigen retrieval (cell conditioning) and antibody incubation from the recommended staining protocol may result in sub optimal staining and false mmr results.It is strongly recommended not to deviate from the recommended staining protocol.Appropriate controls should be employed and documented.Users who deviate from the listed protocol must accept responsibility for interpretation of patient results." the investigation did not identify a product problem.

• Brand Name: VENTANA ANTI-MLH1 (M1) MOUSE MONOCLONAL PRIMARY ANTIBODY
• Type of Device: IMMUNOHISTOCHEMISTRY TEST, DNA MISMATCH REPAIR (MMR) PROTEIN ASSAY
• Manufacturer (Section D): VENTANA MEDICAL SYSTEMS INC; 1910 e innovation park dr; tucson AZ 85755
• Manufacturer (Section G): VENTANA MEDICAL SYSTEMS INC; 1910 e innovation park dr; na; tucson AZ 85755
• Manufacturer Contact: timothy blair ; 1080 us hwy 202 s; building 500, room: 3530; branchburg, NJ 08876 ; 9253534412
• MDR Report Key: 16547585
• MDR Text Key: 311741543
• Report Number: 2028492-2023-00022
• Device Sequence Number: 1
• Product Code: QNH
• Combination Product (y/n): N
• Reporter Country Code: EI
• PMA/PMN Number: P210001
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Foreign,Health Professional
• Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date: 04/06/2023

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 03/15/2023
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Catalogue Number: 08033668001
• Device Lot Number: J21229
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 04/03/2023
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1