KIT COBAS 58/68/8800 MPX 480T US
Received Feb 17, 2026 · Event occurred Jan 16, 2026
Report 2243471-2026-00548 · MDR key 24365004
Device
Generic name
Assay, Hybridization And/or Nucleic Acid Amplification For Detection Of Hepatiti
Manufacturer
Roche Molecular Systems, Inc. - BranchburgCatalog number
09040854190
Lot number
M28098
Product problems
- False Negative Result
Patient
NA · Unknown
- No Clinical Signs, Symptoms or Conditions
Narrative
Description of Event or Problem
THERE WAS AN ALLEGATION OF DISCREPANT HBV RESULTS WITH THE COBAS® MPX KIT (480T) FROM THE COBAS 8800 ANALYZER FOR A SINGLE PATIENT. ON (B)(6) 2026, THE INITIAL 6-POOLED SAMPLE GENERATED A NON-REACTIVE RESULT FOR HIV, HBV, AND HCV. ON (B)(6) 2026, THE INDIVIDUAL DONOR SAMPLE GENERATED A REACTIVE HBV RESULT (CT 42.44) ON ANOTHER COBAS 8800. SEROLOGY TESTING ON THE COBAS E801 GENERATED POSITIVE HBC RESULTS.
Additional Manufacturer Narrative
THE SERIAL NUMBER OF THE COBAS 8800 WAS (B)(6). THE SERIAL NUMBER OF THE SECOND COBAS 8800 WAS (B)(6). THE INVESTIGATION INDICATED NO PRODUCT-RELATED ISSUES WERE IDENTIFIED. THE ROOT CAUSE OF THE DISCREPANCY IS THE DILUTION EFFECT INHERENT IN POOLED NAT TESTING FOR SAMPLES WITH LOW VIRAL TITERS. THE TARGET CONCENTRATION IN THE PRIMARY SAMPLE WAS NEAR THE ASSAY¿S LOD; THEREFORE, THE 1:6 DILUTION REQUIRED FOR THE POOLING PROTOCOL REDUCED THE NUMBER OF TARGET MOLECULES PER REACTION TO A LEVEL WHERE DETECTION BECOMES STOCHASTIC. THIS PHENOMENON, WHERE A LOW-TITER SAMPLE IS NON-REACTIVE IN A POOL BUT REACTIVE IN INDIVIDUAL DONOR TESTING (IDT), DOES NOT REPRESENT A FAILURE OF THE SYSTEM OR THE MPX REAGENTS.