Medical device manufacturer, Roche Limited has issued a medical device safety alert concerning COBAS TaqMan MTB Test Definition File v3.0 for use with AmpliLink 3.3 (Material number 04803531190, all lots).
A recent investigation into the affected product revealed that the Ct cutoff value has been set at 48 rather than the correct value of 50. When using the COBAS TaqMan MTB Test Definition File v3.0 with AmpliLink 3.3, there is a rare circumstance that Ct values of patient samples may fall in the range of 48 to 50. Results falling within this range would have been considered as negatives.
The frequency of results with Ct value between 48 and 50 is rare. Previous data generated indicates that 0.7% of samples fall in the Ct range of 48 to 50. The frequency of the failure mode is estimated to be low and any subsequent health consequences is remote. In addition, Ct value within this range indicates the presence of very low titre of MTB DNA and it is expected that such sample would generate a negative smear test result. Management of such patient will depend on the result of bacterial culture in conjunction with other clinical and laboratory tests. Therefore the risk of causing adverse health consequence is remote and review of previously generated results is not indicated.
An updated CE-IVD TDF, v3.1 with the correct Ct cutoff value of 50 will be released in the near future. As an interim measure, the manufacturer recommends users to review all Ct values after each run. In the unlikely event that samples with Ct values in the range of 48 to 50 are generated, these results should be reported as positive.
According to the local supplier, the affected products were distributed in Hong Kong.
If you are in possession of the affected product, please contact your supplier for necessary actions.
Posted on 12 December 2012