[95963387]
(b)(6), customer, reported that they had discrepant results for three samples that were manually tested with the factor v assay. The customer ran a factor v assay with nine samples on (b)(6) 2017 using ln 189419, and all nine samples provided negative/homozygous wild type (wt) results. Results were reported out. After a single result from the run was questioned, the customer re-tested all nine samples on (b)(6) 2017 using ln 217190. It is not known whether the customer re-extracted the original samples prior to testing on (b)(6) 2017, or if the previously extracted samples from (b)(6) 2017 were re-tested on (b)(6) 2017. The re-testing provided six wt results, two carrier/heterozygous (het) results, and one homozygous mutant (mut) result. The customer stated that the discrepant results were likely caused by an operator error which impacted the original run performed on 10/4/17. The customer frequently tests the factor v and factor ii assays concurrently, on the same assay plate, using the same samples; so the customer believes the factor ii oligo mix was used for the factor v assay. Although the factor v assay was likely performed using the incorrect oligo mix, the assay was valid. It was emphasized to customer that the factor ii and factor v controls are not interchangeable. The controls from the factor v kit should be used with the factor v reagents and same for the factor ii controls and reagents. Customer inquired why the factor v controls would be valid in a factor v run performed with factor ii master mix. Hologic evaluated this issue and determined that factor v and factor ii assay controls do contain a mixture of both targets, but they are filled separately and labeled individually for each assay. Because of this, the assay controls should not be used interchangeably for both assays. When a factor v or factor ii assay is performed, a reaction mix is prepared using a universal buffer, universal enzyme mix, and an assay-specific oligo mix. The assay controls are intended to ensure that proper amplification occurs, but they do not control for severe operator errors such as preparing the factor v reaction mix using the factor ii oligo mix. Per hologic's risk assessment, the customer performed factor v testing with factor ii oligo mix, resulting in incorrect results. The severity associated with incorrect result is serious but the probability of incorrect results is remote. The final risk is assessed as 'as far as possible'.
Patient Sequence No: 1, Text Type: D, B5