Recent Artery Conversations
I would like to check with Arterians on the assays in use for pyruvate: are they lab developed tests or manufacturer kits?
We use the Instruchemie assay (The Netherlands) but there are several issues with it:
1. The assay uses a factor for calculation and not standards.
2. The controls are not in whole blood matrix like patients and when trying to spike them into whole blood the results are not consistent with the liquid samples.
3. The same problem applies when trying to perform AMR / linearity studies.
4. To add to the above, proficiency testing is not available for this analyte and therefore we cannot access its accuracy.
Please share.
My lab is having issues with the CAP NT-proBNP linearity program LN-30.
The four concentration points (mean 62.0, 4127.5, 9103.5 and 15539.0 pg/mL, corresponding to relative concentrations of 0.0, 0.2, 0.4 and 0.6), when compared with the best fit line, show a U-shaped curve, with high biases at the lowest and the highest concentrations and low biases in the two intermediate concentrations . The issue has been seen persistently across cycles. There is no problem with Calibration verification.
According to the participation summary, nonlinearity has been graded in more than 30% of the 39 users of the user group.
Does anyone have any experience in dealing with this?
Please share.
I wanted to get some feedback on reporting results above assay range. If the result higher than CRR, do you report as greater than above AMR value or greater than CRR value? For example, siemens cortisol AMR high value is 75 there is an option to make 1:2 dil which extends reportable range to 150 (Clinical reportable range). If the results >150, will you report as >75 or >150?
Please share.