This summarizes my experiences dealing with the recent world-wide recall of Vitros mALB calibrators and reagents.
Comments welcome, including any better ideas.
Elsewhere, including the US, OCD apparently have offered no help or options to their customers. Ortho Australia have been pro-active, and issued free kits of Roche Tinaquant urine albumin, with a User-defined assay worked up by Royal Children’s Hospital, Melbourne.
We have been using it since last Friday. It gives exactly the same results as the Ortho method- that is, the calibration “errors” which are the justification for the recall, are spurious. They fixed a previous error; probably had let their master calibrator go off in the freezer.
Please, everybody, let us overwhelm all our suppliers with demands that they devote more resources and attention to the backroom boys and girls in their calibrator-setting laboratory. See the letter on sodium shifts in the November Clin. Chem. “Laboratories are struggling with lot-to-lot variation”. Just so.
I suggest that we all propose, that the CEO of OCD (and the other companies too) offer half his next year’s bonus, to be divided among the calibration laboratory staff (not QA, lest there be appearance of conflict of interest), if there are no recalls or retrospective calibrator “adjustments” in the year. Plus provide them with new freezers, better monitoring, and funds to check or replace their master calibrators when they (not the accountants) think it is needed.
How do they do this with sodium? I have found (making up a sweat chloride control) that an old bottle of Analar NaCl was only 97% pure- presumably the rest was H20. Surely they know how to prevent this.
I recently logged a complaint that Calibrator 0260 results in patient plasma Na results 3 mmol/L higher than Cal 0250, and Cal 0261 (the only available option), 2 mmol/L higher.
No admissions yet; but (presumably the higher-ups), they can over-react like this to a non-existent problem??
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The Roche albumin method is 2-point endpoint at 340 nm, R1 150 uL, R2 30 uL. There is one calibrator, cfas PUC, about 400 mg/L. The trick is to define the six calibrators like this:
0, 399.8, 399.9, 400, 400.1, 400.2, with decreasing dilutions specified: 1, 73, 22, 5, 2, 1, and line up 6 cups, saline followed by 5 cfas PUC. Cup 5 needs 250 uL. Lower dilutions require larger samples.
There were several low outliers by the Roche UDA e.g. 120/60, 85/50. Some micro-albuminurias would be missed. I have been working on this for more than a week, and held up reporting Roche results until I had a solution, which I finally got on Sunday afternoon.
The “wet side” of the Fusion does not correct the blank reading for the dilution by R2. Should be x 5/6 for this assay. 5 of 36 urines had a blank >0.4, highest 0.75. Calibrator (400 mg/L) gives 0.6.
Manually making this blank adjustment, makes the result the same as the Ortho method, but this is imprecise and tedious
The official Ortho method appears to ”get away’ with wrong blank correction, by using a much smaller R2/R1 ratio: 9:180 uL
I ran the same method at 620 nm (sensitivity 1/3 of the 340 nm), and the Roche reagents gave the same results as Ortho for these specimens.
I am running all specimens by both methods, and reporting the 620nm result if higher
I will complete a validation for the 620nm method, and switch to it, if the low end imprecision is OK
I will check out the Randox method. If we are lucky we may be able to run a kinetic blank like we do for Randox CRP (and Ortho do for their urine drugs of abuse). I tried this with the Roche, but the reaction is too fast- all over in less than a minute. So why does the Cobas method specify a 10 minute reaction time?
We will have to watch out for blue or green urine- we have had them- check on Google. Our staff are competent, and not only look at the specimens they test, but actually observe them
The Roche method has an even lower prozone limit claim than Ortho- 2500 vs 8000 mg/L. We have had 35,000 mg/L. Such specimens will give an initial result of <100. Recently we had a result of 18,000 mg/L, with no previous. It is essential that all urines be checked for very high values. Dip-sticking urines for albumin may be adequate, but we prefer a more reliable method, and run Urine protein with every albumin, with a lockout rule that prevents authorisation if the protein/albumin ration is >6.
Update: Using the appended protocol at 620 nm, Roche reagent and calibrator, initial within-batch CV at 3.6 mg/L was 1.3%, compared to 4.1% using the original RCH protocol (same parameters except : wavelength: 340 nm, second incubation: 10 minutes)
Robert McFarlane
Network Supervising Scientist, Chemical Pathology, Royal Darwin Hospital
08 89228079 0458 110196
[log in to unmask]
User- defined assays for Vitros Fusion:
Supplies:
Roche Diagnostics – mALB Tina‐quant kit (Cat #: 03576108190)
Roche Diagnostics – C.f.a.s PUC (Protein Calibrator) (Cat #: 03121305122)
Roche Diagnostics – QC Low (Cat#: 03121313122)
Roche Diagnostics – QC high (Cat#: 03121291122)
Ortho Clinical Diagnostics– VITROS User Defined Pack (UD09) (Cat #: 6802254)
Preferred- 620 nm, second incubation: 2 minutes
PROFILE CONFIGURATION
Full Assay Name: Roche ALBUMIN 620 nm Date: 20/11/2011
Short Assay Name: UALB6 Fluid Type: Urine
Assay Model Type: End Point Template: EPT1 R1-S-R2
Cal Model Type: Logit/Log4 Calibrator Bottles: 6 Reagent Reps per Cal: 2
Standard Dilution Factor: 1.0 Diluent: Saline
Reflex Dilution Information
Reflex Dilution: On Dilution Factor: 5.0 Reduction Factor: 1.0
Sample Indices Check: Disabled
Threshold Limits
Hemolysis: 1000 Icterus: 25 Turbidity: 800
Reporting Type: Quantitative Units: mg/L
Significant Digits: 6 Precision Digits: 3
Slope: 1.00 Intercept: 0.000
CuveTip Expiration Time: 35 Temperature Sensitive: No
Ranges
Reference: 0.000 – 900000 Supplementary: 0.000 – 900000 Reportable: 0.000 – 400.000
Initial Absorbance Limits: -0.200 – 2.700 Blank Absorbance Limits: -0.200 – 2.700
Monotonicity: Increase
Max Response High: 3.000 Max Response Low: -3.000
Min Response High: 3.000 Min Response Low: -3.000
Cal Fit Goodness Limit: 0.990
Reportable Conc. Triple Read Limit
Reportable Min 0.000 2.667
Critical Conc.: 20.000 13.300
Reportable Max: 400.000 13.300
Kit Lot Bottle Number Dilution Factor Cal. Value Response Range
74XX 1 1.0 0.000 0.20000
74XX 2 73.0 397.8 0.20000
74XX 3 22.0 397.9 0.20000
74XX 4 5.0 398 *** 0.20000
74XX 5 2.0 398.1 0.20000
74XX 6 3.5 398.2 0.20000
*** replace with actual calibrator value
Protocol Steps
1. Reagent Volume (mL)=150.0, Pack/Bottle=UD09 / A
2. Incubation Seconds=0.00
3. Sample Volume (mL)=9.0
4. Incubation Seconds=280.25
5. Read Wavelength=620 nm
6. Incubation Seconds=14.25
7. Reagent Volume (mL)=30.0, Pack/Bottle=UD09 / B
8. Incubation Seconds=123.50
9. Read Wavelength=620 nm
Original- 340 nm, second incubation: 10 minutes
PROFILE CONFIGURATION
Full Assay Name: Roche ALBUMIN Date: 03/11/2011
Short Assay Name: UALB Fluid Type: Urine
Assay Model Type: End Point Template: EPT1 R1-S-R2
Cal Model Type: Logit/Log4 Calibrator Bottles: 6 Reagent Reps per Cal: 2
Standard Dilution Factor: 1.0 Diluent: Saline
Reflex Dilution Information
Reflex Dilution: On Dilution Factor: 5.0 Reduction Factor: 1.0
Sample Indices Check: Disabled
Threshold Limits
Hemolysis: 1000 Icterus: 25 Turbidity: 800
Reporting Type: Quantitative Units: mg/L
Significant Digits: 6 Precision Digits: 3
Slope: 1.00 Intercept: 0.000
CuveTip Expiration Time: 35 Temperature Sensitive: No
Ranges
Reference: 0.000 – 900000 Supplementary: 0.000 – 900000 Reportable: 0.000 – 115.000
Initial Absorbance Limits: -0.200 – 2.700 Blank Absorbance Limits: -0.200 – 2.700
Monotonicity: Increase
Max Response High: 3.000 Max Response Low: -3.000
Min Response High: 3.000 Min Response Low: -3.000
Cal Fit Goodness Limit: 0.990
Reportable Conc. Triple Read Limit
Reportable Min 0.000 2.667
Critical Conc.: 20.000 13.300
Reportable Max: 400.000 13.300
Kit Lot Bottle Number Dilution Factor Cal. Value Response Range
74XX 1 1.0 0.000 0.20000
74XX 2 73.0 397.8 0.20000
74XX 3 22.0 397.9 0.20000
74XX 4 5.0 398 *** 0.20000
74XX 5 2.0 398.1 0.20000
74XX 6 3.5 398.2 0.20000
*** replace with actual calibrator value
Protocol Steps
10. Reagent Volume (mL)=150.0, Pack/Bottle=UD09 / A
11. Incubation Seconds=0.00
12. Sample Volume (mL)=9.0
13. Incubation Seconds=280.25
14. Read Wavelength=340 nm
15. Incubation Seconds=14.25
16. Reagent Volume (mL)=30.0, Pack/Bottle=UD09 / B
17. Incubation Seconds=617.50
18. Read Wavelength=340 nm
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