Volume 25, Number 6—June 2019
Research Letter
Suboptimal Handling of Piccolo Samples or Reagent Discs for Consideration in Ebola Response
, Stephen R. Welch, Sarah C. Genzer, JoAnn Coleman-McCray, Jessica R. Harmon, Stuart T. Nichol, and Christina F. Spiropoulou
Table
Mean percentage change of clinical chemistry values obtained on the Piccolo Xpress Chemistry Analyzer from blood samples or reagent discs processed under various conditions that deviated from the manufacturer’s recommendations*
| Condition | No. tested | Percentage change compared with baseline |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| GLU | BUN | CRE | CA | ALB | TP | ALT | AST | ALP | TBIL | GGT | AMY | ||
| Sample collection |
|||||||||||||
| WB in EDTA† |
15 |
−3.0 |
0.2 |
−0.8 |
ERR |
4.1 |
−3.0 |
1.4 |
10.9 |
−93.2 |
−0.6 |
21.0 |
−1.7 |
| WB in Na citrate† |
18 |
−30.0 |
−23.3 |
−20.8 |
−59.1 |
−31.0 |
−34.4 |
−36.5 |
−23.6 |
−38.1 |
−6.9 |
−31.3 |
−0.5 |
| Sample handling |
|||||||||||||
| WB 4°C O/N† |
13 |
−19.2 |
1.2 |
−9.4 |
−1.0 |
−2.3 |
0.0 |
1.6 |
20.1 |
−2.5 |
−1.9 |
227.3 |
0.0 |
| WB RT O/N† |
16 |
−76.4 |
1.7 |
−4.7 |
2.0 |
−4.2 |
4.9 |
−0.1 |
37.7 |
−9.3 |
0.6 |
572.3 |
1.2 |
| WB 32°C O/N† |
16 |
−92.6 |
8.9 |
6.4 |
0.7 |
−4.1 |
6.3 |
−0.2 |
64.0 |
−10.5 |
−1.8 |
489.0 |
2.8 |
| WB −20°C O/N† |
3‡ |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
| PL† |
35 |
−0.4 |
1.1 |
13.2 |
1.2 |
1.1 |
0.1 |
2.8 |
−1.5 |
2.1 |
4.7 |
−11.1 |
−0.1 |
| PL RT O/N§ |
15 |
0.4 |
2.9 |
−11.3 |
0.3 |
−4.1 |
1.9 |
−0.4 |
1.8 |
−3.3 |
−4.8 |
1.5 |
−0.5 |
| PL 32°C O/N§ |
18 |
0.2 |
6.1 |
−12.2 |
0.1 |
−6.2 |
2.2 |
−5.5 |
2.1 |
−0.6 |
3.9 |
0.2 |
−0.5 |
| PL −20°C O/N§ |
14 |
−1.1 |
0.4 |
−3.9 |
−2.4 |
−0.6 |
−1.6 |
2.5 |
4.0 |
−5.9 |
−3.6 |
0.0 |
−0.5 |
| PL −20°C O/N +
γ-irradiation§ |
16 |
0.3 |
3.4 |
11.3 |
2.5 |
0.0 |
−4.9 |
−12.3 |
−13.2 |
−15.8 |
1.6 |
−15.8 |
−0.5 |
| Disc handling |
|||||||||||||
| WB + disc RT 7 d† |
15 |
−3.4 |
1.1 |
−3.6 |
−1.4 |
0.9 |
0.6 |
3.0 |
2.2 |
−2.9 |
2.2 |
36.6 |
1.2 |
| WB + disc 32°C 5 d† |
12 |
−4.3 |
0.5 |
56.7 |
0.3 |
1.3 |
0.8 |
−4.1 |
1.8 |
7.6 |
−7.5 |
22.0 |
1.7 |
| WB + disc 32°C 14 d†¶ |
7‡ |
−0.9 |
ERR |
ERR |
−1.8 |
−8.0 |
−0.5 |
5.3 |
−0.2 |
ERR |
0.0 |
0.5 |
−0.5 |
| WB + disc 32°C 5 wk† |
2‡ |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
ERR |
| Intrinsic variation |
|||||||||||||
| ±1 SD |
3.0 |
2.8 |
18.3 |
1.5 |
3.1 |
1.8 |
8.9 |
4.0 |
13.2 |
16.6 |
20.3 |
1.8 |
|
| ±2 SD |
5.9 |
5.7 |
36.5 |
3.1 |
6.2 |
3.7 |
17.7 |
8.1 |
26.5 |
33.3 |
40.6 |
3.7 |
|
| Reference values# | 143 ± 16 mg/dL | 20.5 ± 3.3 mg/dL | 0.32 ± 0.2 mg/dL | 11.4 ± 0.5 mg/dL | 2.9 ± 0.2 g/dL | 5.4 ± 0.3 g/dL | 27 ± 6 U/L | 46 ± 15 U/L | 43 ± 15 U/L | 0.3 ± 0.04 mg/dL | 10 ± 3 U/L | 1,149 ± 131 U/L | |
*All analytes were quantified with the Piccolo General Chemistry 13 reagent discs (https://www.abaxis.com). Baseline values were obtained from aliquots of the same samples run according to manufacturer’s recommendations for comparison. Values in white cells varied by <1 SD; values in light gray cells, by 1–2 SD; and values in dark gray cells, by >2 SD from the determined % intrinsic variation derived from analysis of samples run either sequentially on the same machine or in parallel on different machines. γ indicates γ-irradiated at 5 × 106 rads. ALB, albumin; AMY, amylase; ALP, alkaline phosphatase; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BUN, blood urea nitrogen; CA, calcium; CRE, creatinine; ERR, analyte, sample, or disc error; GGT, γ-glutamyltransferase; GLU, glucose; Na, sodium; O/N, overnight; PL, plasma; RT, room temperature; TBIL, total bilirubin; TP, total protein; WB, whole blood. An expanded version of this table is available online (https://wwwnc.cdc.gov/EID/article/25/6/18-1928-T1.htm).
†Baseline sample: WB.
§‡Smaller sample size tested because tests did not function at indicated condition.
‡§Baseline sample: PL.
¶Only subset of discs (7 of 10) generated values; remainder generated no values because of disc error.
#Reference values for strain 13/N guinea pigs 50–900 d of age, expressed as mean ± SD (10).