[The establishment and application of internal quality control system for real-time quantitative PCR detection of BCR-ABL (P210) transcript levels]

[The establishment and multicenter application of internal quality control system for real-time quantitative PCR detection of BCR-ABL (P210) transcript level]

Objective: The study aims to establish a perfect BCR-ABL (P210) internal quality control system and ensure the long-term stability and comparability of the detection results between laboratories and to popularize and apply it in the three hospitals. Methods: The Qilu Hospital of Shandong University (H1) prepared a set of the BCR-ABL (P210) quality control substances to establish and improve internal quality control system. We went to other three participating hospitals (H2, H3, and H4) to inspect quality control before the measurement. In addition, we mailed 25 sets of quality control substances to each of the hospital for detection. The slope and intercept of the standard curve of each hospital and the detection results were analyzed and statistically judged using the Levey-Jennings quality control chart combined with the Westgard multirule theory. Then, we made a quality control evaluation. Results: ①An internal quality control system for the BCR-ABL (P210) transcript levels monitoring was successfully established for the quality inspection before the measurement, statistical judgment during the measurement, and evaluation after the measurement. ② Both the slope and intercept of the standard curve of the four hospitals was under control. ③The multicenter quality control substance judgment results were as follows: for H1 hospital, two times of "1(2s)" warning were found in the middle-level quality control substance, which was judged as being under control; for H2 hospital, one time of "1(2s)" warning was found for each quality control substance, which was judged as being "2(2s)" out of control; for H3 hospital, its high-level quality control substance violated the "1(3s)" rule, and low-level quality control substance appeared "1(2s)" warning, which was judged as "1(3s)" out of control; and all quality control substances were under control in H4 hospital. ④The quality control evaluation and correction were as follows: two hospitals were under control, and the other two hospitals had an "out of control." We found out the reason for the out of control and corrected them. ⑤The comparisons of the original values of the multicenter quality control substance were as follows: there were statistical differences in the results of high-level quality control substance among the four hospitals, and no significant difference was found in the results of the medium-level and low-level quality control substance. ⑥The comparisons of the IS values of the multicenter quality control substance were as follows: the IS values of the three quality control substance in H2 and H3 hospitals were significantly higher than those of H1 hospital, and H2 hospital was significantly higher than H3 hospital. Conclusion: A perfect and stable internal quality control system for the BCR-ABL (P210) transcripts has been established, which can effectively ensure the accuracy and stability of the clinical detection results. This internal quality control system has been successfully popularized and applied in other hospitals.

[The influence of peripheral blood sample storage and delivery on the quantitative detection result of BCR-ABL (P210) transcript levels]

Objective: To explore the influence of storage and delivery conditions of the peripheral blood samples from patients with chronic myeloid leukemia (CML) on the real-time quantitative PCR (RQ-PCR) detection of the BCR-ABL (P210) transcript levels. Methods: The peripheral blood samples of 84 CML patients were collected. The same sample was divided into different groups according to storage time (0, 6, 12, 24, 48, and 72 h) , temperature (room temperature, 18-24 ℃; low temperature, 2-8 ℃) , and vibration conditions (3, 6, and 12 h) . RQ-PCR was used to detect BCR-ABL (P210) transcript levels of the different groups. This study logarithmically transformed (log(10N)) the original data [BCR-ABL copy number, ABL copy number, and BCR-ABL (P210) transcript levels]. Results: ①Agarose gel electrophoresis showed significant RNA degradation of samples after storage for 48 and 72 h at room temperature. ②Among the overall samples, the BCR-ABL copy number of the samples stored at room temperature for 48 and 72 h was significantly lower than that of the samples stored at low temperature (P<0.05) . However, the BCR-ABL (P210) transcript levels had no significant difference between samples stored at low temperature and room temperature. ③No significant changes were noted in the BCR-ABL (P210) transcript levels at different storage times (6, 12, 24, 48, and 72 h) regardless of storage temperature (P>0.05) compared with that at baseline (0 h, -0.56±1.51) . ④ The BCR-ABL copy number of the overall sample only decreased significantly (P<0.05) at 48 h (2.93±1.59) and 72 h (2.79±1.42) compared with that at baseline (0 h, 3.35±1.60) when stored at room temperature. The ABL copy number in the overall sample decreased significantly at 48 and 72 h (whether low and room temperature; P<0.05) . However, no significant changes were noted in the BCR-ABL (P210) transcript levels after vibration for 3 h (-1.29±1.81) , 6 h (-1.24±1.72) , and 12 h (-1.18±1.68; P>0.05) compared with that at baseline (0 h, -0.60±1.37) . Conclusion: Sample storage time, storage temperature, and vibration can interfere with the results of BCR-ABL and ABL copy number but have no significant effect on the quantitative determination of BCR-ABL (P210) transcript levels. This study provides strong support for the feasibility of transregional transportation of peripheral blood samples from patients with CML.