An interlaboratory comparison study on the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels / 中华血液学杂志

Objective: To investigate the current status and real performance of the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels in China through interlaboratory comparison. Methods: Peking University People's Hospital (PKUPH) prepared the samples for comparison. That is, the fresh RUNX1-RUNX1T1 positive (+) bone morrow nucleated cells were serially diluted with RUNX1-RUNX1T1 negative (-) nucleated cells from different patients. Totally 23 sets with 14 different samples per set were prepared. TRIzol reagent was added in each tube and thoroughly mixed with cells for homogenization. Each laboratory simultaneously tested RUNX1-RUNX1T1 and WT1 transcript levels of one set of samples by real-time quantitative PCR method. All transcript levels were reported as the percentage of RUNX1-RUNX1T1 or WT1 transcript copies/ABL copies. Spearman correlation coefficient between the reported transcript levels of each participated laboratory and those of PKUPH was calculated. Results: ①RUNX1-RUNX1T1 comparison: 9 samples were (+) and 5 were (-) , the false negative and positive rates of the 20 participated laboratories were 0 (0/180) and 5% (5/100) , respectively. The reported transcript levels of all 9 positive samples were different among laboratories. The median reported transcript levels of 9 positive samples were from 0.060% to 176.7%, which covered 3.5-log. The ratios of each sample's highest to the lowest reported transcript levels were from 5.5 to 12.3 (one result which obviously deviated from other laboratories' results was not included) , 85% (17/20) of the laboratories had correlation coefficient ≥0.98. ②WT1 comparison: The median reported transcript levels of all 14 samples were from 0.17% to 67.6%, which covered 2.6-log. The ratios of each sample's highest to the lowest reported transcript levels were from 5.3-13.7, 62% (13/21) of the laboratories had correlation coefficient ≥0.98. ③ The relative relationship of the reported RUNX1-RUNX1T1 transcript levels between the participants and PKUPH was not always consistent with that of WT1 transcript levels. Both RUNX1-RUNX1T1 and WT1 transcript levels from 2 and 7 laboratories were individually lower than and higher than those of PKUPH, whereas for the rest 11 laboratories, one transcript level was higher than and the other was lower than that of PKUPH. Conclusion: The reported RUNX1-RUNX1T1 and WT1 transcript levels were different among laboratories for the same sample. Most of the participated laboratories reported highly consistent result with that of PKUPH. The relationship between laboratories of the different transcript levels may not be the same.

Correlation between myeloperoxidase expression and gene alterations and prognosis in acute myeloid leukemia / 中华血液学杂志

Objective: To analyze the percentage of myeloperoxidase (MPO)-positive acute myeloid leukemia (AML) blast cells, and to explore the correlation of MPO expression with the clinical features, gene alterations, therapeutic response and prognosis of AML. Methods: The expressions of MPO in BM blasts cells of 233 newly diagnosed AML were retrospectived analyzed, they were divided into two groups using the percentage of MPO-positive blast [low (≤70%) and high (>70%)], clinical features, gene alterations, chemotherapy efficacy and prognosis were compared between the two groups. Results: ①Of the 233 patients, 121(51.9%) were in the low MPO group, and the rest 112(48.1%) in the high MPO group. Favorable-risk group according NCCN guidelines of AML was always MPO-high (χ(2)=32.773, P<0.001), while MPO-low was closely related to poor-risk (χ(2)=7.078, P=0.008); ②DNMT3A mutation (χ(2)=6.905, P=0.009), spliceosome genes mutation (SF3B1/SRSF2/U2AF1) (χ(2)=5.246, P=0.022), RUNX1 mutation (χ(2)=4.577, P=0.032), ASXL1 mutation (χ(2)=7.951, P=0.005) and TP53 mutation (P=0.004) were more likely to be seen in the low MPO group, while C-KIT mutation (χ(2)=8.936, P=0.003) and CEBPA mutation (χ(2)=12.340, P<0.001) were more frequent in the high MPO group, especially CEBPA double mutation; ③The rates of first complete remission in the low MPO group were significantly lower than that in the high MPO group (38.8% vs 68.1%, χ(2)=15.197, P<0.001). Multivariate analysis showed that low MPO positivity significantly affected the CR(1) unfavourably. ④The overall survival (OS) and the progression-free survival (PFS) were significantly worse in the low MPO group (18.0% vs 89.4% for OS, and 11.5% vs 56.7% for PFS, P<0.001). Multivariate analysis disclosed that the low number of MPO was significantly unfavourable prognostic factor. ⑤The low MPO group still showed a worse survival even when restricted to the patients with normal karyotype, the OS and the PFS were 31.1% and 18.8% respectively. Conclusions: AML with different MPO expression percentage had a unique gene mutation spectrum. Low expression of MPO was an independent risk factor for CR(1), OS and PFS in AML patients, which may be a simple and highly significant factor for AML patients when evaluating the therapeutic efficacy and prognosis.