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 of NPM1, FLT3-ITD mutations with leukocyte count and myeloblasts percentage in AML patients with normal karyotype / 中国实验血液学杂志

This study was aimed to investigate the correlation of NPM1 and FLT3-ITD mutations with leukocyte count in peripheral blood and bone marrow blasts in patients with acute myeloid leukemia (AML). Fifty-one acute myeloid leukemia patients with normal karyotype from January 2009 to December 2011 were enrolled in this study. The clinical data of 51 cases were analyzed retrospectively. Out of 52 cases 22 were male, and 29 were female. The median age was 47 years old (ranged from 14 to 83 years old). The de novo patients were examined by bone marrow cytomorphology and blood routine analysis. Polymerase chain reaction was used to analyze the NPM1 and FLT3-ITD mutations. The results showed that the patients with NPM1 mutations had higher leukocyte count compared with those without mutations (30.7×10(9)/L vs 8.6×10(9)/L, P = 0.002). FLT3-ITD mutation was related to higher leukocyte count (42.38×10(9)/L vs 11.45×10(9)/L without mutation, P = 0.033) and blasts (74.0% vs 60.25% without mutation, P = 0.036). The leukocyte count and percentage of bone marrow blasts were lowest in the patients with neither mutations, and gradually increasing in the NPM1(-) mutation, FLT3-ITD(-) mutation, and NPM1(+) mutation, FLT3-ITDI(+) mutation, and NPM1(+)/FLT3-ITD(+) mutation groups (P < 0.05). The patients tended to have NPM1 (P = 0.002) and FLT3-ITD (P = 0.033) mutations when their leukocyte counts were more than 12.55×10(9)/L and 37.85×10(9)/L, respectively. Those with bone marrow blast more than 72.25% showed higher rate of FLT3-ITD mutation (P = 0.008). Patients with NPM1 mutations had higher complete remission rate than those without NPM1 mutation (78.13% vs 40.0%, χ(2) = 4.651, P = 0.031) after remission induction therapy. It is concluded that both NPM1 and FLT3-ITD mutations are linked to higher leukocyte count and blast percentage, suggesting that both mutations may be associated with increased proliferation of leukemia cells, and may have a synergistic function in stimulating proliferation.