[Correlation between D-Dimer/Fibrinogen Ratio and Bleeding in Patients with Newly Diagnosed Acute Promyelocytic Leukemia]

OBJECTIVE

To further explore the better indicators for predicting the degree of bleeding associated with newly diagnosed acute promyelocytic leukemia (APL).

METHODS

A total of 131 patients with newly diagnosed APL were classified according to WHO bleeding scales before treatment and divided into two groups: scales 0, 1 and 2 were included in no severe bleeding group, scales 3 and 4 were included in severe bleeding group. The information of the patients were collected, including sex, age, hemoglobin (Hb), white blood cell (WBC) count and platelet (PLT) count, peripheral blood lymphocyte percentage (LYMPH%), peripheral blood monocyte percentage (MONO%), percentage of leukemic cells in pripheral blood and bone marrow, prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB) levels, D-dimer (D-D), D-dimer/fibrinogen ratio (DFR).

RESULTS

Among 131 patients, 110 were classified as no severe bleeding, and 21 were severe bleeding. The results of univariate analysis showed that patients with severe bleeding had significantly higher percentage of leukemic cells in pripheral blood, WBC, D-D, and DFR, as well as longer PT and lower LYMPH%, compared to those with no severe bleeding. Multivariate analysis revealed that DFR (OR =1.054, 95%CI : 1.024-1.084, P < 0.001) and percentage of peripheral blood leukemic cells (OR=1.026, 95%CI: 1.002-1.051, P =0.033) were independent risk factors for severe bleeding. The area under ROC curve (AUC) of peripheral blood leukemic cells, D-D and DFR were 0.748, 0.736 and 0.809, respectively. There was no statistical difference between the peripheral blood leukemic cells and D-D in diagnostic efficacy (P =0.8708). Compared with D-D, DFR had a higher predictive value (P =0.0302). The optimal cut-off value of DFR was 16.50, with a sensitivity of 90.5% and a specificity of 70.0%.

CONCLUSION

DFR has a significant advantage in predicting the degree of bleeding associated with newly diagnosed APL. The greater the DFR value, the heavier the degree of bleeding. The risk of severe or fatal bleeding increases when DFR is greater than 16.50.

[Effects of Cytokines on Early Death in Patients with Newly Diagnosed Acute Promyelocytic Leukemia]

OBJECTIVE

To explore the effect of cytokine levels on early death and coagulation function of patients with newly diagnosed acute promyelocytic leukemia (APL).

METHODS

Routine examination was performed on 69 newly diagnosed APL patients at admission. Meanwhile, 4 ml fasting venous blood was extracted from the patients. And then the supernatant was taken after centrifugation. The concentrations of cytokines, lactate dehydrogenase (LDH) and ferritin were detected by using the corresponding kits.

RESULTS

It was confirmed that cerebral hemorrhage was a major cause of early death in APL patients. Elevated LDH, decreased platelets (PLT) count and prolonged prothrombin time (PT) were high risk factors for early death (P <0.05). The increases of IL-5, IL-6, IL-10, IL-12p70 and IL-17A were closely related to the early death of newly diagnosed APL patients, and the increases of IL-5 and IL-17A also induced coagulation disorder in APL patients by prolonging PT (P <0.05). In newly diagnosed APL patients, ferritin and LDH showed a positive effect on the expression of IL-5, IL-10 and IL-17A, especially ferritin had a highly positive correlation with IL-5 (r =0.867) and IL-17A (r =0.841). Moreover, there was a certain correlation between these five high-risk cytokines, among which IL-5 and IL-17A (r =0.827), IL-6 and IL-10 (r =0.823) were highly positively correlated.

CONCLUSION

Elevated cytokine levels in newly diagnosed APL patients increase the risk of early bleeding and death. In addition to the interaction between cytokines themselves, ferritin and LDH positively affect the expression of cytokines, thus affecting the prognosis of APL patients.

[Mechanism of Proliferation and Apoptosis of Acute Promyelocytic Leukemia Cell Line NB4 Induced by TPA]

OBJECTIVE

To investigate the effect of phorbol-12-myristate-13-ace-tate (TPA) on the proliferation and apoptosis of acute promyelocytic leukemia cell line NB4 and its molecular mechanism.

METHODS

The effect of different concentrations of TPA on the proliferation of NB4 cells at different time points was detected by CCK-8 assay. The morphological changes of NB4 cells were observed by Wright-Giemsa staining. The cell cycle and apoptosis of NB4 cells after TPA treatment were detected by flow cytometry. The mRNA expressions of NB4 cells after TPA treatment were analyzed by high-throughput microarray analysis and real-time quantitative PCR. Western blot was used to detect the protein expression of CDKN1A, CDKN1B, CCND1, MYC, Bax, Bcl-2, c-Caspase 3, c-Caspase 9, PIK3R6, AKT and p-AKT.

RESULTS

Compared with the control group, TPA could inhibit the proliferation of NB4 cells, induce the cells to become mature granulocyte-monocyte differentiation, and also induce cell G1 phase arrest and apoptosis. Differentially expressed mRNAs were significantly enriched in PI3K/AKT pathway. TPA treatment could increase the mRNA levels of CCND1, CCNA1, and CDKN1A, while decrease the mRNA level of MYC. It could also up-regulate the protein levels of CDKN1A, CDKN1B, CCND1, Bax, c-Caspase 3, c-Caspase 9, and PIK3R6, while down-regulate MYC, Bcl-2, and p-AKT in NB4 cells.

CONCLUSION

TPA induces NB4 cell cycle arrest in G1 phase and promotes its apoptosis by regulating PIK3/AKT signaling pathway.

[Effect of a Novel Dihydroartemisinin Dimer Containing Nitrogen Atoms SM 1044 on Apoptosis of Human Leukemia Cell Line NB4-R1]

OBJECTIVE

To investigate the effect of a water-soluble novel dihydroartemisinin dimer containing nitrogen atoms SM 1044 on the apoptosis of all-trans retinoic acid (ATRA) resistant acute promyelocytic leukemia (APL) NB4-R1 cells and its potential mechanism.

METHODS

The effects of SM 1044 on cell apoptosis, mitochondrial transmembrane potential, and the level of reactive oxygen species (ROS) were assessed by flow cytometry. Expressions of apoptosis-related proteins were determined by Western blot. The effects of SM 1044 on MAPK (ERK, JNK) signaling pathway, PML/RARα fusion protein, and expressions of apoptosis-related proteins were detected by Western blot.

RESULTS

SM 1044 could significantly induce apoptosis and the loss of mitochondrial transmembrane potential in NB4-R1 cells, and activate apoptosis-related proteins caspase-3, caspase-8, caspase-9 and poly (ADP-ribose) polymerase (PARP). SM 1044 could also induce NB4-R1 cells to produce ROS. Western blot showed that SM 1044 activated the phosphorylation of MAPK (ERK, JNK) signaling pathway and down-regulated the expression of PML/RARα fusion protein.

CONCLUSION

SM 1044 can induce apoptosis of ATRA resistant APL NB4-R1 cells, which may be related to ROS/ERK and ROS/JNK signaling pathway, and can also induce by down-regulating PML/RARα fusion protein.

[Clinical Analysis of Children with High-Risk Acute Promyelocytic Leukemia]

OBJECTIVE

To explore the treatment of children with high-risk acute promyelocytic leukemia (APL), aiming to improve the prognosis.

METHODS

The clinical datas of 24 children with high-risk APL in our hospital from January 2015 to June 2021 were retrospectively analyzed.

RESULTS

The main manifestations of 24 children (including 15 males and 9 females) were purpura, gingiva bleeding and nasal hemorrhage, with a median age of 7 years old and a median leukocyte count of 28.98 (10-232)×10⁹/L, including 15 cases with leukocyte count between 10×10⁹/L and 50×10⁹/L, 2 cases between 50×10⁹/L and 100×10⁹/L, and 7 cases >100×10⁹/L. The leukocyte count of 2 cases in 3 children admitted from 2015 to November 2016 was >100×10⁹/L, in which 1 case was first treated with homoharringtonine for cytoreduction, 7 days later treated with all-trans retinoic acid (ATRA) after genetic diagnosis, then died of differentiation syndrome and pulmonary hemorrhage after 3 days. The other one was treated with reduced ATRA+daunorubicin+arsenic trioxide (ATO) for induction, then achieved complete remission. The third one with leukocyte count 12×10⁹/L had cerebral hemorrhage before admission and died on the 7th day of treatment. The remaining 21 children were treated with chemotherapy according to the APL regimen for children in South China, including 14 cases with leukocyte count between 10×10⁹/L and 50×10⁹/L, 2 cases between 50×10⁹/L and 100×10⁹/L, and 5 cases >100×10⁹/L. In the 5 children with leukocyte count >100×10⁹/L, 1 case died of cerebral hemorrhage on the second day of oral ATRA before the addition of anthracyclines, 3 cases died of cerebral hemorrhage after the addition of anthracyclines to chemotherapy on the second day of oral ATRA, and another one developed differentiation syndrome after the addition of mitoxantrone on the second day of oral ATRA, then achieved complete remission after ATRA reduction chemotherapy and survived without disease till now. In the 2 children with leukocyte count between 50×10⁹/L and 100×10⁹/L, 1 case died of cerebral hemorrhage on the second day of oral ATRA before the addition of anthracyclines. All the children were followed up until 1st August, 2021, with a median follow-up time of 40 months, including 7 deaths and 1 recurrence in maintenance therapy who achieved second remission after chemotherapy, 14 cases survived in 3 years and 13 cases survived without event. The 7 dead children had a median time from treatment to death of 5 days, including 1 case with leukocyte count between 10×10⁹/L and 50×10⁹/L, 1 case between 50×10⁹/L and 100×10⁹/L, and 5 cases >100×10⁹/L.

CONCLUSION

High-risk APL children with leukocyte count >100×10⁹/L have a high mortality rate. Gradual addition of chemotherapy starting at small doses and early addition of ATO may help to improve the prognosis.