[Therapeutic Effect of PE+CRRT Combined with Chemotherapy on Children with Severe EBV-HLH and Non-EBV-HLH].

OBJECTIVE: To investigate the difference in the therapeutic effect of plasma exchange and continuous renal replacement therapy (PE+CRRT) combined with chemotherapy in the treatment of children with severe Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) and non-EBV-HLH. METHODS: The clinical data of 21 cases of all children with severe HLH treated by PE+CRRT combined with chemotherapy from January 2017 to January 2020 were collected and retrospectively analyzed. According to the presence of EBV infection, the children were divided into EBV+ group and EBV- group. The differences of the observation indexes between the children in the two groups and the improvement of the observation indexes of each group before and after treatment were compared. RESULTS: Among the 21 children, 14 were divided into the EBV+ group and 7 were divided into the EBV- group. There was no difference in age, sex and the number of organ damage between the children in the two groups (P>0.05). Duration of PE+CRRT was longer in the EBV+ group as compared with the EBV- group (P<0.05). Before treatment, the ANC in the EBV+ group was lower than that in the EBV- group (P<0.05), and there was no significant difference in the other observation indexes between the two groups (P>0.05). After treatment, Hb, Fib, APTT, SF, ALT, AST, LDH, Alb, CHE, TBil and TBA of the children in the EBV+ group were significantly improved as compared with those before treatment (P<0.05), but ANC, PLT, TG showed not improve (P>0.05); Fib, APTT, SF, LDH, Alb, and CHE in the EBV- group were significantly as improved compared with those before treatment (P<0.05), while the ANC, PLT, Hb, TG, ALT, AST, TBil, and TBA were not improved (P>0.05). After treatment, the differences of Fib and SF in the children between the EBV+ group and the EBV- group were statistically significant (P<0.05), and there was no significant difference in the other observation indexes of the children between the two groups (P>0.05). Compared with the children before treatment, EBV-DNA in the EBV+ group were decreased significantly in 2-4 weeks after treatment (P<0.05). After PE+CRRT combined with chemotherapy, the overall survival rate of the children with severe HLH was 66.7%, and there was no significant difference in overall survival rate between EBV+ group and EBV- group (P>0.05). CONCLUSION: PE+CRRT combined with chemotherapy can reduce serum ferritin quickly, then improve organ function, and increase the overall survival rate of severe HLH, and it is a good effect on children with severe EBV-HLH and non-EBV-HLH.

[Effect of Silencing and Overexpression of LNK Gene on STAT3 Expression in THP-1 Cells].

OBJECTIVE: To investigate the effect of LNK gene silencing and overexpression on the expression of STAT3 gene in human monocytic leukemia cells (THP-1). METHODS: THP-1 cells were cultured, and the lentivirus was used as a vector to silence and overexpres the LNK gene stably. After transfection for 72 hours, the GFP expression levels were observed by inverted fluorescence microscopy. The lentiviral transfection efficiencies were detected by flow cytometry. The effects of LNK silencing and overexpression were confirmed, and the expression of STAT3 mRNA was detected by RT-PCR. The protein levels of LNK and STAT3 were detected by Western blotting. RESULTS: The GFP expression level of THP-1 cells reached more than 85% after transfection with lentivirus for 72 hours, and the transfection efficiency of cells was above 99%. mRNA expressions levels of LNK and STAT3 in LNK silencing group were signifycantly lower than those in control group, while LNK and STAT3 mRNA levels in the LNK overexpression group was significantly higher than those in control group (P＜0.05). The protein expression levels of LNK and STAT3 in LNK silencing group were significantly lower than those in control group, while that in LNK overexpression group was significantly higher than that in control group (P＜0.05). CONCLUSION: The THP-1 cell line with LNK gene silencing and overexpression has been successfully established. The LNK gene silencing resulted in decrease of STAT3 expression; LNK gene overexpression and leads to inereases of STAT3 expression indicating that LNK participates in the regulation of STAT3.

[Effect of Silencing LNK Gene on the Expression of EPO and EPOR in THP-1 Cells].

OBJECTIVE: To investigate the effect of silencing LNK gene on the expression of EPO and EPOR in acute myeloid leukemia cells (THP-1). METHODS: THP-1 cells were cultured. The lentivirus was used as a vector to silence the LNK gene stably. After 72 hours of infection, GFP expression level was detected by the fluorescent inverted microscopy. The lentiviral Infection efficiencies were monitored by flow cytometry. The LNK silencing effect was confirmed. The mRNA expressions of EPO and EPOR were detected by RT-PCR. The protein levels of LNK, EPO and EPOR were detected by Western blot. RESULTS: At the time-point of 72 hours after lentivirus infection, the expression level of GFP was above 85% detected by fluorescent inverted microscopy. The infection efficiency was above 99% by flow cytometry. mRNA expressions of LNK, EPO and EPOR in LNK silencing group were signifycantly lower than those in control group (P＜0.05). The protein levels of LNK, EPO and EPOR in LNK silencing group were significantly lower than those in the control group (P＜0.05). CONCLUSION: THP-1 cell line of LNK gene silencing has been successfully established,the LNK gene has been silenced, the expression of EPO and EPOR decrease, indicating that LNK may participate in the regulation of EPO and EPOR.

[EPO and EPOR Expression in Patients with Acute Leukemia and Its Clinical Significance].

OBJECTIVE: To investigate the expression of erythropoietin (EPO) and erythropoietin receptor (EPOR) in patients with acute leukemia (AL) and its clinical significance. METHODS: The levels of EPO and EPOR in plasma were determined by ELISA kit. mRNA expression levels of EPO and EPOR were determined by RT-RCR. The protein expression levels of EPO and EPOR were detected by Western blot. RESULTS: The EPO protein levels in marrow plasma of ALL and AML group were significantly higher than those in the control group (P＜0.05), EPOR protein levels in ALL and AML group were significantly lower than those in the control group (P＜0.05). The mRNA levels of EPO and EPOR in ALL and AML groups were significantly higher than those in the control group (P＜0.05). The mRNA levels of EPO and EPOR in the high risk ALL and AML groups were significantly higher than those in the medium, low risk group and the control group (P＜0.05). The protein expression levels of EPO and EPOR in ALL and AML groups were significantly higher than that in control group (P＜0.05). The mRNA levels of EPO and EPOR in ALL and AML groups did not correlate with hemoglobin level and erythrocyte count (P＞0.05). CONCLUSION: The expressions of EPO and EPOR is higher in ALL and AML patients. The expression levels of EPO and EPOR relate with the risk of ALL and AML. High risk patients have higher expression levels of EPO and EPOR, however, the expression levels of EPO and EPOR do not correlate with hemoglobin level and erythrocyte counting.

[Expression and Clinical Significance of STAT3 Genes in Patients with Acute Myeloid Leukemia].

OBJECTIVE: To investigate the expression of STAT3 gene in patients with acute myeloid leukemia and its correlation with clinical characteristics. METHODS: The real-time quantitative RT-PCR was used to detect the level of STAT3 mRNA in bone marrow samples from 38 newly diagnosed patients with acute myeloid leukemia(AML), and its relevance with clinical characteristics and prognosis were statistically analyzed. Western blot was employed to detect the STAT3 protein level in AML patients. The bone marrow cells from 15 healthy subjects were used as control. RESULTS: At the mRNA level, the expression level of STAT3 in the AML group was significantly higher than that in control group (P<0.05). The level of STAT3 in AML group correlated positively with the risk factors of patients (P<0.01，r=0.592）. The STAT3 expression level in the high-risk group was statistically higher than that in the standard-risk group and the control group (P<0.01，P<0.01). Furthermor, there was no statistical difference between the sub-groups of AML (P>0.05). The median survival time of patients in STAT3 low expression group was logner than that in high expression group, but the difference was not statistically significant (P>0.005). The level of STAT3 protein in AML patients was significantly higher than that in control group (P<0.05）. CONCLUSION: The STAT3 gene is highly expressed in AML patients, which may be used as a predictor for high-risk of AML.

[Change of G6PD Activity in Children with Acute Leukemia and Its Clinical Significance].

OBJECTIVE: To explore the change of G6PD activity in children with acute leukemia（AL）and its correlation with the clinical characteristics. METHODS: The G6PD activity in peripheral blood samples from 74 children disagnosed as AL (50 cases of ALL, and 24 cases of AML) was detected by Zinkham method recommended by WHO in 1967, and its relevance with clinical indicators was statistically analyzed. The peripheral blood samples of 70 healthy children were used as the controls. RESULTS: The G6PD activity in ALL and AML groups was significantly lower than that in the control group (P=0.000, P=0.000) and there was no statistical difference between ALL and AML groups. The G6PD activity in bacterial, fungal infection and non-infection groups (no bacterial and fungal infection) were statistically different from control group (P=0.02, P=0.001, P=0.001), respectively. The G6PD activity in bacterial infection group and non-infection group was statistically different from with fungal infection group (P=0.004, P=0.019), respectively. The G6PD activity linearly correlated with leukocyte count and neutrophil percentage in AL children (P=0.000, P=0.001, r=0.465, r=0.434), respectively. The median survival time of G6PD activity deficiency group was higher than that in the normal group, but without statistically significant difference (P=0.4149). CONCLUSION: The G6PD activity in AL children is significantly lower than that in healthy children, and the G6PD activity linearly relates with leukocyte count and neutrophil percentage of AL children. The patients with G6PD activity deficiency is more susceptible to fungal infection, moreover the infection is more serious.

[Variation of STAT3 Gene in Myleproliferative Neoplasms and Its Significance].

OBJECTIVE: To detect the mutation and single nucleotide polymorphisms of STAT3 gene in the patients with myeloproliferative neoplasms (MPN), and to analyze the correlation between STAT3 gene and the subtypes of MPN. METHODS: A total of 147 patients with MPN were selected, including 28 patients with polycythaemia vera (PV), 46 patients with essential thrombocythemia (ET), 10 patients with primary myelofibrosis (PMF), and 63 patients with chronic myeloid leukemia (CML); and 88 healthy persons were used as normal control. DNA of all cases was extracted from bone marrow or peripheral blood, and JAK2V617F gene mutation was detected by allele-specific PCR, then 23 exons of STAT3 gene were amplified by PCR. Mutation and single nucleotide polymorphism of Rs2293152 of STAT3 gene were identified by DNA sequencing. RESULTS: STAT3 gene mutation was found in 8 patients with CML. The mutation rate was 12.7%. the missense mutation（S629T）as found in 3 cases, the synonymous mutation was found in 5 cases (Q469Q 3 cases, G618G 2 cases). One case had mutations at the both sites of S629T and G618G. No mutation of STAT3 gene was found in the normal control group. Rs2293152: detection showed that the G allele of CML group was significantly higher than that of normal control, PV, ET and PMF group (P<0.01), suggesting that the patients with Rs2293152 G allele were more likely to develop CML. The C allele of PV, ET and PMF group was significantly higher than that of CML group (P<0.05), suggesting that the patients with Rs2293152 C allele were more likely to develop PV, ET and PMF. The G allele fiequency of JAK2V617F-negative group was significantly lower than that of the normal control and JAK2V617F positive group (P<0.01), suggesting that the Rs2293152 G allele may be a factor protecting against JAK2V617F mutation. CONCLUSION: In MPN patients, STAT3 gene is unstable and prone to mutation. The different alleles of the Rs2293152 locus of the STAT3 gene are relates with different subtypes and JAK2V617F-negative MPN.