[Detection of alloantibodies against Factor VIII in plasma of patients with hemophilia A and its relationship with Factor VIIIC domain].

This study was purposed to detect the alloantibodies against Factor VIII (FVIII) by ELISA for estimating the incidence of the alloantibodies against Factor VIII (FVIII) in patients with hemophilia A, and to investigate the relationship between factor VIIIC domain and alloantibodies. Total of 140 patients with hemophilia A and 80 normal controls were enrolled in this study, among them plasma FVIII level of 84 patients was less than 1%, plasma FVIII level of 34 patients was between 1% and 5%, and plasma FVIII level of 22 patients was more than 5%. All patients were treated with plasma-derived FVIII concentrate or plasma before. The ELISA plate was coated with McAb (SZ-132) against FVIII prepared in our laboratory, then human recombinant FVIII concentrates were applied. After incubation in room temperature for 2 hours, diluted plasma samples and HRP-conjugated goat anti-human IgG were added successively, finally A490 was recorded. The threshold of alloantibody of patient plasma was set as mean value>3 SD more than control. The plate was coated with antibody against His, then human recombinant FVIII-C1C2 prepared in our laboratory was added. After incubation in room temperature for 2 hours, diluted plasma samples and HRP-conjugated goat anti-human IgG were added successively, finally A490 were recorded. The threshold was set as the mean value>3 SD more than control. The results showed that the alloantibodies against FVIII were found in 56 patients (40%) by ELISA, and 82.1% (46/56) of this kind of alloantibody could interact with the C domain of FVIII. It is concluded that C domain of FVIII is one of the primary binding sites for the alloantibodies against FVIII in Chinese patients with hemophilia A.

[Plasma concentrations of vascular endothelial growth factor and tissue factor in children with acute lymphoblastic leukemia].

OBJECTIVE: To detect plasma concentrations of vascular endothelial cell growth factor (VEGF) and tissue factor (TF) in children with acute lymphoblastic leukemia (ALL) and explore their clinical significance in ALL. METHODS: Thirty-three children with newly diagnosed ALL, including 18 cases of low risk, 7 cases of moderate risk and 8 cases of high risk, were enrolled in this study. Twenty-five patients received a complete remission and 8 cases were in non-remission after conventional remission induction chemotherapy. Plasma concentrations of VEGF and TF in the patients were detected using ELISA before and after treatment. Sixteen healthy children served as normal control group. RESULTS: Plasma concentrations of VEGF and TF in ALL patients before treatment were significantly higher than those in normal controls (P < 0.01). Plasma concentrations of VEGF and TF in the non-remission group before treatment were significantly higher than those in the remission group (P < 0.05) and the control group (P < 0.01). After treatment the plasma concentrations of VEGF and TF in the non-remission group were not significantly reduced and higher than those in the remission and the control groups (P < 0.01). There were significant differences in plasma concentrations of VEGF and TF among the low-risk, moderate-risk and high-risk groups before and after treatment (P < 0.05). Plasma concentrations of VEGF and TF in the high risk group were not significantly reduced after treatment and higher than those in the control group (P < 0.01). A linear correlation was noted between plasma VEGF and TF concentrations in ALL patients before treatment (r=0.50, P < 0.01). CONCLUSIONS: VEGF and TF play an important role in the development of ALL and may be useful to the evaluation of the severity and the outcome in ALL.

[The effect of HGF on graft-versus-host disease and graft-versus-leukemia after allogeneic bone marrow transplantation in acute lymphoblastic leukemia mice].

OBJECTIVE: To investigate the effect of hepatocyte growth factor (HGF) on graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) after allogeneic bone marrow transplantation (allo-BMT) and related mechanism in acute lymphoblastic leukemia (ALL) mice. METHODS: Twenty nude mice were randomly divided into control (group A) and test (group B) groups for monitoring relapse, and 20 BALB/c mice into control (group C) and test (group D) groups for GVHD. HGF as injected from day 0 to day 7 after BMT for groups B and D, while PBS for A and C. CD4(+) and CD8(+) T cell were evaluated by flow cytometry. The survival of mice after BMT was recorded. The level of tumor necrosis factor-alpha (TNF-alpha) was evaluated by ELISA. RESULTS: The median past-BMT survival were 7.00 +/- 1.58, 9.00 +/- 1.58, 11.00 +/- 3.95 and 24.00 +/- 13.44 days for groups A, B, C, D, respectively, being prolonged in group D. HGF could decrease the quantity of CD4(+) T cells [group D (10.39 +/- 1.15)% vs group C (13.50 +/- 1.80)%, P < 0.01] and increase CD8(+) T cell [group D (12.25 +/- 2.85)% vs group C (6.12 +/- 1.99)%, P < 0.01], decrease the level of TNF-alpha in transplanted ALL mice [group D (112.10 +/- 18.99) pg/ml vs group C (143.90 +/- 25.35) pg/ml, P < 0.01] and reduce the degree of GVHD. CONCLUSION: HGF could alleviate post-allo-BMT GVHD but retain GVL effect.

[Effects of HGF on GVHD and Th1/Th2-related cytokines in ALL mice after allo-BMT].

To observe the effects of hepatocyte growth factor (HGF) on graft-versus-host disease (GVHD) and Th1/Th2 related cytokines in mice with acute lymphoblastic leukemia (ALL) after allogenic bone marrow transplantation (allo-BMT), BALB/c mice were conditioned by total body irradiation with 11 Gy and then were transplanted with allogeneic bone marrow after establishing ALL model. BALB/c mice were divided into groups A and B. The mice of group A were injected subcutaneously with HGF from day 0 to 7 after allo-BMT, and the mice of group B were injected subcutaneously with PBS from day 0 to 7 after allo-BMT. The symptoms of GVHD and the GVHD pathological changes of liver and small intestine and skin were observed. The serum levels of both IFN-gamma and IL-4 were determined by ELISA. The results showed that the score of GVHD in group A was lower than that in group B (P < 0.05). The levels of IFN-gamma in both groups A and B were all higher than that in normal group (P < 0.05 and P < 0.001, respectively), However, the level of IFN-gamma in group A was lower than that in group B (P < 0.01). The levels of IL-4 in both group A and B were all lower than that in normal group (P < 0.05), but the level of IL-4 in group A was higher than that in group B (P < 0.05). It is concluded that HGF can alleviates the severity of GVHD, because of its balancing the Th1/Th2-related cytokines after allo-BMT.