Epidemiological characteristics and influencing factors of acute leukemia in children and adolescents and adults: a large population-based study.

OBJECTIVE: To assess the epidemiological characteristics and prognostic factors of acute leukemia (AL) in children and adolescents, and make comparisons between pediatric and adult patients. METHODS: This retrospective cohort study enrolled AL patients from the Surveillance, Epidemiology, and End Results (SEER) 1975-2016. OS in children and adolescents and adults with AL was compared and analyzed separately by age and AL subtype. RESULTS: Totally 61,694 AL patients were identified, with 45,411 (73.6%) adults and 16,283 (26.4%) children and adolescents. From 2000 to 2016, the incidence rates of AL [annual percent changes (APC) = 1.2, 95%CI = 0.9-1.6, P < 0.05] and acute lymphoblastic leukemia (ALL) (APC = 1.5, 95%CI = 1.1-1.8, P < 0.05) in children and adolescents were significantly increasing. For adults, AL (APC = 0.9, 95%CI = 0.3-1.5, P < 0.05), ALL (APC = 2.5, 95%CI = 2.0-3.1, P < 0.05) and acute myeloid leukemia (AML) (APC = 0.9, 95%CI = 0.4-1.5, P < 0.05) had significantly elevated incidence rates. Overall survival (OS) in children and adolescents with AL was significantly higher than that in adults with AL (log-rank P < 0.0001). OS in children and adolescents and adults with ALL, AML and AUL decreased with age (all log-rank P < 0.0001). Older age, male sex and black race were risk factors for the survival of children and adolescents and adults with ALL, AML and AUL. CONCLUSION: From 2000 to 2016, the incidence rates of AL in children and adolescents and adults were increasing. Children and adolescents with AL had significantly better OS than adults with AL, and OS declined with age in both children and adolescents and adults with ALL, AML and AUL.

Evaluation of a two-test strategy for HIV screening in a low-prevalence setting and the indications for optimizing clinical management.

Objectives: To evaluate a two-test strategy for HIV screening in the low-prevalence population and to assess the feasibility of utilizing the optimal signal-to-cutoff (S/CO) threshold on the chemiluminescence immunoassay(CMIA) and an additional rapid test on the gold immune-chromatography assay (GICA) for screening positive patients and optimization of clinical management. Methods: We conducted a retrospective study of samples analyzed by the fourth-generation Architect HIV Ag/Ab combo assay (CMIA) in a large medical center between June 2017 and August 2020. Reactive samples underwent a second screening test using the rapid test GICA, followed by Western blot (WB) as the confirmatory test. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal S/CO. We calculated sensitivity, specificity, and predictive value based on our population. The performance of the single-test strategy (CMIA) was compared with that of the two-test strategy (CMIA and GICA). Logistic regression was used to analyze the factors of clinical characteristics leading to false positive results. Results: A total of 220558 samples were screened by CMIA, and 429 patients met the inclusion criteria. Of these, CMIA produced 199 false-positive results with a median S/CO of 1.93(IQR1.45-3.68) and 230 positive results with a median S/CO of 455.1 (IQR169.3-709.7). The optimal S/CO of the single-test strategy was 8.82, which achieved a sensitivity of 100% and a positive predictive value (PPV) of 90.9%. The two-test strategy (CMIA and GICA) provided a sensitivity of 100% and a PPV of 98.7%, which best correlated with the confirmatory test WB. The combination of S/CO 8.82 on the CMIA assay and additional test results of GICA can be defined as four types used to interpret HIV serostatus. The false positive rate (FPR) was high in the female, the age≤18 group, the pre-operative patients, and the patients from the clinical departments of Pediatrics, Gynecology and Obstetrics, and Oncology, etc. Conclusions: The false positive rate is high in the low-prevalence setting by using CMIA. The two-test strategy (CMIA and GICA) is recommended for HIV screening in hospitals. Hopefully, the clinicians will be able to interpret HIV serostatus and facilitate clinical decision-making while waiting for the confirmatory results.

[Diagnostic Value of MPV, PDW, PAIg and Their Combination for Megakaryocyte Dysmaturity in Children with Acute Immune Thrombocytopenic Purpura].

OBJECTIVE: To investigate the changes of mean platelet volume (MPV), platelet distribution width (PDW) and platelet associated antibodies (PAIg) in children with acute immune thrombocytopenic purpura (aITP), and to explore the diagnostic value of MPV, PDW, PAIg and their combination for megakaryocyte dysmaturity in aITP children. METHODS: Plt count, MPV and PDW of 36 aITP children were measured by using Sysmex XN automatic blood cell analyzer, and 33 children with acquired thrombocytopenic purpura (ATP) without megakaryocyte dysmaturity. The expression of PAIg was detected by flow cytometry, and the number and classification of megakaryocytes in the bone marrow were performed by marrow cytology. The diagnostic significances of MPV, PDW, PAIg and their combination as well as the sensitivity and specificity for megakaryocytes dysmaturity in aITP were assessed through calculating the area under ROC curve (AUC), after determining the influence of each parameters on the megakaryocyte dysmaturity by Logistic regression. RESULTS: MPV, PDW and PAIg of aITP children were significantly higher than those of the ATP children (P＜0.05), while the Plt count and number of thromocytogenic megakaryocytes per area (1.5 cm×3 cm) were less than those of the controls (P＜0.05). Count of RBC and WBC, percentages of neutrophil granulocytes and lymphocydes in aITP were similar to those in the controls（P＞0.05）. The results of Logistic regression showed that Plt count, MPV, PDW and PAIg were the factors influencing megakaryocyte dysmaturity in aITP children, and the regression model has a high statistical significance (χ2=65.491，P=0.001) and r square (R2=0.713). The AUC of the combined detection of Plt count, MPV, PDW and PAIg was 0.863, which was much higher than that of Plt count, MPV, PDW, PAIg individually or in pairs. The sensitivity and specificity of the combined detection were 79.167% and 89.697%, which were higher than those of Plt count, MPV, PDW, PAIg individually or in pairs. CONCLUSION: The diagnostic significance of MPV and PDW for megakaryocyte dysmaturity in aITP are insufficient, but the diagnostic efficacy can be improved by combined examination with PAIg.

Protective effects of membrane-anchored and secreted DNA vaccines encoding fatty acid-binding protein and glutathione S-transferase against Schistosoma japonicum.

In order to explore the high performance bivalent DNA-based vaccine against schistosomes, SjFABP and Sj26GST were selected and used to construct a vaccine. Two strategies were used to construct the bivalent DNA vaccine. In the first strategy, a plasmid encoding antigen in the secreted form was used, while in the other, a plasmid encoding a truncated form of SjFABP and Sj26GST targeted to the cell surface was used. Various parameters, including antibody and cytokine response, proliferation, histopathological examination, and characterization of T cell subsets were used to evaluate the type of immune response and the level of protection against challenge infection. Injection with secreted pIRES-sjFABP-sj26GST significantly increased the levels of antibody, splenocyte proliferation, and production of IFN-γ, compared with membrane-anchored groups. Analysis of splenic T cell subsets showed that the secreted vaccine significantly increased the percentage of CD3(+)CD4(+) and CD3(+)CD8(+) T cells. Liver immunopathology (size of liver granulomas) was significantly reduced in the secreted group compared with the membrane-anchored groups. Moreover, challenge experiments showed that the worm and egg burdens were significantly reduced in animals immunized with recombinant vaccines. Most importantly, secreted Sj26GST-SjFABP markedly enhanced protection, by reducing worm and egg burdens by 31.8% and 24.78%, respectively, while the membrane-anchored group decreased worm and egg burdens by 24.80% and 18.80%, respectively. Taken together, these findings suggest that the secretory vaccine is more promising than the membrane-anchored vaccine, and provides support for the development and application of this vaccine.

[A multi-gene DNA vaccine encoding non-fusion membrane-anchoring antigen against Schistosoma japonicum].

OBJECTIVE: To construct DNA vaccine (pIRES-Sj97-Sj14-Sj26) and study its immunogenicity and protective immunity against Schistosoma japonicum. METHODS: The plasmid pIRES-Sj97-Sj14-Sj26 containing fatty binding protein (Sj14), GST (Sj26) and paramyosin (Sj97) was constructed and expressed on the membrane. RT-PCR was used to detect the expression of Sj14 mRNA, Sj26 mRNA and Sj97 mRNA in the Hela cells, and IFA for detecting the expression of trans-membrane Sj14, Sj26 and Sj97. Sixty BALB/c mice were randomly divided into 3 groups. Mice in each group respectively received normal saline, pIRES blank vector and pIRES-Sj97-Sj14-Sj26 by intramuscular injection. Two weeks after the 3rd immunization, 10 mice from each group were sacrificed and total IgG in serum and the level of IFN-y were detected by ELISA and lymphocyte stimulating index (SI) by MTt. FCM was used to analyze the subgroups of splenocytes. The level of NO secreted by peritoneal macrophages was determined by nitrate reductase approaches. The left 10 mice in each group were challenged with (40 +/- 1) cercariae of S. japonicum by abdominal skin penetration. Forty-five days after challenge, mice were sacrificed, and numbers of recovered worms and hepatic eggs were counted. RESULTS: RT-PCR showed the expression of Sj14 mRNA, Sj26 mRNA and Sj97 mRNA. IFA proved the expression of Sj26, Sj14 and Sj97 protein. Level of total IgG in the vaccination group, saline group and pIRES blank vector group was (5.62 +/- 0.64), (1.22 +/- 0.20) and (1.48 +/- 0.36) mg/ml respectively, showing a statistical significance (P < 0.01, P < 0.05). The NO level in macrophages was (321.19 +/- 18.03), (184.12 +/- 11.05) and (213.51 +/- 15.93) nmol/ml in the 3 groups respectively (P < 0.05), and the lymphocyte stimulating index in the 3 groups was (2.25 +/- 0.29), (1.18 +/- 0.07) and(1.22 +/- 0.09) respectively (P < 0.01). The INF-gamma level was higher in the vaccination group than others (P < 0.01). The percentage of CD4+ and CD8+ T cells increased considerably (P < 0.01). The vaccination group showed a worm reduction rate of 39.9% (P < 0.01) and an egg reduction rate of 43.9% (P < 0.01). CONCLUSION: The vaccine candidate pIRES-Sj97-Sj14-Sj26 induces an immune protection in BALB/c mice against Schistosoma japonicum.

Construction and expression of DNA vaccine pIRES-Sj97-Sj14-Sj26 and its immunogenicity in mice.

To find a new preventive strategy for the infection of Schistosoma japonica, plasmid pIRES-Sj97-Sj14-Sj26 that contains fatty binding protein (Sj14), GST (Sj26) and paramyocin (Sj97) that are expressed on the membrane, was constructed. RT-PCR was used to detect the expression of Sj14 mRNA, Sj26 mRNA and Sj97 mRNA in the Hela cells, the indirect immunofluorescent test was employed for the detection of the expression of trans-membrane Sj26 after the plasmid was transfected into Hela cells. Fifty BALB/c mice were randomly divided into 5 groups and pIRES-Sj97-Sj14-Sj26 plasmid DNA, pIRES-Sj14-Sj26 plasmid DNA, pIRES-Sj26 plasmid DNA, pIRES blank vector and normal saline were respectively injected into the quadriceps muscles of thigh. Eight weeks after the immunization the mice were killed and significantly higher level of IgG was detected in the pIRES-Sj97-Sj14-Sj26 group as compared with the pIRES blank vector, normal saline and pIRES-Sj26 groups (P<0.01) and the pIRES-Sj14-Sj26(P<0.05). Single splenocyte suspension was prepared to detected the level of IFN-gamma by ELISA and the lymphocyte stimulating index (SI) by MTT. SI was significantly higher of in the pIRES-Sj97-Sj14-Sj26 group than in other groups (P<0.01), while the IFN-gamma level was significantly higher the pIRES-Sj97-Sj14-Sj26 group than in pIRES blank vector and normal saline groups (P<0.01), but no significant differences were found when compared with pIRES-Sj14-Sj26 and pIRES-Sj26 groups. Flow cytometery showed that the percent-ages of CD4+ and CD8+ T cells were much higher in the pIRES-Sj97-Sj14-Sj26 group (P< 0.01, P<0.05). It was concluded that pIRES-Sj97-Sj14-Sj26 vaccine may induce stronger immune response in BALB/c mice.

Construction and expression of bivalent membrane-anchored DNA vaccine encoding Sjl4FABP and Sj26GST genes.

In order to construct a eukaryotic co-expression plasmid containing membrane-anchored Sjcl4FABP and Sjc26GST genes and identify their expression in vitro, Sj14 and Sj26 genes were obtained by RT-PCR with total RNA of Schistosoma japonicum adult worms as the template and cloned into eukaryotic expression plasmid pVAC to construct recombinant plasmids pVAC-Sj14 and pVAC-Sj26. Then a 23 amino-acid signal peptide of human interleukin-2 (IL-2) upstream Sj14 or Sj26 gene and a membrane-anchored sequence containing 32 amino-acids of carboxyl-terminal of human placental alkaline phosphatase (PLAP) downstream were amplified by PCR as the template of plasmid pVAC-Sj14 or pVAC-Sj26 only to get two gene fragments including Sj14 gene and Sj26 gene. The two modified genes were altogether cloned into a eukaryotic co-expression plasmid pIRES, resulting in another new recombinant plasmid pIRES-Sj26-Sj14. The expression of Sj14 and Sj26 genes was detected by RT-PCR and indirect immunofluorescent assays (IFA) when the plasmid pIRES-Sj26-Sj14 was transfected into eukaryotic Hela cells. Restriction enzyme analysis, PCR and sequencing results revealed that the recombinant plasmids pVAC-Sj14, pVAC-Sj26 and plRES-Sj26-Sj14 were successfully constructed and the expression of modified Sj14 and Sj26 genes could be detected by RT-PCR and IFA. A bivalent membrane-anchored DNA vaccine encoding Sj14 and Sj26 genes was acquired and expressed proteins were proved to be mostly anchored in cellular membranes.