1.Assessment of transcatheter closure of coronary artery fistula by transthoracic echocardiography
Xing ZHAO ; Xiuzhang Lü ; Jianpeng WANG ; Zhenhui ZHU ; Shiliang JIANG ; Zhongying XU ; Liang XU ; Yanling LIU
Chinese Journal of Ultrasonography 2011;20(2):101-103
Objective To investigate the efficacy of transcatheter closure of coronary artery fistula (CAF) by transthoracic echocardiography(TTE) and the role of TTE in this therapy. Methods CAF were occluded with transcatheter closure techniques in 17 patients. TTE was performed before and after the treatments. The key points were retrospectively analyzed including: the sites of CAF, the position and diameter of CAF,the shape and position of the devices after the intervention,the residual shunt,and cardiac chamber size. Results Before the therapy,TTE made definite diagnosis of CAF. All patients had lesions in single coronary artery, and the diameter of CAF was 2-14 (6.4 ± 3.5)mm. All patients underwent transcatheter closure successfully. TTE revealed the shunts disappear 1-4 days after the occlusion. During a follow-up period of 1- 29 (11.7± 7.9)months,no residual shunts, no complications, and normal size of thecardiac chambers were recognized by TTE. Conclusions The transcatheter closure of CAF has emerged as a less invasive, safe and effective strategy. Echocardiography has important role in primary screening of patients and the follow-up after the treatments.
2.Genetic polymorphism of HPA-1 to-17 alloantigen system in Guangzhou population
Yangkai CHEN ; Xin YE ; Wenjie XIA ; Xiuzhang XU ; Jing DENG ; Yuan SHAO ; Haoqiang DING ; Yongshui FU ; Guangping LUO
Chinese Journal of Immunology 2000;0(08):-
Objective:To characterize the allele frequencies and its polymorphisms of human platelet antigen (HPA) in Guangzhou population.Methods:A total of 500 samples from healthy voluntary platelet donors in Guangzhou were genotyped for HPA-1 to-17 by PCR-SSP.Results:HPA-1a to-17a alleles were found in each of the samples;The gene frequencies of HPA-1a to-17a were 99.8%,99.85%,56.3%,99.9%,98.8%,98.6%,100%,100%,100%,100%,100%,100%,100%,100%,55.1%,and 100%,100% respectively.The gene frequencies of HPA-1b to-6b and-15b alleles were 0.2%,0.15%,43.7%,0.1%,1.2%,1.4% and 44.9% respectively;HPA-7b to-14b and-16b-17b were not detected.In summary Guangzhou population displayed higher frequency of HPA-1a to-17a and HPA-3b,-15b.Compared with those of other Han populations in China,HPA frequency of Guangzhou people was significantly different from that of Beijing;Compared to that of the European,American,English and Egyptians,HPA frequency was different significantly.While HPA frequency was different from those of Japanese and Thais.This study for the first time investigated the assortment of HPA genes and its frequency,there were 40 assortments in Guangzhou population,only 5 assortment of HPA gene frequencies more than 10%,35 assortment of HPA gene frequencies less than 9%.Conclusion:HPA distribution in Guangzhou population appears to have local characteristics.This study confirms the ethnic and original difference of HPA.The allele frequencies and its polymorphisms of HPA in Han population are shown North-South differences.Races and countries outside Asia are also shown differences.The basic information provided by this study of the HPA system polymorphisms is useful to guide the design of the local HPA genotype database of volunteer platelet donors.It's also useful to avoid the PTR,and the HPA related clinical research.
3.Establishment of a cell line expressing the CD36 on human platelets and its application to the detec-tion of anti-CD36 antibodies
Xiuzhang XU ; Santoso SENTOT ; Wenjie XIA ; Haoqiang DING ; Dawei CHEN ; Jing DENG ; Yangkai CHEN ; Jiali WANG ; Yuan SHAO ; Jing LIU ; Xin YE
Chinese Journal of Microbiology and Immunology 2016;36(6):458-462
Objective To establish a cell line stably expressing the human CD36 by using TA clo-ning and cell transfection technology and to analyze its application to the detection of anti-CD36 antibodies. Methods Total RNA was isolated from human platelets and then used to synthesize complementary DNA ( cDNA) . Sequence of the gene encoding CD36 on human platelets was obtained by PCR amplification. The recombinant vector was transformed into TOP10 E. coli after TA cloning. The positive recombinant pcDNA3. 1/V5-CD36 plasmid was screened out by blue-white selection and then sequenced. The correctly constructed plasmid coated with Effectene? Transfection Reagent was transferred into HEK293T cells. Fluo-rescence-activated cell sorting was performed to screen out the cell line that could stably express the CD36 on human platelets. The transfected cell line-based flow cytometry analysis and antibody capture assay ( ACA) were established and used for antibody detection in nine serum samples positive for anti-CD36 antibodies. Results The HEK293T cell line stably expressing the recombinant CD36 was successfully established. Compare with the monoclonal antibody immobilization of platelet antigens assay ( MAIPA) , anti-CD36 anti-bodies could be easily identified in nine serum samples by using the transfected cell line-based flow cytome-try analysis and ACA. Conclusion This study suggests that the HEK293T cells stably expressing the re-combinant CD36 could be used in flow cytometry analysis and ACA for the detection of anti-CD36 antibod-ies. It also paves the way for further researches on the mechanism of CD36 in other diseases.
4.Improvement of Anti-CD36 Antibody Detection via Monoclonal Antibody Immobilization of Platelet Antigens Assay by Using Selected Monoclonal Antibodies
Xiuzhang XU ; Dawei CHEN ; Xin YE ; Wenjie XIA ; Yuan SHAO ; Jing DENG ; Yangkai CHEN ; Haoqiang DING ; Jing LIU ; Yaori XU ; Sentot SANTOSO ; Yongshui FU
Annals of Laboratory Medicine 2023;43(1):86-91
Antibodies against human CD36 are responsible for several immune-mediated disorders. The detection of anti-CD36 antibodies using the standard monoclonal antibody (mAb) immobilization of platelet antigens (MAIPA) assay is hampered by a high frequency of false-negative results, most likely due to competitive inhibition of the mAb used as the capture antibody. We generated a panel of mouse mAbs against CD36 and seven hybridomas (GZ-3, GZ-13, GZ-70, GZ-143, GZ-413, GZ-507, and GZ-608), which were selected for MAIPA assays, as they reacted with mouse and human CD36. Fourteen anti-CD36 sera were assayed; all of which showed a positive reaction in a PakPlus (Immucor GTI Diagnostics, Inc., Waukesha, WI, USA) ELISA-based screening (optical density: 0.257–2.292). When the reference anti-CD36 mAb FA6-152 was used in the MAIPA assay, only 6/14 (42.9%) sera displayed a positive reaction. In contrast, anti-CD36 antibodies were detected in 13/14 (92.9%) sera when GZ-70 and GZ-608 mAbs were used. This significant improvement resulted in the identification of anti-CD36 antibodies by an antigen capture assay. Since patient’s platelets possibly carrying rare native antigens are used, this method will facilitate the identification of new platelet antibodies against CD36 that are involved in immune-mediated thrombocytopenia and other diseases, such as transfusion-related acute lung injury.
5.Construction of eukaryotic expression vector for human platelet CD36 gene 220C>T and 429+4insg variants and analysis of their expressions in HEK293T cells.
Xiuzhang XU ; Haoqiang DING ; Jing LIU ; Wenjie XIA ; Jing DENG ; Yangkai CHEN ; Jiali WANG ; Yuan SHAO ; Dawei CHEN ; Xin YE
Chinese Journal of Medical Genetics 2019;36(2):124-127
OBJECTIVE:
To construct eukaryotic expression vectors for human platelet CD36 gene 220 C>T and 429+4insg variants and analyze their expressions in HEK293T cells.
METHODS:
RNA was isolated from human platelets and reversely transcribed into cDNA. Sequences of 220C>T and 429+4insg variants were derived by PCR amplification. The target sequence was ligated into a pcDNA3.1/V5-His-TOPO vector by TA cloning, which was transformed into TOP10 E. coli. Positive plasmids were screened by blue-white selection. After sequencing, plasmid DNA carrying 220C>T or 429+4insg variant was used to transfect HEK293T cells with the help of effectene. Expression of CD36 protein was then analyzed by flow cytometry and Western blotting.
RESULTS:
An eukaryotic expression vector pcDNA3.1/V5-His-CD36 (220C>T/429+4insg) was constructed by TA cloning. After transfected into HEK293T cells, the 220C>T and 429+4insg variants resulted in CD36 deficiency in HEK cells, which was confirmed by flow cytometry and Western blotting.
CONCLUSION
The 220C>T and 429+4insg variants can cause CD36 deficiency in human platelets. This system may be used for assessing the effect of 220C>T, 429+4insg, and other variants on the expression of CD36.
Blood Platelets
;
CD36 Antigens
;
Cloning, Molecular
;
Escherichia coli
;
Eukaryota
;
Genetic Vectors
;
HEK293 Cells
;
Humans
;
Plasmids
;
Transfection
6.Preliminary study on HUVEC permeability changes in FNAIT induced by CD36 antibody
Yingyi TANG ; Dawei CHEN ; Wenjie XIA ; Xiuzhang XU ; Xin YE ; Bo HE
Chinese Journal of Blood Transfusion 2023;36(9):766-770
【Objective】 To explore the pathogenesis of fetal edema caused by CD36 antibody in fetal/neonatal alloimmune thrombocytopenia (FNAIT), and to provide reference for clinical prevention and treatment. 【Methods】 The established CD36 monoclonal antibody was incubated with human peripheral blood mononuclear cells (PBMC), and the concentrations of cytokines (TNF-α and IL-1β) in the supernatant of cell culture were detected by ELISA. The permeability of endothelial cells were investigated by detecting the fluorescence intensity of FITC-albumin by incubating cytokine-rich cell supernatant with human umbilical vein endothelial cells (HUVEC). 【Results】 Flow cytometry showed that CD36 monoclonal antibody could bind to human monocytes. Compared with isotype IgG control, increased cytokine TNF-α (pg/mL) (407.73±20.40 vs 29.38 ±4.72, P<0.05) and IL-1β (pg/mL) (247.14±83.59 vs 53.68±26.96, P<0.05) were detected in the supernatant of cell culture after incubation of CD36 monoclonal antibody with human PBMC. Detection of fluorescence intensity of FITC-albumin in transwell cultured HUVEC showed that cytokine-rich cell supernatant derived from CD36 monoclonal antibody incubated with human PBMC can increase the permeability of endothelial cells significantly (CD36 antibody vs isotype IgG, MFI value: 492±16 vs 320±11, P<0.05). 【Conclusion】 The effect of CD36 monoclonal antibody on PBMC can increase HUVEC permeability, which may be one of the pathogenesis of fetal edema with FNAIT.
7.Matching strategy for patients with platelet transfusion refractoriness caused by compound antibodies against HLA and CD36
Jing DENG ; Xiuzhang XU ; Huibin ZHONG ; Bi ZHONG ; Yangkai CHEN ; Jing LIU ; Haoqiang DING ; Wenjie XIA ; Dawei CHEN ; Yaori XU ; Xin YE
Chinese Journal of Blood Transfusion 2023;36(6):463-466
【Objective】 To search compatible and suitable platelets for platelet transfusion refractoriness (PTR) patient caused by compound antibodies against HLA and CD36. 【Methods】 ELISA method was used to detect the antibody against platelet antigens and the specificity of HLA-I antibody in PTR patients. The specificity of HLA-I antibody and corresponding epitopes of patients were analyzed using MATCH IT! and HLA Matchmaker software. The HLA genotype of both donor and patient was obtained by HLA-SSO method. Compatible or suitable donor platelets for PTR patients were searched through cross-reactive group (CREG) of HLA-I and HLA epitope-matched approach (Eplet). The matching degree was identified using monoclonal antibody-specific immobilization of platelet antigens (MAIPA) and the platelet suspension immunofluores-cence test (PIFT). Finally, the transfusion effect was evaluated according to the corrected count increment (CCI). 【Results】 Compound antibodies against both CD36 and HLA-I antigens were detected in two PTR patients, and their phenotype of CD36 was conformed to be type I deficient. Through LSA testing, high-frequency of HLA -I antibodies was found in these two patients, and the panel reactive antibody in patients 1 and 2 was 56% (54/96) and 53% (51/96), respectively. According to HLA-CREG and Eplet matching strategies, one donor of grade C-matching with patient 1 and one donor of grade D-matching with patient 2 were screened from the CD36 deficiency donor bank, respectively. And the selected donors avoided the antigen of HLA-I antibody epitope. These results of MAIPA and PIFT also confirmed that no immune response was detected between the patient and the donor. And a CCI of >4.5 within 24 hour of transfusion of compatible platelets was obtained in patient 2. 【Conclusion】 For PTR patients caused by HLA and CD36 compound antibodies, a combination strategy including serological cross-matching, HLA-CREG and Eplet approach should be used to select the CD36 deficient donor platelets which evaded the antigen corresponding to HLA-I antibodies and had the compatible HLA epitopes.
8.Treatment of platelet transfusion refractory caused by anti-HLA in pregnancy complicated with aplastic anemia
Yangkai CHEN ; Xiuzhang XU ; Jiali WANG ; Jing DENG ; Xin YE ; Yuan SHAO ; Haoqiang DING ; Jing LIU ; Wenjie XIA ; Dawei CHEN
Chinese Journal of Blood Transfusion 2021;34(9):967-969
【Objective】 To find the HLA-matched platelets from platelet donor registry and track the transfusion effect for aplastic anemia patients in pregnancy with platelet transfusion refractory (PTR) caused by anti-HLA, so as to support the childbirth and follow-up treatment of the patients. 【Methods】 Antibodies to HPA and HLA were detected by ELISA kit and Luminex, respectively. DNA of the patient and 523 platelet donors from the donor registry were extracted for high-resolution HLA genotyping. The Risk Factors Evaluation Software of PTR was used to select the ABO-compatible and HLA-matched donors, without HLA Eplets specific to the patient. After MASPAT cross matching, the patient was transfused with 1 U of platelets, and the 24h post-transfusion effect was recorded. 【Results】 Only anti-HLAⅠantibody was found in the patient serum, and the specificity Eplet was 65QIA, including HLA-B*27∶08, B*27∶05, B*07∶02, B*55∶01, B*67∶01 and B*54∶01; anti-HLA Ⅱ antibody was negative. The HLA genotypes of both the patient and donor were HLA-A*02∶07, A*11∶01, B*46∶01, B*46∶01, C*01∶02, 01∶03, DRB1*04∶05, DRB1*0901, DQB1*03∶03 and DQB1*04∶01. The results of MASPAT matching were negative. HLA-matched platelets transfusion provided a satisfactory posttransfusion platelet responses in patients(1 before vs 33 ×109/L after). A baby boy was delivered by cesarean section 4 weeks later, and the same donor was recruited due to the mother′s low Plt and bleeding trend. The 24h posttransfusion Plt (×109 / L) rose from 5 to 37 after the secondary transfusion of 1U platelet. The vital signs of the mother and her baby were normal during the two-day follow up. 【Conclusion】 The establishment of blood donor registry and screening of HLA-matched donors is an effective approach to treat PTR caused by HLA antibodies in pregnancy complicated with aplastic anemia.
9.Prediction of B cell epitopes of CD36 and preparation of MAP
Jing LIU ; Xiuzhang XU ; Haoqiang DING ; Jing DENG ; Jiali WANG ; Yangkai CHEN ; Wenjie XIA ; Xin YE
Chinese Journal of Blood Transfusion 2024;37(8):853-858
【Objective】 To analyze the structure of CD36, search the possible B cell epitopes and prepare multi-antigen peptides(MAP) with B cell epitopes, so as to provide a preliminary experimental basis for the preparation of CD36 antibodies using MAP with B cell epitopes. 【Methods】 The potential B cell epitopes of CD36 were analyzed by bioinformatics methods, including physical and chemical properties, secondary structure, potential phosphorylation and glycosylation sites. Eight-branch MAP with CD36 B cell epitopes were synthesized by FMOC using polylysine as the core matrix. The purity of MAPs was analyzed by reverse high-performance liquid chromatography chromatography(RP-HPLC), and the molecular weight of MAPs was determined by mass spectrometry. 【Results】 CD36 is a stable and hydrophilic alkaline protein, with multiple phosphorylation and glycosylation sites and strong antigenicity, and its secondary structure is mainly characterized by irregular curls. Four potential B cell epitopes were obtained and 4 MAPs containing potential B cell epitopes were prepared. RP-HPLC analysis showed that the purity of the MAPs were above 85%, and the molecular weight of 3 MAPs was consistent with the expected theoretical molecular weight. 【Conclusion】 CD36 on platelet has strong antigenicity. MAPs containing CD36 B cell epitopes can provide the experimental basis for the preparation and related research of CD36 antibodies.