Objective To develop an ELISA method for determination of heparin-induced thrombocytopenia (HIT)antibody. Methods The compound formed between human platelet factor 4 (PF4)and heparin was used as the coating antigen,incu-bating the patients plasma with the coating antigen in the well,after washing,the second antibody labeled HRP was added in the well to incubate and washing again,the chromogenic substrates was added in the well to incubate,when the stop reaction was finished,the absorbance A450/A630 was detected,and the test results were judged according to standard,this method was compared with IBL method and was optimized and evaluated the performance.Results An indirect ELISA method was de-velop with the purified human PF4,the optimal dilution of sample and second antibody were 1∶100 and 1∶1 500 which de-tected by the orthogonal test,the intra-and inter-assay average coefficients of variation were 7.66% and 7.76%(<10%) respectively that detected by repeated measurement the three positive standard plasma.Through measureing the 100 healthy human plasm with no history of using heparin,the positive and negative predictive reference values were 0.304 and 0.456. IBL and this method detected 100 hemodialysis patients samples at the same time,and the result of statistical analysis was that,the sensitivity,speciality and accuracy of this method were 90%,97.78% and 90%,respectively.The negative and posi-tive predictive value were 81.8% and 98.88% respectively,and the difference was statistically significant [K=0.84(0.81~1)and Pexac=0.012<0.05].The difference was statistically significant,consistency was optimal,95% confidence interval was 92.59%~92.59%.Conclusion Comparing with the IBL,the method reported by this article had the similar perform-ance and good consistency,and it could satisfy the clinical detection and diagnosis of HIT patients.

【Objective】 To investigate the frequency of CD36 deletion and gene mutation in voluntary blood donors of Zhongshan city, and to explore the possibility of establishing local CD36 negative platelet donor bank. 【Methods】 Platelet CD36 antigen was detected by ELISA in 1 654 voluntary blood donors.Some of the negative samples were confirmed by flow cytometry, and genotyping was also performed. 【Results】 Platelet CD36 antigen was negative in 27 cases, accounting for 1.6% (27/1654), among which 1.6% (18/1149) were males and 1.8% (9/505) were females.No significant difference was noticed between males and females in CD36 antigen deletion cases (P>0.05). Fifteen CD36 negative samples were randomly selected, genotyped and sequenced, with type I deletion in 1 case[ 6.7% (1/15)], type Ⅱ deletion in 14 cases[ 93.3% (14/15)], and gene mutation in exon 3-14 detected in 8 cases. 【Conclusion】 The frequency of platelet CD36 antigen deletion in Zhongshan is comparable to that in other southern regions of China.The establishment of CD36 negative platelet donor bank is conductive to improve the effectiveness of platelet transfusion.

【Objective】 To study the incidence and specificity of platelet antibody in blood donors in Suzhou, analyze the distribution characteristics of platelet antibody in blood donors in this area, and explore the significance of platelet antibody detection in blood donors to reduce the adverse reactions toplatelet transfusion in clinical. 【Methods】 Platelet antibody detection was performed in 2178 blood donors in this area by solid-phase immunosorbent assay. The antibody specificity of the positive samples was analyzed by commercial kit, and the anti-CD36 antibody positive samples were further identified by flow cytometry and gene sequencing. 【Results】 Twelve positive samples were detected by platelet antibody screening, with a positive rate of 0.55%(12/2 178), including 5 males (0.33%, 5/2 178)and 7 females(1.06%, 7/2 178). Among the positive samples, anti-HLA-Ⅰ antibody was identified in 2 cases, anti-CD36 antibody in 1 case, and the antibody specificity was not identified in the other 9 cases. In one case, the positive rate of anti-HLA-Ⅰ antibody PRA was 31.31%(31/ 99), which was mainly specific to anti-B15, anti-B35 and anti-B40. The positive rate of anti-HLA-Ⅰ antibody PRA in the other case was 45.45%(45/ 99), which was mainly specific to anti-A2, anti-A11, anti-A24, anti-A29, anti-A33, anti-A66, anti-B15 and anti-B35. The blood donor with anti-CD36 antibody was type I CD36 deficiency, and 329_330delAC mutation occurred in exon 5. 【Conclusion】 Through antibody screening and specificity identification, the positive rate of platelet antibody in females was significantly higher than that in males(P<0.05). In addition to the common anti-HLA-I antibodies, anti-CD36 antibody was also detected in type I CD36 deficient blood donor. Therefore, the detection of platelet antibodies in blood donors is of certain clinical significance to reduce the adverse reactions to blood transfusion caused by antibodies in platelet products.

【Objective】 To investigate the expression of CD36 antigen in Suzhou area, analyze the type of antigen deficiency and gene mutation, so as to provide references for the establishment of CD36 negative donor registry in Suzhou. 【Methods】 Anticoagulant whole blood samples (805 cases) were randomly collected from healthy blood donors in Suzhou Blood Center. The expression of CD36 antigen on platelet and monocyte was analyzed by flow cytometry to determine the type of CD36 deficiency. The gene mutation type of platelet CD36 antigen-deficient was performed by genomic DNA sequencing. 【Results】 The CD36 deficiency frequency on platelet was 2.48% (20/805), among which TypeⅠ(lacking CD36 expression both on platelet and monocyte) and TypeⅡ(lacking CD36 expression on platelet only) CD36 deficiency accounted for 10% (2/20) and 90% (18/20), respectively. CD36 gene mutations were found in 10 samples, including 3 cases of 329_330 d^elAC, 1 case of 1228_1239 d^elATTGTGCCTATT and 2 cases of 1163 A>T; 1 case of 329_330 d^elAC+ 1172_1183 d^elTATTGGTCAAGC and 287 G>C+ 329_330 d^elAC heterozygous mutation. In addition, 1 case of 745 A>G and 1 case of 806 C>T mutations were novel, and not yet reported. 【Conclusion】 Results showed that the frequency of CD36 antigen deficiency in Suzhou were similar to that reported in southern China, but the mutation sites were slightly different. The establishment of CD36 negative platelet registry could provide negative platelets for patients with transfusion reactions caused by anti-CD36 antibody and improve the effect of clinical platelet transfusion.