Objective To improve HLA genotyping performance in clinical laboratory,the results of National Proficiency Testing（PT）for HLA-A/B/DRB1 low-resolution genotyping were collected and summarized from 2017 to 2020. Methods HLA genotyping results from 2017~2020 PT were analyzed and different kinds of errors were described and classified,and the possible reasons were also analyzed. Results The number of participant laboratories was increasing from 78 to 96 during 2017 and 2020. 12 096 HLA alleles were returned from the participants during the 4 years and total of 127 errors（1.05%）were found. These 127 errors were classified into two major types including 13 technical errors and 114 artificial errors. The proportion of laboratory which made mistakes was 2.56％（2/78）、4.88％（4/82）、8.75％（7/80） and 3.13％（3/96）in 2017,2018,2019 and 2020,respectively. Conclusion There were above 2.5% of laboratories with errors in HLA genotyping PT surveys past four years. More attentions should be greatly paid to clinical HLA genotyping test and the procedure of reporting.

Objective To realize the statistical analysis of data such as fourfold table chi-square test, evaluation and diagnostic test of four-fold table, and paired design of fourfold table chi-square test through Excel, so as to supplement the statistical function of chi-square test of Excel, and apply it to the teaching practice. Methods The statistical program is compiled through Excel VBA program interface to complete fourfold table chi-square and evaluation and diagnostic test, which compared with the case analysis of Health Statistics to vertify the accuracy of results. Results The input parameters include A (positive number in A rest), B (negative number in A test), C (positive number in B test) and D (negative number in B test). According to the above-mentioned conditions, the software automatically outputs the corresponding statistical description parameters: A+C, B+D, A+B, C, D, A+B+C+D, chi-square test, P values, and judgment. The assessment of diagnostic test and paired chi-square input parameters are: A (true positive), B (false positive), C (false negative) and D (true negative) should be numbers, otherwise there is a prompt dialog box. The software output corresponding statistical description parameters automatically according to these conditions: A+C, B+D, A+B, C+D, A+B+C+D, the diagnostic test's sensitivity, specificity, positive predictive value, negative predictive value and accuracy, matching chi-square test, P values and judgment. Conclusion Excel could replace manual process of fourfold tables data, automatically select the corresponding test statistics method, and provide P values and judgment.

Objective To investigate the value of the ratio of neutrophil to lymphocyte (NLR), monocyte to lymphocyte (MLR), platelet to lymphocyte (PLR), and systemic immune inflammatory index (SⅡ) in the diagnosis of lymph node metastasis of gastric cancer. Methods A total of 98 patients, which were screened for gastric cancer in our hospital from January 2017 to December 2019, were divided into gastric cancer group(61 cases) and gastric benign disease group(37 cases) by pathological diagnosis. According to the lymph node metastasis, gastric cancer group was further divided into lymph node metastasis group (35 cases) and non lymph node metastasis group (26 cases). NLR, MLR, PLR and SⅡ were calculated according to the results of preoperative blood routine test, and the efficiency of each index in the diagnosis of lymph node metastasis was analyzed. Results Among 61 cases of gastric cancer, 35 cases had lymph node metastasis, the metastasis rate was 57.38%. The levels of NLR, MLR, PLR and SⅡ in lymph node metastasis group were significantly higher than those in non lymph node metastasis group and gastric benign disease group(P<0.01). The area under ROC curve of NLR, MLR, PLR and SⅡ was 0.761, 0.708, 0.686 and 0.781, respectively. The critical values of NLR, MLR, PLR and SⅡ were 3.23, 0.29, 197.7 and 574.47, respectively. NLR, MLR, PLR and SⅡ were correlated with tumor differentiation, invasion, diameter and stage. Patients with lower differentiation, deeper invasion, larger diameter and higher stage had higher values of NLR, MLR, PLR and SⅡ (P<0.05). There was no significant difference in NLR, MLR, PLR and SⅡ (P>0.05) with tumor location. Conclusion NLR, MLR, PLR and SⅡ are related to the differentiation, invasion, diameter and stage of gastric cancer, which could be helpful for the diagnosis of lymph node metastasis of gastric cancer, and provide a reference for the choice of surgical methods and the scope of lymph node dissection.

Clinical blood transfusion and blood transfusion-related immunity are critical to the survival of the transplant. With the improvement of transplantation technology, liver transplantation, kidney transplantation, small intestine transplantation,lung transplantation uterus transplantation, hematopoietic stem cell transplantation have been realized, and xenogeneic organ transplantation is also actively exploring. Researchers have gradually gained a new understanding of transplantation-related blood transfusion. This paper expatiated on blood immunology related to organ transplantation and hematopoietic stem cell transplantation, perioperative blood transfusion during transplantation and xenotransplantation in the future, in order to provide new ideas for blood transfusion in transplantation technology.