Objective: To conduct screening for rare blood types within important blood group systems for the Chinese population, such as Rh, Duffy, Kidd, P1Pk, Diego, and MNS, in the Guangzhou region, and to establish a corresponding rare blood type database and physical repository. Methods: The saline medium microplate method was used to screen blood donors with the ccDEE phenotype combined with either Jk(a-) or Jk(b-). The polybrene microplate method was employed to screen for donors with Fy(a-), s(-), Lu(b-), Di(b-), k(-), and p phenotypes. The urea lysis microplate method was applied to screen for the Jk(a-b-) phenotype. A high-resolution melting (HRM) curve method was established for screening some donors with the Di(b-) phenotype. Subsequently, expanded phenotyping of antigens in the Rh, Kidd, MNS, Duffy, P1Pk, Lewis, Kell, and Lutheran blood group systems was performed on identified rare blood type donors using monoclonal antibodies. The test results are entered into the Rare Blood Type Bank Management System of the Guangzhou Blood Center, enabling functions such as confirmation reminders and cryopreservation storage when the donor donates again. Red blood cells of rare blood types are processed into frozen red blood cells for long-term storage. Results: Among voluntary blood donors, 16 cases of the ccDEE combined with Jk(a-) phenotype were identified (0.221 7%, 16/7 216); 10 cases of the ccDEE combined with Jk(b-) phenotype (0.138 6%, 10/7 216); 78 cases of the Fy(a-) phenotype (0.169 5%, 78/46 012); 39 cases of the Lu(b-) phenotype (0.138 2%, 39/28 214); 31 cases of the s(-) phenotype (0.081 8%, 31/37 913); 22 cases of the Di(b-) phenotype (0.029 9%, 22/73 691); 30 cases of the Jk(a-b-) phenotype (0.010 1%, 30/298 250); and 1 case of the k(-) phenotype (0.001 3%, 1/77 382), which was further identified as KELnull phenotype (K0). No p phenotype donors were identified (0/88 528). A total of 228 units of frozen red blood cells were prepared. The screening results were compared and analyzed with rare blood type data from other regions. Conclusion: This study, through a combination of different screening methods, significantly improved the efficiency of rare blood type screening while remaining cost-effective. By conducting large-scale screening and performing data informatization processing, a database and physical repository of rare blood types in the Guangzhou region were successfully established. This provides a strong guarantee for the timely supply of blood to patients with difficult-to-match and rare blood types in the region, effectively enhances the level of transfusion safety in the region, and offers a practical paradigm for constructing a comprehensive blood transfusion support system.

Objective To analyze the risk factors and effective predictive indicators for postpartum hemor-rhage(PPH)in pregnant women with severe pre-eclampsia(sPE)in singleton pregnancies.The findings will serve as a valuable reference for the clinical prevention and management of PPH in these patients.Methods A retrospective analysis was conducted on 932 pregnant women with sPE at two tertiary hospitals in Guangzhou from January 1,2016,to December 31,2022.Among these,95 cases were complicated by PPH.A comparative analysis was performed between the sPE group and the sPE with PPH group.Results(1)The incidence of assisted reproductive technology,intrapartum blood loss,placental abruption,elevated D-dimer levels,increased monocyte counts,and higher SIRI levels were significantly higher in the PPH group,whereas platelet counts were significantly lower(P<0.05).(2)The results indicated that intrapartum blood loss,D-dimer levels,and platelet counts were inde-pendently associated with PPH in pregnant women with sPE.(3)The area under the curve(AUC)for intrapartum blood loss,D-dimer,and platelet counts were 0.805,0.717,and 0.571,respectively.The optimal cutoff value for D-dimer was determined to be 2.295 μg/mL.The combined AUC for intrapartum blood loss and D-dimer was 0.859.(4)Intrapartum blood loss values were significantly higher in the PPH group for both vaginal delivery and cesarean section(P<0.001).The corresponding optimal cutoff values were 285 mL and 375 mL,respectively.Conclusions Intrapartum haemorrhage,D-dimer levels,and platelet count were identified as independent risk factors for PPH in pregnant women with sPE.Specifically,pregnant women with sPE who experienced blood loss exceeding 285 mL during vaginal delivery or 375 mL during caesarean section,along with a D-dimer level greater than 2.295 μg/mL,demonstrated an increased likelihood of developing PPH.Therefore,it is crucial to enhance clinical monitoring of these relevant indicators in high-risk populations.

Objective To analyze the risk factors and effective predictive indicators for postpartum hemor-rhage(PPH)in pregnant women with severe pre-eclampsia(sPE)in singleton pregnancies.The findings will serve as a valuable reference for the clinical prevention and management of PPH in these patients.Methods A retrospective analysis was conducted on 932 pregnant women with sPE at two tertiary hospitals in Guangzhou from January 1,2016,to December 31,2022.Among these,95 cases were complicated by PPH.A comparative analysis was performed between the sPE group and the sPE with PPH group.Results(1)The incidence of assisted reproductive technology,intrapartum blood loss,placental abruption,elevated D-dimer levels,increased monocyte counts,and higher SIRI levels were significantly higher in the PPH group,whereas platelet counts were significantly lower(P<0.05).(2)The results indicated that intrapartum blood loss,D-dimer levels,and platelet counts were inde-pendently associated with PPH in pregnant women with sPE.(3)The area under the curve(AUC)for intrapartum blood loss,D-dimer,and platelet counts were 0.805,0.717,and 0.571,respectively.The optimal cutoff value for D-dimer was determined to be 2.295 μg/mL.The combined AUC for intrapartum blood loss and D-dimer was 0.859.(4)Intrapartum blood loss values were significantly higher in the PPH group for both vaginal delivery and cesarean section(P<0.001).The corresponding optimal cutoff values were 285 mL and 375 mL,respectively.Conclusions Intrapartum haemorrhage,D-dimer levels,and platelet count were identified as independent risk factors for PPH in pregnant women with sPE.Specifically,pregnant women with sPE who experienced blood loss exceeding 285 mL during vaginal delivery or 375 mL during caesarean section,along with a D-dimer level greater than 2.295 μg/mL,demonstrated an increased likelihood of developing PPH.Therefore,it is crucial to enhance clinical monitoring of these relevant indicators in high-risk populations.

Objective: To investigate the impact of RHAG 808A variant, commonly identified in the Chinese population, on RhAG protein, RhD and RhCE antigens expression through in vivo and in vitro expression analysis. Methods: A missense mutation of RHAG gene (c. 808G>A, p. Val270Ile) with high frequency was found in KMxD database. Bioinformatics analysis was performed using Polyphen-2 and Provean software. High resolution melting (HRM) method was utilized to screen for the variant carriers in the blood donors. The expression of RhAG protein, RhD and RhCE antigens on the surface of red cells of variant carriers were detected via flow cytometry. Wild-type and mutant vectors of RHAG were constructed and transfected into HEK 293T cells for in vitro expression analysis. Then, the expression of RhAG protein, RhD and RhCE antigens were analyzed by flow cytometry. Results: Polyphen-2 and Provean software suggested that the amino acid change (p. Val270Ile) of RhAG protein may be harmful or neutral respectively. Among the 999 blood donors from Guangzhou Blood Center, 4 homozygous carriers and 99 heterozygous carriers of RHAG 808A mutant allele were identified. The frequency of this allele was 5.4% (107/1 998). No significant differences in RhAG protein, RhD and RhCE antigens expression level was identified between the homozygous carriers, heterozygous carriers of RHAG 808A variant allele and the wild-type individuals. In vitro analysis for antigen expression study obtained the similar results. Conclusion: The RHAG 808A variant allele commonly identified in the Chinese population has no effect on the expression of RhAG protein, RhD and RhCE antigens, so the variant should be a population polymorphism site.

【Objective】 To identify the specificity of alloantibody against high-frequency antigens in one case suffering with severe hemolytic diseases of the fetus and newborn (HDFN) and to screen for matching blood for transfusion. 【Methods】 The HDFN test and the antibody serological identification tests in the mother were performed. Several common high frequency antigens of maternal red blood cells (RBCs) were determined. IgG subtype coated on the RBCs of the newborn was determined. The phagocytic efficiency of the antibody was tested using the monocyte phagocytosis of sensitized erythrocyte by flow cytometry in vitro. Sanger sequencing of DI gene was performed in the mother, father and mother’s brother. The diluted maternal plasma was used for large scale screening of matching blood using IAT in Coomb’s gel card. 【Results】 Di(b-) phenotype was identified in the mother of the newborn and anti-Di^b (titer: 512) related HDN was detected in the newborn. IgG1 and IgG2 subtypes of anti-Di^b were detected and the rate of monocyte phagocytosis was 88.83%(74.7/84.09). The compatible blood was not detected in the maternal relatives. Subsequently, the newborn received the matching RBCs of two Di(b-) donors identified from 5 520 blood donors and discharged from the hospital. We screened out 17 Di(b-) donors out of 51 334 blood donors, indicating that the distribution frequency of Di(b-) among blood donors in Guangzhou was about 0.033% (17/51 334). 【Conclusion】 By serology and molecular biology methods, the newborn was identified with HDFN caused by anti-Di^b, and an effective large-scale screening method for Di (b -) rare blood types was established to find matching blood, which supported the establishment of rare Di(b-) blood database.

Objective:To explore the prevalence and independent associated factors of vascular calcification (VC) in non-dialysis chronic kidney disease (CKD) patients of stage 3-5.Methods:It was a single-center cross-sectional observational study. Non-dialysis stage 3-5 CKD patients ≥18 years old who were admitted to the Department of Nephrology, the First Affiliated Hospital of Sun Yat-sen University from May 1, 2022 to December 31, 2022 with VC evaluation were enrolled. The patients' general information, laboratory examination and imaging data were collected. Coronary artery calcification (CAC), thoracic aorta calcification (TAC), abdominal aorta calcification (AAC), carotid artery calcification and aortic valve calcification (AVC) were evaluated by cardiac-gated electron-beam CT (EBCT) scans, lateral lumbar x-ray, cervical macrovascular ultrasound and echocardiography, respectively. The differences in clinical data and the prevalence of VC at different sites of patients with different CKD stages were compared, and the prevalence of VC at different sites of patients in different age groups [youth group (18-44 years old), middle-aged group (45-64 years old) and elderly group (≥65 years old)] and patients with or without diabetes were compared. Multivariate logistic regression analysis was used to analyse the independent associated factors of VC for different areas.Results:A total of 206 patients aged (51±14) years were included, including 129 (62.6%) males. There were 44 patients with CKD stage 3 (21.4%), 51 patients with CKD stage 4 (24.8%), and 111 patients with CKD stage 5 (53.9%). CKD was caused by chronic glomerulonephritis [104 cases (50.5%)], diabetic kidney damage [35 cases (17.0%)], hypertensive kidney damage [29 cases (14.1%)] and others [38 cases (18.4%)]. Among 206 patients, 131 (63.6%) exhibited cardiovascular calcification, and the prevalence of CAC, TAC, AAC, carotid artery calcification, and AVC was 37.9%, 43.7%, 37.9%, 35.9% and 9.7%, respectively. The overall prevalence of VC in young, middle-aged and elderly patients was 24.6%, 73.6% and 97.4%, respectively. With the increase of age, the prevalence of VC in each site gradually increased, and the increasing trend was statistically significant (all P<0.001). The overall prevalence of VC in CKD patients with diabetes was 92.5% (62/67), and the prevalence of VC at each site in the patients with diabetes was significantly higher than that in the patients without diabetes (all P<0.001). Multivariate logistic regression analysis revealed that age (every 10 years increase, OR=2.51, 95% CI 1.77-3.56, P<0.001), hypertension ( OR=5.88, 95% CI 1.57-22.10, P=0.009), and diabetes ( OR=4.66, 95% CI 2.10-10.35, P<0.001) were independently correlated with CAC; Age (every 10 years increase, OR=6.43, 95% CI 3.64-11.36, P<0.001) and hypertension ( OR=6.09, 95% CI 1.33-27.84, P=0.020) were independently correlated with TAC; Female ( OR=0.23, 95% CI 0.07-0.72, P=0.011), age (every 10 years increase, OR=3.90, 95% CI 2.42-6.29, P<0.001), diabetes ( OR=5.37, 95% CI 2.19-13.19, P<0.001) and serum magnesium ( OR=0.01,95% CI 0-0.35, P=0.014) were independently correlated with AAC. Moreover, age and diabetes were independently correlated with carotid artery calcification, AVC and overall VC Conclusions:The prevalence of VC in non-dialysis CKD patients of stage 3-5 is 63.59%, of which CAC reaches 37.9%, TAC is the most common one (43.7%), while AVC is the least one (9.7%). Age and diabetes are the independent associated factors for VC of all sites except TAC, while hypertension is an independent associated factor for both CAC and TAC.

【Objective】 To solve the difficulty of RhD blood group typing in a patient with double population(DP) of red blood cells for RhD antigen by serological and genotyping analysis. 【Methods】 Separation of the two populations of red blood cells of the patient was performed using capillary centrifugation method. ABO, RhD and RhCE typing, direct anti-human globulin test (DAT), irregular antibody screening, antibody identification and blood crossmatching of the patient were conducted using the standard serological methods. The hybrid Rhesus zygosity analysis of the RHD gene was performed by PCR-RFLP method. RHD and RHCE genotype of the patients were identified by PCR-SSP method. 【Results】 The patient was B type but with DP of red blood cells for RhD, Rhc and RhE antigens. DAT of the patient was positive and the alloanti-D was detected in serum. The RHD zygosity was D-/D- homozygote. PCR-SSP testing showed the RHD gene deletion (RHD * 01N. 01/01N.01 genotype) and Ccee of RHCE genotype in the patient, which was consistent with RHD zygosity analysis. 【Conclusion】 This is a special case with D-negative phenotype which was wrongly detected as D-positive type after D-positive red blood cells transfusion in emergency. When the DP of red cells for D antigen encountered like this case, the RhD typing can be accurately determined by using RHD genotyping analysis to provide strong evidence to the clinical blood transfusion.

Objective:To explore the clinical and histopathologic features of lupus nephritis (LN) patients with positive antineutrophil cytoplasmic antibody (ANCA), so as to provide more theoretical basis to recognize and treat this disease.Methods:Clinical data of biopsy-proven LN patients with ANCA test in the First Affiliated Hospital of Sun Yat-sen University from November 1, 2002 to September 11, 2020 were collected and analyzed retrospectively. The difference of clinical data, laboratory examination, and pathological examination of renal biopsy between ANCA-positive group and ANCA-negative group. The clinicopathological characteristics between different ANCA serotypes were compared.Results:A total of 1 304 patients with LN confirmed by renal biopsy and ANCA test results were enrolled. Eighty ANCA-positive patients from 1 304 LN patients were screened. There are 55(68.8%) ANCA-positive LN patients with positive anti-myeloperoxidase antibodies (MPO). There were 14(17.5%) ANCA-positive LN patients with positive anti-proteinase 3 antibodies (PR3), and 11(13.8%) ANCA-positive patients with double positive antibodies of MPO and PR3. ANCA-positive LN patients had significantly higher serum creatinine [135.5(68.0, 361.8) μmol/L vs 88.0(64.0, 165.0) μmol/L, P=0.004] and blood urea nitrogen [12.35(6.35, 21.18) mmol/L vs 8.60 (5.50, 15.70) mmol/L, P=0.026] as well as lower estimated glomerular filtration rate [45.70(13.83, 84.10) ml·min -1·(1.73 m 2) -1 vs 66.75(38.43, 96.22) ml·min -1·(1.73 m 2) -1, P=0.001] than ANCA-negative patients (stratified sampling of 160 patients). ANCA-positive LN patients had higher chronicity index than ANCA-negative LN patients [3(2, 7) vs 2(0, 5), P=0.006]. There were statistically significant difference in hemoglobin, serum creatinine and estimated glomerular filtration rate among ANCA-positive group, ANCA-negative group, and MPO-ANCA and PR3-ANCA double positive group. MPO-ANCA and PR3-ANCA double positive LN patients had the lowest hemoglobin and estimated glomerular filtration rate, and highest serum creatinine among the three groups (all P<0.05). Conclusions:ANCA-positive LN patients have worse renal function and higher renal histological chronicity index than ANCA-negative LN patients, especially for patients with double positive MPO-ANCA and PR3-ANCA. More stringent monitoring and therapy may be needed in this subgroup of LN patients.

【Objective】 To identify the antibody specificity in a pregnant women who had no history of blood transfusion but presented the antibodies against high-frequency antigens. 【Methods】 ABO, RhD blood group antigens were identified by saline. Antibody screening and identification were performed by saline and indirect Coomb’s technique. Further antibody identification tests were conducted using papain, trypsin and chymotrypsin-treated cells. Antibody titer in serum was tested. PCR amplification and sequencing analysis of 16 exons of ABCG2 gene were conducted. 【Results】 The blood type of the patient were B, RhD positive. The serum reacted with antibody screening/identified cells by indirect antiglobin test(both 2+ ) but not by saline. The agglutination was enhanced after papain treatment (4+ ), but remained unchanged after trypsin and chymotrypsin treatment (2+ ). The IgG titer was 1∶2. The sequencing analysis of ABCG2 gene revealed a homozygous nonsense mutation(c.376C>T, p. Gln126X) in exon 4 of the women. 【Conclusion】 In this case, the development of anti-Jr^a in Jr(a-) mother was stimulated by mother-child serology incompatibility during pregnancy.

【Objective】 To establish an experimental method for detecting phagocytosis of sensitized red blood cells in vitro by flow cytometry. 【Methods】 Mononuclear cells were isolated from the peripheral blood of blood donors and cultured in a cell incubator for 1 hour, and then adherent monocytes were isolated and obtained. Di^b-positive red blood cells (RBCs) were labeled with PKH26 and then sensitized with IgG anti-Di^b. The sensitized RBCs were added to monocytes for in vitro phagocytosis assay. Monocytes were labeled with FITC anti-human CD14, then phagocytosis was measured by flow cytometry, and the phagocytic efficiency was calculated. The method was used to detect the phagocytic efficiency of monocytes on human IgG anti-D sensitized RBCs with different titers. 【Results】 The phagocytic efficiency of monocytes was averaged at 5% (1.2%~7.6%, SD 3.30) versus 81% (71.4%~92.7%, SD 8.65) in the negative versus positive control group, respectively. Phagocytic activity of monocytes mediated by anti-D was correlated with the antibody titer. The phagocytosis efficiency was within 10% when the antibody titer was lower than 32 and increased sharply when the titer was between 32 to 128, it entered a plateau and stabilized at 80% at the titer above 256. 【Conclusion】 A detection platform for detecting phagocytosis-sensitized RBCs in vitro by flow cytometry has been successfully established. It can be used to assess the clinical significance of red blood cell allotype or autologous IgG antibodies.