Objective: To identify the phenotypes, antibodies and explore the molecular mechanisms of a patient who carries antibodies to RBC high-frequency antigens and his family members. Methods: The antibody identification test was performed for the proband by serological methods, and targeted NGS was subsequently used to detect mutations that occurred in blood group genes. Blood samples were collected from the proband and his family members. Sanger sequencing was used to verify the mutation of the XK gene. The expression of Kell blood group antigens was detected by serological methods and flow cytometry. K cells were used to detect the antibody specificity of the proband. The morphology of red blood cells was detected by the scanning electron microscopy. The serum creatine kinase levels of the proband and his family members were analyzed by colorimetric methods. Results: The results of the antibody identification test suggested that the proband might have antibodies to high-frequency antigens. NGS results suggested a homozygous mutation (c. 107G>A) in exon 1 of the XK gene in the proband, resulting in a truncated XK protein. The Sanger sequencing results of the proband were consistent with the NGS results, and the mutation was not found in other family members. The expression of Kell blood group antigens of the proband was not found by serological methods and flow cytometry. The results of the antibody specificity test showed that the proband had anti-Km antibodies. Spike-like changes were identified on red blood cells, and serum creatine kinase level was elevated in the proband. Conclusion: In this study, the McLeod phenotype caused by homozygous mutation (c. 107G>A) of XK gene was identified in Chinese individuals for the first time by the phenotype and molecular mechanism studies. The results of genotyping and phenotyping suggested that the McLeod phenotype caused by the mutation was compatible with the phenotypes of McLeod and K .

OBJECTIVE: To report the blood group antigen and antibody specificity identification methods for a patient with high-frequency antibodies, and the process of finding and providing compatible blood for the patient. METHODS: A patient sent from the Blood Transfusion Department of Shanxi Provincial People's Hospital to Blood Transfusion Technology Research Laboratory of Taiyuan Blood Center in November 2022 was selected for the study. Classical serological methods were used to determine the patient's blood type, screen for unexpected antibodies, identify antibodies, and perform crossmatching. High-frequency antibody identification was carried out using red blood cells treated with various enzymes. Blood group genotyping was conducted using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF) and Sanger sequencing. Multiple strategies were employed to address the patient's blood source problem. The study was approved by the Medical Ethics Committee of Taiyuan Blood Center [Ethics No. 2024 Ethics Review No.(2)]. RESULTS: The patient's blood type was B, RhD positive. Initial screening of the patient's serum with multiple screening cells and antibody identification cells in saline medium was negative, but positive in antiglobulin medium. The patient's serum showed varying reaction intensities with red blood cells treated with different enzymes. MALDI-TOF mass spectrometry and Sanger sequencing revealed a homozygous nonsense variant c.376C>T (p.Gln126Ter) in the ABCG2 gene, resulting in the Jr(a-) phenotype. During family donor selection, the patient's son was found to have a heterozygous variant c.376C>T (p.Gln126Ter), and another heterozygous variant c.421C>A (p.Gln141Lys), which predicted a Jr(a+w) phenotype. Crossmatch tests confirmed the compatibility of blood from the patient's son, which was used to address the urgent blood requirement. Later, rare blood from a Jr(a-) donor from the Guangzhou Blood Center was used for the patient's ongoing treatment, saving the patient's life. CONCLUSION Combining classic serological testing with blood group gene typing techniques successfully identified the rare Jr(a-) blood type and high-frequency anti-Jra antibodies. Enzyme-treated red blood cell identification methods confirmed the presence of anti-Jra antibodies. By searching within the family and seeking help from other blood centers, compatible blood was found. This approach may provide insights for resolving similar complex blood matching problems in the future.
Humans ; Blood Grouping and Crossmatching/methods* ; Blood Group Antigens/immunology* ; Blood Transfusion ; Male ; Isoantibodies/blood* ; Female ; Genotype

OBJECTIVE: To explore the regulatory mechanisms underlying the weak expression of ABO blood group antigens due to variants in the non-coding regions of the ABO gene. METHODS: From June 2014 to October 2023, a total of 29 samples from the Taiyuan Blood Center and local hospitals, which were serologically identified as having weak ABO antigen expression without detectable coding region mutations, were selected for this study. Full-length ABO gene sequencing was performed using third-generation long-read sequencing technology (Pacific Biosciences) to obtain complete haplotype sequences of the ABO gene. Variants in the non-coding regions were compared and identified to infer their regulatory effects on weak antigen expression. The procedures followed in this study were in accordance with the ethical standards of the World Medical Association's Declaration of Helsinki (2013 revision). The Medical Ethics Committee of Taiyuan Blood Center has granted an exemption from ethical review. RESULTS: 18 bp deletions in the -35 to -18 region of the promoter were identified in 7 samples. Variants in intron 1 (+5.8 kb) were detected in 7 samples, including ABO*A (28+5792_5793delCT (1 case) and ABO*B (28+5793T>C) located in the GATA binding region; ABO*B (28+5808C>T) (1 case) in the E-box region; and ABO*B (28+5875C>T) (4 cases) in the RUNX1 binding region. Nucleotide variants at splice sites were detected in 2 samples, namely ABO*B (C.98+1G>A) and ABO*B (C.204-2A>C). CONCLUSION Variants in the non-coding regulatory sequences of the ABO gene are a significant factor contributing to weak ABO antigen expression. In clinical ABO sequencing, it is essential to screen not only the conventional coding regions but also the flanking sequences, introns, and splice sites of the ABO gene to facilitate precise blood transfusion.
ABO Blood-Group System/genetics* ; Humans ; Alleles ; Promoter Regions, Genetic ; Haplotypes ; Introns

Objective To explore the characteristics and influencing factors of adverse reactions of apheresis plasma do-nation in 27 domestic plasma donation stations,and put forward targeted preventive measures.Methods A total of 6 275 plasma donors with adverse reactions from 2018 to 2020 in 27 plasma donation stations in China were selected as the re-search objects.The types of adverse reactions,ages,time of plasma donation and other related characteristics were counted and retrospectively analyzed.Results From January 2018 to December 2020,the incidence of adverse reactions of aphere-sis plasma donation in 27 plasma collection stations was 1.37‰,including vasovagal reaction/hypovolemia(3 208 cases,0.700‰),sodium citrate allergy/hypocalcemia(1 205 cases,0.263‰),hypoglycemia(1 020 cases,0.223‰),syncope(796 cases,0.174‰),hematoma(8 cases,0.002‰),other reactions(36 cases,0.008‰),all of which were non-se-vere adverse reactions.There were significant differences in the incidence of different types of adverse reactions(P＜0.001).The adverse reactions in 2018,2019 and 2020 were compared,and the difference was statistically significant(P＜0.001),with the highest incidence of 1.51‰(2 143/1 414 162)of adverse reactions in 2019 and the lowest incidence of 1.29‰(1 818/1 410 506)in 2020.The difference in the incidence of adverse reactions in different age groups was statistically sig-nificant(P＜0.001),with the highest incidence of 2.61‰(224/85 733)of 18-25 years old,and the lowest incidence of 1.05‰(465/439 786)of 56-60 years old.The incidence of different types of adverse reactions was compared according to different age groups,and significant differences were noticed in the incidence of vasovagal reaction/hypovolemia(P＜0.001),sodium citrate allergy/hypocalcemia(P＜0.05),hypoglycemia(P＜0.001),and syncope(P＜0.001)among dif-ferent age groups,while no significant difference was found in hematoma and other adverse reactions among different age groups(P＞0.05).Conclusion The incidence of adverse reactions in plasma donation is low in China.In the process of plasma donation,attention should be paid to first-time and young(18-25 years old)donors.The incidence of adverse reac-tions in 56-60 years old donors is the lowest,which can provide data support for the age revision of plasma donors in China.

Objective To investigate short-term clinical efficacy of autologous leukocyte-poor platelet-rich plasma(LP-PRP)treatment of knee osteoarthritis(KO A).Methods 85 cases of patients with Keligren Lawrence grade Ⅰ-Ⅲ knee os-teoarthritis in Peking University First Hospital Taiyuan Hospital(Taiyuan Central Hospital)from 2022 to 2023 were collect-ed for autologous LP-PRP collection and quality assessment using a blood component separator,and all patients were treated with autologous LP-PRP.The degree and function of knee pain were assessed by visual analog scale(VAS)and knee arthri-tis index scale(WOMAC)at 1,3 and 6 months after injection.Knee MRI was performed after 6 months of treatment,and the MRI imaging changes before and after treatment were compared.Different influencing factors in the treatment results were grouped and analyzed,mainly including platelet concentration in LP-PRP and K-L grading of knee joint.According to the platelet concentration in LP-PRP,it was divided into three grades,which are low concentration[(＜800)×109/L],medium concentration[(800-1 000)×109/L],and high concentration[(＞1 000)× 109/L];According to the K-L grade of the knee joint,the severity of knee osteoarthritis was divided into three grades:Ⅰ、Ⅱ、Ⅲ.Results The VAS and WOMAC scores at 1,3 and 6 months after LP-PRP treatment were significantly lower than those before treatment,and the difference was sta-tistically significant(P＜0.05).There was a statistically significant difference in the therapeutic effect of different levels of platelet concentration,and when the platelet concentration was more than 1 000×109/L,the significant effect was the most obvious(P＜0.05).The therapeutic effect of different levels of platelet concentration was statistically significant(P＜0.05).MRI showed that the articular cartilage signal was significantly improved after treatment.Conclusion Autologous LP-PRP injection into knee cavity for the treatment of KO A has a good short-term clinical effect in relieving knee pain.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.