Association between ABO blood group/genotype and COVID-19 in a Japanese population.

An association between coronavirus disease 2019 (COVID-19) and the ABO blood group has been reported. However, such an association has not been studied in the Japanese population on a large scale. Little is known about the association between COVID-19 and ABO genotype. This study investigated the association between COVID-19 and ABO blood group/genotype in a large Japanese population. All Japanese patients diagnosed with COVID-19 were recruited through the Japan COVID-19 Task Force between February 2020 and October 2021. We conducted a retrospective cohort study involving 1790 Japanese COVID-19 patients whose DNA was used for a genome-wide association study. We compared the ABO blood group/genotype in a healthy population (n = 611, control) and COVID-19 patients and then analyzed their associations and clinical outcomes. Blood group A was significantly more prevalent (41.6% vs. 36.8%; P = 0.038), and group O was significantly less prevalent (26.2% vs. 30.8%; P = 0.028) in the COVID-19 group than in the control group. Moreover, genotype OO was significantly less common in the COVID-19 group. Furthermore, blood group AB was identified as an independent risk factor for most severe diseases compared with blood group O [aOR (95% CI) = 1.84 (1.00-3.37)]. In ABO genotype analysis, only genotype AB was an independent risk factor for most severe diseases compared with genotype OO. Blood group O is protective, whereas group A is associated with the risk of infection. Moreover, blood group AB is associated with the risk of the "most" severe disease.

Silica microbeads capture fetal nucleated red blood cells for noninvasive prenatal testing of fetal ABO genotype.

ABO hemolytic disease of the newborn (ABO-HDN), which may cause neonatal jaundice and polycythemia, or even stillbirth or neonatal death, is widespread in China. Prenatal testing for the fetal ABO blood group can reduce unnecessary concerns or ensure prompt treatment. Herein, we presented a method to employ high-density silica microbeads (SiO2 MBs) for capturing fetal nucleated red blood cells (fnRBCs) in maternal peripheral blood, and we detected the ABO genotype of the fetus using these captured cells. We evaluated 52 patients using the SiO2 MBs. Among 26 pregnant women with type O blood, 8 (30.8%) of the fetuses had type A blood, 5 (19.2%) had type B blood, and 13 (50%) had type O blood. SRY genes were detected in all 27 male fetuses. This study represents a simple and effective method for noninvasive prenatal detection of the fetal ABO genotype. We believe that this method has great potential for noninvasive prenatal testing of the fetal Rh blood group and other fetal diseases as well.

Rapid ABO genotyping by high-speed droplet allele-specific PCR using crude samples.

BACKGROUND: ABO genotyping has common tools for personal identification of forensic and transplantation field. We developed a new method based on a droplet allele-specific PCR (droplet-AS-PCR) that enabled rapid PCR amplification. We attempted rapid ABO genotyping using crude DNA isolated from dried blood and buccal cells. METHODS: We designed allele-specific primers for three SNPs (at nucleotides 261, 526, and 803) in exons 6 and 7 of the ABO gene. We pretreated dried blood and buccal cells with proteinase K, and obtained crude DNAs without DNA purification. RESULTS: Droplet-AS-PCR allowed specific amplification of the SNPs at the three loci using crude DNA, with results similar to those for DNA extracted from fresh peripheral blood. The sensitivity of the methods was 5%-10%. The genotyping of extracted DNA and crude DNA were completed within 8 and 9 minutes, respectively. The genotypes determined by the droplet-AS-PCR method were always consistent with those obtained by direct sequencing. CONCLUSION: The droplet-AS-PCR method enabled rapid and specific amplification of three SNPs of the ABO gene from crude DNA treated with proteinase K. ABO genotyping by the droplet-AS-PCR has the potential to be applied to various fields including a forensic medicine and transplantation medical care.

Complete Sequencing of the ABO Alleles of the Common ABO Group and Rare ABO Subgroups in Koreans / 대한수혈학회지

BACKGROUND: Complete sequencing, except for intron 1, of the ABO allele in some populations has been reported. However, so far, one report on complete sequencing of the ABO gene in three Korean families with normal ABO phenotypes has been published. This study aimed to establish a reference database of common ABO alleles in Koreans. METHODS: Screening of common ABO alleles, including homozygote form, was performed by direct sequencing of exons 6 and 7 and by real-time PCR using displacing probes in 95 healthy donors. Genomic DNA from the common ABO group (n=8) and some ABO subgroups (n=7) was used in complete sequencing (except for intron 1) of the ABO allele. RESULTS: The sequences of B101/B101 (n=1), O01/O01 (n=1) were identical with the corresponding sequences registered in Genebank. A102 and A105 had a common point mutation, 1142 C>T in intron 4. A102 (n=3/11) and O02 (n=3/3), selected by sequencing of exons 6 and 7, were reclassified into A105 and O65 by whole genomic sequencing, respectively. Analytic results for ABO subgroups were as follows: B3, B101/O01 (n=3) and B101/O02 (n=1); A1B3, A102/B101 (n=1) and A105/B101 (n=1); Ax, A102/O01 (n=1). CONCLUSION: We established a reference database of common ABO alleles in Koreans and found that the molecular basis of introns of ABO alleles in the Korean population differs from that reported in previous studies of other populations.

Application of Real-Time PCR for ABO Genotyping for Large-scale Population Screening / 대한수혈학회지

BACKGROUND: For large-scale population screening, the method of ABO genotyping needs to be simple, accurate and cost-effective. The real-time PCR method has been introduced and it is suitable for dealing with large numbers of specimens. In this study, we examined the ABO genotyping of 1,700 residents of Jeollanam-do for an epidemiologic study by applying the real-time PCR method. METHODS: Genomic DNA was extracted from the peripheral blood samples of 1,700 residents of Jeollanam-do between July 2004 and January 2006 and these samples were stored at -70degrees C. The ABO genotype in all the samples was determined by four-color real-time PCR using displacing probes and three cases that had an atypical real time PCR pattern were confirmed by direct sequencing and PCR-based cloning of exons 6&7 of the ABO gene. RESULTS: The genotyping results of 1,700 samples included O/O (25.6%), A/A (9.1%), A/O (29.1%), B/B (4.5%), B/O (19.8%) and A/B (11.9%), and the allele frequencies of O, A and B were 50.1%, 29.5% and 20.4%, respectively. The frequency of the O allele was lower in the residents of Jeollanam-do than that previously reported for the residents of Kangwon-do (P=0.014), while the frequency of the A allele was higher in the residents of Jeollanam-do than that previously reported for the residents of Kangwon-do (P=0.003). The three cases with atypical results were revealed to be B101/O24, Bvar(296C>T)/O01 and B101/Ovar(801G>T). It takes 6 days to perform ABO genotyping on 1,700 samples by a calculation per test. CONCLUSION: ABO genotyping by real-time PCR using displacing probes can be useful for mass screening for ABO genotyping. In Korea, the frequency of the ABO allele was significantly different among different regions.

Association of ABO genotype with acute rejection in renal transplantation / 中华泌尿外科杂志

Objective To investigate a possible association of donor-recipient compatibility for ABO blood group alleles with acute rejection (AR) in renal transplantation. Methods A study comprising 87 pairs of donor and recipient was performed. The ABO genotype A1, A2, O1, O2, and B alleles of renal transplanted recipients and their respective donors were assessed by PCR amplification with sequence-specific primers (PCR-SSP). Accordingly, recipients were divided into donor-recipient ABO genotype matched and mismatched groups. Results The PCR-SSP based types of all cases showed total concordance with their serologically assigned ABO groups. Fifty pairs (57. 5%) were matched for ABO genotype among the 87 pairs of donor and recipient while 37 (42. 5%) were mismatched, including 1 allele mismatch in 31 pairs (83.8%), 2 alleles mismatches in 6 pairs (16. 2%).The incidence of AR was 12.0% (6 cases) and 29. 7% (11 cases) for ABO genotype matched and mismatched transplant patients, respectively ( P ＜ 0.05). After high dose methylprednisolone (MP)treatment, all cases exepienced reversion of AR except a A2O1 recipient receiving kidney from a A1O1enced 4 AR episodes within 3-10 months, and the period of AR was gradually shortened. After high dose MP was administered empirically, even though short-term improvement of renal function was observed, the serum creatinine continued to increase progressively with decreased efficacy of high dose MP. One year after operation the serum creatinine rose to 441 μmol/L. Conclusions Simultaneous definition of the ABO genotype and HLA is highly feasible. The A2 patient is suitable for receiving kidneys from blood group O donors. DNA mismatch for ABO genotype of renal transplant recipients and their respective donors is an independent risk factor for AR. Genotyping of ABO blood group is conducive to prevent AR.

Allele-related Variation in Minisatellite Repeats Involved in Transcription of the ABO Gene in Korean Blood Donors

BACKGROUND: The CBF/NF-Y enhancer region of ABO gene reported to contain 43bp minisatellite tandem repeats has been rarely reported. We describe here the relationship between minisatellite tandem repeats and ABO alleles in samples from Korean population with common ABO blood group and rare ABO subgroup. METHODS: Sixty one cases of ABO subgroup (14 A2, 12 A2B, 1 Aweak, 7 AweakB, 11 B3, 5 A1B3, 1 A1Bweak, 2 Bweak, and 8 cis-AB) and 41 cases of common ABO blood group (13 A, 6 AB, 11 B, and 11 O) were obtained from healthy donors at the Gwangju-Chonnam Red Cross Blood Center between Sep 2004 and Aug 2005. Red cells were phenotyped by standard serologic tests and genotyped by direct DNA sequencing exon 6 and 7 of the ABO gene. The minisatellite repeats were analyzed by PCR method. RESULTS: The ABO*A101 and *A102 had only one repeat, *B101, *O01 and *O02 had 4 repeats in common ABO blood group, while the *A102, *cis-AB01, and *Aw10 had only one minisatellite repeat and *A201, *A204, *B101, *Bw03, *B306, *O01, and *O02 alleles had 4 repeats and unexpectedly 3 A2 cases with *A102 had 4 repeats in the rare ABO subgroup. CONCLUSION: The minisatellite repeats found in Koreans correlate well with ABO alleles in sample common ABO phenotype, but do not completely correlate with those of ABO subgroup. We revealed here a pattern of the minisatellite repeats in various ABO subgroup in Korea.

ABO Gene Analysis of Discrepant ABO Blood Group in Blood Donors / 대한수혈학회지

BACKGROUND: An exact ABO blood group is essential for prevention of transfusion accident and safe transfusion therapy. It is known that one of causes of ABO discrepancies is ABO subgroup caused by genetic polymorphism. Therefore, we analyzed ABO genotype of ABO discrepancies in blood donors and studied the distribution and cause of ABO discrepancies. METHODS: This study examined 118 samples showing ABO discrepancies of ABO blood typing between May 2003 and Dec 2003. ABO genotyping using the polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) method was performed on 118 samples. Restriction enzymes including BssH II, Kpn I and Alu I were used for PCR-RFLP. RESULTS: The genotypes of 118 cases were composed of 43 cases of A/B, 12 cases of A/O, 10 cases of B/O, 1 case of B/B, 37 cases of cis-AB/O, 4 cases of cis-AB/A, 11 cases of cis-AB/B. The genotype of cis-AB/O showed 32 cases with phenotype A2 B3 , 2 cases with phenotype A2 B, 2 cases with phenotype A1 B3 , 1 case with phenotype Ael B. The genotype of cis-AB/B showed 11 cases with phenotype A2 B, and cis-AB/A showed 2 cases with phenotype A2 B3 , 1 case with phenotype A1 Bx and 1 case with phenotype A1 Bel. CONCLUSION: These data demonstrated that the most frequent genotype of ABO discrepancies in our study is cis-AB. The most predominent phenotype of cis-AB/O is A2 B3 . ABO genotyping is useful in resolving ABO discrepancies, and determination of ABO subgroups.

ABO genotype determination using biological molecular methods

Biological molecular methods were used to determinate ABO genotype determination. This method allowed extract DNA from biological samples (blood, saliva, hair root) for PCR reaction. Using PCR technique and enzymes, there were 1/3 individuals that have homozygote genotypes AA, BB, OO; 2/3 were heterozygote. In addition, this method could determine samples DNA samples from blood stains, saliva stains and hair root cells... So it has very important role in medical examination.

Two Cases of ABO Discrepancy due to Hypogammaglobulinemia / 대한수혈학회지

Two cases of ABO discrepancy were observed in thirty-year old woman with gall bladder abscess and fifty-five-year old woman with hepatocellular carcinoma. Their red cells were typed as group O and their serum had only anti-A antibody. Absence of A and B antigens on their RBCs were confirmed by adsorption elution test and saliva test. The B transferase activities were not demonstrated in their serum. Their ABO genotypes were O/O by sequence specific polymerase chain reaction. Their serum protein electrophoresis showed hypogammaglobulinemia pattern, and immunoglobulin levels (IgG, IgA, IgM) were decreased (39 mg/dL, 46 mg/dL, <5 mg/dL and 63 mg/dL, 65 mg/dL, 12 mg/dL, respectively).