Navigating antenatal complexity: a case report of Bombay blood group and anaemia challenges

The Bombay blood group is a rare blood type, predominantly found in regions with a high prevalence of consanguineous marriages due to its autosomal recessive inheritance pattern. This blood group is unique because individuals lack the H antigen, a precursor to the A and B antigens found in other blood types, making their blood type exceptionally rare. Managing antenatal patients with the Bombay blood group presents significant challenges, especially in cases of anaemia or any instance of blood loss. The primary difficulty arises from the scarcity of compatible blood for transfusion, as individuals with the Bombay blood group can only receive blood from other Bombay group donors. This rarity complicates the management of potential complications during pregnancy, labour, and delivery. To address these challenges, minimizing blood loss is essential during all stages of pregnancy, particularly during labour, Caesarean sections, and in the prevention of postpartum haemorrhage. Effective management requires a multidisciplinary approach, involving obstetricians, haematologists, and blood bank services. One potential strategy to mitigate the risk of blood shortages is autologous blood transfusion. This option can be particularly valuable during pregnancy; however, it requires careful consideration of the potential risks and benefits. The procedure should be conducted under the guidance of healthcare professionals experienced in managing such cases, ensuring the safety and well-being of both the mother and the foetus. In our case report, we present an antenatal patient with anaemia and the challenges encountered during the antenatal and postnatal periods. This case highlights the complexities of managing pregnancies involving the Bombay blood group. It underscores the importance of a well-coordinated, multidisciplinary approach to optimize outcomes for both mother and child.

Molecular mechanism of ABO bood group variation / 中国输血杂志

【Objective】 To study the relationship between ABO subtype, para-Bombay blood group and genotype, so as to explore the possible molecular mechanism of these two blood groups, and provide accurate genetic detection targets and theoretical basis for the accurate identification of ABO blood group. 【Methods】 First, the serology of 24 200 patients with blood type identification in the Ruijin Hospital from February to December in 2022 were analyzed, as well as 10 ambiguous ABO samples from other hospitals(3 were suspected ABO subtype and 7 were suspected para-Bombay blood group). Then ABO subtypes and para-Bombay blood groups were directly sequenced or post-clonal sequencing was performed to analyze ABO, FUT1 and FUT2 gene sequences. 【Results】 Among the 24 200 patients underwent blood type identification, 7 cases of ABO subtypes were detected. Among the 10 ambiguous samples sent by other hospitals, 2 of ABO subtypes, 1 of normal type A, and 7 of para-Bombay blood type were detected. In total, we identified blood types as follows: 1) 9 ABO subtypes: Ael(AEL.02/O.01.02), AelB(AEL.05/B.01), three of B3(2 of B3.03/O.01.01, 1 of B3.03/O.01.02), B(A)(BA.02/O.01.01), ABweak(A1.02/BW.07), Bweak(BW.31 /O.01.02), A2Bweak(A2.05 /BW.31); 2) 7 para-Bombay blood group: ABmh (FUT1*01N.13/FUT1*01N.13), 4 of Amh (3 of FUT1*01N.06/FUT1*01N.13, 1 of FUT1*01N.13/FUT1*01N.13); two of Bmh (FUT1*01N.06 /FUT1*01N.06, FUT1*01N.06/FUT1*01N.13), all of FUT2 of the 7 cases were FUT2*01/FUT2*01. 【Conclusion】 Clinical ABO blood group variant samples need to be identified in combination with serological and molecular biology to improve the accuracy of identification, thus providing a reference for safe blood transfusion, organ transplantation, and the prediction and prevention of fetal-maternal immune hemolytic disease.

Para-Bombay phenotype identification and transfusion strategy / 中国输血杂志

【Objective】 To investigate the serological and molecular biological characteristics of para-Bombay phenotype. 【Methods】 ABO blood type, H antigen and Lewis blood type in one blood sample with discrepancy between forward and reverse blood typing were detected by serological method. Antibody screening and identification and cross-match test were also performed by serological method. ABO blood group genes were detected by PCR-SSP, and FUT1 and FUT2 genes were sequenced. 【Results】 The serological test showed that the Para-Bombay phenotype was Ah secretion. The ABO blood group gene was AO2. FUT1 sequencing revealed two mutations: 235G>C and 881_882delTT. While FUT2 sequencing showed only one mutation 357C>T. 【Conclusion】 The discovery and accurate identification of blood groups is necessary to ensure the safety of blood transfusion. Blood donors of rare blood groups should be informed and recruited to the team of rare blood donors.

Serological characteristics and gene mutation analysis of Para-Bombay blood group / 军事医学

Objective To identify the Para-Bombay blood group on the basis of its serological characteristics .Methods ABO blood typing , H antigen detection , absorption and elution test , and saliva neutralization test were conducted for serological identification of ABO blood group .PCR-SSP was used to sequence FUT1 and FUT2 genes.Results Results of ABO genotyping of eight individuals of the Para-Bombay blood group were consistent with results of their serological blood typing.Among these cases, there were 3 cases of Amh,4 cases of Bmh,and 1 case of Abmh.The results of their FUT1 genotyping were h1h1 in 3 cases, h2h2 in 2 cases and h1h2 in 3 cases.Conclusion The differentce of agglutination intensity between Ac and Bc in reverse ABO blood typing and abnormal Oc agglutination is of greet significance for Para -Bombay blood group.

Molecular genetics analysis and frequency survey of H deficient phenotype / 中国输血杂志

Objective To survey the frequency of H deficient phenotype in blood donor population and analyze the serological and genetic characteristics of these individuals.Methods The H deficient phenotype was screened with anti-H monoclonal antibody.The ABO type was screened with serological method and with sequence specific primer polymerase chain reaction(PCR-SSP).FUT1 and FUT2 gene sequences were analyzed with direct sequencing of PCR products and gene cloning products.Result Of 85 390 blood donors,ten individuals were identified to be para-Bombay phenotype.Four h alleles were found in 14 para-Bombay phenotype individuals,h1(nt547-552?ag),h2(nt880-882?tt),h3(nt658c→t),and h_(new-2)(nt328g→a).The FUT1 genotypes of these para-Bombay individuals were h1/h1(6 individuals),h1/h2(7 individuals) and h3/h_(new2)(1 individual),and the frequency of 4 allele were 67.85%(h1),25%(h2),3.57%(h3),and 3.57%(h_(new-2)),respectively.FUT2 gene was analyzed in 12 para-Bombay phenotype individuals,and a mutation of nt357c→t was detected in all FUT2 gene,another mutation of nt716g→a were heterozygous in 5 individuals with h1/h2 genotype.No null FUT2 gene was detected.In serological analysis,all atypical anti-A or anti-B antibody of 14 para-Bombay individuals were inactive at 37℃,7 individuals had active anti-H antibody at 37℃.Conclusion The frequency of H deficient phenotype in Fujian population is about 1:8 500.The h1 and h2 alleles are predominant in Fujian H deficient individuals on h1-Se~(357) and h2-Se~(357,716) haplotype background.