A case report on para-Bombay blood group

AG Krishnaveni; S Vasanth

doi:10.4103/ajts.AJTS_105_20

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CASE REPORT

Year : 2023 | Volume : 17 | Issue : 1 | Page : 136-138

A case report on para-Bombay blood group

AG Krishnaveni¹, S Vasanth²
¹ Department of Pathology, Government Sivagangai Medical College, Sivagangai, Tamil Nadu, India
² Department of Pharmacology, Government Sivagangai Medical College, Sivagangai, Tamil Nadu, India

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Date of Submission	30-Jun-2020
Date of Decision	19-Jul-2020
Date of Acceptance	06-Mar-2022
Date of Web Publication	12-Dec-2022

Abstract

Rare blood group detection is important as the incidence of these blood groups is very low. These rare blood groups need a transfusion of blood from the same group of people; sometimes, it is not available in blood banks. It is important to detect them in the field of transfusion medicine so that the right transfusion at the right time and for the right patient is ensured. We had one patient who was identified as blood group O in a private laboratory and the patient came to our hospital for anemia during the second trimester of pregnancy whose forward grouping showed no agglutination in the anti-a and anti-b and also no agglutination in the anti-H so we thought it to be Bombay blood group. We performed the reverse grouping and we found agglutination with pooled A cells and pooled B cells but no agglutination in the pooled O cells. We found forward and reverse grouping were discordant so we concluded that the patient had Bombay variant blood group, the secretor status of the patient was done in saliva using hemagglutination inhibition test and we found that the patient had secretion of H substance in the saliva. Rh typing: it was found that the patient had positive in Rh typing. Family members were screened and they all were O positive. Forward and reverse grouping along with the secretor status detection helped to detect the case. This case report highlights the importance of blood grouping forward and reverse and also using Anti-H reagent for blood grouping and also the use of secretor status in the detection of proper blood grouping of the patient.

Keywords: Blood group, forward grouping, para-Bombay blood group, secretor status, secretor status

How to cite this article:
Krishnaveni A G, Vasanth S. A case report on para-Bombay blood group. Asian J Transfus Sci 2023;17:136-8

How to cite this URL:
Krishnaveni A G, Vasanth S. A case report on para-Bombay blood group. Asian J Transfus Sci [serial online] 2023 [cited 2023 Mar 21];17:136-8. Available from: https://www.ajts.org/text.asp?2023/17/1/136/370930

Introduction

Karl Landsteiner Austrian immunologist discovered the blood group antigens and he classified them into A, B, O blood group in 1900 latter another blood group AB was discovered.^[1] Since his discovery, there has been so many advances in the blood transfusion science where unwanted transfusion was avoided due to correct transfusion of blood and blood products to the patient taking place throughout the world. The incidences of rare blood group were very low, but the problem is that certain blood group needs a transfusion of blood from the same blood group person. Para-Bombay blood group which is extremely rare, with only a very few cases being reported and very few of the published studies have reported the prevalence of para-Bombay phenotype in India. Para-Bombay phenotype is characterized by the absence of ABH antigens on red blood cells (RBCs) by the presence of ABH substances in body secretions or by the weak expression of ABH antigens on RBCs with the absence or presence of substances in body secretions. In contrast, Bombay phenotypes have an absence of ABH antigens of both, the RBCs as well as in body secretions.

Case Report

A 25-year-old female patient admitted for anemia during pregnancy. She was Primi and presented in the 22^nd week of gestation. Her hemoglobin was 6.5 g. No history of bleeding disorders and she was not on any medication. She was diagnosed to be o positive blood group by private laboratory. Blood grouping was done for this patient forward grouping was done and we found no agglutination in the Anti-A and Anti- B and also in Anti-H [Figure 1] so we thought it to be bombay blood group. We performed the reverse grouping and we found agglutination with pooled A cells and pooled B cells, but no agglutination in the pooled O cells [Figure 2]. We found forward and reverse grouping were discordant, so we came to the conclusion that the patient had Bombay variant blood group, We decided to check the secretor status of the patient by detection of substance in the saliva and performed by wieners hemagglutination inhibition test^[2] and we found that the patient had secretion of H substance in the saliva [Figure 3]. Rh typing: It was found that the patient had positive in Rh typing. Her family member blood grouping was also performed her parents were O positive and her brother was O positive, husband also O positive all had 4+ agglutination with Anti-h in the forward grouping.

Figure 1: Forward grouping was done and it shows that the group had no agglutination in the Anti-A and Anti-B and no agglutination in the Anti-H, grouping was compared to control. The Rh typing was positive

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Figure 2: The patient showed agglutination with pooled cells of A and B no agglutination with pooled cell of O and compared with control

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Figure 3: Hemagglutination inhibition test was performed and control tube labeled as C shows clear haemaglutination and clear supernatant while the test tube labeled as T shows no hemagglutination that is secretor

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Discussion

Para-Bombay is extremely rare, with only a very few cases being reported and very few of the published studies have reported the prevalence of para-Bombay phenotype in India. Para-Bombay phenotype is characterized by the absence of ABH antigens on RBCs with the presence of ABH substances in body secretions or by the weak expression of ABH antigens on RBCs with the absence or presence of substances in body secretions. In contrast, Bombay phenotypes have an absence of ABH antigens on both, the RBCs as well as in body secretions. As H antigen is the precursor for the A and B antigens, it is expressed on all red cells except in the rare Bombay and para-Bombay phenotype showing its absence or deficiency. The ABO genes determine the presence of A and B antigens, whereas the H antigen is a result of α-(1,2)-fucosyltransferase (FUT) genes. FUT1 (H gene) determines the presence of H antigen on the RBCs and FUT2 (Se gene) in body secretions. FUT1 forms the H antigen, which is preferentially expressed in erythroid tissues and vascular endothelial cells by fucosylation of the Type 2 chain oligosaccharides on red cell glycoproteins and glycolipids^.[3] FUT2 recognizes Type 1 chain precursors to form H Type I antigen in secretions and tissues such as secretory glands and digestive mucosa. Bombay phenotype is characterized by the absence of ABH blood group antigens both on the surface of RBCs and saliva resulting from both silenced mutations in FUT1 (h/h) and FUT2 (se/se) genes.^[4] para-Bombay results from a silenced FUT1 gene (h/h) but an active FUT2 (Se/Se or Se/se) gene to synthesize H Type I antigen (and A/B antigens) in the secretions (H-deficient secretors) that may be adsorbed onto RBCs from the plasma or from a mutated FUT1 gene resulting in great diminished enzyme activity to produce low amounts of H Type II antigen (and A/B antigens) on the surface of RBCs, which could only be detected by adsorption and elution technique.^[4] We report a rare case as its incidence is very low, Only a few cases of para-Bombay were reported in India till now. Our case report also reports this rare case from a tertiary care teaching hospital. This entity is characterized by the absence of H, A, and B antigens on the red cells but their presence in saliva and secretions of gastrointestinal and genitourinary tracts. Our case presented with anemia in second trimester no family history of consanguineous marriage with no history of previous blood transfusion she was diagnosed as blood group O in a private laboratory as they have not used anti-H, proper identification of this phenotype is very important otherwise this particular blood group may be mislabeled as group O.

Conclusion

Para-Bombay phenotype was detected as a result of a discrepancy in cell and serum grouping. This case report highlights the importance of blood grouping forward and reverse and also using Anti-H reagent for blood grouping and also the use of secretor status in the detection of proper blood grouping of the patient.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Chandra T, Gupta A. Prevalence of ABO and rhesus blood groups in Northern India. J Blood Disorders Transfus 2012;3:132.
2.	Cerović R, Juretić M, Balen S, Belusić M, Caser L, Rogić M. Examining the presence of ABO (H) antigens of blood types in the saliva of patients with oral cancer. Coll Antropol 2008;32:509-12.
3.	Luo G, Wei L, Wang Z, Luo H, Zhao Y, Zhang R, et al. The summary of FUT1 and FUT2 genotyping analysis in Chinese Para-Bombay individuals including additional nine probands from Guangzhou in China. Transfusion 2013;53:3224-9.
4.	Storry JR, Johannesson JS, Poole J, Strindberg J, Rodrigues MJ, Yahalom V, et al. Identification of six new alleles at the FUT1 and FUT2 loci in ethnically diverse individuals with Bombay and Para-Bombay phenotypes. Transfusion 2006;46:2149-55.