Oration - Dr Sanmukh Joshi

Original Article:

Title : Discovery of blood groups in India –an update

Author : Sanmukh R. Joshi

Institute : Lok Samarpan Regional Blood Bank and Research Centre, Surat

Correspondence : Dr. Sanmukh R. Joshi, Lok Samarpan Blood Bank and Research Centre, Minibazar, Varachha Road, Surat-395006, Gujarat State, India. Phone (Cell): +91 7715915574. E-mail: sanmukhj@yahoo.com

Running title : Discovery of blood groups

Keywords : Discovery, blood groups, India

Abstract:

Human blood groups comprise over 375 antigens that are classified into 43 blood group systems. These blood groups were discovered over a period of past 120 years. Discovery of different antigens were made in different parts of the World, mainly from the Western countries. India has also contributed its share through original findings as outlined in this article.

Main Article:

Human blood groups comprise over more than 375 antigens, as of 9^th December 2020, which are classified into 43 blood group systems as per genetic association.¹ These were discovered in a span of 120 years, mainly by scientists from the Western World.² India has also made respectable contributions with a few original discoveries.³ Steve Pierce and Marion Reid from the USA have recently compiled data in a form of a book entitled “Bloody Brilliant! A history of Blood groups and Blood groupers”, AABB Press (2016).² The blood groups discovered in India are outlined below:

“Bombay” phenotype

It was discovered in the year 1951 by H.M. Bhatia at the KEM Hospital, Bombay while the search for a compatible blood unit for a patient met with a railway accident.⁴ While the patient was grouped as O, none of the 115 units were found to be compatible due to a presence of an antibody to the high-frequency antigen (HFA) in his serum. In a span of one month, he got another patient with similar features and was compatible with the first case. A deliberate search among the donors yielded one more case with identical character. The blood specimen from these three individuals were referred to the Blood Group Reference Unit in the UK where it was defined as a “new” blood group that was named later as “Bombay group” or Oh phenotype denoting an absence of HFA antigen H on RBCs with naturally occurring regular alloanti-H in plasma.⁴ Discovery was instrumental in understanding the Biosynthetic pathway of the ABH antigens. Later, a systematic survey among the 42,297 persons in Bombay, now known as Mumbai, got 3 individuals with this phenotype showing its incidence as 1:13000 in the city. Further screening on a larger sample size of 1,67,404, the incidence was worked out to be 1:7,600, half of which came from the South-West Maharashtra and Goa.⁵ A systematic survey was carried out among 400 villages in these regions with further improved its occurrence as 1:4000.⁶ Meanwhile, 179 cases were referred from different parts of India, mainly from the Western & Southern regions and 179 of those were identified as the Oh phenotype.⁷ The State-wise distribution showed 122 cases from Maharashtra, 15 cases from Karnataka, 8 cases from Andhra Pradesh (integrated with the present-day Telangana), 6 cases from Goa and 5 from Gujarat. Sporadic cases were also found among the other Indian states as well.⁸,⁹,¹⁰.

I-i- phenotype

The Ii blood group, developmental antigen system, i.e., I antigen, weakly expressed on the RBCs at birth, gradually turns stronger in the first 18 months of life and remains stable through the rest of the life. Conversely, i antigen is strongly expressed at birth and gradually weakens through the period. As such, most adults are typed as I+i- while the Infants are typed as I-i+. The rare adults with I-i+ phenotype, similar to newborns, are under the genetic influence and the heterozygous display an intermediate pattern referred to as I-int. The adults with I-i- phenotype, with suppression of I akin to the newborn, with no compensatory rise of i, as is found in adult-I phenotype, were found among the healthy blood donors with a frequency of 1:900.¹¹ The trait was found to be familial in nature, though it does not follow Mendelian inheritance, presumably due to complexity in interaction at the bio-synthetic level with ABH antigens. One large-kindred family of 95 members distributed in 4 generations, there were 15 subjects were I-i- and 6 others were with partial I expression.¹² The phenotype in this family and 4 other families have carried A₁ or A₁B blood groups and the strength of A₁ antigen was expressed higher than the control groups with the normal complement of the i antigen on their RBCs.

Indian Blood groups

In^a antigen was detected by a contaminant antibody present in the immune anti-D serum referred by a diagnostic firm in Surat.¹³ The additional antibody was isolated by differential absorption-elution experiments using a panel of red cells. It agglutinated by saline tube method but better reactivity was observed by indirect antiglobulin test (IAT). The antibody did not react with RBCs pretreated by papain enzyme. It reacted with RBCs of about 2-3% of the random donors in Mumbai. The isolated antibody from the original serum was sent to the Blood Group Reference Laboratory (BGRL), London where it was confirmed to be directed to a “new” antigen; we named it In^a. The significance of this discovery was appreciated as 30 different anti-D sera produced for reagent preparation were found to have anti-In^a as contaminant antibody with the implication that, some 2-3% D-negative individuals might have erroneously typed and received the D-positive blood transfusion! The reason for the stimulation of anti-In^a in these anti-D sera was that several Rh.D neg (subtype dce/dce) donors were immunized using RBCs of one person (subtype Dce) who incidentally possessed In^a antigen on his RBCs. The discovery paved the way to identify its antithetical antibody, name Salis, to an HFA detected some 6 years earlier. The Salis was renamed as anti-In^b.¹⁴ With this, a new blood group system was born, named INDIAN, and later on assigned the alpha-numeric symbol IN 023 by the International Society of Blood Transfusion. The system was further expanded when other HFAs, INFI (In3) and INJA (In4), INRA (In5), INSL (IN6) were found in people of Moroccan, Pakistani, Indian and Sri Lankan origin respectively.¹⁵,¹⁶,¹⁷

INRA (In5), another HFA, the antibody to which was found in a course of compatibility tests for a female who was posted for surgical treatment.¹⁶ The antigen, sensitive to enzyme papain and chemical AET, was suspected for its specificity within the Indian system. The In^b, an HFA of the INDIAN blood group system was ruled out, as her RBCs were agglutinated by 2 examples of anti-In^b sera. The other HFAs of the system, viz. In3 and In4 were ruled out as our patient's RBCs were typed positive for both these antigens. Her RBCs were also typed positive for other known HFAs outside of the INDIAN blood group system like Kn^a, McC^a, Yt^a, U, Vel, En^a, Kp^b, Js^b, Wr^b, Ge, CD99 excluding these specificities. Besides, the possibility of our patient to be with other rare phenotypes like Gerbich_null, Rh_null, D- -, MkMk, Fy(a-b-), Gy(a-), and K_o, was also ruled out. It was then established that the specificity of antibody in our case was directed to a hitherto unknown antigen. A striking observation on the antibody showing significant weak reactivity with RBCs from Lu(a-b-; InLu type) indicated its specificity within the CD44 (IN) antigens as they are known for suppression on RBCs from the Lu a-b-(InLu) phenotype. Molecular typing showed the exons of the hemopoietic isoform of CD44 (IN) gene with a novel homozygous missense mutation c.449G>A in exon 5 of CD44 encoding p.Arg150His amino acid substitution at the protein level. A novel HFA was named INRA by taking the first 2 letters of the IN system and the last 2 letters of the patient's first name. The ISBT had recognized INRA as a new antigen of Indian blood groups and assigned the alpha-numerical term In5. INRA-negative mutant is very rare as it was not found among 5000 donors tested serologically or by high throughput molecular approach.¹⁸

Other Rare features were reported first time in India include: phenotypes like, Mg,¹⁹ D- -,²⁰ Rh_null,²¹ I-int,²² In(b-),²³ Colton_null,²⁴ r^y,²⁵ Emm_null,²⁶ P_null,²⁷,²⁸ and S-s-U-.²⁹ Of these, the discovery of Emm_null²⁶ in Indian subject proved instrumental in getting the Emm recognized as a new blood group system with symbol ISBT 042. Besides, the powerful lectins like and anti-A₁³⁰ and anti-H³¹ were discovered in seeds of the Indian plants, Dolichos biflorous and Momardica dioica, respectively. Also, the first-ever reported cases of interest include, anti-Le^b causing HDNB,³² transfusion induced anti-In^a,³³ anti-In^b causing HTR,³⁴ citrate-dependent high-titer anti-H in a healthy blood donor,³⁵ Streptomycin dependent panagglutinating antibody in a patient,³⁶ bicarbonate anion dependent ant-”N” as a monoclonal antibody,³⁷ and the spontaneous cold agglutination (SpCA) phenomenon observed among healthy donors,³⁸ RHCE alleles in cis to weak D type 31³⁹ and a novel phenomenon causing blood group anomaly that mimicked B_el, a rare B antigen variant phenotype of the ABO blood group system.⁴⁰

The summarized account on these discoveries on Indian soil is displayed in Table 1.

Table 1.

Chronological account of blood groups and their discoveries on Indian soil

No.	year	Name of Discovery	Mode of Discovery	Stake holders
1	1952	Bombay group	Compatibility tests	Bhende et al. 4
2	1952	Anti-A1 (lectin)	Screening the plant seeds	Bird et al. 30
3	1971	ry	Population survey	Undevia/ Sanghvi25
4	1972	Mg (MNS system)	Grouping anomaly	Joshi et al. 19
5	1973	Ina (New IN system)	QC of antiserum	Badakere et al. 13
6	1973	D - -	HDFN investigation	Badakere/ Bhatia 20
7	1979	I- i-	Deliberate screening	Joshi / Bhatia 11
8	1981	First HDFN to anti-Leb	HDFN investigation	Bharucha et al. 32
9	1992	aHTR to anti-Inb	HTR investigation	Joshi 23
10	1993	Transfusion-induced anti-Ina	Follow-up investigation	Joshi et al. 33
11	1997	Citrate dependent anti-H	Grouping anomaly	Joshi 35
12	2001	Streptomycin-dependent panagglutination	Grouping anomaly	Joshi 36
13	2001	Co(a-b-), AQP1 null	HDFN investigation	Joshi et al. 24
14	2004	Bicarbonate dependent anti-‘N’	Monoclonal anti-‘N’	Iyer et al. 37
15	2005	New anti-H lectin	Screening the plant seeds	Joshi et al. 31
16	2014	I-int	Deliberate screening	Joshi.22
17	2015	New Spontaneous Cold Hemagglutination phenomenon	Observational study	Joshi et al.38
18	2017	INRA (In5, IN system )	Compatibility tests	Joshi et al. 16
19	2017	Rhnull	Compatibility test	Kulkarni et al.21
20	2018	RHCE alleles in cis to weak D type 31 alleles	Weak D investigation	Srivastava et al.39
21	2020	Emm null phenotype, defined new gene PIGG	Compatibility tests	Lane et al.26
22	2020	P null phenotype	Compatibility tests	Shastry et al. 27
23	2021	Pnull phenotype New molecular variant	Compatibility tests	Kanani et al. 28
24	2021	Novel phenomena mimicking the Bel	Grouping anomaly	Joshi et al. 40
25	2021`	S-s-U-, First case in India	HDFN investigation	Dara et al. 29

Conclusion

There are a total of 43 blood group systems recognized as of now. India can boast of contributing 2 blood group systems viz. Indian (ISBT023) and Emm (ISBT042). Besides, there are a number of rare phenotypes of clinical significance found in the Indian population. Supply of blood to the recipient with rare phenotypes like D- -, Rh_null, In(b-), INRA-, Colton_null, P_null, Emm_null, S-s-U- have been proved challenging to provide an appropriate blood unit for transfusion. The rare donor registry is a need of the hour to meet future requirements should their need arises. We have a couple of centers taking initiative in this direction yet enough has to be done to meet eventualities in our Country.