Vox Sang 1988;55:241-243 0 1988 S . Karger AG, Basel 0042-9007/8810554-0241 $ 2 7510

A New Low-Frequency Antigen BOW (Bowyer)

M.A. Chavesa, M.R. Leaka, J . Pooleb, C.M. Gilesb aSouth London Blood Transfusion Centre, London; bBlood Group Reference Laboratory, Oxford, UK

Abstract. BOW is a ‘new’ low-frequency red-cell antigen, detected in 2 unrelated English blood donors, that is sensitive to a-chymotrypsin and pronase. Anti-BOW is present in many polyspecific reagents used to define low-frequency antigens. Red-cell groups of the proposita, R.B., and her family show that the BOW blood group segregates independently from the ABO, Rh, MNSs, PI and Kell blood group systems.

In 1975, the serum from a group A patient, E.G., was matched against donor red cells prior to transfusion. A strong positive reaction with red cells from a single group A donor, R.B. (Bowyer), led to the investigation of her ‘new’ blood group antigen and its world-wide distribution to reference laboratories for exclusion from other known low-frequency antigens. We report our preliminary data on the blood group to be termed, BOW. Another low- frequency antigen, NFLD (700037) [Lewis et al., 1984), appears to be serologically associated with but not iden- tical to BOW [Contreras et al., unpubl. observ.].

Antibody in E.G.’s Serum

The patient, who may have been transfused in her childhood, had to undergo breast surgery and required blood transfusion. Her serum reacted at 37°C by albumin, papain, ficin and antiglobulin techniques with R.B.’s red cells. The antiglobulin reaction was strong with anti-IgG (titre of 32) and negative with anti-C3. The IgG titre was not reduced by addition of plasma from BOW+ or BOW- donors. E.G.’s serum was negative by the IgG antiglobulin technique with many rare red-cell samples. Reiter+ red cells (distributed on SCARF by Ms K. M. Beattie) reacted as strongly as R. B.’s cells, but absorption and elution with Reiter+ cells separated two specificities in E.G.’s serum and showed that R.B.’s cells were Reiter-. Reiter has not been published but is reported to have been involved in haemolytic disease of the newborn [K.M. Beattie, pers.

commun.]. We conclude that E.G.’s serum contains anti- BOW and anti-Reiter. E.G.’s serum did not react with red cells from 466 donors of 0 and A groups after papain treatment.

Antigen on R.B.’s Cells

Initially, the red cells of R.B. were tested against 65 reagents with antibodies for low-frequency antigens: some antisera have single specificities but many are poly- specific. R.B.’s cells reacted with 16 polyspecific reagents but none had a known antibody specificity in common. It has been possible to exclude most other known low- frequency antigens by combining the results of negative reactions of R.B.’s cells with many more antisera with those from E.G.’s serum matched against red cells of rare type. With additional data from reference laboratories, kindly supplied by Dr P. Tippett, Dr A. Lubenko, Prof. M. Lewis and Dr L. Kornstad, it has been shown that R.B.’s BOW antigen is not the same as the following: Cla, Dantu, He, Hil, Hop, Hut, Kam(Far), MI, Mg, M”, Mia, Mit, Mta, Mur, Nob, Nya, Or, Ria, sD, Sj, Sta, Sul, Tm, Vr, Vw, Cw, Cx, DW, EW, V, VS, Rh30(Goa), Rh32(EN), Rh33(Har), Rh35( 1 1 14), Rh36(Bea), Rh37(Evans), Rh40(Tar), Rh42(Ces), Rh43(Crawford), Lug, Lu 14, Kpa, Kpc, Jsa, Ula, Wka, K24, Dia, Sc2, Ytb, Cob, LWb, Ana, Bga, Bgb, Bgc, Bi, Bio-5, Bpa, Bxa, By, Chra, Dha, Fra, Gf, Heibel, Hey, Hga, Hov, Hta, Ina, Jea, JFV, Jna, Kg, Lia, Lsa, Milne, Moa, NFLD, Ola, Osa, Pe, Pollio, Pta, RASM, Rba, Rd,

242 ChaveslLeaklPoolelCiiIcs

Table I. The red-cell groups of the BOW family

BOW familynumbers ABO Rh MN Ss PI Lua Kk Lea Leb Fya Fyb J k a J k b E.G.

Father F. J. A2 CcDee - + + + + + - - + - + + - + + -

Mother L. 1. A , CcDEe + + - + + - + + - + + + - + Brother Pe. J. Al CcDEe - + - + + + - - + - + + + + - t Proposita R. B. A1 CcDee - + + + - - - + + - + Brother Pa. J. A1 CcDee - + - + + + - + + - + + + + - -

Brother A. J. 0 CCDee++ - + - + - + + + + + -

-

+ + - +

- -

Rea, Rla, Swa, Sw(c1ass I), Tcb, TcC, Toa, Tra, Vg, Wb, Wda, WESa, Wra, Wu, and Zd. Some of these antigens are now considered to be obsolete; Bio-5, Hta, Zd [Lubenko, pers. commun.] and MI, Sj, Sul and Tm of the MNS blood group system and Pe and Sk are listed but not numbered by the ISBT Working Party on the Terminology of Red Cell Surface Antigens (ISBT WP). The ISBT WP [ 19881 lists 3 low-frequency antigens that have not been excluded: Rh28(hrH), Rh45(Riv), K23(CENT). Me is not present on NHe(-) samples and Rh22(CE) requires both C and E for expression, so the NHe(-) CcDee cells of R.B. (table I) may be deduced to lack both. Seventeen unpub- lished antigens have also been excluded: S. Allen, Ask- with, Braithwaite, Dickinson, Donaldson, L. Evans, Fleck, Good, Heron, Jones, Maluenda, Mans, Palframan, Reiter, Sadler, Tofts, Tollefsen-Oyen.

R.B.’s cells did not react with lectin preparation of Arachis hypogaea, Dolichos biflorus after removal of anti- Al by absorption, Glycine soja, Salvia horminum, Salvia sclarea and Sophora japonica.

The BOW antigen on R.B.’s cells is insensitive to treatment by papain, ficin, trypsin, 6% AET, l O O m M DTT and chloroquine diphosphate, and therefore is prob- ably not part of the MN, Lutheran, Kell, Duffy, LW, In and HLA blood group systems. However, a-chymotrypsin and pronase removed activity of R.B.’s cells with E.G.’s serum. Spring et al. [1987] have shown that the 70,000- dalton erythrocyte component that expresses Cromer- related antigens is sensitive to a-chymotrypsin and pron- ase. There was no correlation between BOW and the low-frequency antigens of this blood group system: Tcb, TcC and WESa.

A second BOW+ donor was detected by a positive reaction with an anti-Wra typing reagent which was later shown to contain anti-BOW as well. This donor only had 2 BOW- sisters.

One of the polyspecific antisera with anti-BOW, Sit- ton, was screened against papain-treated red cells from

more than 50,000 donors without finding another BOW+, so that no estimate for the frequency has been possible.

Inheritance of BOW

The parents and brothers of R.B. were fully grouped for red-cell and Gm antigens. The red-cell phenotypes are given in the table I. The donor’s mother and brother Pe.J. reacted with E.G.’s serum, which indicates that BOW is inherited as a dominant mendelian character. The family red-cell groups show BOW segregating independently of the ABO, Rh, MNSs, P1 and Kell blood group systems. There was no information for Lutheran, Lewis, Duffy and Kidd blood group systems.

The Duffy blood groups in this family are atypical. The Fy phenotypes of the parents should result in Fy(a+b+) children only, but R.B. is Fy(a-b+). Her Fy(a-) status was carefully checked by testing her cells against many anti- Fya reagents and by showing that they fail to absorb or elute anti-Fya. So it has to be deduced that Fy, the silent allele, is present in both proposita and her father to account for her Fy(a-b+) phenotype. The Gm types (not shown) support the family relationships.

In conclusion, we report Bowyer as a new rare blood group that reacts with many polyspecific antisera used to define low-frequency antigens. The blood group will be added to the list of low-incidence antigens so far unas- signed to a blood group system [Lewis et al., 19851. Dr M. Contreras, of the ISBT WP, has allocated the Bowyer blood group No. 700046 and the symbol BOW. The rela- tionship of BOW to NFLD is presently under investiga- tion.

Acknowledgements

We wish to thank Mrs R.B. and her family for giving blood samples in this study, and Mr D. Harber, Blood Bank, Kings College

A New Low-Frequency Antigen BOW (Bower) 243

Hospital, for obtaining serum from patient E.G. We also acknowl- edge the help from Dr P. Tippett (MRC Blood Group Unit, London), Dr A Lubenko (North London Blood Transfusion Centre), Prof. M. Lewis (Rh Laboratory, Winnipeg) and Dr L. Kornstad (National Blood Group Reference Laboratory, Oslo) in excluding antigens on BOW cells, and thank Ms K. Beattie (Michigan Community Blood Center) for Reiter cells.

Spring, F.A.; Judson, P.A.; Daniels, G. L.; Parsons, S.F.; Mallinson, G.; Anstee, D. J.: A human cell surface glycoprotein that carries Cromer-related blood group antigens on erythrocytes and is also expressed on leucocytes and platelets. Immunology 62: 307-3 13 (1 987).

References Received: March 22, 1988 Revised manuscript received: May I 1, 1988 Accepted: May 11, 1988

Mrs M.R. Leak South London Blood Transfusion Centre 75 Cranmer Terrace GB-London SWl7 ORB (UK)

Lewis, M.; Allen, F.H., Jr.; Anstee, D. J.; et al.: ISBT Working Party on Terminology for Red Cell Surface Antigens: Munich Report. Vox Sang. 49: 171-175 (1985).

Lewis, M.; Kaita, H.; Allderdice, P.W.; Bergren, M.; McAlpine, P. J.: A ‘new’ low incidence red cell antigen, NFLD. Hum. Genet. 67: 270-27 1 (1 984).