Brief Rep0rt s

An Autoantibody with Anti-WrbSpecificity in a Patient with Warm Autoimmune Hemolytic Anemia D. GOLDFINGER, H. ZWICKER, G. A. BELKIN, AND P. D. ISSITT From the Cedars-Sinai Medical Center. Los Angeles. Cali/ornia. and the Paul I . Hoxworrh Blood Center of rhe University of Cincinnari, Cincinnati. Ohio

A patient with warm autoimmune hemolytic anemia ( A I H A ) has been found to possess an autoantibody with W r b specificity. While this is the first known description of W r b specificity in this disease, additional studies on the W r b status of En(a-) cells indicate that autoantibodies previously thought to be anti-Ena are in reality also antiWrb. Autoantibodies with W r b specificity may thus be a rather common finding in patients with A I H A who have been thought to have “panagglutinins” on their red blood cells. Since anti-Wr’ alloantibodies are found frequently in patients with A I H A , it seems possible that the Wright system holds some clue to the pathogenesis of this disease.

MANY CASES of warm autoimmune hemolytic anemia (AIHA) involve auto-antibodies with specificity for antigens in the Rhesus blood group system.8 However, in a significant number of cases the autoantibody appears to be a “panagglutinin,” reacting with all red blood cells tested. These antibodies must have specificities for certain antigenic structures on the red blood cell membrane, but their identities cannot be defined because no cells are available which lack the involved antigen. However, knowledge of the antigenic specificity could be important on two accounts-first, it may aid in finding compatible blood for transfusion to the patient, and, second, involvement of certain specificities may serve as a clue to the etiology and pathogenesis of this disease. In evaluating an autoantibody from a patient with AIHA, we noted that the antiReceived for publication March 17, 1975; accepted April 14, 1975.

body agglutinated all red blood cells tested, but gave weaker reactions with heterozygous Wr(a+b+) cells than with common Wr(ab+) cells. This suggested that the antibody might have specificity for the high-incidence Wrb antigen. This suspicion was confirmed by the series of studies described below. Case Report The patient was a 56-yea?-old Caucasian woman who was found to have AIHA in 1971. At that time she had a hemoglobin of 6.1 g/lOO ml, and a reticulocyte count of 15 per cent. Her hemolytic process was fairly well controlled on 5 mg of prednisone daily maintenance. In October, 1974, she was found to have a hemoglobin of I I .5 g/lOO ml, reticulocytes of 6 per cent, and a strongly positive direct antiglobulin test. Reactions were strong with broad spectrum and antiIgC antiglobulin reagents, and were weak with anti-complement reagents. The patient’s serum was found to contain an irregular red blood cell an tibody. ldentification of the antibody was done by the high protein technique using two drops of patient serum, one drop of a 4 per cent suspension of reagent red blood cells, and two drops of 30 per cent bovine albumin. Reaction mixtures were incubated at 37 C for 30 minutes, centrifuged, and examined for agglutination. They were then tested by the indirect antiglobulin test. Reactions were also done with enzyme-treated red blood cells by the two-stage papain technique. All reactions were read macroscopically and microscopically. Eluates of the patient’s red blood cells were prepared by the cold alcohol technique. Titers were determined by using serial twofold dilutions of the .patient’s serum and eluate.

35 1 Transfusion

July-Aug. 1975

Volume I5 Number4

352

Transfusion July-Aug. 1975

GOLDFINGER, ET AL

Table 1. Titers of Reactivity of Serum and Eluate

Results and Discussion

by Indirect Antiglobulin Technique

Both the serum and eluate showed strong Wr(a-b+) Wr(a+b+) Wr(a+b-) reactions against all common red blood cells tested. Strong agglutination also occurred Serum 32 4 0 using rare red blood cells lacking the Eluate 8 8 0 following high-incidence antigens: Rh ““11, D-, KO, Jk(a-b-), U-negative, Veland sera containing presumed “panagglunegative, Co(a-), Yt(a-), Bombay, and tinins” should be tested with Wr(b-) cells to Lu(b-). Table 1 shows the titers of the reacrule out this possibility. Finally, the demontions against common Wr(a-b+) cells, stration of Wrb autoantibodies, when heterozygous Wr(a+ b+) cells, and the only examined in the light of the high incidence of known Wr(a+b-) cells. These reactions ocin cases of AIHA, sugWr’ alloantibodies curred at the indirect antiglobulin phase. gests that the Wright system may hold some The reactivity of both serum and eluate indiclue to the pathogenesis of this disease. cate that the autoantibody has anti-Wrb specificity. We noted that the antibody reacted weakly with En(a-) red blood cells. The En(a-) cells were tested with anti-Wrb References antiserum and were found to type as I . Adams, J., M. Broviac, W. Brooks, N. R. Johnson, Wr(b-). These findings suggest that antiand P. D. Issitt: An antibody, in the serum of a Wr(a+) individual, reacting with an antigen of En’ specificity reported in cases of AIHAg very high frequency. Transfusion 11:290, 1970. might have been due to anti-Wrb. This 2. Cleghorn, T. E.: The frequency of the Wr’, By and finding is the subject of another report.s M g blood group antigens in blood donors in the south of England. Vox Sang. 5556, 1960. The Wright system of red blood cell anticited in Issitt, P. D., Applied Blood Group 3. -: gens appears to be inherited at a single Serology, Oxnard, Spectra Biologicals, 1970, p. genetic locus at which there are two known 94. alleles, Wr’ and W r b . The Wr’ allele is a 4. Dunsford, I.:The Wright blood group system. Vox low-frequency gene present in less than 0.1 Sang. 4:160, 1954. per cent of most populations s t ~ d i e d . ~ . ~ , ’5. Holman, C . A,: A new rare human blood group antigen. Lancet 2:119, 1953. However, Wrb is a high-incidence gene, and Issitt, P. D., B. G. Pavone, and D. Goldfinger: An 6. only a single individual has been found who is En(a-) red cell sample that types a s Wr(a-b-). Wr(b-).* This subject has in her serum the Transfusion 15:353, 1975. only known anti-Wrb alloantibody. Anti7. Metaxas, M. N . and M. Metaxes-Buhler: Studies on the Wright blood group system. Vox Sang. Wr’ antibodies, on the other hand, are 8:707, 1963. rather common, occurring in approximately 8. Weiner, W. and G. H. Vos: Serology of acquired 1.0 per cent of normal individuals, and are hemolytic anemias. Blood 22:606, 1960. presumably “naturally occurring” anti9. Worlledge, S.: In Proceedings of the American Association of Blood Banks and International bodies.’*5 It has been noted that the inciSociety of Blood Transfusion, Joint Meeting, dence of anti-Wr’ antibodies in patients with Washington, D.C., 1972, p. 43. AIHA is much higher than in normal indiv i d u a l ~ The . ~ reason for the association of Dennis Goldfinger, M.D., Director, Blood Bank, anti-Wr’ alloantibodies with AIHA has Cedars-Sinai Medical Center, 4833 Fountain Avenue, Los Angeles, Calif. 90029. never been explained. Helen Zwicker, M.T., Immunohematologist. This report documents the first case of Gerald A. Belkin, M.D., Attending Hematologist. anti-Wrb autoantibodies in a patient with Peter D. Issitt, F.I.M.L.T., L.I. Biol., Director of AIHA. The finding that En(a-) cells also Laboratories, Paul I. Hoxworth Blood Center, type as Wr(b-) suggests that anti-Wrb may University of Cincinnati Medical Center, 323 I Burnet Avenue, Cincinnati, 0.45229. not be an uncommon specificity in AIHA, ~~

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An autoantibody with anti-Wrb specificity in a patient with warm autoimmune hemolytic anemia.

A patient with warm autoimmune hemolytic anemia (AIHA) has been found to possess an autoantibody with Wrb specificity. While this is the first known d...
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