Flow Cytometric Analysis of Erythrocytic D Antigen Density Profile

Red blood cells (RBC) were studied with flow cytometry (FCM) after staining with a directly fluoresceinated anti-D antiserum. The immunofluorescence distribution profiles were slightly asymmetrical, due to a significant, yet small skewness. This skewness was not associated specifically with D antigen positivity, making a homogeneous, normal D antigen distribution on the RBC very likely. With the exception of Du, D-positive RBC could always be distinguished from D-negative ones. FCM was successful in bringing the following phenomena to light: difference in mean fluorescence intensity between the different rhesus phenotypes, the D gene dosage effect, the depressing effect of C antigen on D antigenicity, the nonspecific attachment of IgG on (D-negative) RBC and rhesus mosaicism. The absolute number of D antigen sites could be calculated, using an absolute fluorescence standard.     

Blood Group A Antigen in Human Erythrocytic Membranes and Membrane Fractions1

Abstract. Erythrocytic membranes from blood group A individuals were assayed for A antigen using a quantitative hemagglutination inhibition technique. The membranes were then extracted for lipid and glycoprotein. Although some A antigen was usually found in the glycoprotein fraction, most of the activity was in the lipid fraction. The sum of A antigen activity in the lipid, glycoprotein, and membrane residue fractions only occasionally was equal to the A activity in the erythrocytic ghosts. However, when certain lipid preparations with little or no A antigen (enhancement factors) were added to the glycolipid fractions, the amount of A antigen demonstrated was usually greatly increased. Under these conditions, the sum of the fractions often was much greater than the A antigen demonstrated in erythrocytic membranes. This suggests that the organization or arrangement of A antigenic determinants in the red cell membrane may not always permit a stoichiometric reaction with anti-A molecules.     

A New Blood Group Antigen, Hov

Abstract. A new blood group antigen, Hov, is described. The antigen is not closely linked to the MNSs, P, Rhesus secretor, Duffy and Kidd loci, and it is not X-linked. 1,155 blood samples were tested; two of these had the new antigen.     

TSEN: A Novel MNS-Related Blood Group Antigen

We report an antibody (anti-TSEN) that recognizes an antigen (TSEN) at the unique amino acid sequence that results from the junction of GPA58 to GPB27 if the GPB carries the S antigen. Red cells from several unrelated donors that possess this specific GP(A-B) hybrid molecule were agglutinated by anti-TSEN. Since a synthetic peptide with the amino acid sequence at this junction (Pro-Glu-Glu-Glu-Thr-Gly-Glu-Met-Gly-Gln-Leu-Val-His-Arg) specifically inhibited anti-TSEN, it must detect an antigen within this novel amino acid sequence. The TSEN antigen has been provisionally assigned the MNS blood group system number 002.033 on behalf of the ISBT Working Party on Terminology for Red Cell Surface Antigens.     

MINY: A Novel MNS-Related Blood Group Antigen

We report an antibody (anti-MINY) that recognises a novel low-incidence MNS-related blood group antigen. Anti-MINY agglutinates all Hil-positive red cells tested (Mi.III, Mi.V, Mi.VI, GP.Kipp, GP.Mor and AG) and Hil-negative TSEN-positive red cells (Mi.IV, JR, JL, Oca. and Rag.). All MINY-positive red cells possess glycophorin A-B hybrid molecules. The MINY antigen occurs at the unique amino acid sequence which results from the junction of glycophorin A58 to glycophorin B27 regardless of whether the glycophorin B gene encodes methionine or threonine at amino acid residue 29 of normal glycophorin B. The MINY antigen has been provisionally assigned the MNS blood group system number 002.034 on behalf of the ISBT Working Party on Terminology for Red Cell Surface Antigens.     

A ''New'' Blood Group Antigen Associated with S and s

Abstract. The serum of a Papuan blood donor contains an antibody to a previously unreported red cell antigen, provisionally called Z, and closely associated with S or s. In both European and Melanesian populations Z is more common than S, because S-positive bloods rarely lack Z, while S-negative bloods not uncommonly possess it. Z is inherited as a dominant character.     

The Rare Blood Group Antigen, Wu

Abstract. The inheritance of the Wu antigen in three families is described. The observations suggest that the antigen is inherited as a Mendelian dominant character. Wu segregates independently of sex and of the ABO, MNSs, Rh, Lutheran, Duffy and Kidd blood group systems. Independence of Kell is also quite likely. Wu is a very rare antigen. The corresponding antibody is not as infrequent. Anti-Wu occurs as a 'naturally occurring' antibody, often together with antibodies against other rare antigens.     

A Novel Variant of the Human Blood Group K1 Antigen

A discrepancy in duplicate anti-K1 typing in a parentage case led to the discovery of an unusual K1 blood group antigen. Red blood cells from the propositus (JC) express a rare variant of the K1 antigen that is detectable by only 8 of 72 sera containing anti-K1. Absorption and elution studies using reactive anti-K1 confirmed the presence of a K1 antigen. Nonreactive anti-K1 was not absorbed by or eluted from JC's red blood cells. Red cells from 3 of the propositus's siblings also had the variant K1 antigen. The variant antigen exhibited qualitative as well as quantitative differences as compared to normal K1, and we have named it K1var.     

RASM, a 'New' Low-Frequency Blood Group Antigen

Abstract. A 'new' low-frequency red cell antigen, RASM, was found in 3 generations of a Caucasian family. It is inherited as a Mendelian dominant character. The propositus, a newborn, had a positive direct antiglobulin test; overt haemolytic disease of the newborn was not present.     

Two Sisters Lacking the Blood Group Antigen Vel

A family is reported in which two sisters are of the rare blood group phenotype Vel negative. This provides the first published evidence that the Vel antigen of Sussman and Miller is, as anticipated, under genetic control. The two sisters further demonstrate that the Vel antigens does not belong to the ABO, secretor or Kidd systems of blood groups.

Résumé

Les auteurs rapportent sur le cas d'une familie dans laquelle deux sœurs sont de phénotype rare Vel négatif. Ceci confirme les anticipations de Sussman et Miller qui pensaient que l'antigène Vel était conditionné génétiquement. Ce cas des deux sœurs démontre en outre que l'antigène Vel n'appartient pas au système de groupe sanguin ABO, secréteur ou Kidd.

Zusammenfassung

Es wird über eine Familie mit zwei Vel-negativen Schwestern berichtet. Diese Familie zeigt, daß es sich beim Vel-Antigen von Sussman und Miller wie erwartet um ein genetisch determiniertes Blutgruppenmerkmal handelt. An Hand der Untersuchung dieser zwei Schwestern konnte gezeigt werden, daß die Vel-Antigene einen vom ABO-, Sekretoren- oder Kidd-Blutgruppensystem unabhängigen Erbgang aufweisen.     

A Murine Monoclonal Antibody Directed against the Gerbich 3 Blood Group Antigen

A murine monoclonal antibody (NaM19-3C4, IgG1, Kappa) was produced from splenocytes of mice immunized with red blood cells. The antibody agglutinated untreated Ge:2,3,4 and Ge:-2,3,4 erythrocytes in indirect antiglobulin test but failed to agglutinate trypsin-treated cells. Gerbich-negative erythrocyte of the Leach- (Ge:-2,-3,-4) and of the Gerbich- (Ge:-2,-3,4) types were not recognized by the antibody. Immunoblotting experiments showed that the antibody bound to glycophorins C and D from control erythrocytes and to the abnormal glycophorin C identified in the Gerbich-negative cells of the Yussef type (Ge:-2,3,4). No binding to the altered glycophorin C from Ge:-2,-3,4 erythrocytes was observed, indicating that the antibody specifically recognized the Ge:3 epitope localized within residues 40-50 of glycophorin C.     

A New Rare Blood Group Antigen, Jea

Abstract. A new rare blood group antigen, Je^a, is described. The antigen is inherited as a dominant character independently of ABO, Rh, MNSs, Lutheran and secretor systems. No further example of the antigen was detected in over 1,000 cell samples, nor was another example of the antibody found in more than 100,000 sera from the Danish population.     

The Sda Blood Group Antigen

Abstract. Material with high Sd^a blood group activity can be prepared from urine by precipitation with ethanol. Partial separation of substances with Sd^a and A activity can be effected by gel-filtration, ultracentrifugation or precipitation with anti-A serum. Substances with Sd^a activity are inactivated by acid, alkali and periodate and are partly soluble in phenol.     

WES, a 'New' Infrequent Blood Group Antigen in Finns

Abstract. A previously unrecognized infrequent blood group antigen WES occurs with a frequency of 0.56% in the Finnish population, but has an ethnically restricted distribution. Apart from Finns it was found only in 2 donors, most likely of African origin, among 4,655 people tested who represented many different ethnic groups. WES is shown to be a dominant autosomally inherited character different from previously published infrequent antigens. The data allow exclusion from almost all established blood group systems. The WES antigen is destroyed by enzymes α-chymotrypsin and pronase. It is also present in plasma of WES+ individuals. Evidence suggests that the soluble form of the antigen is a high molecular weight protein constituent of plasma. Unlike many other antigens present on red cells as well as in plasma, the WES antigen is well developed on red cells of neonates and can also be found in cord serum.     

Cryopreservation Modifies Flow-Cytometric Analysis of Hemopoietic Cells

Although cryopreservation of human bone marrow has become very common in modern medicine, the knowledge on the effects of this procedure on hemopoietic cells is still limited. We herein have investigated whether the process of concentrating of human bone marrow to its buffy coat, the exposure to the cryoprotectant dimethyl sulfoide (DMSO), and/or the rate of controlled freezing/thawing procedures modifies the flow cytometric analysis of human bone marrow cells. We found that both the exposure of marrow cells to DMSO and/or the freezing procedure significantly modifies both the relative proportions of hemopoietic cell subsets and the intensity of expression of certain surface antigens. Thus, percentages of cells expressing CD7, CD13, CD33 and CD34, were found to be lower in both cryopreserved buffy coat and buffy coat merely exposed to DMSO, in comparison to those in untreated coat samples. Moreover, the intensity of the surface expression of CD33 decreased in cells exposed to DMSO, and further in cryopreserved samples. By contrast, the intensity of the CD19 antigen was higher in the last groups of samples than in the buffy coat or the unfractionated human bone marrow. Our present results suggest that flow-cytometric analysis of cryopreserved human bone marrow cells is not fully equivalent to that corresponding to fresh bone marrow or its fractionated buffy coat.     

Blood Group Antigen Survival on Freeze-Dried Erythrocytes and Ghosts after Isolation

To screen and identify irregular antibodies, whatever the technique used, fresh erythrocytes (RBCs) are needed to set up the panel. Solid-phase tests using dried blood cells are available, but the technique is based on the adherence of sensitized RBCs, which have a short life span. We have checked antigen survival on membranes with a saline test and an antiglobulin test for two methods to preserve the antigen substrate: freeze-drying of RBCs and preparation of RBC membranes. The different antigens of the ABO, Rhesus, Kell, P, Lewis, MNSs, Lutheran, Duffy, Kidd and Li systems are well recognized on the membranes after isolation and on freeze-dried cells. Demonstration of antigen survival leads us to consider using membranes or freeze-dried cells in new immunological tests.