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One serum from a blood donor, which had both HIV-antibodies and rheumatoid factor, gave positive results with EIA anti-HIV screening tests and Western blot, but negative results with the Abbott's ENVACOR assay. Moreover, this serum and 5 out of 6 sera containing only rheumatoid factors were able to interfere with ENV and CORE reactions. Rheumatoid factors bind to the beads used in ENVACOR test and are also able to react with the conjugate. Most of the rheumatoid factors bind to the ENV conjugate, though with a wide range of activity. Obvious binding of rheumatoid factors to the CORE conjugate could not be demonstrated. Binding of rheumatoid factors both to the bead and to the conjugate leads to high optical density values and therefore results in the negative range according to the normal interpretation of the ENVACOR competition procedure.

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A 2 years-old Korean girl is seen because of ambiguous external genitalia. Surgical exploration shows the right gonad to be an ovary and the left one to be an ovotestis, thus demonstrating a true hermaphroditism. Cytogenetic studies of peripheral lymphocytes reveal a mixture of 46,XX and 46,XY cells, with a predominant XX cell line. The patient's red cells are composed of two distinct populations differing in three genetically independent blood group systems. The ratios of the two cell lines in various tissues, especially among the cells secreting Lewis antigens, appear to be very different and suggest several hypothesis to explain the highly unusual red cell Lewis phenotype Le (a+ b+). We conclude to a dispermic chimera, however the adopted status of this child prevents any identification of the maternal or paternal contributions. Because of the physical aspect it was decided to remove the ovotestis, to repair the external genitalia and to bring up this child as a female.

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A murine monoclonal antibody (MoAb) designated FA6-152 has been obtained by immunizing mice with fetal erythrocytes. This antibody agglutinates fetal but not adult erythrocytes. Among blood cells, this antibody bound to both adult and fetal monocytes, platelets, and reticulocytes, but did not react with lymphocytes and granulocytes. Fluorescent labeling of marrow cells and of in vitro BFU-E, CFU-GM, and CFU-MK-derived colonies has shown that the antigen defined by FA6-152 MoAb was absent from the granulocytic precursors and was detected on the megakaryocytic lineage at a later stage of differentiation than the platelet-specific markers. In contrast, the antigen appeared as a very early marker of the erythroid differentiation since all erythroblasts, including proerythroblasts, were labeled even before the expression of glycophorin A. Cells from adult marrow and fetal liver were sorted with the FA6-152 MoAb and studied by electron microscopy and cell culture. The negative fraction contained granulocytic, monocytic, and megakaryocytic precursors, whereas the positive fraction was devoid of these precursors and contained monocytes, erythroblasts at all stages of maturation, and a homogeneous population of blasts. Cultures have shown that the only hematopoietic progenitors present in this positive fraction were CFU-E and some BFU-E. The antigenic density was related to the differentiation stage of the erythroid progenitors. In conclusion, this antibody is similar to the previously described 5F1 MoAb (Bernstein and Andrews, J Immunol 128:876, 1982; and Andrews et al, Blood 62:124, 1983) and provides a useful probe for studies leading to improved understanding of normal and malignant erythroid differentiation.

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Starting from 5 human sera containing anti-I cold autoagglutinins, it was possible, using adsorption/elution trials with pig's and rhesus monkey's RBC, to separate 8 anti-I antibodies because 3 of the initial sera were heterogeneous. Each of them had 2 anti-I different as regards the reactivity with the animal RBC and the anti-ID or the anti-IF reactivity. On the whole, among 8 separated fractions 1 reacted only on pig's RBC and had the characteristics of an anti-ID; 3 reacted only on rhesus monkey's RBC and were anti-IF; 4 had a cross-reactivity with pig's and monkey's RBC: 2 of them were anti-IF and 2 anti-ID. Anti-ID fixed preferably on pig's RBC and anti-IF on rhesus monkey's RBC but monkey's RBC are not entirely lacking in ID determinants and pig's RBC in IF determinants.

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Monoclonal anti-A, anti-B, anti-H antibodies have been produced by a murine hybridoma. C57BL/6 mice have been immunized by different red blood cells. The main characteristics of these antibodies are the following: specificity: anti-A agglutination only A cells, including A2, A3, Ax (from a panel of 50 cells); anti-B agglutinates only B cells (B3, Bx, cis Ab and acquired B). Anti-H agglutinates all cells except H-deficient red cells. inhibition: it is only inhibited by the saliva of each corresponding secretor subject. immunofluorescence tests: it is able to detect A,B,H antigens on tissue sections, kidney, pancreas, liver. thermodynamics: the association constant is 2.10(7) 1/ml (for anti-A) and 3.10(8) for anti-B and anti-H. All are IgM. Monoclonal anti-N, and some anti-public antibodies such as anti-gerbich and anti-Rh 17 have been obtained too. All these antibodies could be useful as reagents and for the study of weak groups.

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Difficulty in determining the ABO blood group led to the discovery of an anti-I cold auto-agglutinin in the serum of a blood donor. The peculiarity of this antibody is that its activity is enhanced in the presence of a preservative found in manufactured anti-sera: sodium azide. At 4 degrees C, the auto-antibody agglutinates RBCs even without NaN3 but the drug increases its effect in the cold. At 22 degrees C, the drug is necessary for the adsorption of the antibody on red cells.

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A monoclonal antidigitalin antibody was obtained following the immunization of BALB/mice with digitalin coupled to BSA, and the fusion of lymphocytes from these mice with murin myeloma 8653. The supernatants were screened by a radioimmunoassay in which the supernatant was incubated with digitalin coupled to I125. This monoclonal antibody "Dig 278" has an antigen binding ratio of 95%; is an IgGl; has a titre of 1/1000 and its affinity constant, as determined by a Scatchard plot, was 1,20(9) L/M. By experimenting with the monoclonal antibodies on 15 rabbits, we have obtained the reversal of heart rhythm disorders and the survival of animals injected with a lethal dose of digitalin. All the controls died. This antibody could prove useful in treating advanced cases of digitalin intoxication and for which no satisfactory treatment is available at present.

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A monoclonal antibody (iB5, IgG1 kappa) reacting with human red cells was produced after immunization of BALB/C mice with cord red cells, followed by fusion of the spleen cells with the murine myeloma cell line Ag 8-653. The monoclonal antibody agglutinated blood group N+ much better than M + N-red cells but did not recognize erythrocytes from rare individuals typed as M + N-S-s-U- and those from an En(a-) individual (M.E.P.). However, S-s-U- donors typed as M + N + or M-N+ and En(a-) red cells from donor G.W. were agglutinated. The erythrocyte receptors for iB5 are completely destroyed by papain treatment and significantly decreased by neuraminidase. Interestingly also, the iB5 antibody failed to agglutinate trypsin-treated N+M-S-s-U- erythrocytes. Other investigations have shown that the monoclonal antibody precipitated glycophorin A and B from N+ red cells and only glycophorin B from M+N-erythrocytes. The reactivity of iB5 was further explored by immunostaining following the electrophoretic transfer to nitrocellulose sheets of membrane proteins from common (M and N) and rare erythrocytes [En(a-),S-s-U-, MgMg, McM, St(a+), Mi.V, Mi.III, Tn] separated by SDS-polyacrylamide gel electrophoresis. These studies have clearly demonstrated that the monoclonal iB5 antibody is directed against the homologous N-terminal domain of glycophorin A and B, a specificity which explains the serological reactivity of iB5 against common and rare erythrocytes.

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Seven acquired B samples were studied with selected anti-B sera. Eight sera came from group A subjects, four from group O subjects. The anti-B sera reacting with the acquired B antigen are always a mixture of two kinds of antibodies: a fraction that is only reactive with B antigen, another that is cross-reactive with B and acquired B antigens. In some sera, especially those coming from group O subjects, there is, in addition, a potent antibody of polyagglutination for acquired B red cells. The polyagglutinability associated with acquired B red cells is analysed. According to the results obtained using lectins, four red cell samples are merely acquired B, the three others are acquired B + Tk. The polyagglutinability associated with Tk transformation is non sensitive to acetylation of red cells. The polyagglutinability specific for acquired B is sensitive to acetylation but appears complex in itself. According to the reactivity of selected sera for acquired B samples and the studies of inhibition with simple sugars, there are at least two antigens involved. One of them is present in all of the acquired B samples and it is likely to have arisen from the action of a deacetylase on a structure including N-acetylgalactosamine.

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A murine anti-H monoclonal antibody was produced. This antibody, called sp115, is an IgM that does not agglutinate classical Bombay. Sp115 may differentiate the two categories of H-deficient phenotypes. It detects H substance in both plasma and fresh saliva. Tissue antigen is found when using this antibody. The specificity of sp115 antibody was determined by adsorption with, and elution from synthetic oligosaccharide immunoadsorbents. Sp115 does not distinguish H type-1 and H type 2-structures.

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The maximum level of plasma hemoglobin in standard fresh frozen plasma before freezing has been mixed at 50 mg/l by french regulations. As no reference method is specified by the standards, we have adapted a technique where pseudo-peroxydasic activity of the hemoglobin is revealed by 3,3'-5,5', tetramethylbenzidine, a non carcinogenic chromogen derivate from benzidine. A 4 points reference scale is plotted for each plasma to be tested, thus reducing eventual interferences between pseudo-peroxydasic activity of the hemoglobin and other plasma proteins. We compared our modified technique to other existing ones: Vanzetti's extraction technique [8] whose main drawbacks are the use of flammable solvents and carcinogenic chromogen. Standefer's technique [10] involving plasma preincubation in H2O2 solution, which reveals protein interferences but is imprecise as it relies on only one reference point and does not show whether chromogen saturation is present. The level fixed by regulations is higher than the mean level indicated by our method, based on 118 samples of fresh plasma obtained by double centrifugation of whole blood collected on CPD as anticoagulant. It is also higher than the level indicated by the same method for plasma samples drawn from continuous or discontinuous flow cytapheresis (IBM 2997; Haemonetics V 50) using ACD - A or ACD - AA 16 as anticoagulant. Our method measures with precision low levels in plasma. Furthermore it is cheap, simple and easy to run in a blood transfusion center.

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A murine anti-B monoclonal antibody was obtained by the hybridoma technique. This antibody called anti-B (b-183) is of IgM nature; it is capable of agglutinating normal B, B3, Bx, cis AB and some acquired B red cells. Its association constant is 1.1 X 10(8) l/mol, and appears high compared to those of the monoclonal anti-A. This monoclonal anti-B was used to determine the number of B sites on B3 and Bx red cells.

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This study refers to the use of a monoclonal anti-B antibody of murine origin on Groupamatic MG 50. The monoclonal antibody produces results similar to those obtained with human immune antibodies.

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