Thirty monoclonal anti-Rhesus antibodies were tested : 21 anti-D, 4 anti-E, 4 anti-e and 1 anti-c, ragarding their specificity, avidity, intensity, titer and score. Their type, mode and mean were determined by flow cytometry assay. Then, we tried to determine if the anti-D could adequately dtect Du samples and also studied their behaviour with 13 partial and 2 depleted D antigens.
HLA typing was performed in 35 French Caucasoids with bullous pemphigoid and compared with 160 healthy controls. 47 HLA antigens were characterized by a lymphocytotoxicity micromethod. Analysis of the results only reveals one statistically significant difference: an increased incidence of HLA-DR5, which reaches 51.43% in patients versus 22.42% in controls, with P = 0.0007 and Pc = 0.0329. Several bullous dermatosis are associated with various HLA-DR antigens. These data suggest a direct role of HLA-DR molecules in the constitution of these autoimmune disease. An abnormal expression of DR products on some skin cells membrane would permit the presentation of a non self peptide, accumulated in skin cells, to helper T lymphocytes. An heteroimmunization against the non self peptide could lead to lesion of self cells. This peptide perhaps derives from food protein.
Glycophorins of human erythrocytes have been extensively studied and the structure of three of them is fully (glycophorins A and C) or almost fully (glycophorin B) known [1, 2]. Glycophorins span the erythrocyte membrane and their NH 2 -terminal domains exposed at the cell surface are heavily glycosylated. Glycophorin A occurs in two genetically determined forms carrying at NH 2 -terminal end blood group M and N antigenic determinants. Glycophorin B (blood group Ss glycoprotein) has the structure of NH 2 -terminal region (a.a. residues 1–26) identical to glycophorin A of blood type N, and also shows a high degree of homology with glycophorin A in the internal portion of the molecule, whereas glycophorin C has a different amino acid sequence. The knowledge of structure and orientation in the membrane and genetic differentiation of glycophorins facilitate elucidation of the fine specificity of anti-glycophorin antibodies. The 30 anti-glycophorin-antibodies obtained were tested by agglutination of untreated and modified erythrocytes, immunoblotting, and binding to glycophorin A in microtiter plate ELISA. Moreover, inhibition of antibodies by untreated and modified glycophorin A preparations was studied. The methods used were described in detail in our recent publications [3, 5]. The antibodies could be divided into groups (Table I) , depending on specificity. The 19 antibodies recognized epitopes located at the NH 2 -terminal end of glycophorin A that could be easily shown by specific or distinctly preferable reactivity with blood group M (8 MoAbs) or N (11 MoAbs) antigen. The antibodies with anti-N specificity also reacted with glycophorin B. Among the remaining blood group MN-unrelated antibodies, 4 were specific for glycophorin A, 3 recognized epitopes common for glycophorins A and B, 2 reacted to glycophorin C, and the specificity of 2 antibodies could not be clearly established. The antibodies in each group differed in sub-specificity and antigen-binding properties.
Five monoclonal antibodies were studied ; one human and 4 murines. The human antibody (26 W 12) was anti-K. One of the murine antibodies (20 W 4) was very similar to anti-K and the other 3 (9 W 12, 19 W 2, 20 W 3) recognised high frequency antigens related to the Kell system through their absence from K0 cells.
The 22 antigens of the Kell blood group system are located on a red blood cell (RBC) membrane glycoprotein that shows sequence homology with a family of metalloendopeptidases. Expression of the Kell system antigens is partially governed by XK, an X-linked gene that encodes the Kx protein; absence of Kx results in reduced Kell antigen expression. Almost total absence of Kell antigens from the RBCs of a German man with no symptoms of neuroacanthocytosis could not be due to the Kell-null phenotype, K0, because his RBCs had very weak expression of Kx antigen and his three children were Kp(a + b+). Kell antigens were normal on the RBCs of his son but weak on those of his two daughters. An Nla III restriction fragment-length polymorphism within the KEL gene showed the Kpa/Kpa genotype in the propositus. Sequencing of his XK gene showed a single base change within the donor splice consensus sequence of intron 2. A BsaAl restriction fragment-length polymorphism showed the mutation in both of his daughters but not in his son. The extreme depression of the Kell antigens of the propositus must be due to a combination of effects, ie, homozygosity for Kpa and deficiency of Kx protein, each of which is capable of causing some degree of weakening of Kell antigens.
In this work we studied 21 human monoclonal antibodies (MABs) which appeared during the screening tests to have an anti-Rh (D) specificity. These antibodies were then tested especially by agglutination techniques using a panel of human red blood cells RBC of common and rare phenotypes in order to: Confirm their specificity Investigate their reactivity with Rh variants Determine their in vitro potency (titre and quantitation) using various techniques.
Nous avons réalisé une étude biologique comparative longitudinale de certains paramètres de l'hémostase sur 31 plasmas décongelés au bain-marie à 37° C et au four à micro-ondes prototype D.P.G. Hemocar.
In this trial, we have tested four monoclonal antibodies related to the Lutheran System. These antibodies were studied by serological methods with a panel of red cells of Lutheran common phenotypes and weak variants.
Huit types de variants génétiques de l'albumine sont observés dans la population française. L'analyse des profils électrophorétiques des sérums contenant ces variants, réalisés à 3 pH différents (8,6, 5,0 et 6,9) après addition d'une protéine témoin, la transferrine, permet d'identifier chacun des variants par l'estimation quantitative de ses mobilités relatives. La précision et la reproductibilité de la technique en a fait une méthode de référence couramment utilisée pour l'étude des variants européens.
In this work we studied 18 monoclonal antibodies (MABs) of various specificities directed against Rh, G and LW molecules. These antibodies were tested by agglutination techniques using a panel of human red blood cells (RBC) of common and rare phenotypes in order to: Confirm their specificity Investigate their reactivity with Rh variants Determine their titres using various techniques.
The aims of the work were three-fold : 1) to determine how many D epitopes were recognized by the 7 IgG anti-D monoclonals produced by our own group (4 of which were in the workshop collection) ; 2) to define the epitopes recognized by the other workshop anti-D antibodies ; 3) to determine the relationship between the D, c and E antigens.
The Kell blood group presently includes 23 antigens [1], a null (K0) phenotype, a number of phenotypes characterized by weak Kell antigen activity, and an independent antigen, designated Kx, which appears to play a role in Kell antigen expression. Kell blood-group antigens are markers on the surface-exposed domain of a 93,000 daltons (93 kD) membrane glycoprotein [2]. Intrachain disulfide linkages [3], and probably the proper intra-membrane milieu, are important for the antigenic integrity of Kell 93 kD protein. Separated 93 kD Kell protein does not react by Western blot analysis with the Kell antibody used for its initial immuno-precipitation [1]. Incubation of intact red cells with solutions containing papain/DTT mixture [4] or 2-aminoethylisothiouronium bromide (AET) inactivates all antigens of the Kell complex except for Kx [5]. Five monoclonal antibodies have been examined for serological specificity within the Kell system and for their ability to recognize epitopes on a 93 kD red cell membrane protein by Western blot analysis.
The 4 antibodies were studied by serological methods and by immunoblotting. One antibody (9 W 13) is anti-Lub, the other 3 (9 W 11, 13 W 1, 32 W 2) are only related to the Lutheran system through their reduced expression on Lu (a - b -) cells of the dominant type.
