Alloimmunization against the platelet-specific Zwa antigen, resulting in neonatal alloimmune thrombocytopenia or posttransfusion purpura, is associated with the supertypic DRw52 antigen including DR3 and DRw6.

The strong association between HLA-DR3 and Zwa alloimmunization in Zwa-negative mothers, resulting in the production of anti-Zwa antibodies and ultimately in neonatal alloimmune thrombocytopenic purpura (NAITP) in the newborn, could be confirmed. In addition, we have shown an equally strong association between HLA-DR3 and Zwa alloimmunization in Zwa-negative recipients of blood transfusions, resulting in posttransfusion purpura (PTP). However, the strongest association both in mothers of NAITP patients and in PTP patients was observed with the supertypic DRw52 antigen. In fact, all individuals carried this antigen. Normally, DRw52 includes DR3, DR5, DRw6, and DRw8 almost completely. However, in our material, DRw52 included only DR3 and DRw6 with one exception. Another interesting observation is that all PTP patients were women with previous pregnancies without any clinical signs of a bleeding disorder in their children. This indicates that alloimmunization against Zwa during pregnancy is DR3- and/or DRw52-positive women does not always lead to the development of NAITP, but these women may be at risk for the development of PTP after blood transfusion.

Conventional alloantisera can recognize the same HLA-B27 polymorphism as detected by cytotoxic T lymphocytes.

Subtypes of B27 have been identified by cytotoxic T lymphocytes, biochemistry, molecular biology, and murine monoclonal antibodies. In the present study we describe seven B27 subtype-specific pregnancy sera. The reaction pattern of these B27 subtype-specific sera closely parallels the recognition pattern of B27 subtype-specific cytotoxic T lymphocytes. Because the complete amino acid sequence of the studied B27 subtypes (B27W, B27K, B27C, B27D) is known, it can be determined which amino acid substitutions are responsible for recognition by subtype-specific sera and by cytotoxic T lymphocytes, respectively. It is proposed that B27 subtype-specific sera and B27 subtype-specific cytotoxic T lymphocytes recognize the same epitopes or that a single amino acid change can induce multiple antigenic determinants, which are recognized differentially by antibodies and T cells.

Changes in the surface marker pattern related to maturation in adult acute myeloid leukaemia.

Introduction of the maturation index (MI) as a measure for the degree of maturation improved the subtyping of acute myeloid leukemia (AML). A comparison is made here between the MI and the results of surface marker analysis with a panel of monoclonal antibodies (McAb) in the immunofluorescence technique. The McAb applied in 46 AML patients (greater than or equal to 15 years) were granulocyte specific (MI/N1, UJ 308, B4-3, B13-9), granulocyte-monocyte specific (OKM-1, B2-12) or had specificity for the Ia-like antigen (OKI-1), 'T-cells' (3A1), immature cells (OKT-10) or platelets (C17-28). In 32 of these patients more McAb could be investigated with specificities for granulocytes (VIM-D5), granulocytes-monocytes (RUPI-5), monocytes (MONO BRL, RUPI-4), erythrocytes (VIE-G4) and AML cells (VIM-S8). An increase in surface marker expression evident from the reaction with a number of McAb (UJ 308, B2-12, OKM-1 and OKI-1) paralleled the rise of the MI in FAB M5. A decrease of the expression of antigen detected by OKI-1 paralleled the rise of the MI in FAB M1-3. The granulocyte or monocyte specific McAb, as they are determined on normal human peripheral blood cells, did not distinguish between FAB M1-3 and M5. The maturation index seems to be a valuable tool in understanding the results of surface marker analysis.

[Hemolyzing antibodies to markers of the P blood factor system as a problem in blood transfusion and pregnancy. With reference to serology, biochemistry and genetics]. / Hämolysierende Antikörper gegen Merkmale des Blutfaktorensystems P als Problem für Transfusion und Graviditt. Unter Berücksichtigung von Serologie, Biochemie und Genetik.

The extremely rare phenotypes p, P1k and P2k (0.0005-0.0006%) of the blood group P system are usually found in consanguinous families. In the serum of these persons haemolytic antibodies with the specificity anti-PP1Pk and anti-P are found, causing severe haemolytic reactions after transfusion of incompatible blood. Because of their rarity it is difficult to find compatible blood donors. The antibodies are also associated with abortion early in pregnancy. Since 1948 at the "Institut für Blutgruppenserologie der Universität Wien" 4 persons of the phenotype p and 3 of the type P2k were observed in altogether 5 families. Two of them needed blood transfusions, the one p patient received p blood from her sister, who likewise gave blood to the other p patient. This latter patient additionally received three blood units which had been stored in liquid nitrogen and came from Austria and from the European bank of frozen blood in Amsterdam (Council of Europe). The pedigrees of three families with 5 probands out of the 7 observed cases could be reconstructed and showed consanguinity, partly some generations back. A genetic model valid at the moment for the biosynthetic pathway of the P antigens is demonstrated and the appropriate serological characteristics of the haemolytic antibodies are shown. The seven antibodies are partly IgG and partly IgM antibodies, optimally reacting using the indirect antiglobulin test or enzyme-treated red cells. The range of the antibody titres was between 1:8 and 1:1024. Absorption of Anti-PP1Pk sera with red cells of type P1 to get Anti-Pk and inhibition with hydatidcyst fluid and globoside to receive Anti-P and Anti-P1 + Pk, respectively were partly successful.

[Linguistics in blood group serology]. / Taalkunde in de bloedgroepserologie.

With a view to terminological uniformity, blood group serologists, immunologists and transfusion physicians should refer only to the "ABo' (zero) in stead of the "ABO' system. They also should use "HLA antibodies' in stead of "anti HLA antibodies'. The new Dutch spelling "resus' in stead of "Rhesus' is incorrect from a historical point of view.

[Revised definition of the concept rhesus-negative blood donor; practical experiences]. / Herziene omschrijving van het begrip rhesus-negative bloeddonor; de ervaringen in de praktijk.

In 1987 the Central Medical Blood-transfusion Committee of the Netherlands Red Cross decided to modify their definition of 'Rh-negative' as it applied to blood donors. Until then the term Rh-negative had been reserved for donations that grouped as C- and E-negative and failed to react with IgG anti-D by the indirect antiglobulin test (IAT). From June 1987, however, donations were considered to be Rh-negative if they failed to react with two strong anti-D sera. An evaluation is presented over the first one and a half years of working with the new definition, the problems that were encountered and the measures that are taken to guarantee the quality of Rh testing.