A. van Leeuwen

Simultaneous detection of two cell populations by two-colour fluorescence and application to the recognition of B-cell determinants.

CELL separation techniques, the possibility of recognising different markers by immunofluorescence and functional tests, have subdivided cells once thought to be a homogeneous group into different subclasses. This development has been most prominent for the so-called mononuclear cells. A difficulty inherent in the classification of such subclasses (of, for example, mononuclear cells) is that it is often almost impossible to determine precisely what percentage of the cells belongs to a certain subclass, and whether the sum of the subclasses is equal to, lower than or even higher than 100% of the total of the cells analysed. A typical recent example was the identification of the “null” or K cell1,2. Such analysis is greatly facilitated if we analyse a cell suspension stained with two or more different fluorescent dyes visible at the same time. This is feasible.

LEUKOCYTE GROUPING. A METHOD AND ITS APPLICATION

This study describes the development of a method for the recognition and definition of leucocyte group Four. The method can also be applied to the detection of other leucocyte groups. Essential factors in the method were: a) the use of leucocyte agglutinins formed during pregnancy; b) an insight into the shortcomings of the agglutination test; c) the use of statistical methods to overcome these shortcomings; and d) the use of a panel consisting of the leucocytes of the women who had formed the agglutinins, and of those of their husbands.

Anti HL-A2 inhibitor in normal human serum.

THE finding that allogeneic pig liver transplants frequently survive for a significantly prolonged period of time even without immunosuppression has led to a new line of research1,2. Calne and his colleagues have shown that the recipient of an allogeneic liver transplant showed partial tolerance towards kidney, and to a lesser extent towards skin transplants, when these were obtained from the same animal as was the liver.

HLA-DW3 ASSOCIATED WITH CŒLIAC DISEASE

28 patients with coeliac disease (C.D.) were typed for the HLA-A, -B, and -D loci by several techniques. It was found that C.D. is primarily associated with the DW3 determinant and only secondarily with HLA-B8. The previously described association with HLA-B8 is explained by linkage disequilibrium between HLA-B8 and DW3.

Leucocyte Antibodies in Sera of Pregnant Women

1 The leucocyte agglutinins arising during pregnancy are isoantibodies directed against an antigen present on the leucocytes of the husband and some of the children. 2 With the aid of such sera it is possible to recognize leucocyte groups. 3 These antibodies can cause transfusion reactions. 4 The antigens against which these antibodies are directed are found not only on the leucocytes but also on the thrombocytes, and in placental tissue. They are not found on the erythrocytes. 5 The possible significance of these antibodies in connection with spontaneous abortion is mentioned.

Gluten Sensitive Enteropathy in Spain: Genetic and Environmental Factors

It has been postulated by various investigators that at least two unlinked genes are involved in the predisposition to gluten sensitive enteropathy (GSE). One of these genes is believed to be linked to the major histocompatibility locus (MHC). We call this gene GSE1 and the other, which is not linked to MHC, GSE2. The study of HLA antigens in different populations may help to elucidate the genetics of GSE and to identify the GSE1 gene. We have studied 26 unrelated proven GSE children and 54 controls living in a defined region in Spain, and also performed a family study in 51 relatives of 11 of these children with GSE. These relatives also underwent a physical examination and a routine haematological screening, and in 30 of them a small-intestinal biopsy specimen was investigated. All patients, relatives, and controls were typed for HLA-A, B, C and DR antigens and for glyoxalase-1 (GLO1). Both the population and the family studies have shown that GSE is associated with two alleles at the HLA-DR locus, namely HLA-DRw3 and HLA-DRw7. No association with a particular GLO1 allele was found. Three monozygotic twin pairs, one concordant and two discordant for the disease, are described. In addition, all monozygotic twin pairs in the literature are reviewed and several obtained through personal communication are added.

MATCHING FOR HLA ANTIGENS OF A, B, AND DR LOCI IN RENAL TRANSPLANTATION BY EUROTRANSPLANT

79 patients and their respective cadaveric kidney donors were typed for HLA-A, HLA-B, and HLA-DR antigens using frozen stored spleen lymphocytes and fresh peripheral-blood lymphocytes. The kidney-graft survival-rate at 3 to 18 months was highest when donor and recipient shared one or two DR antigens and three or four A and B antigens. The graft-survival rate was significantly higher (87 +/- 6%) at 18 months in these patients than in less well matched patients (48 +/- 9%).

Cerebriform (Sézary like) mononuclear cells in healthy individuals: A morphologically distinct population of T cells

SummaryThe ultrastructural and surface marker characteristics of lymphocytes in human cord blood and peripheral blood of healthy donors were studied with respect to the presence of cerebriform mononuclear cells similar to those occurring in the dermal infiltrate of patients with mycosis fungoides (mycosis cells), and the skin infiltrate and peripheral blood of patients with Sézary’s syndrome (Sézary cells). Cerebriform monuclear (Sézary-like) cells are characterized by a high nucleus-cytoplasm ratio, deep and narrow nuclear indentations, condensed chromatin at the nuclear membrane and cytoplasm poor in organelles. Of the lymphoid cells in human cord blood and peripheral blood of healthy donors 6.7 and 8.7% respectively proved to be cerebriform mononuclear cells. Since these cells invariably form E-rosettes they are part of the T-cell population in healthy individuals. The finding of similar cells in the skin infiltrate of patch test areas of patients allergic to rubber, formalin and peruvian balsam —an expression of cellular immunity mediated by T-cells —suggests that these cells are reactive T cells.Not all (up to 85%) of the cerebriform mononuclear cells in patients with mycosis fungoides and Sézary’s syndrome have T-cell membrane characteristics as shown by E-rosette formation. This suggests the presence of two populations of cerebriform mononuclear cells in mycosis fungoides and Sézary’s syndrome. The relationship of cerebriform T cells as seen in healthy individuals with cerebriform or atypical mononuclear cells occurring in the Sézary syndrome and mycosis fungoides is discussed.

Neonatal tolerance revisited

Of the many thousand patients who are waiting for a kidney transplant an increasing percentage cannot be transplanted because they have formed broadly reactive leucocyte antibodies. Broadly reactive leucocyte antibodies are here defined as antibodies that react with more than 85°70 of a panel of at least 50 unrelated donors. At present the percentage of such patients in Eurotransplant is over 10070. In the rest of Europe it is nearly 15070 [1]. These patients are very difficult to transplant because the crossmatch with potential donors is nearly always positive. Only if donor and recipient are HLA-A and -B identical or compatible is there a reasonable chance for a negative crossmatch and a successful transplant. However, even with more than six thousand patients on the waiting list of Eurotransplant we are not able to provide an HLA identical graft for more than 5-8070, and this is only possible if the HLAo phenotype of the patient is relatively frequent. It is therefore important to determine whether those patients who often react not only to 85070 of the panel but to almost all panel cells (a so-called 100070 panel reactivity) have formed antibodies against all HLA antigens or whether there remain some antigens towards which they have not formed antibodies. There are two protocols with which one can identify so-called permissible mismatches for these highly immunized patients. We call such anti-

Cell membrane polymorphisms coded for in the HLA-D/DR region I. Relation between D and DR

The relation of HLA-D and -DR determinants was studied in Dutch Caucasoids. The recognition of subgroups of DR4, DR5, and DR7, and the specificities LB12 and LB13 are described. Phenotype and gene frequencies and a Hardy--Weinberg analysis of DR and local (LB) B-cell groups are given. Excellent correlation between D and DR typing was obtained when HTCs were studied by selected B-cell antisera. When the same sera were used to type a panel of D typed cells, the correlation was decreased (with the exception of DR3 and Dw3). In the case of discrepancies the DR specificity, but not the corresponding D specificity, always could be found and not the other way around. The data fit best the assumption that HLA-D and -DR are carried by the same molecule, although they might be different determinants on this molecule. A number of possible explanations for the observed discrepancies has been given.