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C P Engelfriet

Publications and source records attributed to C P Engelfriet.

At least 73 records · Page 4Linked to original sources
PubMed1987

Quantification of platelet-bound alloantibodies by radioimmunoassay: a study on some variables.

Several variables that may affect accurate measurement of platelet-associated IgG (PA-IgG) were studied using a radioimmunoassay of the consumption type. The amount of PA-IgG of washed, unfixed normal donor platelets was 1.0 +/- 0.9 fg IgG/platelet (mean +/- 2 SD). Upon storage of washed platelets in a buffer containing EDTA, the amount decreased significantly to 0.2 +/- 0.2 fg IgG/platelet. Simultaneously, an increase in modal platelet volume was observed. Similar results were obtained when platelets were fixed with paraformaldehyde (PFA). We postulate that this decrease in PA-IgG is caused by the release of plasma IgG entrapped by the surface-connected canicular system of the platelet, when the platelets swell during storage in EDTA or fixation with PFA. This presence of varying amounts of entrapped plasma IgG may cause the wide discrepancies in PA-IgG found in normal donor platelets as well as platelets from ITP patients by other investigators. A good quantification of platelet-bound alloantibodies was possible with our assay when platelets were routinely fixed to diminish the amount of nonspecific PA-IgG. This was demonstrated with different anti-Zwa (= anti-PlA1), anti-Baka and anti-HLA sera. We also observed that fragments of platelets as well as fragments of cells of other types can cause aspecifically increased Pa-IgG values and can thus interfere with the proper measurement of platelet-bound antibodies in all kinds of immunoassays in general.

Absorption↗
PubMed1986

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.

Antibody Formation↗
PubMed1986

ABO and Rhesus phenotyping of fetal erythrocytes in the first trimester of pregnancy.

Determination of fetal red blood cell antigens in early pregnancy can be important in cases with a history of severe haemolytic disease of the newborn. From chorionic villus biopsies (CVB) between the 8th and 12th week of gestation a small number of fetal red blood cells was obtained, inevitably highly contaminated with maternal blood cells. Two techniques were used to demonstrate the minor (fetal) cell population with a blood group antigen differing from the major (maternal) cell population: a solid-phase microfluorescence technique (introduced in this paper) which was compared with the mixed agglutination technique. In series of artificial mixtures of erythrocytes it was shown that with the microfluorescence technique the ABO and Rhesus phenotypes of minor cell populations could be determined at a ratio of 1 in 4000 erythrocytes of the major population, making this technique 4 times as sensitive as the mixed agglutination technique. We further investigated the reliability of the microfluorescence technique to demonstrate antagonistic fetal blood groups in the first trimester of pregnancy. Of 18 women undergoing CVB prior to therapeutic abortion, blood group antagonism (ABO and Rhesus systems) was demonstrate in all 11 cases in which it was present. Therefore, it seems that CVB can be reliably used for the prenatal diagnosis of (recurrent) blood group antagonism.

ABO Blood-Group System↗
PubMed1986

Chronic idiopathic and secondary neutropenia: clinical and serological investigations.

Clinical data on 49 patients with chronic idiopathic neutropenia (CIN) and 42 patients with neutropenia secondary to a well-defined immunological disorder (SN) were collected and related to serological parameters. In 47% of the patients with CIN and 53% of those with SN, a positive direct immunofluorescence test was obtained with granulocytes from the patients. In the sera from the patients in the two groups, antibodies against donor granulocytes were detected by the indirect immunofluorescence test, the leucoagglutination test and/or the granulocytotoxicity test in 15%, 19% and 15%, respectively. The results of the above tests could not be correlated with any clinical or haematological parameter. Immune complexes in the serum were detected by the 125I-Clq-binding test in 29% of patients with CIN and in 58% of those with SN. The presence of serum immune complexes correlated well with the existence of a low neutrophil count, but not with the presence of recurrent infections, with bone-marrow abnormalities, or with positive reactions in other serological tests. The sera of eight out of 14 patients with CIN and seven out of 12 patients with SN had inhibitory activity for myeloid colony formation in vitro (CFU-GM). This CFU-GM inhibitory activity was correlated with the presence of recurrent infections and with hypoplasia of the myeloid compartment of the bone marrow, but not with positive reactions in other tests. We conclude that the 125I-Clq-binding test probably detects circulating immune complexes that induce a shift neutropenia, whereas serum activity inhibitory for CFU-GM possibly relates to clinically more serious forms of neutropenia. The significance of neutrophil-bound Ig and granulocyte-reactive antibodies in the serum is not clear.

Adolescent↗
PubMed1985

Intravenous gammaglobulin therapy in idiopathic thrombocytopenic purpura. Results with the Netherlands Red Cross immunoglobulin preparation.

The effect of high-dose intravenous gammaglobulin (IVG) therapy with a CLB preparation was studied in 42 patients: 8 patients had acute and 26 patients had chronic idiopathic thrombocytopenic purpura (ITP); 5 patients had thrombocytopenia accompanied by various diseases such as systemic lupus erythematosus, auto-immune haemolytic anaemia and neutropenia; 3 patients had hypoplastic anaemia and 1 patient had neutropenia and rheumatoid arthritis. After treatment, a rise in platelet count occurred in about 75% of the patients with ITP, although there was no sustained response in any of the patients. There was no correlation between the strength of platelet antibodies as detected by the direct immunofluorescence test before infusion and the pattern of response to the infusion. In most cases of ITP, no immune complexes, as measured by Clq-binding assay, were observed. Furthermore, we found no relationship between the amount of Clq-binding activity of patients' sera and the reaction pattern after infusion of IVG. Splenectomy of the patient had no influence on the outcome of IVG therapy.

Adult↗
PubMed1985

The serology of febrile transfusion reactions.

Sera from 40 patients with febrile, nonhemolytic transfusion reactions were tested for the presence of alloantibodies using a number of techniques, including immuno-fluorescence tests on granulocytes, lymphocytes and platelets, a modified NIH lymphocytotoxicity test and the leukocyte agglutination test. Cells of at least 9 donors were used as target cells. Alloantibodies were detected in all sera. The frequency of the occurrence of antibodies was not much higher in sera obtained about 1 month after the transfusion reaction as in sera obtained within 4 days. Most of these antibodies were anti-HLA, but quite frequently platelet-specific antibodies were found, and sometimes these were the only antibodies detected. Granulocyte-specific antibodies were the least frequent. The nature of the antibodies was specified by their difference in reactivity with the cells of multiple donors, by applying panels of cells from typed donors and by absorption and elution experiments. It appeared that not only granulocyte-specific but also HLA- and perhaps platelet-specific antibodies may be responsible for a febrile transfusion reaction. We did not find that the occurrence of rigors, together with fever, was associated with particular serologic results.

Adult↗
PubMed1984

Familial thrombocytopenia associated with platelet autoantibodies and chromosome breakage.

An extended family is described in which three members had thrombocytopenia. These affected members had chromosomal changes resembling those found in Fanconi's anaemia, though they lacked the development defects associated with that syndrome. One had bone-marrow hypoplasia and died of squamous cell carcinoma of the mouth at the age of 27. In addition, all three had platelet autoantibodies not found in any other family members tested. There was no linkage between the thrombocytopenia and HLA groups. The nature of the association of thrombocytopenia, platelet autoantibodies and chromosomal abnormalities in this family remains doubtful.

Adolescent↗
PubMed1984

Platelet freezing for serological purposes with and without a cryopreservative.

We compared the reactivity of fresh platelets with platelets frozen in dimethylsulfoxide (DMSO) or without a cryopreservative by testing agglutinating and non-agglutinating platelet-specific alloantibodies in titration. Frozen platelets, irrespective of the method of preservation, showed no loss of antigenicity as compared with fresh platelets. The yield of platelets frozen without a cryopreservative proved to be higher (80%) than platelets frozen in the presence of DMSO (50%). Platelets sensitized with autoantibodies from patients with autoimmune thrombocytopenia could also be stored by simple freezing in platelet-rich plasma and used for (re)testing.

Autoantibodies↗
PubMed1984

Red-cell auto-antibodies mimicking anti-Fyb specificity.

An antibody is described, produced by an Fy(a+b-) woman that at first reacted with her own cells, preferentially with Fy(b+) cells but not with Fy(a-b-) cells. Later, pure anti-Fyb specificity occurred. Elution and absorption studies revealed that the antibody recognized a determinant absent from Fy(a-b-) cells but present on Fy(a+b-) and Fy(a-b+) cells, much more strongly, however, on the latter, and that it was an autoantibody.

Anemia, Hemolytic, Autoimmune↗
PubMed1984

Effect of the binding of anti-Zwa antibodies on platelet function.

Anti-Zwa antibodies can induce a Glanzmann-like platelet dysfunction in normal Zwa-positive platelets. Although a normal shape change and release reaction was always recorded in response to adenosine diphosphate and collagen, the aggregation on these inducers could be completely inhibited by anti-Zwa antibodies. Analogous to the platelets from patients with Glanzmann's thrombasthenia, normal platelets sensitized with anti-Zwa did not associate with fibrinogen upon exposure to adenosine diphosphate. Our data indicate that the binding site for fibrinogen is closely associated with the Zwa-antigenic determinants on the platelet membrane glycoproteins and thus with glycoprotein IIIa which is known to carry Zwa.

Adenosine Diphosphate↗
PubMed1983

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.

Adult↗
PubMed1983

Interference of IgG, IgG aggregates and immune complexes in tests for platelet autoantibodies.

Three techniques, based on the antiglobulin principle, used for the detection of autoantibodies against platelets, were compared; the antiglobulin consumption assay (QACA), the platelet radioactive antiglobulin test (PRAT) and the platelet suspension immunofluorescence test (PSIFT). Upon incubation of normal donor platelets with purified IgG, in concentrations higher than that in serum, an increased amount of platelet-associated IgG was demonstrated only in the QACA. Upon incubation with aggregated IgG, all three tests became positive, but the PSIFT only with high concentrations of aggregates. Binding of soluble C1q-binding immune complexes (IC), which consisted of tetanus toxoid and IgG antitetanus antibodies (TaT) to normal donor platelets, was only detectable in the QACA. However, a positive result was obtained in all three tests with platelets incubated with soluble DNA-IgG-antiDNA antibodies (DaD) IC. Fixation of the platelets with paraformaldehyde prevented the binding and the detection of the DaD-IC, but not of IgG, aggregated IgG or TaT-IC. Eluates from platelets incubated with aggregated IgG, TaT- or DaD-IC did not react with normal donor platelets in the three techniques, in contrast to eluates from platelets sensitized with platelet antibodies.

Antibodies, Antinuclear↗