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C Mueller-Eckhardt

Publications and source records attributed to C Mueller-Eckhardt.

At least 19 recordsLinked to original sources
PubMed1992

Heparin-associated thrombocytopenia: the antibody is not heparin specific.

In this study the hypothesis was assessed whether heparin-associated thrombocytopenia (HAT) may be caused by an antibody dependent on polysulfated oligosaccharide epitopes, present not only on heparin but also on different polysulfated substances such as dextran sulfate and pentosan polysulfate. We found that the major factor for eliciting platelet activation with sera of HAT type II patients is neither the structure nor the AT III binding capacity of an oligosaccharide, but rather its grade of sulfation. This was shown by in vitro crossreactivity studies with 40 sera of HAT type II patients using unfractionated heparins, LMW heparins (Fragmin, Fraxiparin), enoxaparin, LMW heparinoid (Org 10172 and its subfractions), de-N-sulfated heparin, dermatan sulfate, dextran sulfate, pentosan polysulfate and dextran. Platelet activation was measured by the heparin induced platelet activation (HIPA) assay and the serotonin release assay (SRA). The platelet activating factor was isolated with the IgG fraction, but did not bind to heparin and dextran sulfate fixed to a solid phase. By isoimmune fixation electrophoresis a monoclonal gammopathy was ruled out in the three sera assessed. The in vivo effect of different LMW heparins and the heparinoid Org 10172 was observed in 10 patients with HAT type II. In a prospective study, a compatible heparin-like anticoagulant was selected for 10 HAT patients for whom further parenteral anticoagulation was required. The only substance that showed no crossreactivity in vitro was the LMW heparinoid Org 10172, which differs from heparin and LMW heparins by its low-grade sulfation. Upon treatment with the heparinoid, all 10 patients had a good clinical outcome, even if they had previously developed thromboembolic complications under LMW heparin administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Rhesus(D)-IgG-antibodies in the treatment of autoimmune thrombocytopenia].

25 patients with confirmed chronic autoimmune thrombocytopenia (AITP) (20 women, 5 men; mean age 42 [17-75] years) were treated with anti-erythrocytic rhesus (D) antibodies. In the course of 5 days they each received three doses of 1200 micrograms of anti-D IgG antiserum by short-duration infusion. No adverse effects were noted. In 19 out of 25 (76%) the platelet counts (determined on the 6th day after the last infusion) rose by more than 30,000/microliters, in some by over 200,000/microliters. In 6 patients the maximal rise in platelets was below 30,000/microliters. There was little or no fall in haemoglobin concentration in 24 of the patients, although the direct antiglobulin test was clearly positive in all cases. Moderate transitory anaemia occurred in one case only (haemoglobin fell from 12.4 to 8.4 g/dl). The platelet counts gradually declined after treatment, taking several weeks or months to reach their original levels. The mechanism of anti-D therapy in AITP is not fully understood, but it probably depends on competitive inhibition of Fc receptors on phagocytic cells in the reticuloendothelial system.

Adolescent↗
PubMed1992

Heparin-associated thrombocytopenia: successful therapy with the heparinoid Org 10172 in a patient showing cross-reaction to LMW heparins.

A patient suffering from heparin-associated thrombocytopenia (HAT), recurrent arteriothromboses, and acute renal failure after treatment with standard heparin is described. He failed to improve when therapy was continued with low-molecular-weight (LMW) heparin (Fragmin, Kabi Pfrimmer, Erlangen, FRG). By means of the in vitro heparin-induced platelet activation (HIPA) assay it was shown that standard heparin and the LMW heparins Fragmin and Fraxiparin (Sanofi Labaz, Munich, FRG), as well as the enoxaparine Clexane (Nattermann, Cologne, FRG), all induced platelet activation with the patient's serum. In contrast, the LMW heparinoid Org 10172 (Organon, Oss, The Netherlands) did not cause platelet activation. When the patient was subsequently treated by parenteral administration of Org 10172 as anticoagulant over a period of several weeks the number of platelets rapidly increased and the patient almost completely recovered. This case shows that strong in vivo and in vitro cross-reactivity between standard heparin and LMW heparins may occur, but can be avoided by the use of a novel heparinoid, Org 10172. The HIPA assay provides a simple and sensitive laboratory method for the choice of an innocuous heparin or heparinoid for continued parenteral anticoagulation.

Aged↗
PubMed1992

May-Hegglin anomaly: a rare cause of thrombocytopenia.

A family with four and an unrelated family with three individuals affected by the May-Hegglin anomaly are described. Platelet counts were markedly reduced and were correctly determined only in the counting chamber. Bleeding time and platelet aggregation were always normal, but platelet nucleotide concentrations (ATP and ADP) were elevated. The platelet glycoprotein complexes Ib/IX, IIb/IIIa and Ia/IIa were quantitatively normal. Platelet-associated IgG was slightly elevated, although thrombocytopenia was presumably not caused by an immunological mechanism. Morphological investigations showed giant platelets and spindle-shaped inclusion bodies in the granulocytes, while their function (phagocytic capacity, radical production) was normal. To exclude hereditary types of thrombocytopenia, morphological and family investigations are required to avoid misdiagnosis with far-reaching diagnostic and therapeutic consequences.

Blood Platelet Disorders↗
PubMed1992

Alloimmune neonatal neutropenia is a potential side effect of immunization with leukocytes in women with recurrent spontaneous abortions.

Alloimmunization of a mother against granulocytes causing alloimmune neonatal neutropenia (ANN) in her newborn was found likely to be attributed to previous intradermal injections of paternal lymphocytes. Immunotherapy with leukocytes which was performed for recurrent spontaneous abortions hence provides the possibility of granulocyte alloimmunization and increases the risk of the occurrence of ANN.

Abortion, Habitual↗
PubMed1992

Quantitation of granulocyte antibodies in sera and determination of their binding sites.

An enzyme immunoassay using eluates was developed for the quantitation of granulocyte antibodies in sera. Incubation of donor granulocytes with sera containing granulocyte alloantibodies (NA1, NA2, NB1, 5b, HLA) or autoantibodies resulted in a significantly higher amount of immunoglobulin G (IgG) per cell than did incubation with control sera. Ultracentrifugation of the sera prior to testing reduced unspecific binding of IgG to granulocytes. In eight of 10 assessed sera from patients with Felty's syndrome eluted IgG decreased from elevated to normal levels. Ultracentrifugation further allowed determination of the binding sites of granulocyte-reactive alloantibodies. Using sera containing NA1- and NA2-specific alloantibodies 173,000-188,000 binding sites on homozygous and 84,000-110,000 on heterozygous cells were determined. A similar number was found using a Fc gamma receptor III (FcRIII)-specific monoclonal antibody. Granulocytes from patients with paroxysmal nocturnal haemoglobinuria showed greatly reduced binding sites for NA-specific alloantibodies. The binding sites for the human alloantibody NB1 ranged from 36,000 to 318,000 and for the 5b alloantibody from 44,000 to 65,000. Mean values of 139,000 binding sites for HLA antigens and 27,000 binding sites for the FcRII were determined using monoclonal antibodies.

Autoantibodies↗
PubMed1992

Heparin-associated thrombocytopenia in a patient treated with polysulphated chondroitin sulphate: evidence for immunological crossreactivity between heparin and polysulphated glycosaminoglycan.

Heparin-associated thrombocytopenia (HAT) type II, a severe side effect of heparin therapy, is thought to be induced by an immunological mechanism. By crossreactivity studies we have demonstrated that sera of patients with HAT type II activate platelets in vitro not only after the addition of heparin but also after addition of a chemically polysulphated chondroitin-like substance, Arteparon, used for treatment of degenerative joint disease. In addition here, we describe a patient who developed deep venous thrombosis and pulmonary embolism following administration of Arteparon and typical HAT type II with thrombocytopenia, 36 h after the first administration of heparin. This patient had never received heparin, but had repeatedly been treated with Arteparon for degenerative joint disease. We conclude that this patient had been presensitized by Arteparon, as indicated by his clinical course. In vitro studies again confirm crossreactivity between heparin and Arteparon.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1992

Serological and clinical aspects of granulocyte antibodies leading to alloimmune neonatal neutropenia.

Eighteen cases of alloimmune neonatal neutropenia (ANN) were analysed for their clinical and serological properties. Pregnancy was normal in all cases, but a 50% incidence of abortion is recorded. With the exception of two premature babies, all newborns were delivered at term. Omphalitis and mild infections of the skin were predominantly present. None of the new-borns died by overwhelming sepsis. The average duration of neutropenia was 11 weeks (range 3-28 weeks). Intravenous IgG therapy was followed by transient remission in 2 of 4 affected newborns. Antibody differentiation revealed in five sera NA1-, in four sera NA2- and in two sera NB1-specific antibodies. In two sera only HLA antibodies were detectable. Complement activating antibodies were determined in 72% of the sera. Screening for granulocyte-specific antibodies in 1016 postpartum sera of unselected women revealed a total of 11 sera (1.1%) reacting selectively with granulocytes, but only four (0.4%) were directed against a known granulocyte-specific antigen. None of the new-born of mothers alloimmunized to granulocyte antigens developed neutropenia, which suggests an incidence of ANN below 0.1%.

Abortion, Spontaneous↗
PubMed1992

Anti-HPA-4b (anti-Yuk(a)) neonatal alloimmune thrombocytopenia: first report in a Caucasian family.

Neonatal alloimmune thrombocytopenia (NAIT) is caused by platelet antigen incompatibility between the mother and fetus. NAIT is mainly due to alloimmunization; the frequency varying among ethnic groups. In Caucasians HPA-1a is the antigen most frequently implicated. In Japan, NAIT due to anti-HPA-4b antibody has already been described, but this is the first case to be reported in Caucasians.

Adult↗
PubMed1992

Quantitation of soluble HLA class I antigen in human albumin and immunoglobulin preparations for intravenous use by solid-phase immunoassay.

Soluble HLA class I antigens in human plasma preparations possibly play a role in HLA sensitization and modulation of the immune response. We therefore have determined their concentration in albumin and immunoglobulin preparations from several commercial sources and compared these values to the concentration in normal human sera. For this purpose we used a newly developed solid-phase enzyme immunoassay employing rabbit anti-mouse antibody, monomorphic HLA class I monoclonal antibody and a polyclonal enzyme-linked beta 2-microglobulin-specific antiserum. Soluble HLA antigen concentration in 14 albumin batches from 6 manufacturers and in 16 immunoglobulin batches from 11 manufacturers ranged from 0 to 9.6 and from 0 to 20.9 ng/ml. The concentration in normal human sera 1,328 +/- 954 ng/ml (n = 54). We conclude that the concentration of soluble HLA concentration in albumin and immunoglobulin preparations is more than 50 times lower than in normal human serum, but considerable differences exist between products of various manufacturers.

Antibodies, Monoclonal↗
PubMed1992

Results of the DGTI workshop on the evaluation of the reactivity of monoclonal anti-D.

All D+ samples were detected by all monoclonal antibodies without problems. Very few of the 3000 D- samples showed a +/- to ++ reaction with some of the IgG type mabs using the Coombs technique. It is still open whether these are specific reactions with weak positive samples, which were negative with polyclonal sera. IgM type mabs detected up to 100% of the Du samples dependent on the Rh-phenotype and the technique used (CCDuee greater than CcDuee greater than ccDuEe). Most of the CCDuee samples reacted very strong and should no longer be regarded as Du.

Antibodies, Monoclonal↗
PubMed1992

Results of the DGTI workshop on the evaluation of the reactivity of monoclonal anti-D.

All D+ samples were detected by all monoclonal antibodies (mabs) without any problem. Very few of the 3,000 D- samples showed a +/- to ++ reaction with some of the IgG type mabs using the Coombs technique. It is still open whether these are specific reactions with weakly positive samples, which were negative with polyclonal sera. IgM type mabs detected up to 100% of the Du samples dependent on the Rh phenotype and the technique used (CCDuee > CcDuee > ccDuEe). Most of the CCDuee samples reacted very strongly and should no longer be regarded as Du.

Antibodies, Monoclonal↗
PubMed1992

[Detection of platelet-specific alloantigens in 400 unselected blood donors].

Antibodies against platelet specific alloantigens cause neonatal alloimmune thrombocytopenia, posttransfusion purpura, and they are sometimes found in polytransfused patients. In the last few years, new alloantigens were discovered in addition to the Zw-, Bak-, and Ko-alloantigens. In order to obtain representative data for the frequency of all platelet alloantigens in the European population, we typed 400 blood donors of our institution. No significant differences between our findings and data already published were found for the antigens of the HPA-1, -2, -3, and -5 systems; however, no HPA-4b (Yuka)-positive and no Naka-negative individual was found among the 400 blood donors tested. The Siba and HPA-2b antigens proved to be identical. The 'low-frequency' alloantigen Sra was not identified among the 400 individuals tested.

Antigens, Human Platelet↗
PubMed1992

[Clinical and serologic studies in 34 patients with post-transfusion purpura].

Posttransfusion purpura (PTP) is a rare transfusion reaction characterized by a severe bleeding tendency and thrombocytopenia which occurs approximately 1 week after transfusion of platelet-containing blood components in patients previously immunized against platelet alloantigens. 34 cases of PTP were studied. Our patients were all female with a mean age of 60.8 years (35-78 years, n = 32). The inciting blood components were whole blood (4) or red cell concentrates (28). The interval between transfusion and onset of purpura ranged from 2 to 14 days with a clear maximum at 7 and 8 days. In 11 of 13 patients (85%) transfusion was accompanied by febrile, nonhemolytic transfusion reactions. Hemorrhagic symptoms lasted 9.4 days (3-37 days, n = 16). The mean minimal platelet count was 7.1 x 10(3)/microliters [(0-28) x 10(3)/microliters, n = 29]. The platelet count rose to over 50 x 10(3)/microliters after 13.9 days (2-61 days, n = 26), over 100 x 10(3)/microliters after 17.0 days (3-75 days, n = 22). In 1 patient, PTP led to death due to intracranial hemorrhage. 22 patients were treated with corticosteroids, 20 patients with intravenous immunoglobulins (IVIG), 17 of these patients received both. Therapy with IVIG was successful in 14 of 19 patients, whereas platelet transfusions (n = 18) were not able to evaluate the platelet count. Serological analysis showed that antibodies against the HPA-1a antigen either alone (18), in combination with HLA antibodies (12) or with anti-HPA-5b (1) were responsible in 91.2%, while antibodies against other platelet antigens were rarely implicated. In elution experiments HPA-1a antibodies could be eluted from the autologous HPA-1a-negative platelets. We suppose that these antibodies had a pseudo-specificity and were involved in the destruction of the patients' own platelets.

Adult↗
PubMed1992

[Heparin-associated thrombocytopenia: successful therapy of patients after prospective selection of a compatible heparinoid with the heparin-induced platelet activation test].

Diagnosis of HAT type II and treatment of thromboembolic complications in these patients are difficult. Recently we have developed the heparin-induced platelet activation (HIPA) assay which allows a rapid confirmation of the tentative diagnosis of HAT type II. In vitro studies with sera of 25 patients revealed cross-reactivity to the LMW heparins Fragmin, Fraxiparin and Clexane whereas a LMW heparinoid, Org 10172 (Orgaran), did not. In a prospective study this heparinoid was selected for 10 HAT patients, for whom further parenteral anticoagulation was required. In 7 of these patients who received LMW heparins prior to laboratory investigations low platelet counts persisted under treatment with LMW heparins and 2 patients developed additional thromboembolic complications. Upon treatment with Org 10172 platelet counts normalized in 9 patients, in 1 patient thrombocytopenia was unrelated to parenteral anticoagulation, in 1 patient platelet count normalized after discontinuation of Org 10172. We conclude that the HIPA assay allows the laboratory diagnosis of HAT type II and the selection of a compatible heparin or heparinoid for further parenteral anticoagulation.

Cross Reactions↗
PubMed1992

[Clinical importance of granulocyte-specific antibodies].

Clinical and laboratory data of 184 patients with immune neutropenia were evaluated. They suffered from autoimmune neutropenia (n = 165), alloimmune neonatal neutropenia (n = 18) and from transfusion-associated lung injury (n = 1). Autoimmune neutropenia was predominantly found in patients below 3 years. Patients were usually affected by benign bacterial infections. The peripheral blood count showed normal or diminished leukocyte counts with median absolute neutrophil counts of 285 cells/microliters. Bone marrow examination revealed in 60% of the cases a hypercellular marrow with a shift to the left. In 36% the bone marrow was normal and in 4% a hypocellular marrow was found. Spontaneous remission occurred in all newborns and, so far, in 4 patients with autoimmune neutropenia. Symptomatic treatment of the infections was sufficient in most of the patients.

Adolescent↗
PubMed1992

[Granulocyte-specific and HLA antibodies in pregnancy: incidence and clinical value].

Postpartum sera of 1,016 unselected women were examined for granulocyte-specific and HLA antibodies. A total of 11 out of 1,016 sera (1.1%) were only reactive with neutrophils. Cytotoxic HLA antibodies were detected in 24%, noncytotoxic HLA antibodies in 4.8% of the sera. All antibodies belonged to the IgG 1 and IgG 3 subclasses. NA1 and NB1 specificity were each determined in one serum, two sera contained NA2-specific antibodies. After 1 year all antibodies were no more detectable. As none of the newborns from immunized mothers developed neutropenia, the incidence of alloimmune neonatal neutropenia seems to be lower than 0.1%.

Autoimmune Diseases↗