PubMed Health⌕ Search

Biomedical subjects

G Mueller-Eckhardt

Publications and source records attributed to G Mueller-Eckhardt.

72 records · Page 4Linked to original sources
PubMed1983

New evidence for the existence of HLA-B14 subtypes. Linkage with different DR antigens.

In a joint study 109 unrelated HLA-B14 positive individuals were subtyped for the provisional splits 14.1 and 14.2 respectively, based on sera of the 7th and 8th Histocompatibility Workshops. Sixty-eight of these donors as well as 23 families were also typed for DR antigens. Earlier findings concerning a linkage disequilibrium B14.1/Aw32 and B14.2/Aw33 were confirmed. In addition a highly significant association B14.1/DR7 as well as a less striking one for B14.2/DR1 were observed. These findings contribute new arguments for the partition of the B14 antigen.

Genes, MHC Class II↗
PubMed1983

The value of platelet-associated IgG in predicting the efficacy of splenectomy in autoimmune thrombocytopenia.

In a prospective study, the hypothesis of whether the quantitative determination of platelet-associated IgG (PAIgG) in patients with chronic autoimmune thrombocytopenic purpura (ATP) can predict the efficacy of splenectomy, was investigated. PAIgG levels were repeatedly determined in 16 patients with definite ATP pre- and postsplenectomy, and related to platelet counts and platelet mean life span. It was found that patients with an immediate remission after splenectomy tended to have lower PAIgG levels (less than 6%) than failures, but this difference was not statistically significant. We conclude that PAIgG is of limited value for the prediction of the efficacy of splenectomy in ATP.

Adolescent↗
PubMed1982

[Immunothrombocytopenia of the newborn caused by platelet-specific antibodies (anti-P1A1) (author's transl)].

For the first time in the German speaking area 8 cases of neonatal immunothrombocytopenia caused by platelet-specific P1A1 antibodies could be ascertained. The disease is caused by fetomaternal incompatibility against platelet antigens. All mothers were healthy. The children showed a postnatal tendency for petechial haemorrhages. Cerebral haemorrhages occurred in two cases. Optimal treatment consists of administration of P1A1-negative platelets (perhaps of the mother). Demonstration of platelet antibodies is possible nowadays by adequate serological methods.

Adult↗
PubMed1982

Immunogenetic studies of the platelet-specific antigen P1A1 (Zw(a)).

The phenotype frequency of the platelet-specific antigens P1A1/A2 ( = Zw(a,b)) in the German population (N = 711) is 97.75% and 2.25% respectively. The corresponding gene frequencies are P1A1 0.85; P1A2 0.15. The P1A1 determinant is codominantly inherited (19 families; 151 family members). There is a strong gene dosage effect between P1A1 homo and heterozygous individuals. No definite linkage of the locus P1A1 versus the loci HLA-ABC, ABO, or Rh was found.

Antilymphocyte Serum↗
PubMed1982

Platelet associated IgG, platelet survival, and platelet sequestration in thrombocytopenic states.

Platelet-associated IgG (PAIgG), platelet mean life span (MLS), and platelet sequestration sites were studied in 69 patients with immune (ITP) and presumed nonimmune thrombocytopenias (NTP). A shortened MLS was associated with elevated PAIgG (N = 46), and with normal PAIgG (N = 15). Four patients had a normal MLS, but elevated PAIgG, four patients were normal for both parameters. The highest PAIgG values occurred in ITP patients with a very short MLS. Nine NTP patients had also elevated PAIgG, but a normal or slightly shortened MLS. There was a significant double log correlation between PAIgG and MLS for ITP, but not for NTP patients. Judged from the coefficient of determination, only 10% of PAIgG were directly related to a shortened MLS. 70% of patients (N = 63) had exclusively splenic and 30% hepatosplenic sequestration. PAIgG was elevated in 29/44 patients with splenic (66%) and in 16/19 patients with hepatosplenic sequestration (84%). In ITP, PAIgG-positive cases were observed in 69% of splenic v 82% of hepatosplenic sequestration, while in NTP the corresponding figures were 6/11 and 2/2. No significant correlation between PAIgG and either sequestration type was demonstrable. We conclude that in immunologically mediated thrombocytopenia only a small portion of PAIgG accounts for a decreased MLS, and that the concentration of PAIgG per se does not determine the platelet sequestration type.

Adolescent↗
PubMed1982

HLA-B7 on human red blood cells. Improved detection by a radioactive anti-IgG test.

By means of a sensitive radioimmune anti-IgG test (RIAT) HLA-B7 was demonstrated on RBC of all B7 positive individuals (N = 52). Most antigens of the B7 cross-reacting group (B8, 13, w22, 27, 40; N = 36) were also detected. Eluates from B7 positive RBC exhibited clear B7 specificity against RBC as well as lymphocytes.

Blood Platelets↗
PubMed1982

Improved assay for detection of platelet-specific PlA1 antibodies in neonatal alloimmune thrombocytopenia.

A technique is described which permits the detection of platelet-specific, noncomplement-fixing ("blocking') PlA1 antibodies in serologically negative sera of mothers from children suffering from neonatal alloimmune thrombocytopenia. The technique consists of (1) antibody enrichment in eluates prepared from maternal serum and PlA1-positive platelets, and (2) quantitation of antibodies in eluates by the platelet radioactive anti-IgG test. With this assay, PlA1 antibodies were demonstrated in 6 out of 7 maternal sera, and anti-A antibodies in one. It proved valuable also for longitudinal studies for periods up to 30 months after delivery.

ABO Blood-Group System↗
PubMed1980

The role of alloimmunization in platelet survival studies.

The role of platelet alloimmunization in the survival of 51Cr-labeled allogeneic platelets was investigated in 89 patients with severe thrombocytopenias. The serological analysis included HLA typing of patients, screening of their sera in the lymphocytotoxicity test (LCTT), the platelet complement fixation test (PCFT), and the platelet radioactive anti-IgG test (PRAT; N = 38). Platelet donors were selected according to the best available HLA match and crossmatch in LCTT. Alloantibodies against HLA antigens were found in the sera of 17 patients (19.1%). No platelet-specific alloantibodies were detected. The use of compatible, allogeneic platelets permitted the discrimination of diminished platelet production from increased platelet turnover in thrombocytopenic patients with proven alloimmunization. Our results stress the necessity of a serological workup prior to platelet survival studies.

Adult↗
PubMed1980

Post-transfusion thrombocytopenic purpura: immunological and clinical studies in two cases and review of the literature.

Two patients with post-transfusion thrombocytopenic purpura are described, the first cases recognized in Austria and Germany. Both patients were female, 51 and 60 years of age. The purpura was evoked by blood transfusions with a latent period of 2 and 7 days. The thrombocytopenic episode lasted for 22 and 60 days. In one case, thrombocytopenia was associated with agranulocytosis due to transient bone marrow failure. Both patients were negative for the platelet-specific antigen PlA1 (= ZWa). Their sera contained PlA1 as well as potent HLA antibodies. Detailed clinical and serological data are presented. The literature with a total of 25 cases so far reported is surveyed.

Agranulocytosis↗
PubMed1980

The clinical significance of platelet-associated IgG: a study on 298 patients with various disorders.

Platelet-associated IgG (PAIgG) was studied by a quantitative platelet radioactive anti-IgG test (PRAT) in 298 patients. At the time of investigation, 171 patients were thrombocytopenic (platelet count < 100 X 10(9)/l), 127 had normal platelet counts. Patients fell into the following disease categories: Idiopathic thrombocytopenic purpura (ITP) (N = 81), possible ITP (19), acute ITP (9), systemic lupus erythematosus (22), autoimmune haemolytic anaemia of warm-type (18), systemic blood disease (65), liver diseases (35), other (49). A significant elevation of PAIgG was found in all disease categories. There was a significant correlation between PAIgG and the reciprocal values of platelet counts for most disease groups. No relationship was discernible between PAIgG and hypergammaglobulinaemic states (serum IgG > 1.8 g/l). Platelet survival studies (N = 30) revealed that normal and increased values of PAIgG were associated with normal or shortened platelet mean life span. It is concluded that an elevated PAIgG is only one of several factors involved in the development of immunologically medicated thrombocytopenia.

Adult↗
PubMed1980

HLA--C antigens on platelets.

The direct demonstration of HLA-C antigens Cw2, Cw-3, and Cw4 on human platelets is described. The antigens were detected by means of a platelet radioimmune anti-IgG test using acid eluates from platelets and lymphocytotoxic antisera. It is concluded that HLA-C determinants are only weakly expressed on platelets. Individual differences observed reflect antigenic variations.

Antibodies, Anti-Idiotypic↗
PubMed1979

[Immune-haematological diagnosis of neonatal immunothrombocytopenia (author's transl)].

The diagnosis of immunologically caused platelet deficiencies in newborn infants requires use of methods permitting demonstration of platelet auto- and allo-zntibodies, complete and incomplete antibodies. Taking the well known differentiation of neonatal immunothrombocytopenias into auto- and allo-immune diseases as a basis, the immune-haematological findings in eight cases are reported. For the first time two cases are reported in which both idiopathic thrombocytopenic purpura of the mother was known and allo-immunisation against paternal HLA antigens of the child could be demonstrated.

Autoantibodies↗
PubMed1979

HLA antigens in immunologic thrombocytopenic purpura (ITP).

79 patients with definite ITP were investigated for HLA-A, -B, -C antigens. There was an increased frequencey of HLA-B5 in the entire groups (27.8% vs. 16.5% in controls and for HLA-B12 in male patients. However, after correction for the number of antigens tested, the difference of antigen frequencies became insignificant.

Adolescent↗
PubMedDate not supplied

The clinical significance of HLA antigens on red cells. Survival studies in HLA-sensitized individuals.

To investigate the clinical significance of HLA determinants expressed on red cells (RBCs), 51Cr survival studies were carried out in six women (four healthy individuals, two patients with solid carcinoma) immunized against HLA antigens by pregnancy or blood transfusions, respectively. Donors were selected who were compatible in typical RBC antigen systems assayed by conventional techniques but were mismatched for the HLA antigens in question. Crossmatches also were performed with RBC, as well as with lymphocytes, by means of a radioimmune anti-IgG test (RIAT). We found that RBC survival was shortened in all cases. The mean life-span of RBCs depended on antigen specificity rather than on the antibody strength. HLA incompatibility of RBCs could be monitored by the RIAT in all donor/recipient pairs. We conclude that a shortened mean life-span of RBC is to be expected by HLA antibodies, especially when HLA-B7 is involved, but the severity of an in vivo immune reaction in HLA incompatible transfusions cannot be predicted from the in vitro tests used.

Adult↗