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Biomedical subjects

H Matej

Publications and source records attributed to H Matej.

At least 19 recordsLinked to original sources
PubMed1994

Absorption with K562 erythroblastoma cells as a means for discrimination between auto- and alloantibodies in sera of hypersensitized renal patients.

We applied K562 erythroblastoma cell line as a substitute for autologous lymphocytes in the absorption of autoantibodies from sera of 26 hypersensitized renal patients exhibiting high degree of cytotoxic reactivity with a panel of lymphocytes from unrelated individuals (panel reactivity, PRA). All of analysed sera contained allo-reactivity before absorption. After removal of autoantibodies, 85% of the sera still contained alloantibodies whereas in 15% of the sera no alloreactivity was detectable. Absorption of high PRA sera with K562 cells and with autologous lymphoblastoid cell lines derived by transformation with Epstein-Barr virus (EBV-LCL) gave substantially the same results. As autoantibodies have reportedly no effect on kidney graft survival, the autoabsorption of high PRA sera may increase the chance of patients in whom only autoantibodies were detected to receive the transplant. Application of K562 cells, instead of autologous lymphocytes/lymphoblasts, is recommended whenever high numbers of patient's cells are not available. It may be particularly suitable for routine clinical laboratories, not equipped and prepared for derivation and propagation of EBV-LCL.

Adult↗
PubMed1994

Determination of immunoglobulin class of alloantibodies in sera from hypersensitized renal patients.

26 sera from hypersensitized renal patients were analysed for immunoglobulin class of alloantibodies. To assess the participation of IgM and IgG in alloreactivity, sera were treated with dithiothreitol (DTT) or Staphylococcus aureus protein A (SpA), respectively. Treatment with both DTT and SpA was also performed to test the possible contribution of other immunoglobulin classes. Immunological complexes which may mimic alloreactivity were excluded by polyethylene glycol (PEG) treatment. Immunochemically modified sera were tested against a panel of allogeneic B and T lymphocytes. IgG class alloantibodies reactive with B lymphocytes were found two times more frequently than those reactive with T lymphocytes. In 22% of sera only IgM alloantibodies were detected. No contribution of other immunoglobulin classes of immune complexes was seen. Our results show that DTT and SpA treatment are technically simple and reproducible methods of discriminating between IgG and IgM alloantibodies and can be recommended for routine use in clinical analysis of sera from hypersensitized renal patients awaiting kidney graft.

Adult↗
PubMed1992

HLA-DR antigens in children with mumps meningitis.

The frequency of HLA-DR antigens was studied in 54 patients with mumps meningitis, and in two control groups. The first control group comprised 333 randomly chosen subjects while the second group was composed of 46 subjects who have passed mumps without meningitis. The DR5 antigen was more frequent in patients than in the second control group with relative risk of 2.4 and significance at the level of p < 0.05. The p value became insignificant after the correction for the number of antigens investigated.

Child↗
PubMed1992

HLA-A, B, C, and DR gene and haplotype frequencies in 600 poles by a maximum likelihood method of gene counting.

A population sample of 600 healthy, unrelated persons was used for estimating HLA-A, B, C and DR antigen, gene and haplotype frequencies. The Polish population is characterized by a high value of HLA-A10, B13, B27, DR1 and DR5 gene frequencies. Strong gametic associations between genes A1 and B8, A3 and B7, as well as between B8 and DR3, and B7 and DR2, typical for many European populations, are also present in the Polish population.

Adult↗
PubMed1990

[Hodgkin's disease and non-Hodgkin's lymphoma in 2 sisters].

For the first time in the Polish medical literature an appearance is presented of malignant lymphogranulomatosis and of a non-Hodgkin lymphoma in two sisters. A discussion on the etiology of the condition is presented on the ground of the cytogenic studies and tissue compatibilities antigens as well as of the literature of the subject. Genetic background of the two different diseases in two sisters is stressed.

Adult↗
PubMed1989

Allogeneic bone marrow transplantation from HLA-identical siblings following conditioning with busulfan and cyclophosphamide. First results.

In the time period from November 1984 to January 1987 eight allogeneic bone marrow transplantation were performed from HLA-identical siblings. The theoretical chance of success in this group was between 21 and 50%, according to the recent data of the International Bone Marrow Transplant Registry, depending on the diagnosis and clinical condition. The average chance was 37.5%. Haemopoietic reconstitution was achieved in 6 recipients, while 2 died of early complications (cytostatic induced hepatocellular damage and fungal sepsis). Another 3 patients died of complications of the intermediate period (pulmonary bleeding, virus hepatitis, graft rejection). The remaining 3 recipients are alive, in excellent clinical condition, including one girl surviving more than 2 years after the transplantation.

Adolescent↗
PubMed1989

"Lysostrip" experiments with HLA class II antigens. II. Incomplete interdependence of surface mobility of supertypic DR and narrow DR specificities.

Utilizing the lysostrip technique we analyzed the relations between the mobility of supertypic HLA-DRw52 and DRw53, and narrow DR specificities. Different types of determinants were found, the one removed only by supertypic anti-DR allosera, the second removed by narrow anti-DR allosera, and the third removed by supertypic anti-DR and narrow anti-DR allosera as well. The results are discussed in terms of intermolecular complexes formed on cell surface by HLA class II antigens.

B-Lymphocytes↗
PubMed1989

"Lysostrip" experiments with HLA class-II antigens. I. Independent surface mobility of DQ and DR molecules.

We report on results of lysostrip experiments designated to analyse the molecular relations between DQ and DR antigens. The purpose of lysostrip application was to determine whether these antigens can independently be redistributed on B-cell surface by incubation with a specific antibody followed by incubation with F(ab')2 fragments of rabbit antihuman Ig. The obtained results have clearly shown that DQ antigens, and supertypic and narrow DR antigens, move independently, indicating that they are located on separate molecules, supporting the concept of different DQ and DR loci.

B-Lymphocytes↗
PubMed1989

Blood transfusions and the development of cytotoxic antibodies in dialyzed patients.

In our work we investigated factors which can influence the alloimmunization and especially the ranges of cytotoxic antibodies that develop in patients on dialysis awaiting their first graft. Up to 15 liters of administered blood the proportion of immunized patients is rather stabile, not exceeding 50%. After further transfusions the percentage of immunized patients is growing rapidly reaching about 85%. Hyperimmunization, marked by cytotoxic antibodies with more than 80% panel reactivity is significantly more frequent in patients who obtained 15 and more liters of blood. In females the hyperimmunization is about 4 times more frequent than in males.

Antibodies↗
PubMed1989

Association of HLA-DR antigens with the development of cytotoxic antibodies in patients on dialysis.

Association between DR antigens and the occurrence of cytotoxic alloantibodies was studied in 251 patients on dialysis. Patients awaiting their first kidney graft were DR typed, and periodically investigated for the presence of alloantibodies. According to the observed peak panel reactive antibodies (PRA) the patients were divided into 3 groups: A, non-sensitized, B, moderately sensitized, and C, highly sensitized. The antigen DR3 was more frequent in sensitized (groups B + C) than in non-sensitized (group A) patients. This difference was significant on the level of P = 0.003, (Pcorr = 0.02). The antigen DR2 was more frequent in highly sensitized (group C) than in moderately sensitized (group B) patients with P = 0.002, not significant after correction for the number of investigated antigens.

Cytotoxicity, Immunologic↗
PubMed1988

HLA antigens and the antibody response after vaccination to hepatitis B.

The aim of our work was the search for immunogenetic factors that influence the antibody response to HBs antigen. We analyzed the HLA-A, -B, and -DR antigen frequencies in 19 seropositive to HBs and 28 seronegative to HBs healthy persons finding an elevated frequency of B5 in the seropositive group (p value 0.037). After vaccination with Hevac B Pasteur vaccine of the seronegative persons, the low antibody response was associated with B13 (p value 0.041). An association between local side reactions to the vaccine and HLA A3 and B35 were also found (p values 0.042 and 0.022 respectively). The presented p values are not significant after correction for the number of antigens tested and for this reason our findings require confirmation in an independent study.

Adult↗
PubMed1987

HLA as an immunogenetic risk factor in juvenile chronic arthritis.

We investigated the frequencies of HLA-A, -B, -C and -DR antigens in diseased and control group with the aim to find immunogenetic factors that influence the pathogenesis and clinical course of juvenile chronic arthritis (JCA). The study was conducted on 73 JCA patients, 24 boys and 49 girls. On the basis of observed HLA antigen frequencies the relative risks (RR) and their statistical significance as well as the attributable risks (delta) were calculated. In the group of 73 JCA children the only statistically significant finding was a decreased RR for DR7. When the calculations were performed on boys taken from the JCA group, significantly higher RR were found for DR5, B27, B40 and A32. Further analysis was performed on clinically defined subgroups of JCA. In 15 children with pauciarticular persistent arthritis significantly increased RR and delta were found for A25, DR2 and DR3. No significant RR were observed in a subgroup of 44 sero-negative polyarticular arthritis. When only boys of this subgroup were selected for calculations, significantly increased frequencies were found for antigens A32, B40, DR1 and DR5. The reason for a stronger association of immunogenetic risk factors in diseased males than females is discussed.

Arthritis, Juvenile↗
PubMed1987

HLA antigens and susceptibility to myasthenia gravis.

HLA-A, -B, -C and -DR antigen frequencies determined in a group of 73 myasthenia gravis (MG) patients were compared with those of a control group of 205 subjects. The strongest positive association with MG was found antigens B8 and DR3 (relative risks 9.56 and 8.84 respectively). Analysis of our data indicates that both antigens, independently from their linkage disequilibrium, are involved in susceptibility to MG. No relationship between HLA antigens on thymic pathology was observed in our material. In male MG patients the association with DR3 was weaker than in female patients. The difference in DR3 frequency between male and female patients was statistically significant; no significant difference was found for antigen B8. It appears that DR3 contributes to development of MG only in females. In male patients aged more than 30 years at the onset of disease, MG was not associated with B8 or DR3. In contrast, in female patients aged more than 30 years at the onset of disease there was a strong association of B8 and DR3 with the disease.

Adult↗
PubMed1987

Association of HLA antigens with chronic active hepatitis (CAH) in children.

HLA-A and -B antigen frequencies were investigated in a group of 46 children with chronic active hepatitis (CAH) and in a control group of 100 healthy children. The diseased group comprised 43 HBsAg positive and 3 HBsAg negative children. From the antigen frequencies relative risks (RR) were calculated according to the method of Woolf. The A1 and B8 antigens, known to be associated with autoimmune diseases, were only moderately more frequent in the CAH group than in the control. The relative risk for B8 antigen was 2.23 which is near to a significance level of p = 0.05. When the calculations were performed for 43 HBsAg positive CAH children the RR decreased to 1.70. Additionally, observations were performed on associations of HLA antigens with the occurrence of antinuclear antibodies (ANA) and anti-smooth muscle antibodies (SMA). Positive associations were found for ANA with B13 antigen (RR = 14.13) and for SMA with B5 antigen (RR = 13.66) with X2 4.85, and 5.51 respectively, at 1 degree of freedom. The p values, situated between 0.05 and 0.01 were insignificant after the correction for the number of antigens studied.

Adolescent↗
PubMed1986

MLR-stimulating properties of five homozygous typing cells found in an outbred population.

In the characterization of stimulating properties of five HTC's two features were taken into consideration, the reproducibility of stimulation results and the individual cut-off level at which reactions positive for Dw antigen are separated from negative reactions. The reproducibility was characterized by the number of repetitions necessary to diminish the standard error to 10 DNV. Depending on HTC 2-8 repetitions were found to be necessary. The individual cut-off levels were determined with the help of maximal correlation between Dw and DR antigen typing. For different HTC's the levels varied from 22 to 57 DNV.

Breeding↗
PubMed1985

DR antigens as a guide in the search for Dw homozygous typing cells (HTC).

Advantage has been taken from association between DR and Dw genes in the search for homozygous typing cells (HTC). From population data it was calculated that the probability of Dw homozygosity should be about 10 times higher among persons with one identified DR antigen than in a random population. To prove this assumption cells from 11 persons with one DR antigen were tested in different MLR combinations and 5 from them gave reaction patterns typical for HTC. These cells revealed ability to discriminate between high and low MLR responses as indicated by the bimodal or asymmetric curves of distribution of the results.

Alleles↗