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Biomedical subjects

G Michlmayr

Publications and source records attributed to G Michlmayr.

At least 55 records · Page 3Linked to original sources

Immunological characterization of lymphoproliferative disorders by membrane markers.

The characterization of lymphocyte subpopulations by means of surface markers improved our understanding of the immunopathology of lymphoproliferative disorders. In chronic lymphocytic leukemia an accumulation of B-lymphocytes have been documented. The antibody deficiency syndrome in these patients might well reflect a maturation defect of the leukemic B-lymphocytes. In patients with Hodgkin's disease the relative number of B- and T-lymphocytes in the blood was not markedly altered in comparison to normal controls. An increased proliferation primarily of T-lymphocytes however, might suggest their accelerated turnover as an indication of the host response. In most patients with "Non-Hodgkin" lymphomas high numbers of B-lymphocytes were found in affected lymph nodes, and these appear occasionally in the peripheral blood. Differences in immunopathological manifestations of the various subgroups of the "Non-Hodgkin" lymphomas are emphasized and the rare occurrence of lymphomas of T-lymphocytes (mainly observed in lymphoblastic lymphomas and in Sézary syndrome) is discussed. Immunopathological alterations in immunocytomas and the myelomas are considered in respect to the involvement of B-lymphocytes at different stages of maturation.

B-Lymphocytes↗

[Rosette tests in lymphoproliferative diseases].

The percentage and absolute count of B- and T-lymphocytes in the peripheral blood of 170 patients with various lymphoproliferative diseases was determined. T-lymphocytes were assessed by their capacity to form rosettes with unsensitized neuraminidase treated sheep red blood cells, and B-lymphocytes by their capacity to bind immune-complement complexes. The results in CLL, in non-Hodgkin lymphoma and in Hodgkin's disease are discussed with respect to the immunopathology of these diseases.

B-Lymphocytes↗

Surface immunoglobulins and receptor sites for aggregated IgG on leukemic reticuloendotheliosis cells.

On blood lymph nodes and spleen cells of 4 patients with leukemic reticuloendotheliosis (LR) the binding of 125-J-labelled IgG aggregates as well as binding of 125J-labeled anti immunoglobulin sera was studied. Moreover the capacity to form spontaneous rosettes with sheep red blood cells to bind immune complement complexes as well as the proliferative response in the presence of PHA were investigated. On the surface of hairy cells a variety of immunoglobulins were demonstrable. IgG of both types was found to be the predominant surface bound immunoglobulin and evidence was obtained, that these antibodies were adsorbed from the serum via Fc-receptors. In all LR-cases the percentages of T-cell rosettes as well as the PHA responses were decreased when compared with the normal controls. The numbers of immune complement complex binding cells were in the range of the normal controls. Results are discussed with respect to the origin of hairy cells in LR.

Adult↗

Antibodies for T lymphocytes in systemic lupus erythematosus.

Sera of twenty-four patients with systemic lupus erythematosus were evaluated for antibodies cytotoxic for autologous lymphocytes. Such antibodies were domenstrable in twenty-two of these sera, whereas only one out of twenty patients with other connective tissue or lymphoproliferative disease showed a positive test. The antibodies remained detectable even when the patients went into remission. Sera containing the lymphocytotoxic antibodies were tested on cell fractions enriched for T or B lymphocytes. Primarily T lumphocytes wree affected by these antibodies. The presence of antibodies cytotoxic for T lymphocytes corresponded with a deficit of circulating T lymphocytes observed in most of our patients with systemic lupus erythematosys.

Adolescent↗

[Essential mixed cryoglobulinemia with kidney involvement].

Essential mixed cryoglobulin associated with rapidly progressive glomerulonephritis has been observed in a 64-year-old patient. The cryoglobulin consisted of monoclonal IgM-kappa and polyclonal IgG and displayed rheumatoid-factor activity. The antinuclear antibody test was negative. In the immunofluorescent method renal biopsy showed positive staining for IgG; IgM and the early and late complement components. The rheumatoid factor activity of the renal IgM deposits was demonstrated by binding of fluorescent aggregated IgG. There is thus evidence that the vasculitis observed in essential mixed cryoglobulin is caused by IgM-IgG complexes. The differentiation of essential mixed cryoglobulin from lupus nephritis with cryoglobulins is discussed.

Arteritis↗

Insoluble PHA- A B-cell mitogen in man?

Blood lymphocytes of normal individuals and of patients with chronic lymphocytic leukemia were evaluated for their blastogenic response to insoluble PHA. In at least preferential stimulation of normal B-lymphocytes was observed, whereas leukemic lymphocytes were almost insensitive. This result supports the hypothesis of a functionally defective B-lymphocyte population in chronic lymphocytic leukemia.

B-Lymphocytes↗

Increased proliferation of T lymphocytes in the blood of patients with Hodgkin's disease.

We investigated the number of DNA-synthesizing T lymphocytes in the blood of patients with Hodgkin's disease, with infectious mononucleosis and in normal controls. T cells were characterized by their ability to form rosettes with unsensitized neuramidase-treated sheep red blood cells. Cells in DNA synthesis were evaluated autoradiographically after in vitro incubation with [3H]thymidine. Our results indicated a preferential proliferation of T lymphocytes in the blood of patients with Hodgkin's disease and infectious mononucleosis and suggested an increased turnover of these cells.

Adult↗