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Biomedical subjects

P G Sprinz

Publications and source records attributed to P G Sprinz.

3 recordsLinked to original sources

Sex difference in the CD4 + CD45R+ T lymphocytes in normal individuals and its selective decrease in women with idiopathic thrombocytopenic purpura.

Chronic idiopathic thrombocytopenic purpura (ITP) is a well-defined autoimmune hematologic disorder. It is more common in women than men. We have shown that patients with active disease have abnormal T cell subsets which are more perturbed in women than in men and functional abnormalities that are confined to the T lymphocytes. In the current study, the anti-2H4 (CD45R) monoclonal antibody was used to divide the CD4 subset into their CD4+ CD45R+ and CD4+ CD45R- T lymphocytes. The subpopulations were measured in the peripheral blood of 26 women and 15 men with active ITP, 16 women and 8 men with disease in remission, and 33 normal healthy women and men. Normal women had increased percentages (P less than 0.0001) and numbers (P less than 0.005) of the CD4+ CD45R+ lymphocytes compared to normal men. Women with active disease had reduced percentages and numbers of CD4+ CD45R+ lymphocytes compared to normal women (P less than 0.0001) and women with disease in remission (P less than 0.001). Those women with decreased CD4+ CD45R+ lymphocytes had a significantly depressed lymphocyte response to polyclonal T cell mitogens. In contrast, men with active disease had neither such phenotypic changes nor functional correlations. The percentages and numbers of CD4+ CD45R- lymphocytes were not changed in either sex with active disease. In conclusion, women, but not men, with active ITP appear to possess a reduced subpopulation of CD4+ CD45R+ T lymphocytes.

Antibodies, Monoclonal

Depressed functional and phenotypic properties of T but not B lymphocytes in idiopathic thrombocytopenic purpura.

Chronic idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder in which the abnormality in cellular immunity has remained only vaguely defined. Previously we have shown that patients with ITP in its active phase have abnormal T cell subsets. We then examined the phenotypes of T and B lymphocytes in an additional 28 patients with ITP and 32 age- and sex-matched normal controls and compared the lymphocytes' capacity to respond to polyclonal T, T cell-dependent B, and B cell mitogens. Blastogenesis to optimal (5.0 micrograms/mL) and suboptimal (0.5 microgram/mL) concentrations of the polyclonal T cell mitogens were markedly depressed in patients compared with normal controls (P less than .0005). Similarly, a severe depression in response was noted with the polyclonal T cell-dependent B cell mitogen (P less than .000001). No difference was seen, however, with the polyclonal B cell mitogen. The proportions of pan-T and T helper/inducer lymphocytes were significantly depressed (P less than .005 and P less than .000005 respectively), and the T suppressor/cytotoxic lymphocytes increased (P less than .02) in patients relative to controls. But there was no difference in the proportion of B lymphocytes or in their functional response. The abnormal cellular immunity appears to be due to a defect in the T lymphocyte population without involvement of the B lymphocytes.

Adult

An animal model of alloimmune thrombocytopenia. I. The role of the mononuclear phagocytic system (MPS).

To understand better the role of the mononuclear phagocytic system (MPS) in accelerated destruction of donor platelets in man following repeated platelet transfusions, an experimental model has been developed using genetically defined animals. Brown Norway rats were immunized with Lewis platelets. Antibodies were detected by immunofluorescence microscopy, and their effects demonstrated by 111In-labeled platelet clearances in vivo and by measurements of organ radioactivity in sacrificed animals. All immunized rats developed platelet alloantibodies and showed a significant decrease (P less than 0.001) in donor platelet survival with sequestration in both the liver and spleen. Liver to spleen radioactivity ratios in nonimmunized animals were less than 0.1, whereas immunized animals had a ratio between 0.6 and 1.0, indicating relatively greater hepatic clearance of allogenic platelets. Studies currently in progress on the administration of vinca alkaloids to immunized animals suggest that the MPS can be impaired from clearing allogenic platelets. This model, therefore, should be helpful in studying the role of the MPS in platelet destruction.

Animals