Immunodeficiency in chronic uremia. Preliminary evidence for thymosin deficiency

Parathyroid hormone and T-cellular immunity in uremic patients in replacement dialytic therapy

We studied 54 patients in replacement dialytic therapy divided into two groups: Group 1, 26 patients with normal parathyroid hormone (PTH) (10-80 pg/ml): and Group 2, 28 patients with elevated PTH (80-400 pg/ml). Total T lymphocytes, CD4, CD8, and CD4/CD8 ratio were evaluated. We found a reduction of total T lymphocytes in both groups compared with controls. A decrease of CD4 and CD4/CD8 ratio with a rise of CD8 occurred in Group 2 but not in Group 1. In Group 2, PTH presented a linear correlation with CD8 and a reverse correlation with total T cells. CD4, and CD4/CD8 ratio. PTH might act on T-cellular immunity with an immunosuppressive effect from the earlier phases of hyperparathyroidism.

Thymus lymphocytes in uraemic rats and the effect of thymosin fraction 5 in vivo

Thymus lymphocyte subsets in uraemic rats were studied using monoclonal antibodies. Severe and moderate uraemia was induced in rats, and sham-operated and normal rats were used as the controls. As a result, the weight of the thymus decreased in uraemic rats. As for lymphocyte subsets, the frequency of W3/25+OX8+ decreased and those of W3/25-OX8-, W3/25+OX8- and W3/25- OX8+ relatively increased in uraemic rats. All these changes were more significant in severely uraemic than in moderately uraemic rats. When thymosin fraction 5 (TF5) was administered to severely uraemic rats, the weight of the thymus increased and the lymphocytes subsets normalized. These results suggest that uraemia may cause a maturational impairment of thymus lymphocytes by the depression of thymic hormone secretion.

Thymic peptide hormones: basic properties and clinical applications in cancer

The manuscript will provide an in-depth and critical review of the nomenclature, biochemistry, biological properties, and a summary of published and on-going clinical trials with all reported thymic preparations, including both partially purified thymic factors (e.g., thymosin fraction 5, thymostimulin) as well as purified and synthesized thymic peptides (e.g., thymosin alpha 1, thymulin). Particular emphasis will be placed on which thymic peptides should be categorized as true hormones. In addition, the comparative biochemistry and biological activity in animals will be summarized and contrasted for all the currently available thymic factors. The effects, in vitro of thymic factors, on peripheral blood lymphocytes isolated from normal donors and patients with primary immunodeficiency disorders, autoimmune disorders, and neoplastic disorders will also be reviewed. Finally, a detailed critical summary of the clinical trials performed with each of the thymic preparations will be presented with an emphasis on treatment of patients with cancer.

Suppressor cells assayed by numerical and functional tests in chronic renal failure

Suppressor cells were assayed by numerical and functional tests in adults on chronic hemodialysis. Peripheral blood mononuclears (PBM) were classified as total T-cells by E-rosettes and by the monoclonal antibody OKT3, as T-cell subsets by OKT4 (inducer/helper T-cells) and OKT8 (cytotoxic/suppressor T-cells) and as B-cells by the presence of surface immunoglobulin. The suppressive effect of PBM pretreated with either Concanavalin A (Con A), sodium periodate, or serum rich in immune complexes, on normal homologous phytohemagglutinin (PHA) lymphocyte transformation, was determined. Usual tests of T-cell function were not done. T lymphopenia was due to significant diminution (P less than 0.002) in numbers of OKT4+ cells in patients (516 +/- 44 cells/mm3, mean +/- sem) as compared to controls (906 +/- 96 cells/mm3). The number of OKT8+ cells in patients was not different from normal although their percentage (45 +/- 4%) was slightly higher than controls (36 +/- 5%) (P less than 0.10). Suppressor activity using only a suboptimal dose of Con A (5 micrograms/ml), was significantly lower (P less than 0.002) in uremic patients (36 +/- 12%) than in controls (67 +/- 7%). An important finding was that no significant correlations were detected between the numerical and functional assays of suppression used or between any of these immunological tests and biochemical parameters studied. The implications of these results for immunoparesis in uremia are discussed with particular reference to the discordance between marker and functional assays of suppressor cells.

Decreased antibody-dependent and spontaneous cell-mediated cytotoxicity in patients with chronic renal failure

Antibody-dependent and spontaneous lymphocytotoxicity of blood mononuclear cells from 15 patients with chronic renal failure was studied in allogeneic K-562 and xenogeneic chicken erythrocyte test systems. Both antibody-dependent and spontaneous cytotoxic activities were significantly decreased in uremic patients as compared to the corresponding mean values of healthy control persons and non-uremic patients with the same underlying diseases. The addition of autologous serum further reduced the impaired cytotoxic capacity of uremic lymphocytes. Uremic sera also inhibited the antibody-dependent and spontaneous lymphocytotoxicity of healthy individuals.

Lymphocyte populations in maintenance hemodialysis patients - reassessment and analysis of B cell subtypes

Maintenance hemodialysis patients are known to be lymphopenic, and it was previously felt that T and B cells were equally and moderately depressed. With modification of the B cell technique, however, we have shown that MHD patients have a relatively more pronounced depression of B cells, with decreased proportions and markedly reduced total numbers. B cells bearing specific immunoglobulin types are all proportionally reduced. This marked B cell deficiency could be responsible for the increased rate of some infections in MHD subjects. Its relationship to azotemia, malnutrition, toxic or deficiency states, or dialysis itself is unknown, and the stages of cellular maturation or interaction which are affected have not been identified.

The effect of uraemic "middle-sized molecules" on T lymphocyte functions

The activity of the leucocyte inhibitory factor (LIF) stimulated with Concanavalin A was examined in chronic uraemic, haemodialysed patients. It was found that the LIF activity decreased in chronic uraemic patients as compared with the normal controls. The absolute T lymphocyte count and active E rosette formation also decreased. In in vitro experiments the authors have also examined the inhibitory effect of the so-called "middle-sized molecule" (MSM) on uraemic materials separated from the serum and the haemofiltrate. They observed that the materials with a molecular weight of 1000-1500 isolated both from the serum and the haemofiltrate significantly inhibited the Con A stimulated LIF production of normal lymphocytes and decreased the ratio of the active E rosette-forming T lymphocytes. On the basis of their experiments the MSM uraemic materials are considered responsible for the decreased immune reactivity of uraemic patients. These uraemic toxins can be dialysed.