The effect of acute uræmia upon the survival of skin homografts the influence of uræmia upon certain aspects of lymph-node reactivity

Immune response in experimentally induced uremia. VII. Uremic thymocytes amplify the response of control lymph node cells to alloantigens

The effect of experimentally induced uremia in the rat on the synergistic response between thymus cells (TC) and lymph node cells (LNC) was examined. It was found that: (1) Uremic TC and LNC interact in a synergistic fashion which is greater than that observed for control cells; (2) The response of uremic LNC to alloantigens is suppressed when compared to the response of control LNC; (3) Uremic TC provide more help to control LNC in their response to alloantigens than do control TC; and (4) Treatment of uremic rats with cortisone acetate (CA) enhances their TC ability to amplify control LNC response to alloantigens. Thus, it appears that, while the response of uremic LNC to alloantigens is markedly suppressed, there are potent amplifier cells present in the thymus of uremic rats which have the ability to act in synergism with control LNC in response to alloantigens. This effect is significantly greater than the synergistic activity of control thymocytes.

A mouse model for delayed-type hypersensitivity skin changes in chronic renal failure

Cellular immunity in mice with chronic renal failure was assessed by delayed-type hypersensitivity (DTH) skin testing. Normal, sham-operated, and C57BL/6 mice with chronic renal failure were sensitized and challenged with oxazolone, a contact-sensitizing agent. The magnitude of the DTH response was determined by sequential measurements of ear thickness following local challenge. Consistently lower DTH responses were observed in mice with chronic renal failure. DTH responses in mice with renal failure were highest at 48 hr postchallenge (9.3 +/- 1.3) but still significantly lower (p less than 0.05) than those in both sham-operated (12.9 +/- 0.7) and normal mice (12.6 +/- 1.0). When compared with those of the other groups, DTH responses of sham-operated animals were brisker (24 hr), while those of normal mice were more sustained (72 hr). These results confirm previously reported observations in end-stage renal disease patients. The mouse, along with appropriate skin testing, appears to be a useful model for studying cellular immunity in chronic renal failure.

Immune response in experimentally induced uremia. VI. Uremic macrophages are defective in their ability to present antigen to T cells

The ability of uremic lymphocytes to respond to antigens was examined. We have found that (1) The ability of uremic unfractionated lymph node cells to respond to antigens is severely diminished when compared to the response of control cells; (2) Uremic macrophages are defective in their ability to present antigen to T cells; (3) Treatment of control splenic macrophages with monoclonal anti-Ia antibodies diminishes these macrophages' ability to present antigen, while uremic macrophages so treated show little change in their already diminished accessory cell function; and (4) The uremic splenic macrophage population has more small cells and less Ia determinants per cell than do control splenic macrophages as determined by cytofluorographic analysis. The percentage of Ia+ splenic macrophages is similar in control and uremic rats. It appears that the diminished response of uremic cells to antigens is due to the inability of uremic macrophages to present antigen to T cells. This may play a role in the increased rate of infections seen in uremic patients.

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.

Immune potential in human uraemia. 1. Relationship of glomerular filtration rate to depression of immune potential

Aspects of immune potential in uraemic subjects, categorized by glomerular filtration rate, were intercompared and compared with results obtained from a group of normal volunteers. Evidence is presented to show that depression of both cellular and humoral immune potential occurs with progressive reduction of glomerular filtration rate. Lymphocyte transformation testing to the non-specific mitogen PHA revealed a significant elevation of blastogenic response in uraemia after 96 hours of incubation.

Inhibition of cell proliferation in renal failure and its significance to the uraemic syndrome: a review

The effect of acute and chronic renal failure on cell proliferation in rapidly dividing tissues has been examined in man and animal models. The evidence reviewed supports the hypothesis that renal failure results in a general inhibition of cell proliferation. Cell population kinetic studies of gastrointestinal and skin epithelia in experimental acute renal failure show a prolongation of the cell generation cycle. Less detailed investigations of other proliferative cell systems indicate an inhibitory effect on proliferation within the generative compartment of the erythroid series, lymphoid tissue, seminiferous epithelia and wound granulation tissue. This inhibition appears partly responsible for anaemia and impaired wound healing and may contribute to the abnormal immune responses, gastrointestinal tract lesions and male sterility found in renal failure.

[Immune mechanisms in uremia]

There is both clinical and experimental evidence that cellular and humoral immunity are suppressed in patients with renal insufficiency: observations in organ transplantation and in vitro stimulation of lymphocytes from uraemic patients, investigations of acute and late hypersensitivity reactions, the immune response after active immunization as well as changes of immunoglobulins and lymphatic organs in uraemia are discussed in the paper. The underlying mechanisms are complex and not yet fully understood. Lymphopenia, atrophy of the thymus gland, toxic serum factors, induction of enhancing mechanisms by certain serum fractions and metabolic defects of lymphocytes--all were shown to be involved or at least considered to be. At present, however, it is impossible to define their rank of importance and the exact place they may occupy in the genesis of this type of "natural immunosuppression".