In vitro cellular immunity and in vivo delayed hypersensitivity in uremic patients maintained on hemodialysis

Mycobacterium Chelonei Peritonitis in a Patient Undergoing Continuous Ambulatory Peritoneal Dial ysis (CAPD)

This paper describes a case of Mycobacterium chelonei peritonitis associated with continuous ambulatory peritoneal dialysis (CAPD). The patient probably acquired the infection from tap water. He presented with cloudy effluent, abdominal pain and systemic toxicity. Originally, gram stain, Ziehl-Neelsen stain, aerobic and anaerobic cultures were negative. One week later, culture grew an aerobic, fast growing, acid fast bacterium, which later was identified as Mycobacterium chelonei. The peritonitis was treated successfully with erythromycin and catheter removal. The diagnosis of tuberculous and non-tuberculous mycobacterial peritonitis during CAPD can be difficult. Compared to usual bacterial peritonitis associated with CAPD, everything in these cases proves to be nonspecific. Mycobacterial infection should be suspected in all episodes of culture-negative peritonitis especially those which do not respond to usual antimicrobial therapy.

New insights into the thrombopoietic status of patients on dialysis through the evaluation of megakaryocytopoiesis in bone marrow and of endogenous thrombopoietin levels

The thrombopoietic status of patients with uremia remains unclear. This issue was addressed with particular reference to marrow megakaryocytopoiesis and endogenous thrombopoietin (TPO) levels. A study was conducted in 114 patients on hemodialysis, 43 patients on continuous ambulatory peritoneal dialysis, and 48 age-matched controls. Reticulated platelets, a marker of marrow megakaryocytopoiesis, were measured by flow cytometry. Serum TPO levels, platelet-associated IgG (PAIgG) levels, and hepatitis C virus (HCV) antibody titers were also measured by enzyme-linked immunosorbent assay. Circulating and reticulated platelet counts were significantly lower in the patients on dialysis than in the controls. Thrombocytopenia (less than 150 x 10(9)/L) was most frequent in the HCV-positive hemodialysis patients, who had a higher incidences and higher PAIgG titers. The following results were obtained in the HCV-negative dialysis patients: (1) platelet counts chronologically decreased with years on hemodialysis; (2) platelet counts were associated with the reticulated platelet counts; (3) serum TPO levels were significantly elevated in the dialysis patients, responding to the decrease of reticulated platelets; (4) hematocrits had a positive correlation with serum TPO levels, and serum TPO levels were significantly higher in the patients on hemodialysis who did not require recombinant human erythropoietin therapy than in the other patients. In conclusion, thrombocytopenia is a frequent finding in patients on dialysis. The failure of megakaryocyte production could be the principal cause of the platelet reduction, and the peripheral destruction and sequestration of platelets may be concomitantly involved. Elevation of serum TPO may in part serve as an aid to erythropoiesis in dialysis patients.

Functional changes of monocytes due to dialysis membranes

The functional effects directly induced by dialysis membranes on peripheral monocytes were analyzed in a plasma-free model of simulated dialysis using Cuprophan, cuprammonium rayon, polyacrylonitrile, polymethylmetacrilate and polysulphone membranes. A severe reduction of monocyte phagocytosis of IgG-coated erythrocytes was found by using Cuprophan and cuproammonium rayon. The cytofluorimetric analysis of several cell surface receptors, involved in the immune phagocytosis and recognizable by five quoted monoclonal antibodies, did not reveal any significant change. The defective phagocytosis of the IgG-coated erythrocytes by monocytes, due to the exposure to cellulose-derived membranes, was paralleled by an impaired interiorization of heat-aggregated human immunoglobulins, as analyzed by electron microscopy. The cell membrane binding of aggregated immunoglobulins was found to be unaffected. The defect was associated to a remarkably depressed generation of reactive oxygen species after Zymosan stimulation. Therefore, the defective immune phagocytosis induced by exposure of monocytes to cellulosic membranes was not due to a receptor rearrangement or an impaired binding of ingestible particles, but to a reduced internalization capacity probably related to an energy source exhaustion (as shown by the lack of response to stimuli able to induce oxidizing species production). These features are similar to those described in monocytes from acute systemic lupus erythematosus patients.

Persistence of clinical and serologic activity in patients with systemic lupus erythematosus undergoing peritoneal dialysis

To determine whether patients with systemic lupus erythematosus undergoing long-term peritoneal dialysis have persistent clinical and serologic remissions, the clinical courses of eight patients with end-stage renal disease in whom peritoneal dialysis was begun at Rush-Presbyterian-St. Luke's Medical Center between 1981 and 1986 were analyzed. Patients were followed for a mean of 90.1 +/- 28.8 months before dialysis and 20.8 +/- 4.7 months after the initiation of dialysis. Disease activity was quantified for each individual in terms of "flares" per year before and after the initiation of peritoneal dialysis, the means of which were 0.66 +/- 0.46 and 0.94 +/- 0.28, respectively. Comparison of these rates showed no statistical difference. Seven of the eight patients had at least one flare while receiving peritoneal dialysis, all of which required prednisone therapy (mean 31.3 mg per day). The clinical manifestations included fever, rash, myalgias, anemia, leukopenia, serositis, and cerebritis. Eighty-eight percent of these flares had associated worsening of serologic results. Prednisone was discontinued in only one patient at any time during peritoneal dialysis. This experience reveals that patients with lupus continue to show clinical and serologic disease activity and require maintenance prednisone therapy while receiving long-term peritoneal dialysis.

Immunological monitoring in patients with end-stage renal disease

Parameters of cell-mediated immune function were determined in 76 patients with end-stage renal disease. Lymphocyte subpopulations (OKT3, OKT4, OKT8, OKIa1, OKM1, OKT9, OKT10), natural killer (NK)-cell activity (percentage 51Cr release from K562 targets), and delayed cutaneous hypersensitivity were measured and correlated with other variables. The results indicate that (1) uremic patients have a significant diminution in the OKT4-lymphocyte subpopulation and OKT4/OKT8 (helper/suppressor) ratio compared to normal controls; (2 blood transfusions do not induce significant alterations in the helper/suppressor-cell ratio; (3) uremic patients have a significant increase in OKM1 cells compared to normal controls; (4) the majority of uremic patients in this series developed delayed cutaneous hypersensitivity responses to recall antigens and could be de novo sensitized to 2,4-dinitrochlorobenzene (DNCB); (5) skin-test reactivity could not be correlated with total circulating T cells or levels of any lymphocyte subpopulations; and (6) NK-cell activity in uremic patients is not significantly different from that in normal controls. These results highlight the varying levels and function of different lymphocyte subsets in patients with end-stage renal disease when they are treated with chronic maintenance hemodialysis.

Decreased macrophage-mediated suppression of lymphocyte activation in chronic renal failure

Prostaglandin-dependent adherent cell suppressor activity was assessed in patients with end-stage renal insufficiency. Proliferative responses of uremic peripheral blood mononuclear cells to optimal concentrations of phytohemagglutinin and concanavalin A were impaired. Responses to the galactosyl-directed lectins, soybean agglutinin and peanut agglutinin, were, however, normal or supranormal. The addition of 1 microgram/ml of indomethacin, to cell cultures resulted in relatively less potentiation of blastogenic responses to the galactosyl-directed lectins in cells from uremic patients (soybean agglutinin, p less than 0.02; peanut agglutinin, p less than 0.05). Similarly, depletion of adherent cells markedly enhanced blastogenesis induced by the galactosyl-directed lectins in normal cell cultures, whereas the effect was much less pronounced (soybean agglutinin, p less than 0.02; peanut agglutinin, p less than 0.02) in uremic cells. Reduced activity of the adherent cell suppressor system in patients with renal failure might be associated with altered sensitivity of uremic lymphocytes to soluble mediators of suppression. The lymphocytes of uremic patients, depleted of adherent cells, were relatively resistant to the inhibitory action of prostaglandin E1 (0.001 microgram/ml, p less than 0.05, and 0.01 microgram/ml, p less than 0.02) on galactosyl-directed, lectin-induced mitogenesis. In contrast, dibutyryl cyclic AMP (10(-4) M), 8-bromo cyclic AMP (10(-5) M), and 3-isobutyl-1-methyl xanthine (20 micrograms/ml) inhibited both control subject and patient cultures to the same extent. Prostaglandin E1 in combination with methyl isobutyl xanthine produced, in adherent-cell-depleted control subjects, levels of cyclic AMP that were significantly higher than in cells from uremic patients (p less than 0.05). Thus, depressed adherent cell suppressor activity in patients with renal failure may result in part from impaired generation of cyclic AMP by lymphocytes.

Lymphocyte and granulocyte function in zinc-treated and zinc-deficient hemodialysis patients

Lymphocyte blast transformation and granulocyte motility were studied in 20 clinically stable hemodialysis patients, 10 of whom were receiving 50 mg of zinc (as zinc acetate) per day and 10 of whom were not. Plasma zinc concentration was significantly higher in zinc-treated than in untreated patients (108 +/- 5 vs. 82 +/- 2 micrograms/dl). Mononuclear cell subpopulation analysis showed equivalent proportions of T lymphocytes and monocytes in both groups, but B lymphocytes were reduced in untreated patients (10 +/- 0.7 vs 14 +/- 0.5%). Lymphocyte blast transformations in response to nonspecific mitogens, soluble antigen and mixed lymphocyte culture were not significantly different in the two groups, nor was lymphocyte zinc concentration. Zinc-treated patients showed significantly greater granulocyte responsiveness to zymosan-activated serum (21 +/- 1 vs. 14 +/- 2 mean), greater chemokinetic activity (50 +/- 4 vs. 27 +/- 3 mean) and higher granulocyte zinc concentration (114 +/- 6 vs. 47 +/- 2 micrograms/10(6) cells) than untreated patients. Granulocyte zinc correlated significantly with plasma zinc (r = 0.81, P less than 0.001) and with granulocyte motility (r = 0.63, P = 0.001). Moderate zinc deficiency in hemodialysis patients does not result in abnormal lymphocyte blast transformation in vitro, but it does result in granulocyte zinc depletion and impaired granulocyte motility.

Tuberculous peritonitis in patients undergoing chronic home peritoneal dialysis

Peritonitis is a well-recognized complication of chronic peritoneal dialysis. However, in many instances the etiology of the peritonitis remains obscure despite intensive evaluation. Recent reports have suggested that pulmonary and extrapulmonary tuberculosis occurs with increased incidence in chronic hemodialysis patients. We report the first three cases of tuberculous peritonitis occurring in patients being treated with chronic intermittent peritoneal dialysis. The lack of active tuberculosis elsewhere and the predominance of polymorphonuclear leukocytes in peritoneal fluid made the diagnosis particularly difficult in this setting. The characteristics of the peritoneal fluid are quite similar to that seen in bacterial peritonitis, and unlike that found in peritonitis due to tuberculosis in nondialyzed patients. Tuberculous peritonitis should be suspected in peritoneal dialysis patients with chronic or relapsing peritonitis in whom the diagnosis of bacterial or fungal peritonitis cannot be confirmed.

Development of anergy to delayed-type hypersensitivity antigens following renal allotransplantation

A study is reported of patients receiving 180 renal allotransplants and at risk for 1 or more years who had pretransplant and posttransplant skin tests using delayed type hypersensitivity (DTH) recall antigens. Pretransplant skin testing revealed an incidence of 14% anergic patients prior to a first transplant, and 35% were anergic prior to a second allograft. There was a statistically significant correlation between pretransplant anergy and age, as well as a significant correlation between pretransplant anergy and time of dialysis-dependent uremia. The conversion to the anegic state posttransplant in those patients with surviving allografts increased annually for the first 5 years as a linear function, with 69% of the population at risk with their first transplant exhibiting anergy by 5 years. In those patients receiving second renal transplants, all were anergic by 4 years posttransplant. In vitro tests of lymphocyte function using mitogen stimulation did not reveal significant differences between anergic and responsive patients. In this series of 180 allografts there were 14 late deaths. Eleven of these were in anergic patients and in 10 instances were related to sepsis or malignancy. Three patients who were skin-test responsive at the time of death died from cardiovascular causes. It is concluded that there is an increasing risk of the development of anergy to DTH antigens posttransplant and that the type of late mortality may be marked by this hyporeactive state.

Effect of haemo- and peritoneal dialysis on the cell-mediated immune response in chronic uraemia

Lymphocytopenia, decreased spontaneous rosette formation, and a decreased T lymphocyte count have been found in patients with non-uraemic glomerulonephritis (71 cases) and in different stages of uraemia (68 cases). In chronic glomerulonephritis and in the early stage of uraemia, cell-mediated hypersensitivity (lymphocyte migration inhibition) to glomerular basement membrane (GBM) characteristic of glomerulonephritis could be demonstrated. Hypersensitivity disappeared in the terminal stage of uraemia indicating endogenous immunosuppression.