Low serum albumin in elderly continuous ambulatory peritoneal dialysis patients is attributable to high permeability of peritoneum.

Our study was carried out to investigate changes in nutrition and individual peritoneal membrane transport characteristics in elderly patients on continuous ambulatory peritoneal dialysis (CAPD), expressed as the personal dialysis capacity (PDC). We performed 376 PDC tests in 229 non diabetic patients who were undergoing CAPD from May 1995 to May 1999 in a multicenter study in Japan. We divided the patients into three groups: elderly (age > or = 65 years, n = 56), middle-aged (age 50-65 years, n = 150), and young (age < 50, n = 170). No significant differences were seen in duration of CAPD and incidence of peritonitis between the groups. We then compared the peritoneal function calculated by PDC test in the groups. Serum levels of albumin in elderly patients were significantly lower than those in middle-aged and young patients (elderly: 3.2 +/- 0.1; middle-aged: 3.4 +/- 0.1, p = 0.0447 vs elderly; young: 3.4 +/- 0.1, p = 0.0272 vs elderly). Plasma protein loss from the peritoneum in elderly patients was significantly higher than in middle-aged and young patients (elderly: 0.11 +/- 0.01; middle-aged: 0.09 +/- 0.01, p = 0.0136 vs elderly; young: 0.09 +/- 0.01, p = 0.0161 vs elderly). No significant differences in ultrafiltration volume and water permeability were seen between the groups. Peritoneal area in the elderly group was significantly higher than in the middle-aged and young groups. Peritoneal creatinine clearance (CCr) and Kt/V in elderly patients were significantly higher than in middle-aged and young patients. However, no significant difference in protein nitrogen appearance (PNA) or protein catabolic rate (PCR) was seen between the groups. Urea and creatinine generation rates in elderly patients were significantly lower than in the middle-aged and young patients. These data show that elderly patients receiving CAPD are well maintained from the perspective of urea and water metabolism, indicating that CAPD therapy for the elderly is more acceptable than expected. However, caution should be exercised, owing to the lower serum albumin seen in elderly patients.

[Serum transferrin receptor level as an index of the response to erythropoietin therapy for anemia in pre-dialysis patients with chronic renal failure].

In order to reveal whether serum transferrin receptor (sTfR) can serve as an index in erythropoiesis during recombinant human erythropoietin (rHuEpo) therapy for anemia in pre-dialysis patients with chronic renal failure, we analyzed hematopoietic parameters and sTfR levels in 26 patients who were newly administered rHuEpo. sTfR was determined as sTfR transferrin complex (TRC) using the enzyme linked immunosolvent assay (ELISA) and the latex agglutination nephelometric immunoassay (LA). The therapeutic effect of rHuEpo was expressed as the change in the Ht from the start of treatment to 8 weeks later. (delta Ht). Ht, RBC and Hb levels were significantly increased at 4 and 8 weeks after initiating rHuEpo treatment. Furthermore, sTfR levels were significantly increased at 2 and 4 weeks after the start of rHuEpo treatment. Absolute changes in the sTfR level (sTfR before - sTfR after) and rates of change (absolute change/sTfR before x 100) at, 2, 4 weeks after the start of rHuEpo treatment showed a significant positive correlation with delta Ht. These results indicate that sTfR is a useful marker as an index of therapeutic effect of rHuEpo for anemia in pre-dialysis patients with chronic renal failure.

Effects of monocyte-macrophage colony-stimulating factor (M-CSF) on in vitro erythropoiesis of marrow progenitor cells from patients with renal anemia.

We examined the influence of monocyte-macrophage colony-stimulating factor (M-CSF) on erythropoiesis both in vitro and in vivo in 98 patients with chronic renal failure who were undergoing hemodialysis. Serum levels of M-CSF and the clinical response to therapy with human recombinant erythropoietin (Epo) were analyzed. The following results were obtained: 1) The serum level of M-CSF was 6.90 +/- 2.41 ng/ml in the patient population (n = 98), but only 2.0 +/- 0.3 ng/ml in 10 healthy donors. 2) 41 of the 98 anemic patients were treated with various doses of Epo for 3 months, and the average increase in the blood hemoglobin level during this period was 26.1 +/- 12.5 mg/dl/unit of Epo/kg patient's b.w./week. Lower levels of M-CSF before treatment significantly predicted a better response to subsequent Epo therapy (r = -0.496, p < 0.001). 3) When cultured with a maximally stimulatory amount of Epo (10 IU/ml), the number of marrow early erythroid progenitor cells (burst-forming unit for erythroid, BFU-E) in patients was identical to that in normal donors, while the number of late progenitors (colony-forming unit for erythroid, CFU-E) was relatively lower in patients. 4) The addition of recombinant M-CSF to the culture resulted in suppression of erythroid progenitor cell growth in the patient population, but induced enhancement in normal donors. The inhibitory effect of M-CSF on the patients' cells was not eliminated by the addition of antibodies against interleukin-1 alpha/beta, tumor necrosis factor-alpha, or interferon-alpha/beta/gamma. Supernatants from marrow mononuclear cells cultured in the presence of M-CSF carried this inhibitory effect on marrow CD34+ cells obtained from patients. Together, these results suggest that M-CSF aggravates a previously existing decreased sensitivity of erythroid progenitor cells to Epo in some patients with renal anemia.

Thyroid nodules in female uremic patients on maintenance hemodialysis.

We investigated the incidence of thyroid nodules in female uremic patients on maintenance hemodialysis using a high-frequency sonographic scanner. In 47 (21.0%) of the 224 female normal controls and 33 (55.0%) of the 60 female patients, thyroid nodules were detected. The difference in these incidences between controls and patients was significant. There were no differences in age, duration of hemodialysis, the level of blood urea nitrogen, parathyroid hormone or thyroid stimulating hormone between the patients with thyroid nodules and those without nodules. Although there is a correlation between uremia and the development of thyroid nodules, the details of the underlying mechanism of their association remain unclear.

Measurement of serum levels of macrophage colony-stimulating factor (M-CSF) in patients with uremia.

Serum levels of monokines, including macrophage colony-stimulating factor (M-CSF), tumor necrosis factor-alpha (TNF-alpha), interleukin-1 alpha (IL-1 alpha) and IL-1 beta (IL-1 beta), were measured in patients with chronic renal failure in an attempt to clarify the kinetics of these cytokines in the course of renal anemia. M-CSF was the only monokine detectable in the serum from all patients as well as healthy donors, making this cytokine feasible and reliable for serial evaluations. On all occasions, the level of M-CSF in uremic patients was significantly higher than that in healthy donors (29.4 +/- 12.3 vs. 5.5 +/- 1.1 ng/mL). In patients undergoing hemodialysis, the serum level of M-CSF was greater than that in patients undergoing continuous ambulatory peritoneal dialysis or in uremic patients without dialysis therapy. No difference was observed, however, in the levels of IL-1 alpha, IL-1 beta and TNF-alpha levels in these groups. Patients with severe anemia were subsequently treated with 60 to 80 U/kg per week of human recombinant erythropoietin (rhEpo) for 3 months. After this replacement therapy, hemoglobin levels increased with a variable change ranging from 0 to 3.5 g/dL. The pretherapy M-CSF level, however, was found to predict statistically the response to the therapy (p < 0.05). Patients with a lower pretherapy value responded better to rhEpo therapy; those with a higher level showed a minor degree of response. From these results, we postulate that the elevated M-CSF serum level in uremic patients is in part a consequence of the dialysis procedure and that rhEpo therapy is more effective in patients who are under sophisticated dialysis protocol and have a lower M-CSF level.

Impaired production of burst promoting activity by blood mononuclear cells from chronic uremic patients.

The ability of blood mononuclear cells (MNC) to produce burst promoting activity (BPA) was evaluated in 31 patients with chronic renal failure. The BPA of cells from uremic patients, with or without hemodialysis, was consistently lower than that of 17 normal donors (mean 64%, P less than 0.01). Coculture of MNC with recombinant erythropoietin (rEpo) in vitro did not increase BPA production. Five of 31 patients received in vivo treatment with rEpo (1,500 units x3/week) and showed therapeutic benefit, but in all patients the BPA production remained low. On the other hand, in four patients who were on a hemodialysis protocol and subsequently underwent renal transplantation, impaired BPA production was resolved quickly, and at the same time the number of circulating BFU-E and the hemoglobin level increased toward normal ranges. Furthermore, such impaired BPA production was not observed in patients receiving continuous ambulatory peritoneal dialysis. These observations suggest that decreased production of BPA may play a role in the development of anemia associated with chronic uremic patients, and the correction of BPA production by the improvement of hemodialysis procedure may result in more effective therapy with rEpo for those patients.

[Evaluation of BPA secretory ability from blood mono-nuclear cells in uremic patients after renal transplantation or rEpo treatment].

Conditioned media (CM) of phyto-hemagglutinin-stimulated lymphocytes from chronic uremic patients were studied for burst promoting activity (BPA), using methylcellulose cultures with cord blood cells as a target population. Renal transplantation procedure was followed by a prompt rise of BPA, as well as the number of blood burst-forming unit erythroid (BFU-E) and hemoglobin levels, while no change in BPA and blood BFU-E number was observed in patients receiving rEpo and recovering from anemia. Thus, low BPA secretion from blood cells may have a role in the development of anemia in uremic patients.

Lymphocytes after autologous and allogenic bone marrow transplantation.

Lymphocyte reconstitution after bone marrow transplantation (BMT) was analyzed using two-color flow-cytometry in 18 patients and the differences between allogenic and autologous BMT were studied. The CD8 (+) CD11b (+) and CD8 (+) Leu7 (+) suppressor subsets were increased while the CD4 (+) 2H4 (+) suppressor inducer subset was decreased in both groups after BMT. These variations of suppressor associated subsets persisted for more than 100 days and were considered to be related to immunologic abnormalities in post-BMT patients. In addition, Ia (+) T cells were increased in both autologous and allogenic BMT patients. This increase appears not to be caused by reaction to allo-antigens, but rather reflects the reconstitution of the lymphocyte system after BMT. In contrast, the CD16 (+) NK cell subset was increased specifically in allogenic BMT patients and only for a short time following transplantation.

Interferon-induced resistance of tumor target cells against lysis by interleukin-2-activated killer cells.

IFN-gamma has been shown to decrease the susceptibility of target cells to NK cell-mediated cytotoxicity. In this report, the effect of IFN-gamma on the sensitivity of target cells to killing by various human lymphocyte cytotoxic activities such as NK/K, IL-2-augmented NK/K cell activity, and IL-2-activated killer activity were studied. Although NK-sensitive K562 cells showed marked resistance to NK cell activity as previously reported, the resistance was overwhelmed by augmentation of NK activity with IL-2. IL-2-activated killer cell activity, which can lyse NK-resistant tumor cell lines upon culture in IL-2, showed decreased cytotoxicity against most of the IFN-gamma-treated target cells tested. By contrast, no decrease of target cell sensitivity to K cells was observed, even though K cells were treated with IL-2. These findings suggest that as far as NK-resistant tumor cells are concerned, an IFN-dependent mechanism inhibits the Fc receptor-independent mediators of tumor surveillance, but not Fc receptor-dependent ones. This should be considered when planning adoptive immunotherapy of IL-2-activated killer cells for human malignancy.

Phenotypical and functional heterogeneity of the large granular lymphocytes increased after various treatments in a patient with combined immunodeficiency.

A boy with combined immunodeficiency having low natural killer (NK)-cell activity received thymopoietin pentapeptide (TP-5) treatment, transplanted with T cell-depleted HLA-haploidentical bone marrow (BMT) cells from his father and with thymus tissue from an infant at different times during the first year of life. He showed a marked increase in large granular lymphocytes (LGL) both during the treatment with TP-5 and after BMT. The LGL generated following TP-5 injection had a T3+Leu11- surface phenotype and low NK activity. In contrast, the LGL appearing after BMT showed T3-, Leu7+, and/or Leu11+ surface phenotypes, had high NK- and K-cell activities, and were lymphokine-activated killer (LAK)-cell precursors. These killer activities were assigned to the Leu7-Leu11+ subset and proved to be of recipient origin. LGL proliferation following BMT was accompanied by neutropenia, which was improved in association with a reduction in the number of LGL and the appearance of T cells of BMT donor origin following thymus transplantation. This suggested the inhibition of granulopoiesis by the LGL and an in vitro study revealed that the Leu7+Leu11- subset of LGL suppressed the growth of granulocyte/macrophage colony-forming units. These results indicated that phenotypically different LGL could be generated by different treatments and that the LGL showing NK activity were distinct from those regulating granulopoiesis. It was also suggested that the generation of LGL was controlled by T cells.

The lymphocyte subpopulations involved in cytotoxicity generated by co-culture with autologous and allogeneic Epstein-Barr virus-transformed cell line.

When peripheral blood lymphocytes from healthy adults are cultured with autologous (auto) or allogeneic (allo) Epstein-Barr virus-transformed cells (LCL), non-specific killer activity against NK-sensitive K562 and NK-resistant Raji, as well as specific killer activity against LCL is enhanced or generated. We analyzed the cell subsets possessing such cytotoxicity using monoclonal antibodies (MoAb). OKT3, a MoAb to T cell receptor-associated molecule, added in the effector phase suppressed the killer activity against LCL but not against Raji or K562. In contrast, OKT3 added in the induction phase abolished the generation of cytotoxicity against all targets. The addition of OKT8 in either the effector or induction phase inhibited anti-LCL killing induced by stimulation with alloLCL. This suggests that CD8 is required for recognition of alloLCL. The treatment of effector cells with MoAb and complement(C) revealed that killers against LCL were OKT8+ Leu11-, and those against K562 were OKT8- Leu11+. When auto-LCL were used as stimulator, removal of OKT4+ cells in the induction phase diminished the cytotoxicity against all targets, indicating that CD4+ T cells recognize autoLCL. Elimination of CD8+ cells from responder did not decrease the generation of killer activity. Further experiments suggested that this was caused by the coexistence of CD4+ killer cells or by the increase of residual CD8+ effector cells.