Effect of probucol in a murine model of slowly progressive polycystic kidney disease

Epithelial proliferation, extracellular matrix remodeling, and interstitial inflammation are central elements in the pathogenesis of slowly progressive polycystic kidney disorders. Probucol, an antioxidant that lowers plasma cholesterol, has been shown to decrease smooth muscle cell proliferation and macrophage accumulation in blood vessels and to prevent restenosis after coronary angioplasty. We determined in 30-day-old male BDF1-pcy hybrid mice (derived from mating DBA/2FG-pcy and C57BL/6FG-pcy) the effect of probucol administered in the diet (1%) for 200 days on kidney weight relative to body weight (KW/BW), cyst expansion, renal interstitial fibrosis, and serum urea nitrogen (SUN) concentration. Animals were fed a moderately high-protein diet (HPD, 36%) to accentuate the development of renal cysts and to promote interstitial fibrosis. Probucol decreased serum cholesterol from 68 to 16 mg/dL but had no effect on food intake or body weight. Probucol decreased relative kidney size from 4.16% +/- 0.55% to 2.64% +/- 0.12% KW/BW (P < 0.01), SUN from 30.5 +/- 1.8 to 25.9 +/- 1.0 mg/dL (P < 0.05), cystic index from 2.45 +/- 0.11 to 1.36 +/- 0.10 (P < 0.01), and fibrosis index from 2.40 +/- 0.11 to 1.82 +/- 0.08 (P < 0.01). We conclude that probucol ameliorates the progressive deterioration in renal function and structure in pcy mice ingesting a relatively high level of dietary protein.

Over-expression of the decoy receptor 3 (DcR3) gene in peripheral blood mononuclear cells (PBMC) derived from silicosis patients

Dysregulation of apoptosis, particularly in the Fas/Fas ligand (FasL) pathway, is considered to be involved in the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE). Recently, a soluble decoy receptor, termed decoy receptor 3 (DcR3), that binds FasL and inhibits FasL-induced apoptosis, has been identified. Silicosis is clinically characterized not only by respiratory disorders but by immunological abnormalities. We have found that serum soluble Fas (sFas) levels are elevated in silicosis patients and that sFas message is dominantly expressed in PBMC derived from these patients. This study examined DcR3 gene expression in PBMC derived from patients with silicosis, SLE, or progressive systemic sclerosis (PSS), and compared it with that in healthy volunteers (HV). The relative expression level of the DcR3 gene was examined in PBMC derived from 37 patients with silicosis without clinical symptoms of autoimmune disease, nine patients with SLE, 12 patients with PSS, and 28 HV using the semiquantitative multiplex-reverse transcriptase-polymerase chain reaction (MP-RT-PCR). The correlation between the relative expression level of the DcR3 gene and multiple clinical parameters for respiratory disorders and immunological abnormalities in individuals with silicosis was analysed. The DcR3 gene was significantly over-expressed in cases of silicosis or SLE when compared with HV. In addition, the DcR3 relative expression level was positively correlated with the serum sFas level in silicosis patients. It is unclear, however, whether over-expression of the DcR3 gene in silicosis is caused by chronic silica exposure, merely accompanies the alteration in Fas-related molecules, or precedes the clinical onset of autoimmune abnormalities. It will be necessary to study these patients further, establish an in vitro model of human T cells exposed recurrently to silica compounds, and resolve whether the increase in DcR3 mRNA expression is a cause or consequence of disease.

Serum levels of soluble Fas ligand in patients with silicosis

Certain patients with silicosis have been reported to exhibit immunological abnormalities such as the appearance of antinuclear antibodies and the occurrence of autoimmune diseases. Fas ligand (FasL) is a type II membrane protein which induces apoptosis by binding to its membrane receptor, Fas. FasL is converted to a soluble form by a metalloproteinase-like enzyme. We have already found serum soluble Fas (sFas) levels in silicosis patients as well as in patients with systemic lupus erythematosus (SLE) to be significantly higher than those in healthy volunteers. To examine further the role of the Fas/FasL system in silica-induced immunological abnormalities, we investigated serum soluble FasL (sFasL) levels in silicosis patients with no clinical symptoms of autoimmune diseases, using ELISA for sFasL. Although the serum sFasL levels in patients with SLE were significantly higher than those in healthy volunteers and showed a slight positive correlation with serum sFas levels, those in silicosis patients exhibited no significant difference from those in healthy volunteers, and there was no correlation with serum sFas levels. However, sFasL levels were elevated in silicosis patients with slight dyspnoea or normal PCO2 among various clinical parameters of silicosis. It may be speculated that the immunological disturbances presented by the abnormalities of apoptosis-related molecules in silicosis patients do not occur with a similar degree of respiratory involvement. Further studies are required to clarify which kinds of factors are involved in silicosis patients who exhibit immunological abnormalities.

Evaluation of cases with silicosis using the parameters related to Fas-mediated apoptosis

To establish a new clinical index for immunological abnormalities occurring in silicosis, several clinical parameters related to Fas-mediated apoptosis; i.e., membrane Fas expression on peripheral blood lymphocytes (mFas), serum soluble Fas levels (sFas), serum soluble Fas ligand levels (sFasL), and soluble/membrane Fas mRNA expression ratios (s/mFas ExR) in peripheral blood mononuclear cells (PBMC) were investigated. Fifty-eight silicosis patients with no clinical symptoms of autoimmune diseases were the subjects of this study. Factor analysis was performed using 12 clinical parameters including four parameters related to Fas-mediated apoptosis. Two common factors were identified. Factor 1 which consisted of the following parameters; duration of exposure, symptomatic dyspnea, PO2, PCO2, and A-aDO2, should be designated as the respiratory factor for cases with silicosis. The parameters of factor 2 were serum IgG, sFas with high factor loading, titer of ANA, sFasL, and s/mFas ExR. These parameters of factor 2 are indicative of the immunological disorders occurring in silicosis cases. Some cases exhibited abnormalities in parameters of factor 2 but not factor 1. The factor analysis clearly demonstrated that the parameters related to Fas-mediated apoptosis should be the most beneficial for predicting the pre-clinical status of complicated autoimmune diseases in silicosis.

Closely linked polymorphic markers for determining the autosomal dominant allele (Cy) in rat polycystic kidney disease

The Han:SPRD strain is an SD-background strain known to be a model of polycystic kidney disease (PKD) expressed through an autosomal dominant gene (Cy). However, different genotypes of this strain cannot be identified in the neonatal period. First, to establish an accurate method of determining the genotypes (Cy/Cy, Cy/+, +/+) which cause different disease progressions, we used polymorphic markers on rat chromosome 5. PCR products of tissue DNA templated with D5Rat9 showed distinct patterns on electrophoresis indicating three genotypes. Second, to determine whether the same locus plays a major role in expressing PKD, we performed linkage analyses in a [BN x (BN x Han:SPRD)F1] backcross. Cy/Cy and Cy/+ also caused PKD in a BN background. In this backcross, we discovered that D5Rat11 is located closer to the Cy locus than D5Mgh10, which is regarded as one of the closest loci. We conclude that D5Rat9 and D5Rat11 are useful markers for determining the presence of the Cy allele, which is regarded as the gene responsible for PKD.

A mild transient decrease of peripheral red blood cell counts induced by a suprapharmacological dose of pegylated human megakaryocyte growth and development factor in rats

Previous studies have shown that pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) at suprapharmacological dose induces a mild transient decrease of red blood cell counts according to thrombopoiesis in normal mice. To unravel the mechanism underlying this mild transient decrease of red blood cells, we have studied the effect of PEG-rHuMGDF on the circulating plasma and blood volume, and the serum biochemical parameters of anaemia and splenectomy. Also, we have performed histological studies of the bone marrow and the spleen of PEG-rHuMGDF-treated rats. PEG-rHuMGDF (300 microg kg(-1)]) or vehicle was subcutaneously administered to rats once a day for up to five days. From day 6 after the start of PEG-rHuMGDF administration, the platelet counts and plateletcrit levels were significantly increased, reaching peak values on day 10, and recovering to normal by day 20. The red blood cell counts and the haematocrit levels were significantly decreased on day 6 to 13. The decreases in red blood cell levels and haematocrit produced by PEG-rHuMGDF treatment were mild and had recovered by day 15. The plasma and blood volumes were significantly increased on day 10 in PEG-rHuMGDF-treated rats. No alteration of the serum biochemical parameters for anaemia, iron or total bilirubin, were observed on day 10. The histological examination on day 10 revealed a marked increase in megakaryocytes and a slight decrease in erythropoiesis in the bone marrow of rats that received PEG-rHuMGDF (300 microg kg(-1)). There was also a slight increase in splenic megakaryocytes and erythropoiesis. The decrease of red blood cells by PEG-rHuMGDF was not affected by splenectomy. These results suggest that the mild transient decrease of red blood cells induced by PEG-rHuMGDF treatment for up to five days is based mainly on the increases in the plasma and blood volume. These events are secondary changes due to the regulation of the excess production of megakaryocytes in the marrow and the peripheral platelets.

Exploitation of the continuum between early ischemia/reperfusion injury and host alloresponsiveness: indefinite kidney allograft survival by treatment with a soluble P-selectin ligand and low-dose cyclosporine in combination

BACKGROUND

We have shown previously that sPSGL, a soluble glycoprotein ligand for P and E selectins, reduces the events associated with ischemia/reperfusion injury of the kidney. In the present study, we have attempted to modulate differentially early inflammatory influences and later host alloresponsiveness in an LBNF1-Lewis renal graft model by treatment with sPSGL in combination with a marginally effective dose of cyclosporine (CsA).

METHODS

Four experimental groups were studied: group 1=control animals receiving vehicle only; group 2=sPSGL monotherapy alone; group 3=low-dose CsA; group 4=sPSGL plus low-dose CsA. Grafts were removed at 1, 3, 5, and 7 days (n=3/time point) and assessed by histology, immunohistology, and reverse transcriptase-polymerase chain reaction. Long-surviving grafts in recipients of groups 3 and 4 were followed functionally for more than 28 weeks.

RESULTS

Graft function was prolonged indefinitely in recipients in group 4, all of which survived for more than 200 days. In contrast, survival of animals in groups 1 and 2 was not increased substantially, whereas only 4 of 17 animals in group 3 (23.5%) survived more than 24 days (P<0.01). Five days after engraftment, necrosis was relatively minimal in group 4 organs but pronounced in those of the other groups. By immunohistology, numbers of infiltrating CD4+ and CD8+ T cells and ED1+ macrophages were significantly diminished in group 4 allografts compared with those of the other groups. Serial assessment of chemokine and cytokine mRNA expression confirmed these findings. The long-term effects of CsA treatment alone were compared with those of sPSGL in combination with CsA. Proteinuria remained virtually absent in group 4 recipients. Morphologically, the few long-surviving grafts in group 3 showed signs of chronic rejection; those in group 4 remained relatively normal.

CONCLUSIONS

Although treatment with sPSGL alone showed no apparent influence on the acutely rejecting transplants, at least by the parameters examined in this study, it produced indefinite survival of kidney grafts when used in combination with low-dose CsA. The data support the influence of early nonspecific injury on later immunological rejection.

Effects of KRN4884 (a novel K+ channel opener), levcromakalim, nilvadipine and propranolol on endothelin-1-induced heart disorders in anesthetized rats

The effects of KRN4884 (5-amino-N-[2-(2-chrolophenyl)ethyl]-N'-cyano-3-pyridinecarboxa midine), a novel K+ channel opener, on the electrocardiogram changes caused by the intracoronary administration of endothelin-1 (ET-1) were studied in anesthetized rats and compared with the effects of levcromakalim, a K+ channel opener; nilvadipine, a Ca2+ antagonist; and propranolol, a beta-adrenoceptor antagonist. KRN4884 (50 microg/kg, i.v.) and levcromakalim (300 microg/kg, i.v.) inhibited the ST segment elevation and the development of arrhythmias induced by ET-1 (5 microg, i.c.) and decreased the incidence of death. Nilvadipine (300 microg/kg, i.v.) and propranolol (1000 and 3000 microg/kg, i.v.) each prevented the ST segment elevation, but the suppressions of the occurrence of arrhythmias produced by nilvadipine and propranolol were less than that shown by KRN4884. KRN4884 (30 and 50 microg/kg, i.v.), levcromakalim (100 and 300 microg/kg, i.v.) and nilvadipine (100 and 300 microg/kg, i.v.) significantly decreased the mean blood pressure in a dose-dependent manner, but propranolol did not. The heart rate was decreased by nilvadipine (100 and 300 microg/kg, i.v.) and propranolol (1000 and 3000 microg/kg, i.v.), but was not affected by KRN4884 (30 and 50 microg/kg, i.v.) or levcromakalim (100 and 300 microg/kg, i.v.). These results suggest that pretreatments with KRN4884 and levcromakalim are more effective on ET-1-induced electrocardiogram changes than those with nilvadipine and propranolol.

Chronic rejection: increasing evidence for the importance of allogen-independent factors

Chronic rejection is a process caused by an interplay of different risk factors. Early injury regardless of type, seems to be an important prognostic event. Later insults appear to contribute. As the individual components of the process are increasingly dissected and understood, means to modulate or normalize them will be forthcoming.

Soluble Fas mRNA is dominantly expressed in cases with silicosis

Although it is well known that cases with silicosis exhibit various immunological abnormalities, the mechanisms involved in the occurrence of immuno-dysfunction or dysregulation induced by silica compounds have not yet been determined. Fas is a well-known cell surface molecule that is involved in the apoptosis pathway that belongs to the tumour necrosis factor-receptor family. Soluble Fas (sFas) is produced as an alternatively spliced product of the Fas gene and protects cells from apoptosis due to antagonization of the binding between membrane form of the Fas gene (mFas) and the Fas ligand. To determine the role of the Fas/Fas ligand system in silica-induced immunological abnormalities, we investigated Fas and Fas-ligand message expression levels using the multiplex reverse transcription-polymerase chain reaction (RT-PCR) method with peripheral blood mononuclear cells from silicosis cases with no clinical symptoms of autoimmune diseases. Although the relative expression levels of the Fas or Fas-ligand genes were not remarkably altered in these cases, we observed the sFas message was dominantly expressed compared with mFas expression. These results suggest that self-recognizing clones in cases with silicosis survive for decades, escaping the exclusion mechanisms induced by apoptosis. Then they cause the appearance of autoantibodies and the acquisition of autoimmune diseases sequentially.

Infection-associated macrophage activation accelerates chronic renal allograft rejection in rats

BACKGROUND

The influence of infection-associated cellular activation on chronic rejection of kidney grafts was assessed in an established rat model by administration of lipopolysaccharide (LPS), an endotoxin and a potent stimulator of various cell populations including mononuclear cells and renal epithelial cells.

METHODS

Lewis recipients of F344 kidneys were treated with low-dose cyclosporine (1.5 mg/kg/day x 10 days). Animals with well-functioning grafts received a single dose of LPS (2 mg in 1 ml of NaCl, intraperitoneally) at 4 or 8 weeks after engraftment. Untreated control rats, which later experienced chronic rejection, were given 1 ml of NaCl.

RESULTS

Administration of LPS during the early quiescent phase of chronic rejection accelerated the chronic process, functionally (proteinuria), morphologically, immunohistologically, and by reverse-transcriptase polymerase chain reaction as compared with untreated controls. Infiltration of macrophages and their associated factors was especially affected.

CONCLUSIONS

As the later events of chronic rejection seem to be mediated primarily by macrophages and their products, administration of LPS accelerated the tempo and activity of these cells in the development of chronic rejection. These findings may explain the clinical observation that infection may be an important risk factor for chronic allograft rejection.

The role of transforming growth factor-beta in PEG-rHuMGDF-induced reversible myelofibrosis in rats

Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) injected at a suprapharmacologic dose (100 microg/kg) daily for 5 d in normal rats caused marked increases in marrow megakaryocytes and platelet counts at 6-8 d followed by gradual decreases to control levels at 10-20 d. Interestingly, in addition to the expected thrombopoiesis, PEG-rHuMGDF was associated with myelofibrosis with a predominance of reticulin fibres at day 10 followed by complete normalization by day 20. At 6-8 d, the levels of transforming growth factor-beta1 (TGF-beta1) in the extracellular fluid of the marrow, the platelet poor plasma, and the platelet extract were increased 23-, 7- and 2-fold, respectively. The elevated levels of TGF-beta1 were gradually reduced to baseline levels at 13-20 d in accordance with the normalization of myelofibrosis and thrombopoiesis. An ultrastructural analysis showed that large fragments of megakaryocytes were deposited in the marrow parenchyma of PEG-rHuMGDF-treated rats at day 6. PEG-rHuMGDF administration at pharmacologic doses (1 and 10 microg/kg) did not induce the deposition of reticulin fibres in the marrow. These findings suggest that TGF-beta1 leaked from megakaryocytes is involved in the development of the PEG-rHuMGDF-induced myelofibrosis and that this is a reversible process related to the regulation of the excess production of platelets.

Elevated soluble Fas/APO-1 (CD95) levels in silicosis patients without clinical symptoms of autoimmune diseases or malignant tumours

Soluble Fas (sFas) is produced as translation products of alternative mRNA splicing, and antagonizes the membranous Fas molecule in Fas/Fas ligand interactions. We investigated the serum sFas levels in 64 Japanese silicosis patients with no clinical symptoms of autoimmune diseases or malignant tumours, using ELISA for sFas. The serum sFas levels in the silicosis patients were significantly higher than those in healthy volunteers. Elevated serum sFas levels were also detected in patients with systemic lupus erythematosus but, unexpectedly, no difference was observed in sFas levels between progressive systemic sclerosis patients and healthy volunteers. On the other hand, there was no significant difference in the expression of Fas on peripheral blood lymphocytes between the patients with silicosis and age-matched healthy volunteers. These observations provided the first evidence that serum sFas levels are elevated in silicosis patients without clinical symptoms of autoimmune diseases or malignant tumours. It remains to be clarified whether patients with elevated sFas levels have a tendency to develop autoimmune diseases later, or whether some other distinct factor(s) is necessary to initiate the progression of autoimmune diseases.

Sequential cellular and molecular kinetics in acutely rejecting renal allografts in rats

The initial (0-24 hr), early (3-5 days), and late (7-14 days) events occurring in LBNF1 renal allografts transplanted into Lew recipients were examined to define precisely the sequential cellular and molecular kinetics during acute rejection. Grafts and spleens were harvested at 3, 6, 12, and 24 hr, and at 3, 5, 7, and 14 days and processed for morphology, immunohistology, and reverse transcriptase-polymerase chain reaction. Various factors (mRNA) were up-regulated sequentially in the allografts over time. In the initial phase, E-selectin and complement (C1 and C3) expression was noted within 6 hr, peaking by 24 hr. RANTES (regulated upon activation, normal T cell expressed and secreted) increased within 6 hr, and then again between 3 and 6 days. By immunohistology, MHC class II was up-regulated consistently after day 1. Intercellular adhesion molecule-1 expression increased after day 3; lymphocyte function-associated antigen-1+ infiltrating leukocytes peaked at day 5. Infiltrating CD8+ T lymphocytes increased strikingly between days 1 and 3, peaking at day 5; CD4+ cells infiltrated more slowly until day 5. The kinetics of ED1+ macrophages were similar to those of lymphocyte function-associated antigen-1+ cells. The CD4+ T cell-derived product, interleukin (IL)-2, peaked at 7 days. Interferon-gamma increased progressively up to 14 days. By 3 days, the macrophage-associated factor, transforming growth factor-beta, peaked; this was followed by increased IL-6 expression by day 5. IL-1, tumor necrosis factor-alpha, and inducible nitric oxide synthase increased slowly until day 7, declining thereafter. Endothelin increased progressively over the 14-day follow-up period. Cytokine dynamics occurring in host spleen were similar to those noted in the allografts. Although acute rejection is primarily T cell mediated, adhesion molecules, macrophages, and their associated products may influence initial and later changes. The brisk expression of complement, E-selectin, and RANTES within the first few hours after engraftment may occur secondary to ischemic injury and trigger subsequent immunological events. Macrophages and their products may play a larger role in the process than hitherto appreciated.

Improvement of thrombocytopenia following bone marrow transplantation by pegylated recombinant human megakaryocyte growth and development factor in mice

We examined whether pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) is capable of improving thrombocytopenia and promoting thrombopoietic reconstitution following lethal irradiation and bone marrow transplantation (BMT) in mice. Immediately after receiving 10 Gy whole body irradiation (day 0), male C3H/HeN mice were inoculated with 10(6) bone marrow cells obtained from syngeneic mice. Circulating platelet counts decreased to below 4% of the normal counts with a nadir on day 10, and then returned to the normal level on day 28 in the control mice undergoing BMT. Subcutaneous consecutive treatment with PEG-rHuMGDF at doses from 10 to 300 micrograms/kg/day from day 1 for 13 days significantly improved the platelet nadir and promoted platelet recovery. The white blood cell counts and hemoglobin concentration following BMT were not influenced by the PEG-rHuMGDF. PEG-rHuMGDF-injection starting from day 5 did not improve the platelet nadir following BMT. Furthermore, administration with PEG-rHuMGDF on alternate days at 55.7 micrograms/kg/day for 7 days or at an interval of 3 days at 78 micrograms/kg/day for 4 days (twice a week for 2 weeks) had a significant efficacy, but these administration regimens had less efficacy than consecutive administration at 30 micrograms/kg/day for 13 days. The numbers of megakaryocytes and megakaryocyte progenitor cells decreased to 5 and 0.2% of normal level, respectively, in the control mice. Consecutive administration of PEG-rHuMGDF enhanced the recovery of the mean number of these cells compared to those in vehicle-treated mice, although such effects were not statistically significant except for the number of megakaryocyte progenitors on day 12. These results suggest that consecutive treatment with PEG-rHuMGDF beginning from the day after BMT may be effective in improving thrombocytopenia following BMT.

In vivo effects of pegylated recombinant human megakaryocyte growth and development factor on hematopoiesis in normal mice

The in vivo effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), a truncated molecule of recombinant human thrombopoietin modified with polyethylene glycol, were investigated in normal Balb/c mice. PEG-rHuMGDF was more potent in producing platelets and the dose-response curve was steeper compared with the case of the nonpegylated form of this molecule. Five consecutive injections with PEG-rHuMGDF caused a dose-dependent increase in peripheral platelet counts with a peak on day 8. There was a dose-dependent rise in platelet counts on day 8 at daily doses from 0.333 to 30 micrograms/kg. Intermediate doses of PEG-rHuMGDF (1.111 to 10 micrograms/kg/day) caused a significant decrease in mean platelet volume, and conversely, higher doses of PEG-rHuMGDF (30 to 270 micrograms/kg/day) induced a dose-dependent increase in mean platelet volume. There was a dose-dependent decrease in hemoglobin concentration with a minimum on day 8 but no significant reduction in reticulocyte counts following PEG-rHuMGDF administration. White blood cell counts were unchanged by PEG-rHuMGDF treatment. Marrow megakaryocyte size enlarged to 1.5-fold and the number of marrow megakaryocytes increased to sixfold by consecutive administration of PEG-rHuMGDF at 30 micrograms/kg/day. A twofold increase in the number of marrow megakaryocytic progenitor cells (colony-forming units-megakaryocyte) was also observed. Marrow erythroid progenitor (colony-forming units-erythroid) counts decreased but splenic colony-forming units-erythroid, marrow and splenic erythro/myeloid progenitor cell counts, and splenic granulocyte/macrophage progenitor cell counts increased with PEG-rHuMGDF treatment. Marrow and splenic erythroid burst-forming cells were unchanged. These results indicate that PEG-rHuMGDF, a truncated molecule of thrombopoietin, is a potent stimulator for megakaryopoiesis and thrombopoiesis, and also affects the development of other hematopoietic cells in normal mice.

Management conditions during dialysis therapy influence the occurrence of complications after renal transplantation?

We investigated whether the management condition of patients during dialysis therapy has an influence on the occurrence of complications after renal transplantation. Thirty-one patients who underwent renal transplantation were investigated: thirteen received kidneys from living related donors and 18 received cadaveric transplants. The relations between weight gain ratio, cardiothoracic ratio (CTR) and blood pressure during dialysis and the rate of episodes of acute rejection or infection after renal transplantation were analyzed. The rate of acute rejection tended to be higher among patients whose CTR was less than 45% than in those whose CTR was 45% or more. There was no relation found between the rate of infection after transplantation and weight gain ratio. CTR, or blood pressure during dialysis therapy. These results suggest the possibility that the management condition of patients during dialysis therapy influences the rate of acute rejection after these patients undergo renal transplantation.