SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Phagocyte function in immunosuppressed allograft recipients is regularly diminished and correlates to leucopenia in only 50% of cases. Significantly reduced phagocyte function carries a 50% risk of septic complications. Monitoring of phagocyte function can be helpful in assessing defense reserves in the compromised host.
A major dilemma in pancreas transplantation is the lack of reliable methods for the early detection of allograft rejection. Over a 26-mo period, 70 rejection episodes occurred in 36 patients (13 isolated-pancreas, 23 simultaneous pancreas-kidney recipients) with pancreaticoduodenocystostomy. A total of 300 radionuclide pancreas examinations were performed (mean 8.3/patient) utilizing 99mTc-labeled DTPA. Computer analysis generated a quantitative measure of blood flow to the allograft (technetium index, TI). Rejection episodes were defined as isolated pancreas, isolated kidney, or combined pancreas-kidney. Mean urinary amylase (UA) levels and TI during normal allograft function were 30,256 U/L and 0.57%, respectively, whereas levels heralding rejection were 6873 U/L and 0.39% (P less than .05). The treatment of rejection based on kidney dysfunction or combined pancreas-kidney dysfunction resulted in significantly higher graft salvage and a lower incidence of hyperglycemia compared with isolated-pancreas-allograft rejection. After therapy, a TI greater than 0.3% was associated with 95.9% graft survival, whereas levels less than 0.3% resulted in a 72.7% rate of graft loss (P less than .001). Similarly, pancreas allografts with a UA greater than 10,000 U/L had 92.2% functional survival, whereas levels less than 10,000 U/L resulted in a 53.3% rate of graft loss (P less than 0.001). Overall, reversal of rejection occurred in 80% of cases, with 10 pancreas and 2 kidney allografts lost due to rejection. Monitoring pancreas-allograft function by UA, TI, and renal function in simultaneous transplants allows for the timely diagnosis and successful treatment of pancreas-allograft rejection.
Platelet activating factor (PAF) is a potent lipid mediator with a broad range of biologic activities. Experimental evidence suggests that PAF plays a role in the pathogenesis of a variety of inflammatory processes including allograft rejection. In this study, we evaluated the effects of the PAF antagonist BN52021 on the course of renal allograft rejection in a rat model. Kidneys from ACI (RT1a) rats were transplanted into fully allogeneic PVG (RT1c) rat recipients. Animals received 60 mg/kg/day of the PAF antagonist or vehicle beginning immediately prior to the transplantation procedure. In rats treated with the PAF antagonist, allograft GFR and plasma flow were maintained at levels that were significantly greater than controls. Despite the improvement in renal allograft function, BN52021 had no effect on allograft histomorphology and both groups manifested intense inflammatory cell infiltration consistent with acute cellular rejection. PAF antagonism reduced urinary excretion of thromboxane metabolites and decreased thromboxane production by homogenates prepared from kidney allografts. The PAF antagonist had no effect on urinary excretion of peptidoleukotriene metabolites or on the production of LTB4 by allografts. These data support a role for PAF in the pathophysiology of acute renal allograft rejection, and they suggest that the hemodynamic effects of PAF during rejection may be mediated through stimulation of thromboxane A2. In view of the beneficial effects of PAF blockade in rejection as well as recent reports describing efficacy in models of cyclosporine nephrotoxicity, PAF antagonists may have clinical applications in human renal allograft recipients.
BACKGROUND: Renal ischemia/reperfusion (I/R) injury is associated with delayed graft function and decreased long-term allograft function. However, most experimental studies evaluating renal I/R injury have focused on acute events after ischemia. T cells are potential candidates to link preservation injury, alloimmunity, and fibrosis. We hypothesized that severe renal I/R injury would generate long-term kidney damage and immune changes. METHODS: C57BL/6 mice underwent 60 minutes of warm unilateral I/R injury or sham surgery and were studied for 6 weeks. Serum creatinine, renal histology, and albumin excretion were measured. Phagocyte infiltration, CD4+ infiltration, renal cytokine expression, and splenic lymphocyte intracellular cytokine production were also measured in mice at 6 weeks. RESULTS: Serum creatinine levels rose following 60 minutes of unilateral I/R injury compared to sham mice. Histologic analysis of ischemic kidneys at 6 weeks revealed a pronounced loss of tubular architecture and infiltration of inflammatory cells. Phagocyte and CD4+ T-cell infiltration were significantly increased in ischemic kidneys. This was accompanied by a significant increase in interleukin (IL)-1beta and regulated upon activation, normal T-cell expressed and secreted (RANTES) expression. Despite similar splenic CD4 and CD8 numbers, intracellular cytokine staining of T cells revealed a significant increase in interferon-gamma (IFN-gamma) in I/R injury mice compared to sham mice. CONCLUSION: Persistent renal and extrarenal immune responses occur after a single episode of severe I/R injury. These immune processes resulting from injury could in turn have long-term consequences on progression of renal disease in transplanted and native kidneys.
Isogeneic or allogeneic thyroid glands were implanted into thyroidectomized recipeint rats. These grafts, either fresh or cultured, were placed in hamstring muscle pocket or under the renal capsule. Survival and function of the grafts were evaluated by: restoration of normal levels of serum thyroxine, weight gain, kidney transamidinase (a thyroxine-induced enzyme), and histological appearance of re-excised implants. A isografts, fresh and cultured, functioned well as ectopic thyroid glands, though restoration of normal serum thyroxine levels was more rapid for the fresh implants. Fresh allografts functioned transiently but then failed due to rejection. No function was detected for cultured allografts, and rejection was seen histologically. The rat thyroid allograft therefore differs from the rat parathyroid allograft, which often can function for several months despite histological evidence of rejection. Maintenance in tissue culture prior to implantation does not appear to alter the longterm immunogenicity of either organ.
BACKGROUND: There is a great deal of controversy surrounding the issue of hormone replacement therapy after transplantation. The question whether or not this therapy has effects in cardiac allograft vasculopathy (CAV), the Achilles heel of cardiac transplantation or other unique aspects of allograft function is still unknown. METHODS: We investigated the long-term effect of 17beta-estradiol as well as phytoestrogen Coumestrol, a synthetically produced phytoestrogen, on the development of CAV and the degree of fibrosis in an ovariectomized female heterotopic chronic allograft model (LEW-F344). RESULTS: We found that, 150 days after transplantation, no significant effect of estrogen application on intimal thickening of coronary arteries was observed. 17beta-estradiol and phytoestrogen Coumestrol did significantly reduce the perivascular immune reaction. However, the immune effect had no consequence on the intensity of CAV. Although neither 17beta-estradiol nor phytoestrogen Coumestrol revealed a positive effect on CAV, the group of animals treated with 17beta-estradiol showed the highest decline in heart function and the most distinct fibrosis. CONCLUSIONS: 17beta-estradiol does not affect CAV positively, but worsens cardiac allograft function and leads to increased fibrosis. This is the first study showing a negative effect of 17-beta-estradiol after heart transplantation in the long term.
INTRODUCTION: Survival following lung transplantation is less than 50% at 5 years, mainly due to immune-mediated chronic rejection. Recently a novel subset of T cells, CD4-veCD8-ve CD30+ve, so-called double negative (DN) CD30+ve T cells, has been described and shown to be responsible for tolerance in an animal model of skin transplantation. METHODS: We investigated 18 lung transplant recipients for the presence of DN CD30+ve T cells in resting peripheral blood and also following in vitro stimulation of recipient peripheral blood mononuclear cells (PBMCs) with donor spleen cells. RESULTS: Small percentages (0.2% to 6%) of DN T cells are detectable in resting PBMCs of human transplant patients (n = 18), but these did not correlate with allograft function, acute rejection episodes, HLA mismatch, or CMV status. On repeated stimulation of recipient PBMCs (two exposures) in vitro by donor spleen cells (2:1 ratio stimulators to responders) the percentage of DN CD30+ve T cells within the lymphocyte pool correlated with preservation of allograft lung function (both for FEV(1), P = .009, and FEF(25-75), P = .036) and was inversely correlated with grade of chronic rejection. On repeated exposure of recipient PBMCs to donor spleen cells with a 1:1 ratio the percentage of DN CD30+ve T cells correlated with the number of acute rejection episodes of grade 2 or greater. The total number of HLA mismatches correlated with the percentage DN CD30+ve T cells present after primary stimulation of recipient PBMCs with donor spleen cells (1:1 ratio). The number of mismatches at the B locus inversely correlated with the percentage of DN CD30+ve T cells after primary stimulation of recipient PBMCs with donor spleen cells (1:1 ratio; P = .031, n = 18). CONCLUSION: Percentages of DN CD30+ve T cells present following repeated stimulation of recipient PBMCs by donor spleen cells correlated with preservation of graft function following lung transplantation.
A case of recurrent lupus nephritis involving a renal allograft in a 28-year-old woman is described. The transplant was made after 2 years of hemodialysis. The allograft function remained stable for 2 years after the transplant. Clinical course, serologic tests, and renal histopathologic findings at the time of recurrence paralleled those seen in the patient's primary disease. There were no changes of transplant rejection. One year of follow-up shows a stable allograft renal function despite the histological and clinical recurrence of systemic lupus erythematosus.
OBJECTIVES: Traditional open donor nephrectomy is associated with good donor outcomes and excellent allograft function. Laparoscopic donor nephrectomy may accomplish these same goals with less morbidity. We report our initial experience with hand-assisted laparoscopic living donor nephrectomy using a commercially available hand-assist device. METHODS: Donor and allograft outcomes for the first 30 patients undergoing hand-assisted laparoscopic live donor nephrectomy in our institution were prospectively analyzed. RESULTS: Hand-assisted laparoscopic donor nephrectomy was successfully completed in 29 (97%) of 30 donors. Organ dissection was carried out purely laparoscopically. Vessel division and allograft extraction were performed using a hand-assisted technique. The average operative time was 275 minutes (range 193 to 360), with an estimated blood loss of 99 mL (range 50 to 300). Pneumoperitoneum was consistently maintained during the hand-assisted portion of the procedure. The mean warm ischemic time was 72.5 seconds (range 30 to 165). On average, the regular diet was resumed after 2.2 days (range 1 to 3), and patients were discharged home 3.4 days (range 2 to 5) after surgery. Eight minor complications occurred in the donor group. Immediate graft function occurred in all 30 cases. No ureteral complications occurred. The recipient creatinine levels ranged from 0.6 to 2.4 mg/dL at an average follow-up of 11.5 months (range 1 to 23). CONCLUSIONS: Laparoscopic donor nephrectomy is technically feasible and can be performed with minimal morbidity. Hand-assisted kidney extraction may help to facilitate immediate allograft function by minimizing the warm ischemic time.
BACKGROUND: Depletion of neutrophils (PMNs) and inhibition of PMN endothelial adhesion ameliorate post-ischemic lung reperfusion injury. Lidocaine reduces PMN adhesion to endothelial surfaces in vivo, and inhibits upregulation of PMN-CD11b/CD18 (Mac-1) in vitro. We evaluated the effect of lidocaine on reperfusion injury, PMN adhesion, and PMN migration in preserved lung allografts. METHODS: Donor lungs were flushed with modified Euro-Collins solution (4 degrees C) after prostaglandin E1 administration (250 micrograms), inflated with 550 mL (inspired oxygen fraction = 1.0), and stored for 24 hours at 1 degree C. Left lung allotransplantation was performed in 13 mongrel dogs. Immediately after reperfusion the recipient right pulmonary artery and bronchus were ligated to permit assessment of allograft function during a 6-hour postreperfusion period. Allograft gas exchange (every 15 minutes) and hemodynamics (every 60 minutes) were assessed. Peripheral blood PMN CD11b expression was determined by flow cytometry. After sacrifice allograft bronchoalveolar lavage fluid PMN count and allograft tissue myeloperoxidase activity were measured. Two groups were studied: In group I (n = 8) lidocaine hydrochloride was added to the donor flush (20 mg/L) solution. In addition lidocaine was given to the recipient at the time of thoracotomy (intravenous bolus of 4 mg/kg) followed by a continuous infusion of 4 mg/kg/h during implantation and the assessment period. Three dogs that did not reach effective lidocaine blood levels at the time of reperfusion (3 to 4 micrograms/mL) were excluded from analysis. Group II animals (n = 5) received no lidocaine. RESULTS: Gas exchange in group I was superior throughout the assessment period (p < 0.05). Bronchoalveolar lavage fluid PMN count in group I was reduced (0.36 x 10(6)PMN/mL versus 6.2 x 10(6) PML/mL; p < 0.03). Group I allograft myeloperoxidase activity was 0.17 U/mg/min compared with 0.28 U/mg/min in group II (p < 0.01). In lidocaine-treated animals PMN CD11b expression was maintained at basal levels 2 hours after reperfusion, compared with group II, in which upregulation of CD11b was observed. Lower lobe wet/dry ratio was not different in the two groups. CONCLUSIONS: Our observations indicate that lidocaine reduces reperfusion injury and inhibits PMN adhesion and subsequent migration to the lung allograft.
Hypomagnesemia, which is frequently observed in patients treated with calcineurin inhibitors to prevent rejection after allogeneic transplantation, has been associated with a faster rate of decline in allograft function. The effect of hypomagnesemia on lung allograft has not been reported yet. In our model of isolated mouse lung, we have evaluated the early effects of allogeneic lung perfusion with blood from magnesium (Mg)-deficient mice for 3 h on lung activation and remodelling, compared to isogeneic perfusion. Hypomagnesemia (0.21+/-0.07 mmol Mg(2+)/l) was observed in blood from Mg-deficient mice, but no inflammatory pattern. The mRNA level of the intercellular adhesion molecule (ICAM)-1, but neither of the vascular cell adhesion molecule (VCAM)-1, nor of the cytokines tumor necrosis factor (TNF)alpha and interleukin (IL)-2, was enhanced (p<0.05). Although caspase-3 mRNA was transiently enhanced, no apoptotic cells were evidenced in lung tissues even after 3 h. Using cDNA array, we found that the genes encoding RANKL, RANK, TNFR2, NFATX, IL-1R2, IL-6R gp130, SOCS3, PDGFRB, P63, CSF3R, CXCL1, CXCL5, CX3CL1, CSF1, which are involved in inflammation and apoptosis regulation, were markedly up-regulated in allogeneic conditions. Our results support a limited allogeneic activation and an early stage of the inflammatory process in lung, at the time of inflammatory cell recruitment without lung tissue remodelling, as a result of hypomagnesemia. These findings suggest that cyclosporine-related hypomagnesemia, observed in most of the transplanted patients, does not constitute an additional risk for lung allograft outcome.
BACKGROUND: The critical nephron mass needed to meet the metabolic demands of an individual depends on the body-weight. This study evaluated the effect of the kidney transplant ultrasonographic size to recipient body-weight ratio (Tx/W) on the outcome of kidney transplantation. METHODS: A consecutive series of 104 cadaveric renal transplants was studied. Transplant cross-sectional area (TXSA) was measured ultrasonographically in the first week after transplantation as an index of renal size. A 'nephron dose' index (Tx/W) was calculated by dividing TXSA by recipient weight and was used to define three groups of patients, with high (more than 0.45), medium (0.3-0.45) or low (less than 0.3) Tx/W ratios. Isotope glomerular filtration rate (GFR) measurements were made at 1, 6 and 12 months after transplantation. RESULTS: The serum creatinine level was significantly lower in the first 5 years after transplantation in patients with a high Tx/W ratio than in those with a medium or low ratio. GFR measurements were marginally higher in the groups with a high and medium Tx/W ratio compared with the low Tx/W group. A statistically significant association between Tx/W ratio and graft survival was not found. CONCLUSION: The renal transplant size to recipient weight ratio was an important determinant of long-term renal allograft function in this study. Extreme mismatching between allograft and recipient size should be avoided where possible, but the findings presented require confirmation in larger studies before clear recommendations can be made about size matching and kidney allocation.
From June 1977 to March 1985, 572 renal transplants were performed at The University of Texas Medical School at Houston. This represented 220 patients (151 cadaveric [CAD] and 69 living-related donor [LRD] recipients) treated with azathioprine and prednisone (Aza-Pred) and 352 patients (250 CAD and 102 LRD) treated with cyclosporine (CsA) and Pred. Sera from each recipient before and after transplant (Tx) as well as from each of their 436 donors (265 CAD and 171 LRD) were retrospectively tested for the presence of antibody to the human T cell lymphotrophic virus type III (HTLV-3) by enzyme immunoassay (EIA) and Western Blot analysis. Of the 436 donors tested, only 1/265 (0.38%) CAD donors were both EIA repeatedly reactive and Western Blot positive, whereas none of the 171 LRD were reactive. Pre-Tx, 4/401 (1.0%) CAD and 1/171 (0.6%) LRD recipient sera were EIA repeatedly reactive, however, all 5 were to be Western Blot negative. Post-Tx, 4.2% of the sera (24/572, 4 LRD and 20 CAD recipients) were EIA-reactive. All 20 CAD recipient sera were subsequently found to be negative with Western Blot testing. However, 2 LRD sera (2/572, 0.35%) displayed EIA reactivity as well as Western Blot positivity. One LRD, Western-Blot-positive recipient is alive and well with a functioning allograft 39 months post-Tx, whereas the second LRD, Western Blot positive recipient died of septic complications 16 months post-Tx. Finally, the recipient of the Western-Blot-positive CAD allograft is alive with a well-functioning graft and remains EIA and Western-Blot-negative 36 months post-Tx.
CD4 monoclonal antibody therapy prolongs allograft survival in a variety of experimental models and is currently undergoing clinical trials, though surprisingly little is known about the effects of CD4 mAb therapy on intragraft effector mechanisms that mediate rejection. We previously reported the significantly improved survival of (LEWxBN)F1 cardiac allografts in LEW rats treated for 10 days with the new CD4 mAb, BWH-4, at a dose of 700 micrograms/day, i.v., starting at the time of engraftment. Thus, CD4-treated rats showed prolongation of allograft survival to a median of 37 days (range 22 to greater than 100 days) post-Tx, compared with rejection at 7 days in untreated controls. We now report the results of detailed immunohistologic studies of allografts collected from these rats. Comparison of acutely rejecting allografts in untreated rats with well-functioning allografts collected at day 7 post-Tx from CD4-treated rats showed that CD4 mAb: (1) significantly reduced mononuclear cell infiltration, interstitial edema, hemorrhage formation and vascular and extravascular thrombosis; (2) inhibited mononuclear cell induction of receptors for IL-2 and transferrin, and upregulation of class II antigens and ICAM-1 on leukocytes and endothelial cells; (3) suppressed intragraft mononuclear cell and/or endothelial production of the cytokines IL-1, IL-2, IL-6, IFN-gamma, and TNF; and (4) blocked upregulation of endothelial tissue factor and downregulation of thrombomodulin, and consequently inhibited fibrin deposition. Studies of allografts from CD4-treated rats collected at day 30 post-Tx, prior to clinical rejection, showed a resurgence of CD4+ cells within allografts and a dense cellular immune response. We conclude that short-term CD4 mAb therapy has potent and extensive inhibitory effects on cytokine-related mononuclear cell and endothelial activation in vivo, blocking multiple afferent and efferent steps of the alloresponse.
We report an experience with 71 simultaneous kidney-pancreas transplant (SKPT) recipients receiving daclizumab induction in combination with tacrolimus (TAC), mycophenolate mofetil (MMF), and steroids. The mean follow-up time was 5.9+/-2.5 (SD) months (range 0.5-11 months). The study population included 47 males (65%) and 24 females (35%) with a mean age of 40+/-8 years. The mean pretransplant duration of diabetes and dialysis were 25+/-8 and 1.5+/-0.9 years (34 hemodialysis, 16 peritoneal dialysis), respectively. Mean HLA match was 1.2+/-1.5, with one patient receiving a second transplant. The mean cold ischemic times for the kidney and the pancreas were 15+/-5 and 16+/-4 hr, respectively. Six-month patient, kidney, and pancreas graft survival and rejection rates were 97, 96, 93, and 35%, respectively. There were two deaths, one due to fungal infection and the other due to a cardiac event. There were three kidney graft losses, two immunological, and one death with function. Of the five pancreas graft losses, two were due to infection, one immunological, one thrombosis, and one death with function. The patient population was then stratified according to the number of daclizumab doses: 4-5 doses (n=45) or 1-3 doses (n=26). There were no differences in patient and kidney graft survival rates, 98 vs. 96%, and 92 vs. 92%, respectively. However, there was a trend toward improved pancreas graft survival in the group receiving 4-5 doses (96%) compared with 1-3 doses (85%), P=0.07. Although more patients receiving 1-3 doses had rejection (54%) than patients receiving 4-5 doses (24%), there was no dose response relationship between the total number of doses or the adjusted total mg/kg dose and time to rejection. All patients with functioning grafts have good renal and pancreas allograft function at 6 and 12 months. The overall incidence of major infection was 27% and there were no differences in the incidence of infection between the two groups. No major adverse events were attributed to daclizumab use. In conclusion, excellent short-term outcomes were noted in this retrospective, multicenter survey of initial experience with daclizumab induction in combination with TAC, MMF, and steroids in SKPT recipients. Optimal dosing strategies for SKPT recipients remain to be determined.
Twenty-one juvenile-onset diabetic patients with azotemic nephropathy underwent coronary angiography and left ventriculography before renal transplantation or chronic hemodialysis. Two-year survival of 12 patients with no coronary artery disease (group A) was 88% compared to 22% for nine patients with coronary artery disease (group B) (P less than 0.025). Each group A patient underwent renal transplantation (nine live-related, three cadaveric). Four group B patients received cadaveric allografts. Among group A patients two cadaveric allografts functioned while in group B patients no allografts were successful. In the absence of coronary artery disease, results were similar to those reported for nondiabetic persons. In the presence of coronary artery disease, 62% of the deaths were due to myocardial infarction or sudden death. These results indicate that atherosclerotic coronary artery disease is a major determinant of survival in diabetic patients undergoing chronic hemodialysis or renal transplantation.
We studied the serum lipid profiles of 29 children, 3.9-17.9 years of age who were 0.6-7.6 years after renal transplantation (Tx). Twenty normoglycemic and non-proteinuric children had a well functioning allograft and 5 children had reduced renal function. Both groups were at least 7 months on alternate day corticosteroid (ADCS) therapy. Four additional patients had good renal function but were only 2.3 +/- 0.5 months on an ADCS regimen. Fifteen normal children served as controls. The levels of serum triglycerides (STG) and total cholesterol (CHOL) were elevated and high-density lipoprotein CHOL (HDL-CHOL) were low in all patients compared to control subjects (p less than 0.01). Their cardiovascular risk factor (CHOL/HDL-CHOL) was increased. The lipid abnormalities were most prominent in Tx patients with reduced graft function. These data show that treatment with ADCS does not prevent post-Tx hyperlipidemia. More insight is needed into the mechanisms responsible for the hyperlipidemia after Tx in order to reduce possible future morbidity (and mortality) from premature cardiovascular disease in this group of young, high-risk patients.
A patient with membranous nephropathy (MN) received a renal allograft from his brother. The allograft functioned immediately but nephrotic range proteinuria developed seven days after transplantation in the absence of any signs of rejection. Renal function deteriorated five weeks after transplantation due to ureteric obstruction. Nephrostomy drainage resulted in the return of renal function to normal and demonstrated that the allograft was the source of the nephrotic range proteinuria. An open renal biopsy of the allograft performed at the same time revealed the presence of recurrent MN. The recipient was investigated in an attempt to identify possible humoral immune mechanisms that may explain this very rapid recurrence of MN.