Sirolimus in association with mycophenolate mofetil induction for the prevention of acute graft rejection in renal allograft recipients

INTRODUCTION

A previous trial in renal transplantation comparing sirolimus (rapamycin) to cyclosporine (CsA) in a triple-drug therapy regimen with azathioprine and corticosteroids found that the incidence of acute rejection was similar (approximately 40%) with a trend for better renal function with sirolimus.

METHODS

In 14 European centers, first cadaveric renal allograft recipients were randomized to receive sirolimus (n = 40) or CsA (n = 38) in an open-label design. All patients received corticosteroids and mycophenolate mofetil 2 g/day. Sirolimus and CsA were concentration controlled; trough levels of mycophenolic acid and prednisolone were also measured.

RESULTS

At 12 months, graft survival (92.5% sirolimus vs. 89.5% CsA), patient survival (97.5% sirolimus vs. 94.7% CsA), and the incidence of biopsy-proven acute rejection (27.5% sirolimus vs. 18.4% CsA) were not statistically different. The use of antibodies to treat suspected rejection episodes was also similar (7.5% sirolimus vs. 5.3% CsA). More sirolimus patients received bolus steroid therapy (20 vs. 11, P = 0.068). From month 2 onward, the calculated glomerular filtration rate was consistently higher in sirolimus-treated patients. The adverse events reported more frequently with sirolimus were thrombocytopenia (45% vs. 8%) and diarrhea (38% vs. 11%). In the CsA group, increased creatinine (18% vs. 39%), hyperuricemia (3% vs. 18%), cytomegalovirus infection (5% vs. 21%), and tremor (5% vs. 21%) were observed significantly more often.

DISCUSSION

Patient and graft survival and the incidence of biopsy-proven acute rejection at 12 months were comparable between sirolimus and CsA, whereas safety profiles were different. These data suggest that sirolimus may be used as primary therapy for the prevention of acute rejection.

Complement genes strongly predict recurrence and graft outcome in adult renal transplant recipients with atypical hemolytic and uremic syndrome

Atypical hemolytic and uremic syndrome (aHUS) is a severe disease strongly associated with genetic abnormalities in the complement alternative pathway. In renal posttransplantation, few data are available on recurrence risk and graft outcome according to genetic background in aHUS patients. The aim of this study was to identify risk factors for recurrence and transplant outcome and, in particular, the role of complement gene abnormalities. We retrospectively studied 57 aHUS patients who had received 71 renal transplants. A mutation in complement gene was identified in 39 (68%), in factor H (CFH), factor I (CFI), membrane cofactor-protein (MCP), C3 and factor B (CFB). At 5 years, death-censored graft survival was 51%. Disease recurrence was associated with graft loss (p = 0.001). Mutations in complement genes were associated with higher risk of recurrence (p = 0.009). Patients with CFH or gain of function (C3, CFB) mutations had a highest risk of recurrence. M-TOR inhibitor was associated with significant risk of recurrence (p = 0.043) but not calcineurin inhibitor immunosuppressive treatment (p = 0.29). Preemptive plasmatherapy was associated with a trend to decrease recurrence (p = 0.07). Our study highlights that characterization of complement genetic abnormalities predicts the risk of recurrence-related graft loss and paves the way for future genetically based individualized prophylactic therapeutic strategies.

Induction versus noninduction in renal transplant recipients with tacrolimus-based immunosuppression

BACKGROUND

The aim of this study was to compare the efficacy and safety of induction treatment with antithymocyte globulins (ATG) followed by tacrolimus therapy with immediate tacrolimus therapy in renal transplant recipients.

METHODS

This 12-month, open, prospective study was conducted in 15 centers in France and 1 center in Belgium; 309 patients were randomized to receive either induction therapy with ATG (n=151) followed by initiation of tacrolimus on day 9 or immediate tacrolimus-based triple therapy (n=158). In both study arms, the initial daily tacrolimus dose was 0.2 mg/kg. Steroid boluses were given in the first 2 days and tapered thereafter from 20 mg/day to 5 mg/day. Azathioprine was administered at 1-2 mg/kg per day.

RESULTS

At month 12, biopsy-confirmed acute rejections were reported for 15.2% (induction) and 30.4% (noninduction) of patients (P=0.001). The incidence of steroid-sensitive acute rejections was 7.9% (induction) and 22.2% (noninduction)(P=0.001). Steroid-resistant acute rejections were reported for 8.6% (induction) and 8.9% (noninduction) of patients. A total of nine patients died. Patient survival and graft survival at month 12 was similar in both treatment groups (97.4% vs. 96.8% and 92.1% vs. 91.1%, respectively). Statistically significant differences in the incidence of adverse events were found for cytomegalovirus (CMV) infection (induction, 32.5% vs. noninduction, 19.0%, P=0.009), leukopenia (37.3% vs. 9.5%, P<0.001), fever (25.2% vs. 10.1%, P=0.001), herpes simplex (17.9% vs. 5.7%, P=0.001), and thrombocytopenia (11.3% vs. 3.2%, P=0.007). In the induction group, serum sickness was observed in 10.6% of patients. The incidence of new onset diabetes mellitus was 3.4% (induction) and 4.5% (noninduction).

CONCLUSION

Low incidences of acute rejection were found in both treatment arms. Induction treatment with ATG has the advantage of a lower incidence of acute rejection, but it significantly increases adverse events, particularly CMV infection.

Tacrolimus once daily (ADVAGRAF) versus twice daily (PROGRAF) in de novo renal transplantation: a randomized phase III study

This multicenter, 1:1-randomized, parallel-group, noninferiority study compared the efficacy and safety of twice-daily tacrolimus (Tacrolimus BID; Prograf) and once-daily tacrolimus prolonged release (Tacrolimus QD; Advagraf), combined with steroids and low-dose mycophenolate mofetil without antibody induction, in 667 de novo kidney transplant recipients. A double-blind, double-dummy 24-week period was followed by an open extension of up to 12 months posttransplant. Biopsy-proven acute rejection rate at 24 weeks (primary endpoint, per-protocol analysis) was 15.8% for Tacrolimus BID versus 20.4% for Tacrolimus QD (p = 0.182; treatment difference 4.5%, 95% confidence interval-1.8%, 10.9%, just outside the prespecified 10% noninferiority margin). Kaplan-Meier 12-month patient and graft survival rates were 97.5% and 92.8% for Tacrolimus BID and 96.9% and 91.5% for QD. Both treatment groups showed equally well-maintained renal function at 12 months (mean creatinine clearance approximately 67 mL/min) and similar adverse event profiles. Overall results obtained with either Tacrolimus QD or BID, without antibody induction, were good, supporting use of the once-daily formulation as an effective alternative to the established twice-daily formulation.

Disposition of basiliximab, an interleukin-2 receptor monoclonal antibody, in recipients of mismatched cadaver renal allografts

BACKGROUND

Basiliximab is an interleukin-2 receptor (IL-2R; CD25) chimeric monoclonal antibody for immunoprophylaxis against acute rejection in renal transplantation. Its pharmacokinetics were characterized in a multicenter open-label, prospective dose-escalation study to identify a single-dose regimen providing IL-2R-saturating serum concentrations in the critical first posttransplant month.

METHODS

Thirty-two recipients of primary, mismatched cadaver kidneys were enrolled: 20 men and 12 women, who were 47+/-11 years old and weighed 65+/-12 kg. The immunosuppression regimen consisted of steroids and azathioprine from day 0 and cyclosporine from day 10. Basiliximab was infused over 30 min as a single dose preoperatively.

RESULTS

Thirty patients were evaluable for basiliximab pharmacokinetics: 24 received 40 mg and 6 received 60 mg. Basiliximab was well tolerated without evidence of cytokine-release syndrome, hypersensitivity reactions, or anti-idiotype antibody response. Peak concentration and area under the concentration curve increased proportionally with dose. Postinfusion concentrations declined in a biphasic manner with a terminal half-life of 6.5+/-2.1 days. Weak, widely dispersed correlations were noted between body weight versus distribution volume (r=0.29) and versus clearance (r=0.45), suggesting no clinical relevance for weight-adjusted dosing. There were no apparent gender-related differences in basiliximab disposition. Previous phase II data indicated that serum concentrations in excess of 0.2 microg/ml are sufficient to saturate IL-2R epitopes on circulating T lymphocytes. Concentrations were above this threshold for 26+/-8 days (range 16 to 46) at the 40-mg dose level and for 32+/-11 days (range 22 to 51) at the 60-mg dose level.

CONCLUSIONS

Total basiliximab doses of 40-60 mg were well tolerated, nonimmunogenic, and estimated to provide immunoprophylaxis to cover the first posttransplant month.

Seasonal changes in blood pressure in patients with end-stage renal disease treated with hemodialysis

BACKGROUND

Many factors contribute to the regulation of blood pressure. The role of climate has received relatively little attention.

METHODS

During a four-year period, we determined the influence of climate on blood pressure in 53 patients with end-stage renal disease treated with hemodialysis. For each patient, blood pressure was measured before each of three dialysis treatments per week for an average of 31 months. The dose of dialysis (urea clearance multiplied by the length of dialysis and divided by the distribution volume of urea) and protein catabolism rate were assessed monthly. We then analyzed the monthly mean values for blood pressure, pulse, and body weight in relation to the monthly values for temperature, relative humidity, and atmospheric pressure recorded in Montpellier, France.

RESULTS

The maximal monthly temperature varied from 10 degrees C in the winter to 31 degrees C in the summer, and the minimal monthly temperature from 1 degree to 20 degrees C. The mean (+/-SE) systolic and diastolic blood pressure was highest during the winter (153+/-3/82+/-2 mm Hg) and lowest during the summer (141+/-3/75+/-2 mm Hg). The seasonal pattern was evident throughout the four-year period. Blood pressure was correlated inversely with monthly maximal temperature (r= -0.65 and P<0.001 for systolic pressure; r= -0.71 and P<0.001 for diastolic pressure) and directly with minimal humidity (r=0.45 and P=0.002 for systolic pressure; r=0.43 and P=0.003 for diastolic pressure). Changes in protein catabolic rate, weight gain during dialysis, and dialysis dose were not related to changes in blood pressure.

CONCLUSIONS

In patients with end-stage renal disease treated with hemodialysis, blood pressure varies seasonally, with higher values in the winter and lower values in the summer.

Converting-enzyme inhibitor versus calcium antagonist in cyclosporine-treated renal transplants

The influence of antihypertensive treatment on the long-term evolution of arterial pressure and renal function was studied in a prospective controlled trial conducted in renal transplant recipients treated by cyclosporine. Within six months after transplantation, patients were randomly allocated to treatment by the angiotensin-converting enzyme inhibitor, lisinopril (ACEI, alone or associated with frusemide; N = 14), or the calcium antagonist, nifedipine (CA, alone or associated with atenolol; N = 11). Glomerular filtration rate (TcDTPA clearance) and effective renal plasma flow (hippuran clearance) as well as 24-hour urinary excretion of electrolytes and albumin were estimated at about 1 and 2.5 years of follow-up. Before initiation of antihypertensive therapy, the two groups were similar with regards to mean arterial pressure (119 +/- 2 vs. 120 +/- 4 mm Hg), effective renal plasma flow (285 +/- 26 vs. 248 +/- 33 ml/min/1.73 m2) and glomerular filtration rate (59 +/- 4 vs. 61 +/- 8 ml/min/1.73 m2 in the ACEI and CA groups, respectively). Both ACEI and CA treatments were associated with no change in renal function, a similar change in mean arterial pressure (ACEI -18 +/- 3; CA -13 +/- 5 mm Hg) and identical trough blood levels of cyclosporine. Urinary albumin excretion did not change significantly in any groups. Of interest, only in the ACEI group did filtration fraction significantly decrease (from 0.22 +/- 0.01% to 0.19 +/- 0.01% at final studies). These results indicate that in cyclosporine-treated transplant recipients, a satisfactory control of hypertension is obtained by chronic ACEI, which is as effective on arterial pressure as a combination of CA and atenolol.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxidative stress and lipid abnormalities in renal transplant recipients with or without chronic rejection

BACKGROUND

The histological picture of chronic rejection with endothelial lesions and vascular hyperplasia resembles the early arteriosclerotic lesions. As increasing evidence suggests a role for oxidative stress in arteriosclerosis, we examined whether chronic rejection in renal transplant recipients was associated with increased oxidative stress markers.

METHODS

We investigated lipid metabolism and oxidative stress in 77 renal transplant recipients. Group I patients (n=34; 48+/-2 years old, 12 women, 22 men) had no clinical or histological signs of chronic rejection, whereas group II patients (n=43; 47+/-3 years old, 15 women, 28 men) had histologically proven chronic rejection. All patients were treated with cyclosporine and steroids. Lipid metabolism was evaluated by determining total cholesterol, triglycerides, high-density lipoprotein cholesterol, apolipoproteins AI and B, and lipoprotein (a). Oxidative stress was evaluated by determining: (i) the end product of lipid peroxidation, malonyldialdehyde (MDA), and erythrocyte polyunsaturated fatty acids; (ii) the nonenzymatic antioxidant system: erythrocyte alpha-tocopherol and glutathione; and (iii) the enzymatic antioxidant system: erythrocyte superoxide dismutase and plasma glutathione peroxidase. Results were compared with those of a control group (38 healthy volunteers).

RESULTS

Compared with controls, renal transplant recipients had significantly increased total cholesterol, triglyceride, and apolipoprotein B levels; they also had, in association with these lipid abnormalities, a significant increase in MDA and a significant decrease in erythrocyte polyunsaturated fatty acids, as well as a significant decrease in enzymatic and nonenzymatic antioxidant defense mechanisms. In contrast to lipid disturbances, where no difference was observed between groups I and II, markers of oxidative stress were significantly higher in group II compared with group I (MDA: 1.87+/-0.43 and 1.62+/-0.31 nmol/ml, respectively, P<0.05). The red blood cell antioxidative defense mechanisms were significantly decreased in group II compared with controls (erythrocyte alpha-tocopherol: 0.61+/-0.38 and 1.08+/-0.31 mg/L, respectively, P<0.01; superoxide dismutase: 1.08+/-0.2 and 1.32+/-0.31 U/mg Hb, respectively, P<0.01).

CONCLUSION

Our data show that oxidative stress with a decrease in antioxidant defenses is associated with kidney transplantation. In addition, oxidative stress markers are particularly increased in transplant recipients with chronic rejection, which suggests that oxidative stress may participate in the development and/or progression of vascular lesions observed in these patients.

Long-term improvement in renal function after cyclosporine reduction in renal transplant recipients with histologically proven chronic cyclosporine nephropathy

BACKGROUND

Chronic cyclosporine (CsA) nephropathy, which has been unequivocally documented in recipients of heart, heart-lung, liver, or bone marrow transplants, as well as in nontransplant situations, usually results in a progressive deterioration of renal function. In this study, we assessed the potential reversibility of chronic CsA nephropathy in renal transplant recipients.

PATIENTS AND METHODS

Twenty-three renal transplant patients with biopsy-proven CsA nephropathy associated with long-term CsA administration (27+/-4 months) were followed up for more than 2 years after CsA reduction (18/23 patients) or withdrawal (5/23 patients) and addition of azathioprine. Changes in effective renal plasma flow and glomerular filtration rate were assessed before and 2 years after CsA reduction, whereas serum creatinine, proteinuria, blood pressure, and CsA concentrations were monitored up to 5 years.

RESULTS

At 2-year follow-up, glomerular filtration rate increased from 40+/-3 to 47+/-4 (P<0.05) and effective renal plasma flow from 217+/-23 to 244+/-24 ml/min/1.73 m2 (NS). Mean arterial pressure significantly decreased from 98.7+/-2.9 to 93.1+/-2.7 mmHg (P<0.05). There was no significant change in renal vascular resistance, filtration fraction, or albumin excretion. A significant decrease in serum creatinine was also observed during the whole follow-up (73+/-6.5 months). CsA reduction was followed by only one episode of acute reversible rejection; chronic rejection developed in three patients 2 years or later after CsA reduction.

CONCLUSIONS

These data suggest that CsA nephropathy participates in graft dysfunction in a small group of renal transplant recipients. In addition, graft dysfunction may be reversible when CsA dosage is reduced early after diagnosis of chronic CsA nephropathy.

A randomized study evaluating cinacalcet to treat hypercalcemia in renal transplant recipients with persistent hyperparathyroidism

Persistent hyperparathyroidism (HPT) after kidney transplantation (KTx) is associated with hypercalcemia, hypophosphatemia and abnormally high levels of parathyroid hormone (PTH). In this randomized trial, cinacalcet was compared to placebo for the treatment of hypercalcemia in adult patients with persistent HPT after KTx. Subjects were randomized 1:1 to cinacalcet or placebo with randomization stratified by baseline corrected total serum calcium levels (≤11.2 mg/dL [2.80 mmol/L] or >11.2 mg/dL [2.80 mmol/L]). The primary end point was achievement of a mean corrected total serum calcium value<10.2 mg/dL (2.55 mmol/L) during the efficacy period. The two key secondary end points were percent change in bone mineral density (BMD) at the femoral neck and absolute change in phosphorus; 78.9% cinacalcet- versus 3.5% placebo-treated subjects achieved the primary end point with a difference of 75.4% (95% confidence interval [CI]: 63.8, 87.1), p<0.001. There was no statistical difference in the percent change in BMD at the femoral neck between cinacalcet and placebo groups, p=0.266. The difference in the change in phosphorus between the two arms was 0.45 mg/dL (95% CI: 0.26, 0.64), p<0.001 (nominal). No new safety signals were detected. In conclusion, hypercalcemia and hypophosphatemia were effectively corrected after treatment with cinacalcet in patients with persistent HPT after KTx.

An acetohydroxy acid synthase mutant reveals a single site involved in multiple herbicide resistance

Acetohydroxy acid synthase (AHAS) is an essential enzyme for many organisms as it catalyzes the first step in the biosynthesis of the branched-chain amino acids valine, isoleucine, and leucine. The enzyme is under allosteric control by these amino acids. It is also inhibited by several classes of herbicides, such as the sulfonylureas, imidazolinones and triazolopyrimidines, that are believed to bind to a relic quinone-binding site. In this study, a mutant allele of AHAS3 responsible for sulfonylurea resistance in a Brassica napus cell line was isolated. Sequence analyses predicted a single amino acid change (557 Trp-->Leu) within a conserved region of AHAS. Expression in transgenic plants conferred strong resistance to the three classes of herbicides, revealing a single site essential for the binding of all the herbicide classes. The mutation did not appear to affect feedback inhibition by the branched-chain amino acids in plants.

Impact of early or delayed cyclosporine on delayed graft function in renal transplant recipients: a randomized, multicenter study

The benefit of delayed cyclosporine in reducing risk of delayed graft function (DGF) is not clearly established. This study compared early vs. delayed cyclosporine microemulsion (CsA-ME) inde novorenal transplant patients. Patients were randomized to early (day 0, n=97) or delayed (day 6, n=100) CsA-ME at an initial dose of 8 mg/kg/day with dose adjusted according to C2 level. All patients received enteric-coated mycophenolate sodium (EC-MPS), steroids and an anti-interleukin-2 receptor antibody. In both groups, 33% of patients were at high risk of DGF; 26 patients (26.8%) in the early CsA-ME group and 23 patients (23.0%) in the delayed CsA-ME group experienced DGF (n.s.). Renal function at 3 months was comparable (creatinine clearance 51.1 mL/min with early CsA-ME and 53.8 mL/min with delayed CsA-ME), and remained similar to 12 months. Treatment failure, defined as biopsy-proven acute rejection, graft loss or death, did not differ significantly at 12 months (23.7% with early CsA-ME vs. 29.0% with delayed CsA-ME). Biopsy-proven acute rejection occurred in 15.5% of early CsA-ME and 26.5% of delayed CsA-ME patients (n.s.). Both regimens were well tolerated. These data suggest that early or delayed introduction of CsA-ME results in similar renal function in renal transplant patients regardless of DGF risk level.

Monthly screening for BK viremia is an effective strategy to prevent BK virus nephropathy in renal transplant recipients

BACKGROUND

BK polyomavirus virus (BKV) nephropathy (BKVN) is the most common viral infection that affects renal allografts. Because a specific antiviral therapy is lacking, BKVN may result in graft dysfunction and/or loss. We prospectively analyzed whether monthly nucleic acid testing (NAT) for BKV replication in blood and immediate reduction of immunosuppression (IS) could prevent BKVN.

METHODS

NAT was performed at monthly intervals for 6 months and then at 12 months in 119 de novo renal transplant recipients. In viremic patients (presumptive BKVN), a graft biopsy was systematically performed and IS was immediately reduced.

RESULTS

BKV viremia occurred in 13 (10.9%) patients after a median time of 90 days (23-241); 77% of patients were viremic before month 4. After reduction of IS, viral load was undetectable in 11 patients, remained low in 1, and continued to increase in 1 patient who developed definitive BKVN despite reduction of IS, and finally returned to dialysis 6 months after transplantation.

CONCLUSION

BKV infection is an early complication. Monthly NAT in blood during the first 6 months and immediate reduction of IS in viremic patients almost completely prevent definitive BKVN.

Low dose antithymocyte globulins in renal transplantation: daily versus intermittent administration based on T-cell monitoring

BACKGROUND

Despite the long history of use of antithymocyte globulins (ATG) in renal transplantation, ideal doses and duration of ATG administration based on the monitoring of T lymphocytes have yet to be defined.

METHODS

Two immunosuppressive regimens based on low-dose rabbit ATG (Thymoglobuline; Imtix-Sang-stat, Lyon, France) were assessed during the first year after transplantation: daily ATG (DATG; n=23) where 50 mg of ATG was given every day and intermittent ATG (IATG; n=16) where similar doses of ATG were given for the first 3 days and then intermittently only if CD3+ T lymphocytes (measured by flow cytometry) were > 10/mm3. Both groups received steroids, azathioprine, and cyclosporine.

RESULTS

ATG-induced depletion was similar for peripheral blood lymphocytes and T cells in both groups: it began at day 1 after transplantation, was submaximal at day 3, and reached maximum intensity between days 6 and 8, from which time cell counts progressively increased. However, T-cell depletion was still present at day 20. The total ATG dose per patient (381.5+/-121 vs. 564+/-135 mg/patient) and the mean cumulative daily dose of ATG (0.60+/-0.17 vs. 0.80+/-0.14 mg/kg/day) were significantly lower in the IATG group (P=0.0001 and 0.0006, respectively). The overlap of ATG and cyclosporine treatment was 6.7+/-3 vs. 7.4+/-4.3 days (P=NS), and the mean duration of ATG therapy was 11.3+/-3.2 vs. 11.6+/-2.7 days in the IATG and DATG groups, respectively (P=NS). ATG was given in an average of one dose every 1.6 days in the IATG group compared with one dose daily in the DATG group (P=7 x 10(-7)). There was no significant difference in renal graft function, the number of acute graft rejections, or ATG-related side effects and complications. Despite the daily immunological follow-up, there was a net saving of $760/patient in the cost of treatment in the IATG group.

CONCLUSION

IATG had the advantage of a reduction in the dose of ATG and in the cost of treatment, while offering similar T-cell depletion and effective immunosuppression. This approach could be proposed as an induction protocol, particularly for patients with poor graft function in whom cyclosporine introduction has to be delayed or those with increased risk of cytomegalovirus infections or secondary malignancies.

Daclizumab Versus Rabbit Antithymocyte Globulin in High-Risk Renal Transplants: Five-Year Follow-up of a Randomized Study

We previously reported a randomized controlled trial in which 227 de novo deceased-donor kidney transplant recipients were randomized to rabbit antithymocyte (rATG, Thymoglobulin) or daclizumab if they were considered to be at high immunological risk, defined as high panel reactive antibodies (PRA), loss of a first kidney graft through rejection within 2 years of transplantation, or third or fourth transplantation. Patients treated with rATG had lower incidences of biopsy-proven acute rejection (BPAR) and steroid-resistant rejection at 1 year. Patients were followed to 5 years posttransplant in an observational study; findings are described here. Treatment with rATG was associated with a lower rate of BPAR at 5 years (14.2% vs. 26.0% with daclizumab; p = 0.035). Only one rATG-treated patient (0.9%) and one daclizumab-treated patient (1.0%) developed BPAR after 1 year. Five-year graft and patient survival rates, and renal function, were similar between the two groups. Overall graft survival at 5 years was significantly higher in patients without BPAR (81.0% vs. 54.8%; p < 0.001). In conclusion, rATG is superior to daclizumab for the prevention of BPAR among high-immunological-risk renal transplant recipients. Overall graft survival at 5 years was approximately 70% with either induction therapy, which compares favorably to low-risk cohorts.

Cells surrounding haemodialysis-associated amyloid deposits are mainly macrophages

Dialysis-related amyloidosis is a type of amyloidosis which had beta 2-microglobulin as the major protein constituent and occurs predominantly in haemodialysis patients. Its prevalence is very high with increasing time on dialysis treatment and its pathogenesis is not completely understood. While remarkable progress has been made in the identification of the components of the deposits, there are no reports characterizing the cells surrounding the amyloid fibrils. To characterize the cellular composition of the amyloid material, specimens from seven patients treated by maintenance haemodialysis were studied with immunoperoxidase labelling using monoclonal antibodies to leukocytes (CD3, CD14, CD68, CD4, CD8, CD45). The results were very reproducible for the seven deposits assessed: Of the 182 +/- 26 leukocytes/0.2 mm2 of amyloid tissue expressing the 71.5-CD45 marker (common leukocyte), 91 +/- 6% were CD68 (KP1) positive (monocyte macrophage). No CD3-positive cells (T-cell marker) were found in six of the seven patients, with only 1.6% in the remaining one. The present study shows that although amyloidosis has classically been considered as an acellular pathology, clearly there are cells surrounding amyloid fibrils. Strikingly, these cells are almost exclusively macrophages; there are no lymphocytes or granulocytes. The putative role of macrophages in the pathogenesis of beta 2-microglobulin amyloidosis remains to be established. However, the identification and quantitation of the cells surrounding the amyloid deposits may be important for subsequent studies to elucidate amyloid pathogenesis and particularly protein-cell interactions.

Evolution of coronary artery calcifications following kidney transplantation: relationship with osteoprotegerin levels

We prospectively assessed the evolution of coronary artery calcification (CAC) and osteoprotegerin (OPG) levels after renal transplantation (RT). Eighty-three recipients were followed-up prospectively during 1 year. Blood was collected before (baseline) and after RT for determination of mineral metabolism parameters including OPG. CAC was measured by multidetector computed tomography at transplantation (baseline) and 1 year later. Progression of CAC was defined as a difference between the follow-up square-root transformed volume (SRV) and the baseline SRV >or= 2.5. By multivariate analysis, baseline OPG level, age and low LDL levels were significantly associated with baseline CAC. RT was accompanied by mineral metabolism improvement with a decrease of OPG from 955 [395-5652] to 527 [217-1818] pg/mL and parathyroid hormone from 94 [1-550] to 62 [16-410] pg/mL. Thirty-one percent of patients did not exhibit CAC at baseline. CAC diminished in 14.5%, stabilized in 59.2% and progressed in 26.3% of patients. Baseline CAC was associated with progression (OR 2.92 [1.02-8.36]). No significant association was found between OPG and CAC progression despite a higher baseline OPG level in progressors (1046 [456-3285]) vs. non-progressors (899 [396-5952] pg/mL). CAC at baseline, but not 1 year after RT, is independently associated with baseline OPG; posttransplant CAC progression is predicted by baseline CAC score.

Renal transplantation relieves the symptoms but does not reverse beta 2-microglobulin amyloidosis

Renal transplantation is considered to be the treatment of choice of dialysis-related beta 2-microglobulin amyloidosis (DRA), as it provides near-normal serum levels of beta 2-microglobulin and obviates the need for dialysis. However, the long-term outcome of DRA after transplantation has not been fully assessed, and its evolution after transplant failure has not been reported. This study examined 17 patients with histologically confirmed DRA who underwent kidney transplantation and had a dialysis-free follow-up period in excess of 1 yr. Immunosuppressive treatment included low-dose prednisolone, cyclosporine, and/or azathioprine. Symptoms related to DRA were sought at every outpatient visit, and bone x-rays were performed at time of transplantation and annually thereafter. The number and size of the bone cysts were determined. Most of the DRA symptoms, and particularly shoulder stiffness, disappeared within the first wk after transplantation and this persisted throughout the transplant follow-up period (58.5 +/- 9 months). However, the number of bone cysts remained remarkably constant even in those patients with still-functioning grafts (12 +/- 7.5 and 12.1 +/- 7.7, before and at last transplantation follow-up examination, respectively). Beta 2-microglobulin amyloid was found to be present in one patient operated on for hip fracture 2 yr after receiving a well-functioning transplant. Seven patients experienced graft failure and returned to dialysis after 47 +/- 39 months of transplantation. Severe DRA symptoms reappeared strikingly early after resuming hemodialysis, and five out of the seven patients required surgery for carpal tunnel syndrome, three of them within the first yr (mean, 17 +/- 12 months). The number of cysts significantly increased from 17 +/- 11 to 21 +/- 11 during the second dialysis period. These findings provide further evidence suggesting that although the clinical expression of DRA is arrested during transplantation, the anatomical lesions and the pathological processes underlying it are unlikely to be reversed.

Transmission of Mycobacterium tuberculosis with renal allografts

Disseminated tuberculosis occurred in 2 allograft recipients of kidneys procured on the same donor. Both recipients were treated by low dose prednisolone and azathioprine, and one of them was on a special protocol including antilymphocyte globulins as rejection prophylaxis. None of them experienced acute rejection. The early posttransplant period was uneventful except for the occurrence of mild viral infections in both cases (herpes simplex virus in case 1 and cytomegalovirus in case 2). 2 and 6 months after transplantation, respectively, patient 1 developed acute fever, asthenia, and disorientation while patient 2 presented with spiking fever and miliary pneumonitis. Mycobacterium tuberculosis grew in the urine of both recipients in the absence of clinical genitourinary symptoms. The two mycobacterial species had the same bacteriologic characteristics and the same antibiotic sensitivity. As the recipients had no evidence of a previous history of active tuberculosis, it is suggested, as for some other infectious agents, that mycobacterium was transmitted along with the transplanted kidneys.

Acute adaptative changes to unilateral nephrectomy in humans

Renal function was monitored in 20, living-related kidney donors before and after uninephrectomy. Urinary protein excretion and retinoid metabolism respectively were studied in 10 and 6 of these donors. The functional adaptation was characterized by an increase in glomerular filtration rate and tubular function, which began in the first two days after uninephrectomy. Changes in tubular function were also demonstrated by significant increases in the urinary excretion of beta 2 microglobulin (beta 2M), retinol binding protein (RBP), kappa and lambda light chains of immunoglobulins. In addition, a protein identical to or homologous to cellular retinoic acid binding protein (CRABP), appeared in the urine after nephrectomy. We did not find CRABP in serum samples either before or after nephrectomy, suggesting that urinary CRABP was synthesized by the remaining kidney. Increases in serum levels of Vitamin A and RBP were also observed in the post-nephrectomy period. These modifications in retinol metabolism suggest that these substances could have a role as renotropic growth factors in compensatory hypertrophy.

Extracellular vesicles miRNA-21: a potential therapeutic tool in premature ovarian dysfunction

Chemotherapy induces an irreversible premature ovarian dysfunction (POD). Amniotic fluid mesenchymal stem cells (AFMSCs) can rescue fertility; however, the notion that stem cells can rejuvenate follicles is highly controversial due to the predetermined ovarian reserve. This study aims to isolate AFMSC-derived extracellular vesicles (EVs) and investigate their abundancy for the anti-apoptotic miRNA-21 as a means of ovarian restoration. Female rats were divided into healthy controls and POD-induced groups. The POD induced groups were subdivided into three groups according to the therapies they received: placebo-treated POD, AFMSC and EVs groups. Rats were assessed for serum anti-Müllerian hormone (AMH) levels, ovarian caspase 3 and PTEN protein levels in the ovarian lysate. Total follicular counts (TFCs) were estimated from stained ovarian sections. Functional recovery was investigated through daily vaginal smears and mating trials. In vitro chemical transfection of the AFMSCs with selective miRNA-21 mimics/inhibitors followed by isolation of EVs for therapy was conducted in two additional groups. At the interval points studied, treatment with AFMSCs and EVs equally restored TFC, AMH levels, regular estrous cycles and fruitful conception, while it both diminished caspase 3 and PTEN levels. EVs carrying miRNA-21 mimics recapitulated the short-term effects. Placebo-treated POD or EVs carrying miRNA-21 inhibitors showed augmented ovarian follicular damage demonstrated the low AMH levels, TFC and high levels of PTEN and caspase 3. miRNA-21 allowed regeneration by modulating PTEN and caspase 3 apoptotic pathways. Our findings exemplify that EVs could serve as an innovative cell-free therapeutic tool functioning through their miRNA content and that miRNA-21 has a chief regenerative role through modulating PTEN and caspase 3 apoptotic pathways.

Early corticosteroid avoidance in kidney transplant recipients receiving ATG-F induction: 5-year actual results of a prospective and randomized study

One hundred ninety-seven patients received anti-T-lymphocyte globulins Fresenius, mycophenolate mofetil and delayed cyclosporine, and were randomized to ≥6-month corticosteroids (+CS; n=99) or no CS (-CS; n=98). One- and five-year actual graft survival (censored for death) was 93.2% and 86.4% in the +CS group versus 94.9% and 89.8% in the -CS group (5-year follow-up, p=0.487). Freedom from clinical rejection was 86.9% and 81.8% versus 74.5% and 74.5% (p=0.144), respectively, at 1 and 5 years; 5-year freedom from biopsy-proven rejection was 88.9% versus 83.7% (p=0.227). More late first rejections occurred in the +CS group. Significantly lower 5-year graft survival in patients experiencing rejection was observed for +CS (55.6% vs. 92.0%; p=0.005) with 8/18 versus 2/25 graft losses. Renal function at 5 years was stable and comparable (median serum creatinine, 159 vs. 145 µmol/L; creatinine clearance, 53.5 vs. 56.6 mL/min). More +CS patients developed diabetes, dyslipidemia and malignancies. Rejections in -CS patients occurred early after transplantation and did not impair long-term renal function. In patients receiving CS, rejections occurred later and with a higher risk for subsequent graft failure. A similar and not inferior 5-year efficacy profile and a reduced morbidity were observed in CS-free patients compared to patients who received CS for at least 6 months.

High-molecular-mass proteins in haemodialysis-associated amyloidosis

1. Protein constituents were determined in eight amyloid deposits from eight patients (five male and three female), 53 +/- 4 years of age, treated by haemodialysis for 9-20 years using only cuprophane membranes and operated for carpal tunnel syndrome. 2. Soluble proteins were removed by solubilization in phosphate-buffered saline after osmotic lysis. The proteins of the insoluble fibrils were characterized by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and two-dimensional gel electrophoresis, and immunologically identified by Western blotting. 3. In addition to beta 2-microglobulin, alpha 2-macroglobulin was identified in the fibrillar material. The presence of these two proteins in amyloid deposits was confirmed by immunofluorescent microscopic studies. 4. Our data confirm the presence of beta 2-microglobulin in haemodialysis-associated amyloidosis, and also suggest a possible role for alpha 2-microglobulin: it may protect beta 2-microglobulin from proteolytic digestion, leading to its accumulation in intact form and to amyloid fibril formation.