Gunnar Tydén

KIDNEY DONORS LIVE LONGER

BACKGROUNDnA very important issue in living kidney donor transplantation is whether the donation is safe for the donor. The aim of this study was to examine survival and causes of death in kidney donors and to assess the renal function in those who had donated a kidney more than 20 years ago.nnnMETHODSnA total of 459 living donor nephrectomies were performed in Stockholm from 1964 until the end of 1994. By using national registers, all 430 donors living in Sweden were traced. Donor survival was analysed using the Kaplan-Meier method. Expected survival was computed using the Hakulinens method and was based on national mortality rates.nnnRESULTSnForty-one subjects had died between 15 months and 31 years after the donation. The mortality pattern was similar to that in the general population, the majority dying of cardiovascular diseases and malignancies. After 20 years of follow-up, 85% of the donors were alive, whereas the expected survival rate was 66%. Survival was thus 29% better in the donor group. One third of the donors (aged 46-91 years) who had donated >20 years ago had hypertension. There was a deterioration in the renal function with increasing age, similar to what is seen among normal healthy subjects. The average glomerular filtration rate in donors aged 75 years and over was 48 ml/min/1.73 m2.nnnCONCLUSIONSnTo donate a kidney does not seem to constitute any long-term risk. The better survival among donors is probably due to the fact that only healthy persons are accepted for living kidney donation.

ABO Incompatible Kidney Transplantations Without Splenectomy, Using Antigen‐Specific Immunoadsorption and Rituximab

ABO incompatible kidney transplantations have previously only been performed after several preoperative sessions of plasmapheresis and splenectomy, with the conventional triple‐drug immunosuppressive protocol being reinforced with antilymphocyte globulin and B‐cell‐specific drugs, such as cyclophosphamide or deoxyspergualine. We have designed a protocol without splenectomy, based on antigen‐specific immunoadsorption, rituximab and a conventional triple‐drug immunosuppressive protocol. The protocol calls for a 10‐day pretransplantation conditioning period, starting with one dosage of rituximab and followed by full dose tacrolimus, mycophenolate mofetil and prednisolone. Antigen‐specific immunoadsorption was performed on pretransplantation days −6, −5, −2 and −1. After the last session, 0.5 g/kg of intravenous immunoglobulin (IVIG) was administered. Postoperatively, three more apheresis sessions were given every third day. Furthermore, if there was a significant increase in the antibody titers, extra sessions were considered. Eleven patients have received transplants with this protocol. The ABO antibodies were readily removed by the antigen‐specific immunoadsorption and were kept at a low level post‐transplantation by further adsorptions. There were no side effects and all patients have normal renal transplant function. We conclude that after an infusion each of rituximab and IVIG, and antigen‐specific immunoadsorption; blood group‐incompatible renal transplantations can be performed with excellent results using standard immunosuppression and no splenectomy.

No evidence of accelerated loss of kidney function in living kidney donors : Results from a cross-sectional follow-up

Background. There is a lack of kidneys available for kidney transplantation, and living donors are increasingly used. It is important to examine the possible long-term adverse affect on the renal function and blood pressure of the donors. Methods. We have made a comprehensive follow-up of all living kidney donors at our center from 1964 to 1995. Of 402 donors still alive, we were able to get information about serum creatinine, urinary proteins, and blood cells in urine using reagent strips, and blood pressure from 87%. The glomerular filtration rate (GFR) was estimated using a formula and was measured with Iohexol clearance in 43 of the donors. Individual data on GFR and the prevalence of hypertension were compared with the age- and gender-expected values. Results. The mean age of the examined donors was 61 years (SD:13) at follow-up, and the time since donation was 12 years (SD:8). The average estimated GFR was 72% (SD:18) of the age-predicted value. The ratio of the estimated to the predicted GFR showed no correlation to the time since donation, indicating that there is no accelerated loss of renal function after donation. GFR below 30 ml/min was found in five donors. No donor died in uremia or had dialysis treatment before death. However, three donors developed renal disease, and one was in dialysis treatment. In two of these cases, hereditary factors were possibly involved. Hypertension was present in 38% of the donors but the age-adjusted prevalence of hypertension among donors was not higher than in the general population. Significant proteinuria (≥1.0 g/L) was found in 3% and slight proteinuria (<1.0 g/L) in 9% of the donors. Proteinuria was associated with hypertension and a lower GFR. Conclusions. On average, the remaining renal function of kidney donors did not deteriorate more rapidly than what may be expected from ageing. However one-third of the female and half of the male donors developed hypertension and, approximately, 10% displayed proteinuria. Nevertheless, our study supports the continued use of living kidney donors if strict criteria are used for acceptance.

Successful Abo-incompatible kidney transplantations without splenectomy using antigen-specific immunoadsorption and rituximab

Background. Historically, ABO-incompatible kidney transplantations have only been undertaken after splenectomy and unspecific plasmapheresis and with quadruple drug immunosuppression plus B-cell specific drugs. We have evaluated a protocol for ABO-incompatible kidney transplantation without splenectomy using antigen-specific immunoadsorption, rituximab, and a conventional triple-drug immunosuppressive regimen. Methods. The protocol called for a 10-day pretransplant conditioning period starting with one dosage of rituximab and followed by full dose tacrolimus, mycophenolate mofetil, and prednisolone. Antigen-specific immunoadsorption was performed on pretransplant days −6, −5, −4, and −1. After the last session, 0.5 g/kg of intravenous immunoglobulin was administered. Postoperatively, three more apheresis sessions were given every third day. Furthermore, if there was a significant increase in the antibody titers, extra sessions were considered. Results. Four patients have received transplants with this protocol. The donor-recipient blood groups were A2/O, B/O, B/A, and A1/O. The ABO-antibodies were readily removed by the antigen-specific immunoadsorption and were kept at a low level posttransplantation by further adsorptions. There were no side effects, and all patients have normal renal-transplant function. Conclusions. We conclude that after one infusion each of rituximab and intravenous immunoglobulin and antigen-specific immunoadsorption, blood–group-incompatible renal transplantations can be performed with standard immunosuppression and without splenectomy.

Comparing Mycophenolate Mofetil Regimens for de Novo Renal Transplant Recipients: The Fixed-Dose Concentration-Controlled Trial

Background. Fixed-dose mycophenolate mofetil (MMF) reduces the incidence of acute rejection after solid organ transplantation. The Fixed-Dose Concentration Controlled trial assessed the feasibility and potential benefit of therapeutic drug monitoring in patients receiving MMF after de novo renal transplant. Methods. Patients were randomized to a concentration-controlled (n=452; target exposure 45 mg hr/L) or a fixed-dose (n=449) MMF-containing regimen. The primary endpoint was treatment failure (a composite of biopsy-proven acute rejection [BPAR], graft loss, death, or MMF discontinuation) by 12 months posttransplantation. Results. Mycophenolic acid (MPA) exposures for both groups were similar at most time points and were below 30 mg hr/L in 37.3% of patients at day 3. There was no difference in the incidence of treatment failure (25.6% vs. 25.7%, P=0.81) or BPAR (14.9% vs. 15.5%, P>0.05) between the concentration-controlled and the fixed-dose groups, respectively. We did find a significant relationship between MPA-area under the concentration–time curve on day 3 and the incidence of BPAR in the first month (P=0.009) or in the first year posttransplantation (P=0.006). For later time points (day 10, month 1) there was no significant relationship between area under the concentration–time curve and BPAR (0.2572 and 0.5588, respectively). Conclusions. There was no difference in the incidence of treatment failure between the concentration-controlled and the fixed-dose groups. The applied protocol of MMF dose adjustments based on target MPA exposure was not successful, partly because physicians seemed reluctant to implement substantial dose changes. Current initial MMF doses underexpose more than 35% of patients early after transplantation, increasing the risk for BPAR.

Randomized trial of tacrolimus versus cyclosporin microemulsion in renal transplantation.

Abstractu2002This study was undertaken to compare the efficacy and safety of tacrolimus (Tac) with the microemulsion formulation of cyclosporin (CyA) in children undergoing renal transplantation. A 6-month, randomized, prospective, open, parallel group study with an open extension phase was conducted in 18 centers from nine European countries. In total, 196 pediatric patients (<18 years) were randomly assigned (1:1) to receive either Tac (n=103) or CyA microemulsion (n=93) administered concomitantly with azathioprine and corticosteroids. The primary endpoint was incidence and time to first acute rejection. Baselinecharacteristics were comparable between treatment groups. Tac therapy resulted in a significantly lower incidence of acute re-jection (36.9%) compared with CyA therapy (59.1%) (P=0.003). The incidence of corticosteroid-resistant rejection was also significantly lower in the Tac group compared with the CyA group (7.8% vs. 25.8%, P=0.001). The differences were also significant for biopsy-confirmed acute rejection (16.5% vs. 39.8%, P<0.001). At 1 year, patient survival was similar (96.1% vs. 96.6%), while 10 grafts were lost in the Tac group compared with 17 graft losses in the CyA group (P=0.06). At 1 year, mean glomerular filtration rate (Schwartz estimate) was significantly higher in the Tac group (62±20 ml/min per 1.73 m2, n=84) than in the CyA group (56±21 ml/min per 1.73 m2, n=74, P=0.03). The most frequent adverse events during the first 6 months were hypertension (68.9% vs. 61.3%), hypomagnesemia (34.0% vs. 12.9%, P=0.001), and urinary tract infection (29.1% vs. 33.3%). Statistically significant differences (P<0.05) were observed for diarrhea (13.6% vs. 3.2%), hypertrichosis (0.0% vs. 7.5%), flu syndrome (0.0% vs. 5.4%), and gum hyperplasia (0.0% vs. 5.4%). In previously non-diabetic children, the incidence of long-term (>30 days) insulin use was 3.0% (Tac) and 2.2% (CyA). Post-transplant lymphoproliferative disease was observed in 1 patient in the Tac group and 2 patients in the CyA group. In conclusion, Tac was significantly more effective than CyA microemulsion in preventing acute rejection after renal transplantation in a pediatric population. The overall safety profiles of the two regimens were comparable.

Recurrence of Autoimmune Diabetes Mellitus in Recipients of Cadaveric Pancreatic Grafts

Insulin-dependent diabetes mellitus is an autoimmune disease in which the beta cells of the islets of Langerhans are selectively destroyed.1 In a patient with this disease, a transplanted pancreas should be as susceptible to the autoimmune process as the native pancreas. Indeed, insulin-dependent diabetes mellitus can recur in an immunocompetent or minimally immunosuppressed recipient of a pancreatic transplant from an identical twin or HLA-identical sibling.2 Usually, however, the degree of immunosuppression required to prevent rejection is sufficient to prevent autoimmune damage to the pancreatic graft.3 We report on two patients who underwent pancreatic transplantation with poor HLA matching and in .xa0.xa0.

Implementation of a Protocol for ABO-incompatible kidney transplantation--a three-center experience with 60 consecutive transplantations

Background. A new protocol for ABO-incompatible kidney transplantation has recently been introduced. We report here on the joint experience of the implementation in Stockholm and Uppsala, Sweden and Freiburg, Germany. Methods. The new protocol utilizes antigen-specific immunoadsorption to remove existing ABO-antibodies, rituximab, and intravenous immunoglobulin to prevent the rebound of antibodies, and conventional tacrolimus, mycophenolate-mofetil, and prednisolone immunosuppression. Sixty consecutive ABO-incompatible kidney transplantations were included in the study. The outcome is compared with the results of 274 ABO-compatible live donor transplantations performed during the same period. Results. Two of the ABO-incompatible grafts have been lost (non-compliance and death with functioning graft). All the remaining 58 grafts had good renal function at a follow-up of up to 61 months. We did not observe any late rebound of antibodies and there were no humoral rejections. Graft survival was 97% for the ABO-incompatible compared with 95% for the ABO-compatible. Patient survival was 98% in both groups. There was a significant variation in preoperative A/B-antibody titer between the centers, with a median 1:8 in Uppsala, median 1:32 in Stockholm and median 1:128 in Freiburg. More preoperative antibody adsorptions were therefore needed in Freiburg than in Stockholm and Uppsala. Conclusions. The new protocol was easily implemented and there were no graft losses that could be related to ABO-incompatibility. A significant inter-institutional variation in the measurement of anti-AB-antibodies was found, having a substantial impact on the number of immunoadsorptions and consequently on the total cost for the procedure. A standardized fluorescence-activated cell sorting technique for antibody quantification is much needed.

ABO-Incompatible Kidney Transplantation Using Antigen-Specific Immunoadsorption and Rituximab: A 3-Year Follow-up

Background. In 2001 a protocol for ABO-incompatible (ABOi) kidney transplantation based on antigen-specific immunoadsorption and rituximab was introduced at our center, short-term results being comparable with those of ABO-compatible (ABOc) living donor kidney transplantation. Of greater importance, however, is long-term graft function, thus far not evaluated. The aim of this study was therefore to assess long-term results of this protocol. Methods. Twenty ABOi kidney recipients with more than 12-month follow-up were included in the study: all adult crossmatch negative ABOi kidney recipients (n=15) were compared with an adult ABOc living donor recipient control group (n=30), and all pediatric ABOi kidney recipients (<16 years of age) (n=5) were compared with a group of pediatric ABOc kidney recipients (n=18). Results. Mean follow-up was three years. There was no significant difference in patient survival, nor in graft survival or in the incidence of acute rejection in any of the groups. In the adult kidney recipients mean glomerular filtration rate was equivalent at all time points (79–83 mL/min), as was &Dgr;s-creatinine. In the pediatric groups, &Dgr;s-creatinine was similar but glomerular filtration rate lower among the ABOi kidney recipients. There was a significant reduction (P<0.0001) without rebound in A/B antibody titers after transplantation (median IgG 1:2 and median IgM 1:1>1 year posttransplant) compared with pretransplant levels (median IgG 1:32 and IgM 1:16). Conclusion. We conclude that ABOi kidney transplantation using antigen-specific immunoadsorption and rituximab is equivalent to ABOc living donor kidney transplantation. ABOi transplantation after this protocol does not have a negative impact on long-term graft function.

Pharmacodynamics of rituximab in kidney allotransplantation.

The anti‐CD20 antibody rituximab has recently gained interest as a B‐cell depleting agent in renal transplantation. However, little is known about the pharmacodynamics of rituximab in renal transplant recipients.