Long term outcome of renal allografts in patients with immunoglobulin A nephropathy

Recurrent glomerular disease is an important cause of late allograft loss in renal transplant recipients. Immunoglobulin A nephropathy (IgAN) is a leading cause of end-stage renal disease (ESRD) worldwide and its recurrence has been reported in allografts. The present study examined outcomes following renal transplantation (RTX) in 101 patients with ESRD due to biopsy-proven IgAN, in comparison to non-IgA patients, and evaluated the incidence of recurrence. The study population (mean age 34.8 +/- 7.7 years; males 62.2%; Chinese 88.3%) underwent RTX under CsA immunosuppression between November 1984 and December 2004; as two patients underwent retransplantation during the study period, 103 allografts (56.3% cadaveric) were included for retrospective analysis. At time of analysis on 1 January 2005, 78 (75.7%) renal allografts (IgAN RTX) were functioning, of which 51 (49.5%) had normal serum creatinine, 27 (26.2%) had chronic allograft dysfunction, while 25 had graft losses, either due to patient death with functioning grafts (5.8%) or withdrawal to dialysis (18.5%). Persistent microscopic haematuria, not attributable to other causes or proteinuria > 1 g/day occurred in 42.7% and 13.6% of allografts respectively. Of 29 allografts biopsied for evaluation of proteinuria and/or renal dysfunction post-RTX, 8 (27.6%) had IgAN (overall histological recurrence, 7.8%). Of these, three had graft loss due to recurrent IgAN, three had elevated serum creatinine, while two had normal serum creatinine. Overall five and ten year patient survivals for IgAN RTX were 95.3% and 82.2%, and five and ten year actuarial graft survivals were 82.3% and 67.8% respectively. Five and ten year patient and graft survivals for IgAN RTX were not significantly different from that for non-IgAN RTX. In summary, RTX patients with IgAN have a low incidence of documented histological recurrence and recurrence contributing to graft loss occurs in only 2.9%. These results suggest that RTX is an excellent modality of renal replacement therapy in this population.

Conversion From Mycophenolate Mofetil to Enteric-Coated Mycophenolate Sodium in Stable Maintenance Renal Transplant Patients: Pooled Results From Three International, Multicenter Studies

BACKGROUND

Mycophenolate mofetil (MMF) is effective in renal transplant patients but concerns remain over its gastrointestinal (GI) tolerability. Enteric-coated mycophenolate sodium (EC-MPS; myfortic) has been developed with the intention of improving mycophenolic acid-related GI tolerability.

METHODS

Data were pooled in a planned analysis of three subprotocols of the myfortic Prospective Multicenter Study (myPROMS). In a 6-month study, efficacy and safety of converting stable renal transplant recipients from MMF to a bioequivalent dose of EC-MPS for mycophenolic acid exposure were evaluated. Treatment efficacy was recorded and graft function was assessed by measuring serum creatinine and estimating creatinine clearance. Adverse events (AEs) and infections were monitored and the incidence of EC-MPS dose changes was recorded.

RESULTS

A total of 588 patients were recruited, 564 (96%) of whom completed the study. The rate of treatment failure (defined as biopsy-proven acute rejection, graft loss, or death) was 1.9%, with no episodes of graft loss and only one death reported during the study. Renal function remained stable throughout the trial. EC-MPS was well tolerated; the majority of AEs were mild or moderate in severity. Dose reductions or interruptions were required by 6.3% and 1.9% of patients, respectively. Gastrointestinal AEs occurred in 138 patients (23.5%). The rate of dose adjustment as a result of a GI AE was 2.2%.

CONCLUSIONS

Equimolar conversion from MMF to EC-MPS in maintenance renal transplant patients was safe and maintained efficacy.

3rd College of Physicians’ Lecture – Translational Research: From Bench to Bedside and From Bedside to Bench; Incorporating a Clinical Research Journey in IgA Nephritis (1976 to 2006)

Translational research (TR) can be defined as research where a discovery made in the laboratory (bench) can be applied in the diagnosis, treatment or prevention of a disease. Examples of medical discoveries contributing to translational medicine (TM) include the isolation of insulin by Banting (Nobel Laureate, 1923), the discovery of penicillin by Alexander Fleming (Nobel Laureate, 1945) and recently the discovery of the role of bacterium Helicobacter pylori in the causation of gastritis and peptic ulcer by Marshall and Warren (Nobel Laureates, 2005). Clinical research (CR) would be a more appropriate term for the bulk of research work undertaken by doctors. CR embraces both clinical based and laboratory-based research. The terminology “bedside to bench” applies more to CR as opposed to “bench to bedside” in the case of TR. But regardless of who does it, as long as the discovery can be translated to the bedside and results in improvement in patient care it can be considered a contribution to TM. Our work spans a 30-year period, involving laboratory-based research, clinical trials and genomics of IgA nephritis (Nx). This is a series of work to elucidate the pathogensis and therapy of IgANx. Plasma beta-thromboglobulin (BTG) an in-vivo index of platelet aggregation and anti-thrombin III increase due to a constant thrombogenecity resulting from platelet degranulation formed the basis for anti-platelet and low-dose warfarin therapy. A study of the natural history of IgANx revealed 2 courses, a slowly progressive course with end-stage renal failure (ESRF) at 7.7 years and a more rapid course at 3.3 years. Triple therapy (cyclophosphamide, persantin and low-dose warfarin) delayed progression to ESRF by about 8 years and for some patients up to 20 years. Documentation of abnormal suppressor T cell function provided the basis for immune therapy. Four patterns of proteinuria were present in IgANx and it is the quality and not so much the quantity of proteinuria which determined the prognosis. Low molecular weight proteinuria was a bad prognostic marker. A controlled therapeutic trial using ACEI/ATRA showed that therapy decreases proteinuria, improves renal function and converts non-selective to selective proteinuria. Subsequent work confirmed that it was the ATRA, not the ACEI which contributed to improved renal function. Individual anti proteinuria response to ATRA varies depending on ACE gene polymorphism. We found that the II genotype of the ACE gene was renoprotective and patients with this genotype had significantly reduced incidence of ESRF compared to those with the DD genotype. Patients responsive to ATRA therapy can retard progression to ESRF by up to 32 years. Mild renal failure can be reversed with possible regression of glomerulosclerosis because of glomerular remodelling by ATRA. Key words: Genomics, Glomerulonephritis, History, Therapy, Translational medicine

3rd College of Physicians' lecture--translational research: From bench to bedside and from bedside to bench; incorporating a clinical research journey in IgA nephritis (1976 to 2006)

Translational research (TR) can be defined as research where a discovery made in the laboratory (bench) can be applied in the diagnosis, treatment or prevention of a disease. Examples of medical discoveries contributing to translational medicine (TM) include the isolation of insulin by Banting (Nobel Laureate, 1923), the discovery of penicillin by Alexander Fleming (Nobel Laureate, 1945) and recently the discovery of the role of bacterium Helicobacter pylori in the causation of gastritis and peptic ulcer by Marshall and Warren (Nobel Laureates, 2005). Clinical research (CR) would be a more appropriate term for the bulk of research work undertaken by doctors. CR embraces both clinical based and laboratory-based research. The terminology "bedside to bench" applies more to CR as opposed to "bench to bedside" in the case of TR. But regardless of who does it, as long as the discovery can be translated to the bedside and results in improvement in patient care it can be considered a contribution to TM. Our work spans a 30-year period, involving laboratory-based research, clinical trials and genomics of IgA nephritis (Nx). This is a series of work to elucidate the pathogensis and therapy of IgANx. Plasma beta-thromboglobulin (BTG) an in-vivo index of platelet aggregation and anti-thrombin III increase due to a constant thrombogenecity resulting from platelet degranulation formed the basis for anti-platelet and low-dose warfarin therapy. A study of the natural history of IgANx revealed 2 courses, a slowly progressive course with end-stage renal failure (ESRF) at 7.7 years and a more rapid course at 3.3 years. Triple therapy (cyclophosphamide, persantin and low-dose warfarin) delayed progression to ESRF by about 8 years and for some patients up to 20 years. Documentation of abnormal suppressor T cell function provided the basis for immune therapy. Four patterns of proteinuria were present in IgANx and it is the quality and not so much the quantity of proteinuria which determined the prognosis. Low molecular weight proteinuria was a bad prognostic marker. A controlled therapeutic trial using ACEI/ATRA showed that therapy decreases proteinuria, improves renal function and converts non-selective to selective proteinuria. Subsequent work confirmed that it was the ATRA, not the ACEI which contributed to improved renal function. Individual anti proteinuria response to ATRA varies depending on ACE gene polymorphism. We found that the II genotype of the ACE gene was renoprotective and patients with this genotype had significantly reduced incidence of ESRF compared to those with the DD genotype. Patients responsive to ATRA therapy can retard progression to ESRF by up to 32 years. Mild renal failure can be reversed with possible regression of glomerulosclerosis because of glomerular remodelling by ATRA.

Preventing renal transplant failure

INTRODUCTION

Allograft failure due to immunological or non-immunological causes or a combination and patient death after transplantation are the 2 major causes of renal transplant loss. This paper reviews the various causes of allograft failure and explores strategies for its prevention.

RESULTS

Immune mechanisms of renal allograft failure are those mediated by acute and chronic rejection and are initiated by human leukocyte antigen (HLA) disparity between donor and recipient and increased recipient immune responsiveness that results in pre-sensitisation against HLA antigens. Better HLA matching between donor and recipient in both live-donor and cadaveric renal transplant recipients and the use of more potent immunosuppressants has reduced the incidence of acute rejection and resulted in improved overall graft survivals in recent years. However, as the use of more potent immunosuppression increases the risk of infections and malignancy, tailoring therapy by administering more potent immunosuppression to those at higher immunological risk may result in a better balance between the risks and benefits of immunosuppressive therapies. Ischaemia of the donor kidney, calcineurin inhibitor (CNI), mediated nephrotoxicity, reduced renal mass, hypertension, hyperlipidaemia and infections contribute to allograft failure through non-immunological mechanisms. Indeed, any cause of renal injury that results in nephron loss, either immunological or non-immunological, leads to reduced renal mass and initiates further renal damage due to hyperfiltration. Optimising these factors and minimising CNI nephrotoxicity are critical in reducing chronic allograft failure.

CONCLUSIONS

Optimising each of these time-dependent and immunosuppressive drug-related factors would allow the maximization of renal allograft function and survival.

Spectrum of severe infections in an Asian renal transplant population

Infections in renal transplant recipients (RTX) account for 26% of hospitalization days annually and 40% of overall mortalities. A retrospective study of infections requiring hospitalization occurring among 725 Asian RTX in 2002 was performed.

RESULTS

Serious infections requiring at least one hospitalization occurred in 9.2% of RTX (n = 67). Multiple pathogens affected 28.4% of patients, resulting in 118 infectious episodes during 93 hospitalizations. Mean age of affected patients was 48 years and female to male ratio was 2:1. Forty-one (61.2%) had impaired renal function (serum creatinine >141 mumol/L). Mean duration of hospitalization per patient was 17 days and the in-patient mortality rate was 17.9% eighty-one (87%) hospitalizations were for late infections (>6 months posttransplant). Cyclosporine (CsA) with prednisolone with or without azathioprine was the immunosuppressant in 62.7% (n = 42) of RTX but proportionally, infections were more frequent among RTX on other more potent immunosuppressants (n = 21; 7.4% CsA-based vs. 19.3%, potent, P < .05). Bacterial, viral, fungal, and Pneumocystis carinii infections comprised 64.4%, 20.3%, 5.9%, and 4.2% respectively. Urinary tract infection, pneumonia, and bacterial septicemia (35.52%, 31.6%, and 11.8%, respectively) were the major presentations. E. coli, cytomegalovirus (CMV), and Candida were the most common pathogens. Notably, 13 out of 18 (72.2%) viral CMV infections were co- infections, occurring together with bacterial infections.

CONCLUSIONS

Late infections with the use of potent immunosuppressives and concurrent CMV reactivation are a major cause of morbidity. Longer antibacterial prophylaxis and closer monitoring for CMV infections may help reduce morbidity.

Immunosuppression use in renal transplantation from Asian transplant centers: A preliminary report from the Asian Transplant Registry

Since the first renal transplant (RTx) in 1956 in Asia in Japan, over 100,000 RTx have been performed in over 300 centers across the region. A survey was conducted to evaluate immunosuppression (IS) use among Asian RTx. Briefly, directors of RTx centers were surveyed regarding IS use for RTx performed at their centers in 2001 for (1) induction therapy, (2) maintenance IS therapy at hospital discharge, (3) antirejection treatment (REJ) to 1 year post-RTx, and (4) maintenance IS therapy to 1 year post-RTx. Categories and types of IS included in the survey were polyclonal antilymphocyte antibodies (PAB), OKT3, IL2 receptor antibodies (IL2RAb), corticosteroids (CS), cyclosporine (CyA), tacrolimus (Tac), azathioprine (Aza), mycophenolate mofetil (MMF), Mizoribine (Miz), Sirolimus (Sir), and other agents. Though only 17 RTx centers in Asia responded to the survey, a wide variation in IS use was demonstrated. In the 334 living and 85 cadavericRTx among whom actual usage was reported, induction therapy was used in only 18.4% of Asian RTx (14.1%, IL2RAb; 4.3%, PAB), in contrast to the 59.3% reported as using induction IS among RTx from the UNOS database in the same year. For maintenance therapy at hospital discharge, 87.1% of Asian RTx received CyA-based IS while only 12.4% received Tac-based therapy. This is in contrast to the 55.3% use of Tac for new RTx in the United States. Generic CyA has widespread use in Asia with over 29.9% on CyA using generic versus the Neoral formulation. Azathioprine is still the predominant antimetabolite in use in Asian RTx, with MMF being used in only 33.6% of patients, in contrast to its 77% usage in the United States. Usage of Tac and MMF for maintenance therapy was significantly higher among cadavericRTx (P < .005). Corticosteroids were used in 51.1% of REJ episodes while PAB or OKT3 were used in 31.9% and 17% of REJ episodes, respectively. As these results may be skewed due to participation of few centers in the survey, greater participation will ensure more accurate evaluation of immunosuppression use in Asia for de novo RTx.

Conversion from mycophenolate mofetil to azathioprine in high-risk renal allograft recipients on cyclosporine-based immunosuppression

OBJECTIVE

In a randomized control trial of mycophenolate mofetil (MMF) versus azathioprine (AZA) with cyclosporine and steroids, we demonstrated that MMF reduced acute rejection (AR) among renal allograft recipients (RTX) who were of low to moderate risk. However, 10% had AR when converted from MMF to AZA at 6 months, postrenal transplantation (RT). Two clinical markers, abnormal serum creatinine (SCr) and proteinuria at 6 months, post-RT, were associated with AR postconversion. The present study examined the safety of such conversion in selected high-risk RTX at 1 year of MMF therapy.

METHODS

Thirteen high-risk RTX receiving MMF for either high panel reactive antibody (n = 9) or following AR (n = 4), with normal SCr and no proteinuria at 1 year, were selected for conversion. The incidence of AR, adverse events, and renal parameters (SCr, creatinine clearance, proteinuria) at 6 months postconversion was evaluated. Eight high-risk RTX who did not meet these selection criteria were retrospectively reviewed and used as controls.

RESULTS

Renal parameters (SCr 123 +/- 26 vs 129 +/- 27 mumol/L; pre- vs postconversion) were not significantly different; no episodes of AR or proteinuria were documented. Azathioprine was discontinued in two patients due to leukopenia. In the control group, one patient had graft loss from chronic rejection, whereas one developed posttransplant lymphoproliferative disease necessitating MMF withdrawal.

CONCLUSION

These results suggest that selective conversion from MMF to AZA after 1 year is safe, even in high-risk RTX. Normal SCr and absence of proteinuria are good screening parameters to identify patients at low risk for AR following such conversion.

Improving cadaveric organ donation rates in kidney and liver transplantation in Asia

In the year 2001, cadaveric kidney and liver transplant rates (CadTx) in countries with well-established transplant programs such as the United States and Spain ranged from 51 to 61.9 and 18.7 to 31.3 per million population (pmp), respectively. However, overall kidney and liver transplant rates in Asia are significantly lower at 4.3 and 0.3 pmp, respectively. Improving CadTx rates to meet the needs of organ failure patients poses several unique challenges in Asia. Across Asia, there is a wide disparity in prehospital emergency services and intensive care facilities that allow victims of cerebrovascular accident or trauma to be sent to hospitals for optimal management. Identification of the brain-dead victim in an intensive care setting, donor referral to an organ procurement coordinator/network, making the request for organ donation, and obtaining consent for organ donation from the family are other critical issues that impact on successful cadaveric donation. While affirmative legislation regarding organ donation is existent in most Asian countries, religious, ethnic, and cultural influences on concepts of death and the sanctity of the human body remain major barriers to obtaining consent for cadaveric donation. Although there are no overt objections to CadTx among the major religions of Asia, perceptions to the contrary largely limit consent for organ donation from potential donor families. Development of transportation and communication networks, public and donor hospital education programs, legislative initiatives such as presumed consent, and establishment of effective organ procurement practices are all key initiatives that will improve CadTx rates. Broadening donor criteria as with the use of expanded criteria donors, including non-heart-beating and older donors, may further improve cadaveric donation rates by as much as 20%. Finally, ethical transplant practices that prohibit trade in organs will promote an environment conducive to cadaveric donation. Together with efforts to increase living donor TX transplant rates, it is hoped that these measures will increase the supply of organs so as to meet the needs of organ failure patients in Asia.

Hand-assisted laparoscopic living donor nephrectomy

INTRODUCTION

Laparoscopic living donor nephrectomy (LDN) for renal transplantation is increasingly being performed to improve donor outcomes, by reducing perioperative morbidity without adversely impacting on allograft function in the recipient. We report our initial experience with hand-assisted LDN.

MATERIALS AND METHODS

From March 2002 to January 2003, 10 hand-assisted LDNs were performed in 2 institutions. Potential donors were evaluated for suitability, which included a renal angiogram. Only donors with uncomplicated vascular arrangements of the left kidney were offered this technique. During surgery, dissection of the donor kidney was performed laparoscopically, aided by the surgeon 's non-dominant hand inserted into the abdominal cavity through a hand-assist device via a 7-cm abdominal incision. The graft was subsequently delivered through the incision.

RESULTS

The mean operating time was 163.5 +/- 32 minutes and the mean warm ischaemic time was 2.16 +/- 0.72 minutes. There were no conversions to the open nephrectomy technique or requirement for perioperative transfusions. Postoperatively, patients returned to normal diet by 1.8 +/- 0.8 days and needed opiate analgesia up to a maximum of 48 hours. On average, the patients started ambulation at 2.1 +/- 0.9 days and were discharged 4 +/- 1.5 days after surgery. There were no significant complications other than 3 superficial wound infections. All grafts had immediate graft function. Serum creatinine levels of all recipients fell within 24 hours and reached baseline at a mean of 5.7 +/- 4.6 days.

CONCLUSIONS

Hand-assisted LDN is safe, feasible and can be performed with minimal morbidity. It also allows for excellent allograft function.

Pregnancy after renal transplantation: experience in Singapore General Hospital

INTRODUCTION

Renal transplantation offers the best hope for those women with end-stage renal disease who wish to have children. However, pregnancy after renal transplantation is associated with increased maternal and fetal morbidity. The aim of this retrospective study was to review the outcome of pregnancy in renal transplant patients in Singapore General Hospital.

MATERIALS AND METHODS

Forty-two pregnancies, occurring between December 1986 and December 2000, in 25 out of 141 renal transplant women in their reproductive age group (18 to 45 years old) were identified from our high-risk pregnancy record and retrospectively analysed.

RESULTS

Thirteen (31%) pregnancies were unsuccessful; 10 abortions, 2 ectopic pregnancies and 1 stillbirth. The remaining 29(69%) successful pregnancies were complicated by maternal anaemia (65.5%), superimposed hypertension (44.8%), premature rupture of membranes (27.6%), urinary (17.2%) and lower genital tract (13.8%) infections, abnormal glucose tolerance test (13.8%), premature delivery (44.8%), low-birth-weight babies (44.8%), small-for-gestational-age babies (20.7%) and intrauterine growth restriction (20.7%). There were no documented cases of multiple pregnancies, congenital anomalies or deterioration of renal function. The outcome of pregnancy was not statistically influenced by preconception renal function and transplant-conception interval.

CONCLUSIONS

Successful pregnancy is possible in women after renal transplantation. Such pregnancy is often associated with increased maternal and fetal complications and should be managed by a multidisciplinary approach in a tertiary centre. The function and survival of renal allograft was not adversely affected by pregnancy.

Case reports of low dose cyclosporine. A therapy in adult minimal change nephrotic syndrome

INTRODUCTION

Many centres still use steroids to induce remission in patients with minimal change nephrotic syndrome (MCNS) and failing that to give a course of cyclophosphamide, though some centres are already using cyclosporine A (CsA) as an alternative. We report the benefits of CsA therapy in 3 adults with difficult to treat MCNS in whom low dose CsA therapy proved to be efficacious.

CLINICAL PICTURE AND OUTCOME

The first patient had her 1st relapse after 8 years and thereafter had 2 more relapses, within 3 months of each other, in spite of therapy with cyclophosphamide. With CsA therapy, at a dose of 3.5 mg/kg body weight (BW)/day, she achieved lasting remission of 22 months as of September 1999 and is still in remission. The second patient had his relapses of nephrotic syndrome over a period of 10 years when treated with prednisolone and cyclophosphamide. On the 13th relapse, he achieved a remission lasting 21 months after a 3 month course of CsA at a dose of 4 mg/kg BW/day. With the 14th relapse, he took half the dose of CsA prescribed [only the morning dose of neoral CsA (2 mg/kg BW/day)] and still achieved a remission and has been in remission since. The third patient was a young woman, married for 2 years without children. She could not tolerate prednisolone because of erosive gastritis and she responded to a pulse dose of intravenous cyclophosphamide for her 1st episode of nephrotic syndrome with complete remission. However, when she relapsed 5 months later she did not respond to a similar dose of i.v. cyclophosphamide and was therefore treated with CsA (4 mg/kg BW/day) which induced a prompt remission 1 month after commencement of therapy and she is still in remission. The trough CsA levels for the 3 patients (range 41 to 107 ng/mL) and the calculated average CsA levels were lower than that used for post renal transplant immunosuppression. The trough CsA levels were, however, similar to that used in patients with MCNS from other series, though achieved at lower CsA doses.

CONCLUSION

Our study shows that low dose CsA is a useful agent for induction of remission of MCNS and maintenance of lasting remission. A low dose CsA regimen will make CsA more affordable.