Prevalence, Characteristics, and Outcomes of Incidental IgA Glomerular Deposits in Donor Kidneys

Introduction

Incidental IgA deposits in donor kidneys have unknown sequelae and may predate clinical kidney disease if primed by adverse immunologic or hemodynamic stimuli or may remain dormant.

Methods

The presence of incidental IgA in post-implantation (T₀) biopsies from living (LDK) and deceased donor (DDK) kidneys, and its relationship to post-transplant patient and graft outcomes was investigated in an ethnically diverse US population at a large transplant center.

Results

Mesangial IgA was present in 20.4% of 802 T₀ biopsies; 13.2% and 24.5% of LDK and DDK, respectively. Donors with incidental IgA deposits were more likely to have hypertension and be of Hispanic or Asian origin. Intensity of IgA staining was 1+ (57.3%), 2+ (26.8%), or 3+ (15.8%) of the T₀ IgA+ biopsies. Mesangial pathology correlated with higher-intensity IgA staining with less clearance on follow-up (53.8%) versus 79.2% without mesangial pathology. IgA cleared in 91%, 63%, and 40% of follow-up biopsies with 1+, 2+, and 3+ IgA staining, respectively. Early post-transplant rejection and rejection-related graft loss occurred more frequently in IgA+ kidney recipients; however, 5-year kidney function and graft survival were comparable to kidneys without IgA.

Conclusion

This first and largest report of incidental IgA in T₀ biopsies of LDK and DDK in a US ethnically diverse population demonstrated no adverse association between the presence of IgA in donor kidneys and graft or patient survival. Whether IgA in donor kidneys represents latent IgA nephropathy (IgAN) is uncertain; nevertheless, living donors who demonstrate IgA on T₀ biopsy deserve careful follow-up.

Donor-related diabetic nephropathy: a comprehensive clinicopathological study

Knowledge on renal involvement in kidney donors with diabetes, that is, diabetic nephropathy (DN), is limited. During the 7 years (2010-2017), 921 postperfusion biopsies were performed for living donors (14%) or deceased donors (86%). The Renal Pathology Society classification schema for DN (class 0-IV) was used. Biopsies with light microscopic changes of DN (at least class IIa) were selected for study. Eleven biopsies (1.2%) showed DN, all from deceased donors (class IIa in 8, class IIb in 2, and class III in 1 biopsy). The glomerular basement membrane thickness ranged from 439 ± 52 to 725 ± 82 nm. These biopsies also displayed arterionephrosclerosis. They were from 9 deceased donors (fulfilling clinical criteria for acceptance in all, diabetes ;[>6 years] in 8, hypertension in 6, and proteinuria [1+] in all). Follow-up biopsies (5-342 weeks after transplant) showed DN of the same class (7 biopsies), probably progression (1), or progression (3). At follow-up (15-416 weeks), all recipients were alive. One graft was lost at 76 weeks because of progressive DN. The other 10 grafts were functioning, but the serum creatinine reached 2.0 to 2.7 mg/dL in 5 of them. Although diabetes is frequent in kidney donors, donor-related DN is unusual. It is observed only in deceased donors, but the risk factors for its development are not known. Donor-related DN may be stable or progress. Whether it resolves, especially for DN in early phase, remains unknown. It may adversely impact the graft outcome with a magnitude proportional to the severity of the tissue injury in the postperfusion biopsies.

Expression of Transforming Growth Factor-β by Human Islets: Impact on Islet Viability and Function

Transforming growth factor-β1 (TGF-β1) is a pleotropic cytokine that promotes angiogenesis and extracellular matrix protein synthesis in addition to its immunosuppressive effects. The purpose of this study is to identify optimal conditions for in vivo expression of TGF-β1 by human islets to exploit the possible beneficial effects and minimize undesirable side effects. We transduced human islets with adenoviral vectors encoding the active form of Ad-TGF-β1 or Ad-LacZ to test the effects of TGF-β1 gene expression on islet in vivo function following their transplantation into a NOD-SCID mouse model. Islets were transduced with multiplicity of infection (MOI) of 20, 10, 5, and 2.5 per islet cell. At a MOI ranging from 2.5 to 20, expression of TGF-β1 in islet supernatant persisted for 1–2 months and ranged from 153 ± 5 to 2574 ± 1299 pg/ml, respectively. Transduction with the lowest MOI (2.5) did not compromise the in vivo production of human C-peptide. We conclude that TGF-β1 expression in transplanted islets does not compromise viability and that adenoviral transduction with the TGF-β1 gene has a dose-dependent effect, with larger MOIs being deleterious. The data also indicate that in vitro culture system and the in vivo NOD-SCID model could be used successfully to evaluate the nonimmune effects of gene transduction.

Disparate rates of acute rejection and donor-specific antibodies among high-immunologic risk renal transplant subgroups receiving antithymocyte globulin induction

Lymphocyte-depleting induction lowers acute rejection (AR) rates among high-immunologic risk (HIR) renal transplant recipients, including African Americans (AAs), retransplants, and the sensitized. It is unclear whether different HIR subgroups experience similarly low rates of AR. We aimed to describe the incidence of AR and de novo donor-specific antibody (dnDSA) among HIR recipients categorized by age, race, or donor type. All received antithymocyte globulin (ATG) induction and triple maintenance immunosuppression. A total of 464 HIR recipients from 2007 to 2014 were reviewed. AR and dnDSA rates at 1 year for the entire population were 14% and 27%, respectively. AR ranged from 6.7% among living donor (LD) recipients to 30% in younger AA deceased donor (DD) recipients. De novo donor-specific antibody at 1 year ranged from 7% in older non-AA LD recipients to 32% in AAs. AA race remained as an independent risk factor for AR among DD recipients and for dnDSA among all HIR recipients. Development of both AR and dnDSA within the first year was associated with a 54% graft survival at 5 years and was an independent risk factor for graft loss. Despite utilization of recommended immunosuppression for HIR recipients, substantial disparities exist among subgroups, warranting further consideration of individualized immunosuppression in certain HIR subgroups.

Observations on the use of cidofovir for BK virus infection in renal transplantation

BACKGROUND

In renal transplantation, BK virus infection can result in significant graft nephropathy and loss. While reduction in immunosuppression (IS) is considered standard therapy, adjunct agents may be warranted. Data are suggestive of a possible role of cidofovir for the management of BK. This study aims to describe the course of BK viremia (BKV) in a large cohort of renal transplant patients receiving adjunct cidofovir.

METHODS

We evaluated kidney and kidney-pancreas recipients who received cidofovir combined with reduced IS for management of high-level BKV or BK virus nephropathy (BKVN). We examined the rate and timing of BKV clearance, and performed a multivariate analysis to identify risk factors associated with long-term (>6 months) viremia.

RESULTS

In total, 75 patients received a median of 13 doses of cidofovir in conjunction with reduced IS; 32 patients (43%) had short-term BKV (≤6 months), and 43 (57%) had long-term BKV. Overall, 53 of 75 patients (71%) eventually cleared BKV at a median of 4.2 months (interquartile range 2.1-9.3 months). Independent factors associated with long-term BKV included older age (odds ratio [OR] 1.1, P = 0.02), delayed graft function (OR 31.4, P = 0.01), and higher peak BKV (OR 12.8, P = 0.02), while BKV reduction by at least 1 log(10) copies/mL at 1 month of treatment was associated with clearance within 6 months (OR 49.3, P < 0.01). Patients with earlier clearance maintained stable graft function and no graft losses, while long-term BKV was associated with a 15% decline in estimated glomerular filtration rate.

CONCLUSIONS

Adjunct cidofovir resulted in preservation of renal function when viral clearance occurred within 6 months of initiation. This retrospective review defines factors predicting response to cidofovir in conjunction with reduced IS for BKVN or high-level BKV. Still, considering cost, frequency of administration, and treatment duration, a randomized trial is necessary to define the exact utility of cidofovir in the setting of BK virus infection.

Tubulointerstitial nephritis in systemic lupus erythematosus: innocent bystander or ominous presage

SLE-associated tubulointerstitial injury (SLE TIN) is increasingly recognized in two forms, i.e., secondary and primary. The secondary form coexists with lupus glomerulonephritis, whereas the primary form develops against the background of no or mild glomerular or vascular involvement. Secondary SLE TIN is frequent, but its frequency and severity correlate with the class of the associated lupus glomerulonephritis (GN), being almost universal in Class IV lupus GN and less frequent in GN of other classes. Although the presence of underlying GN may mask its clinical manifestation, secondary SLE TIN has a major prognostic implication for the renal outcome. Yet, SLE TIN is not factored in the current therapy-focused International Society of Nephrology/Renal Pathology Society schema of renal lupus classification, and its management remains to be elucidated. The pathogenesis of secondary SLE TIN is either immunologic, i.e., the tubulointerstitial injury being mediated by SLE-related immunologic mechanisms akin to those responsible for lupus GN; or non-immunologic, i.e., a nonspecific tubulointerstitial injury secondary to any type of advanced glomerular lesion, regardless of etiology. Primary SLE TIN is rare with about 15 reported cases. It has a rather uniform and distinctive clinical manifestation including acute kidney injury with no or mild proteinuria. It responds well to steroid and usually carries a good prognosis. Its pathogenesis is almost certain immunologic, with immunoglobulin/complement deposits along the tubular basement membrane in each reported case. In spite of these profound clinical implications, the current review underlies a limited knowledge on the pathobiology of SLE TIN.

A surgeons' guide to renal transplant immunopathology, immunology, and immunosuppression

The response to allografting involves adaptive and innate immune mechanisms. In the adaptive system, activated T cells differentiate to cytotoxic effectors that attack the graft and trigger B cells to differentiation to plasma cells that produce anti-HLA antibodies. The innate immune system recognizes antigens in a non-specific manner and recruits immune cells to the graft through the productions of chemotactic factors, and activation of cytokines and the complement cascade. In the kidney the tubules and the endothelium are the targets of the rejection response. Immune suppression is effective in modulating the adaptive immune system effect on graft histology.

De novo donor specific antibodies and patient outcomes in renal transplantation

Single antigen identification of HLA antibodies is used to detect donor specific antibodies (DSAs). However, the impact of DSA elements such as class, relative strength, duration, and longitudinal effect on graft function and survival, remains unclear. Routine DSAs (LabScreen, One Lambda, Inc., Canoga Park, CA) and metabolic studies were performed at 1, 3, 6, 9, and 12 months post-transplant, and every 6 months for renal transplant recipients from 7/2007-7/2010 (n = 389). Biopsies were evaluated by updated Banff 2005 guidelines after two consecutive positive DSAs. Based on these tests, 25% of recipients developed de novo DSA. Those with DSA had increased acute rejection episodes (AR), higher creatinine (Scr), and worse graft survival. Three subgroups of these patients were identified based on duration: persistent DSA (> 1), isolated DSA, or no DSA. Persistent DSA patients were more likely to be African American, and have higher mean fluorescence intensity (MFI) and AR rates. Persistent DSA patients, with or without AR, had elevated Scr. Recipients with DQ-only DSA had higher rates of antibody mediated rejection (AMR). From this, we conclude that routine posttransplant DSA monitoring identifies recipients at risk for graft damage or loss. Persistent de novo DSAs correlated with inferior graft outcomes and AMR. With or without AR, DSA persistence was associated with worse outcomes, possibly warranting intervention. De novo DQ-DSA may be a biomarker for chronic damage and/or AMR, while an isolated DSA determination appears clinically insignificant.

A review of the evidence for use of thymoglobulin induction in renal transplantation

Depleting antilymphocyte, or antithymocyte antibodies, have long been an integral part of induction regimens and continue today to be used in the management of patients at risk of early rejection or those in whom the introduction of calcineurins or other immune suppressants must be delayed. Registry data demonstrate that the most commonly used depleting antibody, rabbit anti-human thymocyte globulin (rATG), is associated with improved outcomes following renal transplantation in high-risk patients, particularly in conjunction with steroid-avoidance regimens. Two prospective randomized trials in high-risk renal allograft patients have also demonstrated an advantage of r-ATG induction compared to the nondepleting interleukin receptor (IL2RA) antibodies. In low-immunologic-risk patients, however, r-ATG induction and IL2RA induction appear to be equivalent in terms of rejection prophylaxis and long-term function. Other studies have shown that sequential rATG-containing regimens were superior to no induction and allowed for successful late introduction of calcineurin inhibitors. The side effect profile of the depleting antibody included increased incidence of fever, hematologic abnormalities, cytomegalovirus infections when prophylaxis was not employed, and in some studies, increased incidence of posttransplant lymphoproliferative disease. This review describes the evidence supporting the use of depleting ATGs in kidney transplantation.

The inflammatory cascade in acute pancreatitis: relevance to clinical disease

Acute pancreatitis is an inflammatory condition that is initiated by the intra pancreatic activation of proteases. Pancreatic enzyme activation triggers a local and systemic inflammatory response that is associated with recruitment of inflammatory cells into the pancreas and a widespread up-regulation of inflammatory markers in distant tissues.

Acute antibody-mediated rejection of renal transplant: pathogenetic and diagnostic considerations

CONTEXT

Acute antibody-mediated rejection (AMR) has emerged recently as an important cause of graft failure.

OBJECTIVE

To review the pathogenetic, clinicopathologic, and diagnostic considerations of AMR.

DATA SOURCES

Review of literature and the authors' experience.

CONCLUSIONS

Acute antibody-mediated rejection is mediated by antibodies specific for donor antigens, which bind to target antigens and activate the complement system, culminating in tissue injury. The clinical manifestation of AMR is not specific, and transplant biopsy is needed for diagnosis. The glomeruli show thrombosis or neutrophils or mononuclear leukocytes in capillary lumens. The tubulointerstitial compartment shows edema, hemorrhage, necrosis, mild inflammation, and neutrophils or mononuclear leukocytes in the peritubular capillary lumens. The blood vessels show thrombosis, thrombotic microangiopathy, fibrinoid necrosis, or transmural vasculitis. Strong staining for C4d in the peritubular capillaries is characteristic. A definitive diagnosis of AMR requires (1) morphologic evidence of acute tissue injury, (2) immunopathologic evidence for antibody action, and (3) serologic evidence of circulating donor-specific antibodies. Acute antibody-mediated rejection should be suspected if some but not all 3 criteria are met. Since effective treatment is currently available, accurate and timely diagnosis of AMR is essential.

Pancreas allograft biopsies in the management of pancreas transplant recipients: histopathologic review and clinical correlations

CONTEXT

Pancreas transplantation has become a therapeutic option for patients with type 1 diabetes mellitus who are in end-stage renal failure. It also is indicated for a subset of nonuremic, insulin-dependent diabetics who experience extreme difficulties in maintaining proper glucose homeostasis by insulin therapy that compromises their productivity and safety.

OBJECTIVE

To provide a review of the literature and expert experiences for understanding the histologic findings in pancreas transplantation.

DATA SOURCES

The published literature between 1990 and 2005 was reviewed for this report. Additionally, personal files of the author were used, along with biopsy slides that were used for figures.

CONCLUSIONS

Pancreas transplantation reestablishes the physiologic state of insulin secretion, and pancreas transplant recipients are able to maintain a state of long-term euglycemia and are less likely to be exposed to hyperglycemia and its systemic complications. Key to the success of transplantation is the scrupulous management and close monitoring of the pancreas transplant recipients. To that end, histologic evaluation of pancreas allografts assumed a pivotal role in management of pancreas allograft dysfunction episodes, and in some centers surveillance biopsies are used to monitor immunologically high-risk situations.

BK virus-induced tubulointerstitial nephritis in a child with acute lymphoblastic leukemia

We report a case of BK virus-induced tubulointerstitial nephritis in a child with acute lymphoblastic leukemia. Primary BK virus infection was exacerbated by chemotherapy-induced immunodeficiency. Careful administration of chemotherapy and anti-viral therapy prevented further damage. This diagnosis should be considered in children who experience renal dysfunction during cancer treatment.

Analgesic nephropathy selectively affecting a unilateral non-functioning hypoplastic kidney

Analgesic nephropathy results from chronic abuse of non-narcotic analgesics, most frequently with the use of phenacetin and mixed analgesic preparations. Renal papillary necrosis and chronic interstitial nephritis with progressive scarring are characteristic of the histopathology of analgesic nephropathy. Typically, papillary necrosis in these patients is bilateral and affects almost all renal papillae. This report describes a case of severe analgesic nephropathy that discriminantly affected a unilateral non-functioning kidney and spared the contralateral normally developed kidney. The patient herein consumed therapeutic doses of acetaminophen and naproxen daily and for several years. We estimated the cumulative doses of acetaminophen and naproxen used by the patient during that period to be approximately 1.0 and 0.4 kg, respectively. The cumulative dose of acetaminophen is at the threshold of doses that were traditionally associated with an increased risk for end-stage kidney failure. Simultaneous intake of both analgesics could have had a synergetic adverse effect on renal function. This case also demonstrates that preexisting renal insufficiency is prerequisite to the development of analgesic nephropathy. Conversely, kidneys with normal function are resistant to the chronic nephrotoxicity associated with habitual analgesic use.

Diagnosis of de novo localized thrombotic microangiopathy by surveillance biopsy

Thrombotic microangiopathy has been reported in association with calcineurin inhibitors and less frequently with sirolimus in renal transplant patients. The diagnosis of thrombotic microangiopathy is typically made by diagnostic biopsy in the setting of allograft dysfunction. The finding of thrombotic microangiopathy on surveillance biopsy without a significant elevation of baseline serum creatinine is unusual. The optimal treatment of this disorder remains controversial. Treatment strategies have included dose adjustment, drug substitution, plasmapheresis, and intravenous immunoglobulin G. We report a case of de novo thrombotic microangiopathy diagnosed by surveillance biopsy in a patient without hematologic abnormalities or elevated serum creatinine. This patient had resolution of the renal lesion following conversion from tacrolimus to sirolimus-based immunosuppression.

Acute oxalate nephropathy associated with orlistat, a gastrointestinal lipase inhibitor

Orlistat is an oral inhibitor of gastrointestinal lipase used for weight reduction in obese patients. Although most adverse drug effects manifest in the gastrointestinal tract, this is the first reported case of orlistat-induced acute kidney injury secondary to acute oxalate nephropathy in a white woman with underlying chronic kidney disease. Acute kidney injury was associated temporally with an increased dose of orlistat and the development of increased fat malabsorption (more frequent loose oily stools). Urine sediment showed abundant calcium oxalate crystals and increased 24-hour urine oxalate concentration. Kidney biopsy showed deposition of calcium oxalate crystals within tubular lumens, consistent with acute oxalate nephropathy. Orlistat therapy was discontinued, and oral fluid intake was increased. A second kidney biopsy performed 1 month later to evaluate the slow resolution of kidney failure did not show calcium oxalate crystals within tubules. A steady improvement in renal function subsequently was observed. Results of a repeated 24-hour urine oxalate collection performed 3 weeks later when kidney function had improved were within normal limits.

Changes in Abdominal Wounds Following Treatment With Sirolimus and Steroids in a Rat Model

Wound healing complications have been observed in patients receiving sirolimus (SLR). This study examined the degree and duration of delayed healing in various protocols using SLR. Sprague-Dawley rats underwent a standard midline abdominal incision and wound closure. Groups of 6 rats each were randomized to receive different doses of SLR (2 and 5 mg/kg) with or without loading dose (10 mg/kg x3 days), and with or without steroids (20 mg/kg x3 days followed by 5 mg/kg for 2 weeks). Rats were humanely killed on postoperative days 5, 10, or 15. Wound breaking force was measured using the EHMI BIAX-II instrument and tensile strength was calculated. Wounds in control animals had gradual increase in tensile strength during the 15-day observation. In contrast, high and loading doses of SLR caused reduction in wound strength until day 10, but the wounds' tensile strength became equivalent to control by day 15. The addition of steroids prolonged wound recovery with low doses of SLR until day 15 and had very profound effects on healing in high-dose SLR-treated animals (>50% reduction) that continued beyond the 2 weeks of observation. Low doses of SLR in non-steroid-treated animals had a short-term (5-day) impact on wound healing; high dose and loading doses delayed healing for 10 to 15 days. The addition of steroids had a synergistic effect on delayed wound healing, particularly in animals receiving high-dose SLR, which demonstrated prolonged wound weakness. These results may provide practical guidelines for postoperative introduction of SLR in the context of various clinical protocols.

Serial Peripheral Blood Cytotoxic Lymphocyte Gene Expression Measurements for Prediction of Pancreas Transplant Rejection

Acute rejection after pancreas transplantation remains a significant problem and contributes to immunological graft loss. No clinical markers of pancreas rejection have been universally accepted. The purpose of this study was to investigate the use of genetic markers; granzyme B, perforin, and HLA-DRA in the peripheral blood of pancreas transplant recipients. These genes have been identified in renal and islet cell transplant recipients as noninvasive tools to predict acute rejection. Blood samples were collected weekly for up to 1 year posttransplant. Surveillance biopsies of the pancreas were scheduled at weeks 2, 4, 8, and 12 as part of the typical posttransplant protocol for patients with pancreas alone or pancreas after kidney transplantation. Exclusion criteria included a diagnosis of biopsy-proven chronic rejection alone, pancreatitis, or kidney rejection within 2 months after pancreas biopsy. Gene expression levels of granzyme B, perforin, and HLA-DRA were compared in patients with (n = 7) and without biopsy proven acute rejection (n = 7). Recipients with acute rejection showed increased expression of granzyme B, HLA-DRA, as well as perforin genes compared to patients without biopsy-proven rejection. In addition, we observed that elevation of these genes occurred as early as 4 weeks before the traditional biopsy diagnosis, while the recipients with no rejection showed no change in gene expression. Our data indicated that serial measurements of peripheral blood granzyme B, perforin, and HLA-DRA gene expression can be a useful tool to predict pancreas rejection in its earliest stage.

Five years' experience with thymoglobulin induction in a pediatric renal transplant population

Antibody induction therapy is used in the majority of pediatric patients undergoing renal transplantation. Our center has previously reported short-term outcomes with TMG as induction therapy. We now present our experience over the last five yr. Patients received TMG intra- and post-operatively at a dose of 1.5 mg/kg/day. The dose was decreased to 0.75 mg/kg/day or held dependent on the patient's WBC and platelet counts. Post-transplant immunosuppression also included corticosteroids, MMF, and either TAC or CSA. Patient and graft survival, number of acute rejection episodes, creatinine clearance, incidence and type of infections, and trough levels of calcineurin inhibitor drugs were monitored during the follow-up period. Thirty-four renal transplants were performed in 33 pediatric patients ranging in age from 1.7 to 17.8 yr. Seventeen rejection episodes occurred during the time of follow-up with three patients having more than one episode, but only three episodes occurred within the first year after transplantation. Three patients had graft loss in the first week after transplantation from primary non-function (1) or technical failure/thrombosis (2). Graft losses occurred in seven additional patients during the time of follow-up with the first loss occurring at 17.7 months. Among patients with functional grafts at one wk after transplant, graft survival at one and three yr was 100% and 73% respectively. There were no patient deaths. There were no cases of post-transplant lymphoproliferative disease or other malignancy. One patient had symptomatic CMV disease. TMG is safe and effective as induction therapy in pediatric renal transplant patients. Late graft loss remains a challenge in the pediatric patient population, particularly in adolescents.

Clinical utility of histological features of polyomavirus allograft nephropathy

BACKGROUND

The purpose of this study was to determine if histological features of polyomavirus allograft nephropathy (PVAN) are associated with the clinical presentation and outcomes of PVAN.

METHODS

We examined the histological features of initial and follow-up biopsies of 20 kidney and kidney-pancreas transplant recipients with PVAN during a time prior to routine surveillance. The subjects' demographics, clinical characteristics, and outcomes were compared based upon classification of histological features of PVAN on initial biopsy.

RESULTS

Diabetes mellitus (45%) and a history of tacrolimus-induced nephrotoxicity (35%) appeared to be prevalent in subjects with PVAN. Although histological severity of PVAN did not predict or correlate with the clinical course of PVAN, subjects with pattern C on initial PVAN biopsy presented later posttransplant, had higher serum creatinine level at presentation, and had significant allograft deterioration at follow-up than subjects with either pattern A or B on initial biopsy. Resolution of PVAN was noted in 60% of follow-up biopsies and occurred more frequently in subjects with pattern B on initial biopsy. Most subjects developed chronic allograft nephropathy after PVAN and viral clearance did not abrogate the progression to chronic allograft nephropathy.

CONCLUSIONS

These data indicate that histologic patterns of PVAN may have clinical correlation to disease presentation and prognosis.

Short-term outcomes of severe lupus nephritis in a cohort of predominantly African-American children

Renal involvement is one of the major determinants of the outcome in patients with systemic lupus erythematosus. Although African-American ethnicity has been suggested to be a poor prognostic factor in severe lupus nephritis in adult patients, information on outcomes of African-American children with this disease is still very limited. We retrospectively studied the patients diagnosed with severe lupus nephritis by renal biopsy at Le Bonheur Children's Medical Center from January 1990 to December 2003. All patients were below the age of 18 years at the time of biopsy. Clinical features assessed included age, gender, race, estimated glomerular filtration rate (GFR), presence of hypertension, gross hematuria, degree of proteinuria, complement 3 and 4 levels, serum albumin, renal histology and dose of oral prednisone. Forty-four patients were studied: 82% were African-American and 89% were female. Mean age at biopsy was 14.2+/-3 years (median 15.0 years; range 4.7 years to 17.0 years). Renal biopsies were assessed according to the WHO classification. Twenty-seven percent, 43%, and 30% were in class III, IV and V, respectively. At presentation, 55% had hypertension and 23% had a history of macroscopic hematuria. The patients had varying degrees of proteinuria, including 18% with nephrotic syndrome. Eighteen percent had moderate renal insufficiency with estimated GFRs less than 50 ml/1.73 m2 body surface area per minute. All the patients were treated with corticosteroids. Sixty-eight percent also received cyclophosphamide and 20% received either mycophenolate mofetil (MMF) or azathioprine (AZA). Two patients developed end stage renal disease and required chronic dialysis within 12 months of biopsy. At the 12-month follow-up visit, 23% of patients had complete remission and 48% had partial remission. The mean estimated GFR had increased from 96.0 ml/1.73 m2 per minute to 124 ml/1.73 m2 per minute (P=0.03). Mean serum creatinine levels decreased from 1.62 mg/dl to 0.91 mg/dl (P=0.03). Complement 3 levels increased from 54.3 mg/dl to 90.3 mg/dl (P<0.01). Mean serum albumin levels also increased from 2.8 mg/dl to 3.6 mg/dl (P<0.01) and urine protein-to-creatinine ratio decreased from 5.8 to 1.0 (P<0.01). The average prednisone dose decreased from 0.96 mg/kg per day to 0.41 mg/kg per day (P=0.64). In our center, with predominantly African-American children, patients with lupus nephritis presented similarly to those in other studies with predominantly Caucasian patients, and short-term renal outcomes were not different.

C1q nephropathy: features at presentation and outcome

The study population comprised all 20 patients followed since 1990 through December 2004 at the Le Bonheur Children's Medical Center with diagnosis of C1q nephropathy (55% boys; 60% African Americans). All were aged under 18 years at biopsy (mean 11.2 years, 65% aged 11 or over); the youngest presented at age 10 months and progressed to end-stage renal disease at 14 months. None had clinical or laboratory features of systemic lupus erythematosis or membranoproliferative glomerulonephritis. Clinical features assessed at diagnosis were age, gender, blood pressure, history of macroscopic hematuria, urinary protein to creatinine ratio, serum creatinine, estimated glomerular filtration rate, renal histology, and pattern for immunofluorescent reactants. At the time of biopsy 40% had nephrotic syndrome and 30% nephrotic range proteinuria without nephrotic syndrome. Three patients with nephrotic syndrome also had chronic renal insufficiency at diagnosis. The most common histological feature was focal segmental glomerulosclerosis in 40%, but 30% had minimal change lesion. Four patients, all with nephrotic syndrome at diagnosis, progressed to end-stage renal disease. Of the 12 patients not presenting with nephrotic syndrome, none had chronic renal insufficiency at last follow-up. Kidney survival was 94% and 78% at 1 and 5 years, respectively, in all patients and 88% and 49% in those presenting with nephrotic syndrome.

Pediatric IgA nephropathy: clinical features at presentation and outcome for African-Americans and Caucasians

AIM

To determine the disease severity at onset and outcome for African-American and Caucasian pediatric patients with IgA nephropathy diagnosed at the Le Bonheur Children's Medical Center since 1990.

DESIGN/METHODS

The study population included all patients diagnosed with IgA nephropathy at the Le Bonheur Children's Medical Center from January 1990 through February 2004. All were below age 18 at biopsy. Clinical features assessed at diagnosis were age, gender, presence of hypertension, history of macroscopic hematuria, degree of proteinuria, severity of renal histology and pattern for immunofluorescent reactants.

STATISTICS

Student's t-test was used to compare age at biopsy and length of follow-up between the 2 groups. Fisher's exact test was used to compare features at presentation and patterns of immunofluorescence. Kidney survival was predicted by the Kaplan-Meier method.

RESULTS

Forty-seven patients (17 African-American, 29 Caucasian) were studied. Clinical features at diagnosis and pattern for all immunofluorescent reactants did not differ significantly between the 2 groups. Mesangial deposition of C1q occurred in 4/17 African-Americans as compared to 1/27 Caucasians (p = 0.06). Four patients (2 African-Americans, 2 Caucasians) progressed to end-stage renal disease. Predicted kidney survival was 96% (94% in African-Americans and 97% in Caucasians) at 1 year and 91% (94% in African-Americans and 89% in Caucasians) at 5 years from diagnosis. Mean time from diagnosis to end-stage renal disease or last follow-up was 3.3 years (3.8 for African-Americans, 3.0 for Caucasians). Macroscopic hematuria occurred prior to diagnosis for 90% of the Caucasian as compared to 61% of the African-American patients (p = 0.03). Urinalysis was normal at last follow-up visit for 24% of African-American patients and 32% of Caucasian patients.

CONCLUSION

In a relatively small sample from a single center, except for the difference in macroscopic hematuria, clinical features at diagnosis and outcome of IgA nephropathy appear similar for African-American and Caucasian pediatric patients.

Comparison of sirolimus-based calcineurin inhibitor-sparing and calcineurin inhibitor-free regimens in cadaveric renal transplantation

INTRODUCTION

This study examines the efficacy and toxicity of sirolimus used as primary immunosuppression in combination with reduced dose tacrolimus (calcineurin inhibitor [CI]-sparing regimen) or mycophenolate mofetil (CI-free regimen) in high-risk cadaveric renal transplantation.

METHODS

Seventy subjects were treated in a quadruple sequential protocol in which 41 were treated with a CI-sparing regimen and 29 were treated with a CI-free regimen. The efficacy and toxicity profiles of these regimens were prospectively monitored and compared.

RESULTS

The study consisted of African Americans (71%), cadaveric donors (100%), donors aged more than 50 years (30%), and patients with delayed graft function (47%). At 1 year, patient survival, graft survival, and incidence of biopsy-proven acute rejection were 98%, 80%, and 10%, respectively, in the CI-sparing group and 100%, 89%, and 7%, respectively, in the CI-free group. Three-month protocol biopsies were performed in 41% (17/41) and 67% (20/29) of the subjects in the CI-sparing and CI-free groups, respectively. Subclinical rejection was detected in 6% (1/17) and 15% (3/20) of the subjects in the CI-sparing and CI-free groups, respectively. Histologic evidence of chronic allograft nephropathy was more prevalent in the CI-sparing group. At 1 year, the mean estimated creatinine clearance was higher in the CI-free group than in the CI-sparing group (72.4 +/-20.0 mL/min vs. 50.5 +/-20.8 mL/min, P <0.01). The two regimens had similar toxicity profiles (hospital readmission, infection, wound complications, and metabolic complications).

CONCLUSIONS

Both sirolimus-based CI-sparing and CI-free regimens are safe and effective in a population with high immunologic risk. The CI-free regimen is associated with better renal function at 1 year post-transplant. Long-term follow-up will aid in determining the risk and benefit ratio of these regimens.

Renal pathology and clinical presentations of polyomavirus nephropathy in simultaneous kidney pancreas transplant recipients compared with kidney transplant recipients

INTRODUCTION

The purpose of this study was to describe and compare the renal histopathology and clinical course of simultaneous kidney-pancreas transplant (SKP) recipients with kidney transplant (KT) recipients with polyomavirus nephropathy (PVN).

METHODS

Between 1997 and 2002, 20 patients (7 SKP, 13 KT) were diagnosed with PVN. Clinical characteristics and outcomes of PV-N were correlated with histopathologic examinations of renal allograft biopsy and compared between SKP and KT recipients.

RESULTS

There were no differences in demographics between SKP and KT recipients with PV-N. The mean time to PVN was 611 (172 to 1174) days posttransplant in SKP and 343 (83 to 720) days posttransplant in KT (P =.05). The serum creatinine at the time of diagnosis was similar between SKP and KT recipients. All patients were treated with reduction in immunosuppression. After a median follow-up of 2 years, the patient survival was 71% in SKP and 100% in KT. Four grafts (57%) were lost owing to PVN in SKP group and three grafts (23%) were lost owing to PVN in the KT group. More patients (43%) in SKP had a history of acute rejection prior to diagnosis of PVN compared to KT (8%) and biopsy-proven tacrolimus nephrotoxicity prior to PVN was more common in SKPT (86%) than in KT (8%) patients (P <.05). SKP patients with evidence of diffuse fibrosis and high total sum scores at time of presentation all subsequently lost their grafts.

CONCLUSIONS

SKP recipients with PVN had a worse clinical course than KT recipients.

Observations regarding the use of sirolimus and tacrolimus in high-risk cadaveric renal transplantation

BACKGROUND

Balancing the risk of acute rejection (AR) with drug-induced toxicities complicates the selection of the optimal immunosuppressive regimen, especially in the high-risk renal transplant recipient. This study was designed to determine the optimal dosage combinations of tacrolimus and sirolimus in a high-risk cadaveric renal transplant population.

METHODS

Primary cadaveric renal transplant recipients were randomly assigned to receive either standard tacrolimus (trough levels of 10-15 ng/mL) plus reduced sirolimus (trough levels of 5-10 ng,mL) (Group I) or to receive reduced tacrolimus (trough levels of 5-10 ng,mL) plus standard sirolimus (trough levels of 10-15 ng/mL) (Group II). All patients received Thymoglobulin induction and steroids.

RESULTS

Thirty-nine (16 in Group I and 23 in Group II) high-risk renal transplant recipients (100% cadaveric donors, 79% African-American recipients, and 59% delayed graft function) are the subjects of this report. At 6 months, the patient survival rate was 94 and 100% and the graft survival rate was 94 and 83% in Groups I and II, respectively. The incidence of biopsy-proven AR was 6 and 5% in Groups I and II, respectively. Eight patients (50%) in Group I required discontinuation of tacrolimus, seven because of biopsy-proven tacrolimus nephrotoxicity and one secondarily to interstitial pneumonitis. Wound complications were the most frequent adverse event reported in both groups.

CONCLUSIONS

The combination of tacrolimus and sirolimus was associated with a low risk of AR in this cohort of high-risk renal transplant recipients. However, 50% of patients who received standard tacrolimus and reduced sirolimus combination had to be discontinued from the regimen because of biopsy-proven nephrotoxicity. These preliminary results provide evidence that sirolimus should not be added to tacrolimus without dosage adjustments. We have discontinued recruitment of patients to the standard tacrolimus and reduced sirolimus combination and we have tightened our criteria for selection of marginal donor kidneys with our high-risk renal transplant recipients.

PRESERVATION OF HUMAN PANCREATIC ISLET IN VIVO FUNCTION AFTER 6-MONTH CULTURE IN SERUM-FREE MEDIA1

BACKGROUND

Culturing human islets in Memphis serum-free media (M-SFM) is associated with excellent postculture recovery, in vitro function, and in vivo survival. The authors investigate the possibility of preserving islet function for extended periods (6 months) in culture and describe the in vitro and in vivo functional outcomes associated with these extended culture times.

METHODS

Human islets isolated from three cadaveric donor organs were cultured in M-SFM for 1, 3, or 6 months before transplantation under the kidney capsule of nonobese diabetic (NOD)-severe combined immunodeficiency (SCID) mice. In vitro function was measured by static incubation at the time of transplantation. In vivo function was assessed by measuring human insulin and C-peptide production, and by the ability of 6-month cultured islets to cure streptozotocin-induced diabetes in this mouse model.

RESULTS

Islet recovery ratios after 1 month in culture ranged from 85% to 88% and declined to 28% to 53% after 6 months of culture (P <0.01). Insulin stimulation indices did not differ among the fresh or the 6-month cultured preparations. All preparations cultured for 1 to 3 months functioned in the NOD-SCID mice. After 6 months of culture, two of the three preparations demonstrated in vivo function and were able to cure streptozotocin-induced diabetes.

CONCLUSIONS

These data demonstrate that human islets can be cultured in M-SFM for extended periods and still retain in vitro and in vivo function and the ability to cure experimental diabetes. The ability to maintain islets in culture for prolonged periods is an important step toward the development of islet tissue repositories and distribution centers.

Borderline changes in the banff schema: rejection or no rejection?

The relationship between acute renal allograft rejection and histopathologic biopsy alterations recognized by the Banff Schema as "borderline changes" is not clear. Some evidence supports the contention that about one third of patients with borderline infiltrates and clinical evidence of graft dysfunction do indeed have acute rejection, which, if left untreated, progresses to a histologically more advanced stage of rejection. Several investigators recognize that not all patients with mild tubulitis respond clinically to antirejection therapy; a significant number of these biopsy specimens display additional histological alterations. The most common concurrent lesions are chronic allograft nephropathy, arteriolar lesions consistent with calcineurin inhibitor toxicity, acute tubular necrosis, and obstructive nephropathy. Management of patients with borderline changes must tightly correlate the pathologic features and the clinical information.

Long-term experience with simultaneous kidney-pancreas transplantation with portal-enteric drainage and tacrolimus/mycophenolate mofetil-based immunosuppression

Refinements in surgical techniques and advances in clinical immunosuppression have led to steadily improving results in pancreas transplantation (PTX). Although there is renewed interest in enteric exocrine drainage, most PTXs are performed with systemic venous delivery of insulin. To improve the physiology of PTX, we developed a novel technique of portal venous delivery of insulin and enteric drainage of the exocrine secretions (portal-enteric [P-E]). The purpose of the study was to analyse outcomes in patients undergoing PTX with P-E drainage and contemporary immunosuppression.

MATERIALS AND METHODS

From January 1997 through September 2002, we performed 67 primary simultaneous kidney-PTXs (SKPT) with P-E drainage. Maintenance immunosuppression consisted of tacrolimus (TAC), mycophenolate mofetil (MMF) and steroids. No antibody induction therapy occurred in 33 patients (49%) with the remainder receiving daclizumab (n = 15), basiliximab (n = 2), or thymoglobulin (n = 14) induction therapy. The patient group included 38 males and 29 females with a mean age of 39.7 year (range 23-58) and a mean duration of pretransplant diabetes of 24.5 year (9-46). Fourteen patients (21%) were African-American.

RESULTS

The mean waiting time for SKPT was 3.3 months (range 0.1-10). Mean kidney and pancreas cold ischaemia times were 15.1 and 15.4 h, respectively. Patient, kidney and pancreas graft survival rates were 97%, 92.5% and 82%, respectively, with a mean follow-up of 20 months (range 1-56). Two deaths (one sepsis, one cardiac event) occurred at 1 month after SKPT; both patients died with functioning grafts (DWFG). Three patients (4.5%) had delayed renal allograft function and received temporary dialysis after SKPT. Five kidney graft losses occurred (two DWFG, one thrombosis, two chronic rejection). All but four patients (6%) had immediate PTX function. A total of 12 pancreas graft losses occurred (two DWFG, five thrombosis, five chronic rejection). The incidence of acute rejection was 28%, but no grafts were lost due to isolated acute rejection. The incidence of major infection was 51%, but only five patients (7.5%) developed cytomegalovirus infection. A total of 19 patients (28%) underwent early relaparotomy within 3 months of SKPT. The composite endpoint of no rejection, graft loss, or mortality was attained by 63% of patients. At present, 58 patients (87%) are both dialysis and insulin-independent (including four retransplants).

CONCLUSION

These findings suggest that SKPT with P-E drainage and contemporary immunosuppression may result in excellent intermediate-term outcomes.

Observations on the use of sirolimus and tacrolimus in high-risk renal transplant recipients

Sirolimus is the first of a group of mammalian target of rapamycin inhibitors to be introduced for clinical use in the United States. At the University of Tennessee in Memphis, we have evolved strategies for the use of sirolimus in kidney transplant recipients; which utilize the drug as a primary immunosuppressant and exploit its potential for preserving renal function. Conversions from the calcineurins to sirolimusbased immunosuppression established the efficacy of calcineurin-free immunosuppressants in selected high-risk patients. The conversion experience stimulated the design of protocols for primary use of sirolimus. Posttransplant use of sirolimus was associated with low incidence of rejection whether sirolimus was used with low-dose Prograf or in calcineurin-free protocols. Primary use with full-dose Prograf was associated with a high incidence of calcineurin-related nephrotoxicity and was abandoned in our program. Hematologic and lipid side effects were manageable, as was an observed increase in wound-healing problems and lymphocele formation. Continuous modifications of the sirolimus protocols to increase our benefit-to-risk ratio are ongoing and indicate a continued role for the drug in posttransplant immune suppression.

Thymoglobulin for induction or rejection therapy in pancreas allograft recipients: a single centre experience

PURPOSE

To review the safety and efficacy of thymoglobulin in pancreas transplant patients receiving tacrolimus and mycophenolate mofetil.

METHODS

Retrospective, single centre analysis of 45 patients transplanted between 1995 and 2000 who received 54 courses of thymoglobulin, including 36 courses in 29 solitary pancreas transplant recipients (16 pancreas alone, 13 pancreas after kidney transplants) and 18 courses in 16 simultaneous kidney-pancreas transplant patients. Thirty-two patients (71%) were primary pancreas transplants, 10 (22%) were second transplants and three (7%) were third transplants. Of the 54 treatment courses, 19 (35%) were for induction, 27 (50%) were for primary rejection and eight (15%) were rescue therapy for rejection. All rejection episodes were biopsy-proven in at least one organ.

RESULTS

The median thymoglobulin dose was 1.5 mg/kg/d with a mean of six doses (range 3-10). Dose reduction or interruption was required in 28 courses (52%), most often due to leukopenia (n = 24), fever (n = 2) and thrombocytopenia (n = 2). Thymoglobulin was resumed in all but three patients, two with persistent fever and one with infection. Infectious complications (n = 25) occurred in 17 patients (38%) within 30 days and included bacterial (n = 16), cytomegalovirus (n = 4), polyoma (n = 1), fungal (Candida albicans, n = 1), toxoplasmosis (n = 1) and ehrlichiosis (n = 2). Post-transplant lymphoproliferative disease occurred in two patients (4%) at a mean of 70 d post-thymoglobulin treatment. In the 19 patients that received thymoglobulin induction, one simultaneous kidney-pancreas transplant, two pancreas alone and four pancreas after kidney transplant recipients developed rejection (37% incidence), while all remaining patients followed by surveillance protocol biopsies were rejection-free. In the 35 patients that received thymoglobulin for rejection, reversal occurred in 26 of the patients (74%). Rejection recurred within 30 d in five patients and post-treatment biopsies revealed persistent rejection in three of 20 pancreas and two of eight renal biopsies. After a mean follow-up of 6 months, the actual patient and pancreas graft survival rates were 93% and 71%, respectively.

CONCLUSION

Thymoglobulin was effective as induction therapy in high-risk pancreas transplant recipients, and resulted in initial reversal of rejection in 74% of patients. Dose adjustments were required in over half the cases and were usually due to leukopenia. Infections occurring subsequent to thymoglobulin were not uncommon and reflected the immunosuppressive burden of the patient population.

Improving results in solitary pancreas transplantation with portal-enteric drainage, thymoglobin induction, and tacrolimus/mycophenolate mofetil-based immunosuppression

Advances in surgical techniques and clinical immunosuppression have led to steadily improving results in pancreas transplantation (PTX). The purpose of this study was to analyze retrospectively the outcomes in patients undergoing solitary PTX with portal-enteric (P-E) drainage and contemporary immunosuppression. From June 1998 through December 2000, we performed 28 solitary PTXs with antibody induction and tacrolimus/mycophenolate mofetil maintenance therapy. The first 13 patients received daclizumab (DAC) induction, while the next 15 received thymoglobulin (rabbit anti-human thymocyte gamma globulin; Thymo) induction. The study group included 13 pancreas alone (PA) and 15 sequential pancreas-after-kidney-transplantations (PAKT). Solitary PTX was performed with P-E drainage in 18 patients and systemic-enteric (S-E) drainage in ten. Patient and pancreas graft survival rates were 96% and 79%, respectively, with a mean follow-up of 22 (range 1-39) months. The 1-year actual death-censored pancreas graft survival rate was 89%. One PAKT patient died with a functioning graft at 1 month; three patients (11%) experienced early graft loss due to thrombosis and were excluded from the immunological analysis, leaving 24 evaluable patients. The incidence of acute rejection was 54%, including 50% in PA and 58% in PAKT recipients ( P=NS). In patients receiving Thymo induction, the rate of acute rejection was slightly lower (43% Thymo vs 70% DAC). Moreover, P-E drainage was associated with a slightly lower rate of acute rejection (44% P-E vs 75% S-E; P=NS). In patients with both Thymo induction and P-E drainage ( n=11), there was a tendency toward less rejection (the incidence of acute rejection was 36%). Two immunological graft losses occurred (one due to non-compliance), both in patients with P-E drainage. Only one patient had a cytomegalovirus (CMV) infection. Event-free survival (no rejection, graft loss, or death) was slightly higher in patients receiving Thymo (47%) than in those on DAC (23%) induction ( P=NS). We can conclude that solitary PTX with P-E drainage and Thymo induction may be associated with improved intermediate-term outcomes and a possible immunological advantage.

Polyomavirus in kidney and kidney-pancreas transplant recipients

PURPOSE

To report the incidence and clinical characteristics of polyomavirus (PV) nephritis in kidney (KTX) and kidney-pancreas transplant (KPTX) recipients.

METHODS

Single center retrospective analysis of all cases of PV nephritis in KTX and KPTX patients transplanted between 1994 and 1999.

RESULTS

Thirteen (5 KTX and 8 KPTX) patients (2.1%) had PV nephritis diagnosed on multiple biopsies (n = 22) among 504 KTX and 106 KPTX recipients. The incidence of PV nephritis was higher in cadaver donor transplants (2.6% cadaver vs. 0.7% living donors), after KPTX (1% KTX vs. 7.5% KPTX), in males (3.3% male vs. 0.7% female), and in diabetic patients (4.4% diabetic vs. 0.8% nondiabetic). The mean time to diagnosis of PV nephritis was 18 (range 6-48) months after KTX and 17 (range 9-31) months after KPTX. Three KTX patients and 5 KPTX patients had calcineurin inhibitor toxicity on biopsy prior to developing PV nephritis. Reduction in immunosuppression occurred in 100% of KTX and 63% of KPTX patients. Three patients (23%) developed rejection within 3 months of diagnosis of PV, 1 after a reduction in immunosuppression. Despite multiple antiviral treatment regimens, renal allograft failure requiring dialysis occurred in 60% of KTX and 50% of KPTX patients. All KPTX patients remain insulin independent and 2 were successfully retransplanted with living donor kidneys. 2 patients (15%) died but there was no mortality directly related to the virus.

CONCLUSIONS

Polyomavirus nephritis may be increasing in incidence and appears to be unresponsive to either conventional antiviral agents or a reduction in immunosuppression. Most of our cases occurred in male diabetic patients undergoing cadaveric donor transplantation and were preceded by biopsy-proven nephrotoxicity. Further studies are needed to better define the pathogenesis of PV and effective antiviral treatment.

Renal allograft loss as the result of polyomavirus interstitial nephritis after simultaneous kidney-pancreas transplantation: results with kidney retransplantation

BACKGROUND

Polyomavirus (PV) infection in kidney transplant patients has been reported to cause interstitial nephritis and subsequent graft loss. The cornerstone of current therapy is a reduction in immunosuppression, which can subsequently lead to kidney allograft rejection. This dilemma becomes even more challenging in the setting of simultaneous kidney-pancreas transplantation, because a reduction in immunosuppression may result in rejection of the pancreas allograft. Antiviral therapy has not been shown to be clinically successful in decreasing the risk of graft loss secondary to PV infection. Furthermore, because of limited experience, the decision to perform retransplantation in patients who lost their primary kidney grafts to PV interstitial nephritis becomes a difficult one.

METHODS

Retrospective review and case studies.

RESULTS

We report two successful living donor kidney retransplants in simultaneous kidney-pancreas transplant patients who lost their first kidney grafts to PV infection. Both patients are receiving rimantadine therapy and performing well, with functioning kidney and pancreas grafts and no evidence of recurrent PV interstitial nephritis 22 and 37 months after retransplantation.

CONCLUSIONS

Although follow-up is limited, our initial experience would indicate that graft loss secondary to PV interstitial nephritis is not an absolute contraindication for kidney retransplantation.

Improving results in solitary pancreas transplantation with portal-enteric drainage, thymoglobin induction, and tacrolimus/mycophenolate mofetil-based immunosuppression

Advances in surgical techniques and clinical immunosuppression have led to steadily improving results in pancreas transplantation (PTX). The purpose of this study was to analyze retrospectively the outcomes in patients undergoing solitary PTX with portal-enteric (P-E) drainage and contemporary immunosuppression. From June 1998 through December 2000, we performed 28 solitary PTXs with antibody induction and tacrolimus/mycophenolate mofetil maintenance therapy. The first 13 patients received daclizumab (DAC) induction, while the next 15 received thymoglobulin (rabbit anti-human thymocyte gamma globulin; Thymo) induction. The study group included 13 pancreas alone (PA) and 15 sequential pancreas-after-kidney-transplantations (PAKT). Solitary PTX was performed with P-E drainage in 18 patients and systemic-enteric (S-E) drainage in ten. Patient and pancreas graft survival rates were 96% and 79%, respectively, with a mean follow-up of 22 (range 1-39) months. The 1-year actual death-censored pancreas graft survival rate was 89%. One PAKT patient died with a functioning graft at 1 month; three patients (11%) experienced early graft loss due to thrombosis and were excluded from the immunological analysis, leaving 24 evaluable patients. The incidence of acute rejection was 54%, including 50% in PA and 58% in PAKT recipients ( P=NS). In patients receiving Thymo induction, the rate of acute rejection was slightly lower (43% Thymo vs 70% DAC). Moreover, P-E drainage was associated with a slightly lower rate of acute rejection (44% P-E vs 75% S-E; P=NS). In patients with both Thymo induction and P-E drainage ( n=11), there was a tendency toward less rejection (the incidence of acute rejection was 36%). Two immunological graft losses occurred (one due to non-compliance), both in patients with P-E drainage. Only one patient had a cytomegalovirus (CMV) infection. Event-free survival (no rejection, graft loss, or death) was slightly higher in patients receiving Thymo (47%) than in those on DAC (23%) induction ( P=NS). We can conclude that solitary PTX with P-E drainage and Thymo induction may be associated with improved intermediate-term outcomes and a possible immunological advantage.

Impact of hepatitis C virus status in pancreas transplantation: a case controlled study

Available data suggest that hepatitis C virus positive (HCV+) renal transplant patients may be at an increased risk of morbidity and mortality compared with HCV- patients. Limited data are available regarding the impact of HCV status in pancreas transplant patients. We compared the outcomes of 10 HCV+ patients undergoing pancreas transplantation (seven simultaneous kidney-pancreas, one pancreas after kidney, two pancreas alone) between 1/96 and 10/99 with 20 HCV- recipients that were matched for age, race, gender, timing of transplant, type of pancreas transplant, and surgical technique. Length of follow-up was not significantly different between the HCV+ group compared with the HCV- group (24 +/- 14 vs. 20 +/- 13 months; p=0.45). There was a trend toward a higher incidence of all cause mortality in HCV+ recipients compared with HCV- recipients, 30 vs. 10%, respectively (p=0.17). Additionally, the HCV+ recipients had a trend toward a higher incidence of sepsis-related mortality compared with HCV- recipients, 20 vs. 5%, respectively (p=0.19). Renal allograft survival was 50% in the HCV+ group compared with 94% in the HCV- group (p=0.02). Pancreas allograft survival was not significantly different between the groups, 60 vs. 80%, respectively (p=0.24). At 3, 6, 12 months, and end of follow-up, there were no differences in serum creatinine, amylase, C-peptide, or fasting glucose levels. However, there was a significantly higher incidence of proteinuria at last follow-up in the HCV+ recipients with a renal allograft when compared with HCV- recipients, 50 vs. 12.5%, respectively (p=0.05). In order to maintain comparable glycemic control between the groups, there was a significant increase in oral hypoglycemic requirement in HCV+ recipients compared with HCV- recipients, 33 vs. 0%, respectively (p=0.01). These data suggest that HCV+ pancreas transplant patients may be at an increased risk of graft dysfunction and morbidity. Further studies with more patients and longer follow-up are needed to fully define the impact of HCV status on pancreas graft survival and function.

Angiotensin-converting enzyme genotype and outcome in pediatric IgA nephropathy

Angiotensin-converting enzyme (ACE) I/D polymorphism has been implicated as a genetic marker for progression of glomerular disease. Studies of ACE genotypes in adults with IgA nephropathy (IgAN) have yielded conflicting results. We performed ACE genotyping on 79 patients with IgAN diagnosed prior to age 18 years who had either progressed to end-stage renal disease (ESRD) or are now more than 5 years post biopsy. Mean follow-up was 14.8 years for those with normal renal function. Forty-three (54.4%) subjects had normal renal function and a normal urinalysis at last evaluation. Sixteen (20%) progressed to ESRD and 1 has chronic renal insufficiency. Kaplan-Meier survival curves for progression to ESRD did not differ significantly for the ACE DD, ID, and II genotype groups (P=0.095, log-rank test). By univariate analysis, presence of hypertension and degree of proteinuria at diagnosis, and unfavorable histology but not ACE genotype, was significantly associated with progression to ESRD. In the Cox proportional hazards model that included grade of proteinuria, the ACE D allele was a significant independent predictor of outcome with a hazard ratio of 2.37 (P=0.031). Our data, while inconclusive, suggest that the ACE D allele may associate with poor outcome in pediatric IgAN.

Initial clinical experience with interleukin-2 receptor antagonist induction in combination with tacrolimus, mycophenolate mofetil and steroids in simultaneous kidney-pancreas transplantation

Since 1996, our standard immunosuppressive protocol for simultaneous kidney-pancreas transplantation (SKPT) has been tacrolimus (TAC), mycophenolate mofetil (MMF) and steroids without antibody induction. When basiliximab and daclizumab, monoclonal antibodies directed against the interleukin-2 receptor (IL-2R), became available, we selectively added these agents to our standard protocol. The purpose of this prospective, open-label study was to evaluate the safety and efficacy of IL-2 receptor antagonists in SKPT. From April 1998 to August 1999, 35 SKPTS were performed. One patient with delayed graft function received Thymoglobulin and was excluded; 17 received no induction, and 17 received IL-2R antagonists (9 basiliximab, 8 daclizumab) as induction. Demographic- and transplant characteristics were similar between the two groups. At 6 months, patient survival was 88 % (15/17) in the induction arm compared to 100 % (17/17) in the no-induction arm, P = NS. The 2 causes of death were sepsis and hemolytic uremic syndrome, and both patients died with functioning grafts. Death-censored pancreas and kidney graft survival rates in the induction and the no-induction groups were 88 % vs. 100 % respectively, in both groups. The incidence of acute rejection (kidney or pancreas) at 6 months did not differ between the two groups (35 % in both groups). Biopsy proven pancreas and kidney acute rejections were 35 % vs. 24 % and 12 % vs. 12 % in the induction- and no-induction groups, respectively. The incidences of major infection and readmission did not differ between groups. TAC trough levels and mean daily doses of TAC, MMF and steroids did not differ between the two groups at 1, 3, and 6 months. The incidence of event-free survival (no death, rejection, or graft loss) at 6 months was 59 % (10/17) in the induction and 65 % (11/17) in the no-induction group. Basiliximab and daclizumab appear to be safe in SKPT. However, the preliminary results of this study do not demonstrate a significant benefit in either reducing the incidence of acute rejection or improving outcomes at 6 months. Larger studies with longer follow-up are needed to confirm these findings.

Initial clinical experience with interleukin-2 receptor antagonist induction in combination with tacrolimus, mycophenolate mofetil and steroids in simultaneous kidney-pancreas transplantation

Since 1996, our standard immunosuppressive protocol for simultaneous kidney-pancreas transplantation (SKPT) has been tacrolimus (TAC), mycophenolate mofetil (MMF) and steroids without antibody induction. When basiliximab and daclizumab, monoclonal antibodies directed against the interleukin-2 receptor (IL-2R), became available, we selectively added these agents to our standard protocol. The purpose of this prospective, open-label study was to evaluate the safety and efficacy of IL-2 receptor antagonists in SKPT. From April 1998 to August 1999, 35 SKPTS were performed. One patient with delayed graft function received Thymoglobulin and was excluded; 17 received no induction, and 17 received IL-2R antagonists (9 basiliximab, 8 daclizumab) as induction. Demographic- and transplant characteristics were similar between the two groups. At 6 months, patient survival was 88 % (15/17) in the induction arm compared to 100 % (17/17) in the no-induction arm, P = NS. The 2 causes of death were sepsis and hemolytic uremic syndrome, and both patients died with functioning grafts. Death-censored pancreas and kidney graft survival rates in the induction and the no-induction groups were 88 % vs. 100 % respectively, in both groups. The incidence of acute rejection (kidney or pancreas) at 6 months did not differ between the two groups (35 % in both groups). Biopsy proven pancreas and kidney acute rejections were 35 % vs. 24 % and 12 % vs. 12 % in the induction- and no-induction groups, respectively. The incidences of major infection and readmission did not differ between groups. TAC trough levels and mean daily doses of TAC, MMF and steroids did not differ between the two groups at 1, 3, and 6 months. The incidence of event-free survival (no death, rejection, or graft loss) at 6 months was 59 % (10/17) in the induction and 65 % (11/17) in the no-induction group. Basiliximab and daclizumab appear to be safe in SKPT. However, the preliminary results of this study do not demonstrate a significant benefit in either reducing the incidence of acute rejection or improving outcomes at 6 months. Larger studies with longer follow-up are needed to confirm these findings.

A 9-year experience with 126 pancreas transplants with portal enteric drainage

HYPOTHESIS

A novel technique of pancreas transplantation (PTX) with portal venous delivery of insulin and enteric exocrine drainage (portal enteric) was developed at our center to improve the PTX procedure.

DESIGN

Case series.

SETTING

Single-center experience at a university hospital.

PATIENTS AND INTERVENTION

From October 1990 through December 1999, we performed 126 PTXs with portal enteric drainage, including 90 simultaneous kidney PTXs (SKPT) and 36 solitary PTXs (18 sequential PTXs after kidney transplantation and 18 PTXs alone).

MAIN OUTCOME MEASURES

Patient and graft survival rates; medical and surgical morbidity. Three groups, representing 3 eras of immunosuppression, were compared. Thirty patients underwent SKPT with muromonab-CD3 induction and cyclosporine-based therapy in era 1 (October 1990 through June 1995); 42 SKPTs received tacrolimus and mycophenolate mofetil-based immunosuppression without antibody induction in era 2 (July 1995 through May 1998); and 18 SKPTs were performed in era 3 (June 1998 through December 1999) with either basiliximab or daclizumab induction.

RESULTS

One-year patient survival rates after SKPT were 77% in era 1, 93% in era 2, and 100% in era 3 (P =.03). The 1-year kidney graft survival rates were 77% in era 1, 93% in era 2, and 94% in era 3 (P =.08). The 1-year pancreas graft survival rates after SKPT were 60% in era 1, 83% in era 2, and 83% in era 3 (P =.06). The incidences of rejection (63% vs. 33% vs. 39%; P<.001) and thrombosis (20% vs. 7% vs. 6%; P<.001) were decreased in eras 2 and 3.

CONCLUSION

Simultaneous kidney PTXs with portal enteric drainage can be performed with improved outcomes.

Renal allograft outcomes in African American versus Caucasian transplant recipients in the tacrolimus era

METHODS

Between January 1995 and December 1999, 185 kidney transplants were performed with tacrolimus (TAC)-based immunosuppression including 120 African American (AA, 65%) and 65 Caucasian recipients (C, 35%). Mean follow-up was 34 months. The AA group was characterized by a higher incidence of renal disease due to hypertension (72% AA vs 37% C, P <.001), pretransplant dialysis (95% AA vs 82% C, P =.003), waiting time (1.9 years AA vs 1.1 years C, P =.02), cadaveric donation (88% AA vs 68% C, P =.01), HLA mismatching (mean 3.5 AA vs 2.4 C, P <.001), and delayed graft function (DGF; 50% AA vs 22% C, P =.001).

RESULTS

The 5-year actuarial patient and graft survival rates were 96% AA versus 83% C (P = NS) and 83% AA versus 75% C, (P = NS), respectively. The incidence of acute rejection (21% AA vs 12% C, P = NS) and mean time to acute rejection (12 months AA vs 11 months C) were similar. Although the incidence of chronic allograft nephropathy (CAN) was comparable (7% AA vs 5% C), the mean time to CAN was shorter in AA recipients (18 months AA vs 37 months C, P =.03).

CONCLUSIONS

These results suggest marked improvement in post-transplant outcomes in the TAC era in patients with multiple immunologic risk factors including AA ethnicity, cadaveric donor source, DGF, and HLA mismatching.

Portal-enteric pancreas transplantation at the University of Tennessee, Memphis

The UT Memphis group has made a number of important contributions to the field of PTX, including: 1) pioneering studies on the effects of PTX on autonomic neuropathy, 2) comprehensive reports dealing with quality of life after PTX, 3) seminal studies on the metabolic effects of PTX with portal venous delivery of insulin, 4) refining and perfecting a novel technique of PTX with portal venous drainage of insulin and primary enteric drainage of the exocrine secretions, 5) describing a safe outpatient percutaneous technique of pancreas allograft biopsy, 6) developing the use of glucose tolerance for rejection surveillance, and 7) managing PTX patients with biopsy-directed immunosuppression and no anti-lymphocyte induction therapy. The P-E technique has the potential to become the standard of care in the near future because it is more physiologic, normalizes carbohydrate and lipid metabolism, and minimizes complications attributed to the transplant procedure. In addition, we have been actively involved in studying new immunosuppressive regimens in order to improve and simplify the care of the PTX recipient. We believe that PTX will remain an important treatment option for IDDM until other strategies are developed that can provide equal glycemic control with less or no immunosuppression and less overall morbidity.

A prospective comparison of simultaneous kidney-pancreas transplantation with systemic-enteric versus portal-enteric drainage

OBJECTIVE

To compare pancreas transplantation with systemic-enteric (SE) versus portal-enteric (PE) drainage in a prospective fashion.

SUMMARY BACKGROUND DATA

To improve the physiology of pancreas transplantation, the authors developed a new technique of portal venous delivery of insulin and enteric drainage of the exocrine secretions.

METHODS

During a 26-month period, the authors prospectively alternated 54 consecutive simultaneous kidney and pancreas transplants to either SE (n = 27) or PE (n = 27) drainage. The two groups were well matched for numerous characteristics. Maintenance immunosuppression in both groups consisted of tacrolimus, mycophenolate mofetil, and steroids.

RESULTS

Patient survival rates were 93% SE versus 96% PE; kidney graft survival rates were 93% in both groups. Pancreas transplantation survival (complete insulin independence) was 74% after SE versus 85% after PE drainage with a mean follow-up of 17 months. The mean length of initial hospital stay was 12.4 days in the SE group and 12.8 days in the PE group. The SE group was characterized by a slight increase in the number of readmissions. The incidences of acute rejection (33%) and major infection (52%) were similar in both groups. The incidence of intraabdominal infection was slightly higher in the SE group. However, the early relaparotomy rate was similar between groups. The composite endpoint of no rejection, graft loss, or death was attained in 56% of SE versus 59% of PE patients.

CONCLUSIONS

These results suggest that simultaneous kidney and pancreas transplantation with SE or PE drainage can be performed with comparable short-term outcomes.

Patterns of cytomegalovirus infection in simultaneous kidney-pancreas transplant recipients receiving tacrolimus, mycophenolate mofetil, and prednisone with ganciclovir prophylaxis

BACKGROUND

The impact of tacrolimus (TAC), mycophenolate mofetil (MMF) and steroid immunosuppression on cytomegalovirus (CMV) infection in combination with ganciclovir prophylaxis in simultaneous kidney-pancreas transplantation (SKPT) has not been well studied.

METHODS

A retrospective analysis was made of 75 SKPTs performed between 1 January 1996 and 7 January 1999. All patients received ganciclovir for 3 months, but CMV donor (D)+ / recipient (R)- patients received ganciclovir for 6 months.

RESULTS

16/74 (22%) were CMV D+/R-, 25 (33%) D+/R+, 16 (22%) D-/R+, and 17 (23%) D-/R- (1 patient with unknown donor serology was excluded). The mean time to CMV infection was 198 days post-transplant. The incidence of either CMV infection or tissue invasive CMV disease was 16/74 (22%), including 9 (12%) with CMV infection and 7 (10%) CMV disease. The one-year patient, kidney, and pancreas graft survival rates were 91%, 89%, and 83%, respectively. The mean follow-up was 29 months (minimum of 12 months). CMV infection was not associated with an increased incidence of graft failure or mortality. The D+/R- group had the highest incidence of CMV infection (44%) compared with the other serologic groups (17%, P=0.02). Concurrent CMV and rejection occurred more frequently in the D+/R- than the other serologic groups (25% vs. 7%, P=0.03). The D-/R- group had the best outcomes, with no CMV infection, improved kidney graft survival at the end of follow-up (82% vs. 72%, P=0.04) and the highest event-free survival (no CMV infection, rejection, or graft loss) when compared to the other groups (76% vs. 33%, P<0.01).

CONCLUSIONS

Compared to previous studies, ganciclovir prophylaxis delayed the onset and reduced the severity of CMV infection in patients receiving TAC, MMF, and steroids. Despite ganciclovir prophylaxis, CMV seronegative patients receiving CMV D+ organs had worse outcomes than seronegative recipients receiving CMV D- organs.