Michael J. Hanaway

Alemtuzumab induction in renal transplantation.

BACKGROUND There are few comparisons of antibody induction therapy allowing early glucocorticoid withdrawal in renal-transplant recipients. The purpose of the present study was to compare induction therapy involving alemtuzumab with the most commonly used induction regimens in patient populations at either high immunologic risk or low immunologic risk. METHODS In this prospective study, we randomly assigned patients to receive alemtuzumab or conventional induction therapy (basiliximab or rabbit antithymocyte globulin). Patients were stratified according to acute rejection risk, with a high risk defined by a repeat transplant, a peak or current value of panel-reactive antibodies of 20% or more, or black race. The 139 high-risk patients received alemtuzumab (one dose of 30 mg, in 70 patients) or rabbit antithymocyte globulin (a total of 6 mg per kilogram of body weight given over 4 days, in 69 patients). The 335 low-risk patients received alemtuzumab (one dose of 30 mg, in 164 patients) or basiliximab (a total of 40 mg over 4 days, in 171 patients). All patients received tacrolimus and mycophenolate mofetil and underwent a 5-day glucocorticoid taper in a regimen of early steroid withdrawal. The primary end point was biopsy-confirmed acute rejection at 6 months and 12 months. Patients were followed for 3 years for safety and efficacy end points. RESULTS The rate of biopsy-confirmed acute rejection was significantly lower in the alemtuzumab group than in the conventional-therapy group at both 6 months (3% vs. 15%, P<0.001) and 12 months (5% vs. 17%, P<0.001). At 3 years, the rate of biopsy-confirmed acute rejection in low-risk patients was lower with alemtuzumab than with basiliximab (10% vs. 22%, P=0.003), but among high-risk patients, no significant difference was seen between alemtuzumab and rabbit antithymocyte globulin (18% vs. 15%, P=0.63). Adverse-event rates were similar among all four treatment groups. CONCLUSIONS By the first year after transplantation, biopsy-confirmed acute rejection was less frequent with alemtuzumab than with conventional therapy. The apparent superiority of alemtuzumab with respect to early biopsy-confirmed acute rejection was restricted to patients at low risk for transplant rejection; among high-risk patients, alemtuzumab and rabbit antithymocyte globulin had similar efficacy. (Funded by Astellas Pharma Global Development; INTAC ClinicalTrials.gov number, NCT00113269.).

FN18-CRM9 immunotoxin promotes tolerance in primate renal allografts

BACKGROUND Transplant tolerance, rather than immunity, may be favored in the setting of a lower mature lymphoid mass in the recipient induced by anti-T cell agents. A novel immunosuppressive agent, FN18-CRM9, known to specifically kill T cells with great potency, was evaluated in a transplant model. METHODS In order to ablate recipient T cells, the immunotoxin FN18-CRM9 was administered to rhesus monkey recipients of MHC-mismatched renal allografts. Donor lymphocytes were injected intrathymically into some animals. RESULTS All monkeys with T-cell depletion by immunotoxin had prolonged allograft survival, and tolerance confirmed by skin grafting has been confirmed in five of six long-surviving recipients. CONCLUSIONS In this clinically relevant model, profound but transient T-cell depletion by a single agent substantially promotes tolerance.

The role of anti-Galalpha1-3Gal antibodies in acute vascular rejection and accommodation of xenografts.

BACKGROUND A major impediment to the transplanting of porcine organs into humans is the susceptibility of porcine organs to acute vascular rejection, which can destroy a vascularized xenograft over a period of hours to days. Acute vascular rejection of porcine-to-primate xenografts is thought to be triggered by binding of xenoreactive antibodies to the graft. We tested whether antibodies, binding to Galalpha1-3Gal epitopes in porcine tissue, initiate this phenomenon. METHODS AND RESULTS Specific depletion of anti-Galalpha1-3Gal antibodies from the blood of baboons, using extracorporeal perfusion of separated plasma through columns of Sepharose beads covalently linked to the antigenic trisaccharide, Galalpha1-3Galbeta1-4GlcAc, averted the development of acute vascular rejection in porcine organs transgenic for human decay-accelerating factor and CD59. More importantly, after immunodepletion was stopped and Gala1-3Gal antibodies were allowed to return, these same organs continued to function and remained pathologically normal and thus seemed to achieve a state of accommodation. CONCLUSION These results demonstrate that anti-Galalpha1-3Gal antibodies cause acute vascular rejection and suggest that depletion of these antibodies leads to accommodation of the donor cardiac xenograft and could supply an important model for additional study.

Are concerns over right laparoscopic donor nephrectomy unwarranted

ObjectiveTo examine the ability of several large, experienced transplantation centers to perform right-sided laparoscopic donor nephrectomy safely with equivalent long-term renal allograft function. Summary Background DataEarly reports noted a higher incidence of renal vein thrombosis and eventual graft loss. However, exclusion of right-sided donors would deprive a significant proportion of donors a laparoscopically harvested graft. MethodsA retrospective review was performed among 97 patients from seven centers performing right-sided laparoscopic donor nephrectomy. Surgical and postoperative demographic factors were evaluated. Complications were identified and long-term renal allograft function was compared with historical left-sided laparoscopic donor nephrectomy cohorts. ResultsRight laparoscopic donor nephrectomy was performed for varying reasons, including multiple left renal arteries or veins, smaller right kidney, or cystic right renal mass. Mean surgical time was 235.0 ± 66.7 minutes, with a mean blood loss of 139 ± 165.8 mL. Conversion was required in three patients secondary to bleeding or anatomical anomalies. Mean warm ischemic time was limited at 238 ± 112 seconds. Return to diet was achieved on average after 7.5 ± 2.3 hours, with mean discharge at 54.6 ± 22.8 hours. Two grafts were lost during the early experience of these centers to renal vein thrombosis. Both surgical and postoperative complications were limited, with few long-term adverse effects. Mean serum creatinine levels were higher than open and left laparoscopic donor nephrectomy on postoperative day 1, but at all remaining intervals the right laparoscopic donors had equivalent creatinine values. ConclusionsThese results confirm that right laparoscopic donor nephrectomy provides similar patient benefits, including early return to diet and discharge. Long-term creatinine values were no higher than in traditional open donor or left laparoscopic donor cohorts. These results establish that early concerns about high thrombosis rates are not supported by a multiinstitutional review of laparoscopic right donor nephrectomies.

Donors with central nervous system malignancies: are they truly safe?

Background. In an era of organ shortage, the use of expanded or marginal donors has been attempted to increase transplantation rates and diminish waiting list mortality. One strategy is the use of organs from patients with a history of or active central nervous system (CNS) tumor. Methods. Sixty-two recipients were identified as the recipients of organs from donors with a history of or active CNS malignancy. Patient demographics, donor tumor management, incidence of tumor transmission, and patient survival were examined. Results. Of the organs recovered and transplanted from donors with astrocytoma, 14 were associated with at least one risk factor including high-grade tumor (n=4), prior surgery (n=5), radiation therapy (n=4), and systemic chemotherapy (n=4). One tumor transmission was identified at 20 months posttransplant with the patient expiring from metastatic disease. Twenty-six organs were transplanted from glioblastoma patients with 15 demonstrating risk factors including high-grade tumor (n=9) and prior surgery (n=10). Eight transmissions were identified with a range of 2 to 15 months posttransplant, with seven patients dying as the result of metastatic disease. Seven organs were used from donors with a medulloblastoma. Three transmissions were identified at a range of 5 to 7 months, all associated with ventriculoperitoneal shunts. Two medulloblastoma recipients died as the result of metastatic disease, whereas the third is alive with diffuse disease. The rate of donor tumor transmission, in the absence of risk factors, was 7%, whereas in the presence of one or more risk factor this rate dramatically rose to 53% (P <0.01). Conclusions. Organs from donors with CNS tumors can be used with a low risk of donor tumor transmission in the absence of the following risk factors: high-grade tumors, ventriculoperitoneal or ventriculoatrial shunts, prior craniotomy, and systemic chemotherapy.

Analysis of Factors that Influence Survival with Post-Transplant Lymphoproliferative Disorder in Renal Transplant Recipients: The Israel Penn International Transplant Tumor Registry Experience

Significant mortality is associated with post‐transplant lymphoproliferative disorder (PTLD) in kidney transplant recipients (KTX). Univariate/multivariate risk factor survival analysis of US PTLD KTX reported to Israel Penn International Transplant Tumor Registry from November 1968 to January 2000 was performed. PTLD presented 18 (median) (range 1–310) months in 402 KTX. Death rates were greater for those diagnosed within 6 months (64%) versus beyond 6 months (54%, p = 0.04). No differences in death risk for gender, race, immunosuppression, EBV, B or T cell positivity were identified. Death risk increased for multiple versus single sites (73% vs. 53%, hazards ratio (HR) 1.4). A 1‐year increase in age increased HR for death by 2%. Surgery was associated with increased survival (55% vs. 0% without surgery) (p < 0.0001). Patients with allograft involvement, treated with transplant nephrectomy alone (n = 20), had 80% survival versus 53% without allograft removal (n = 15) (p < 0.001). Overall survival was 69% for allograft involvement alone versus 36% for other organ involvement plus allograft (n = 19 alive) (p < 0.0001). Death risk was greater for multiple site PTLD and increasing age, and risks were additive. Univariate analysis identified increased death risk for those not receiving surgery, particularly allograft involvement alone.

Medial Fibrosis, Vascular Calcification, Intimal Hyperplasia, and Arteriovenous Fistula Maturation

BACKGROUND Arteriovenous fistulas (AVFs) for hemodialysis frequently fail to mature because of inadequate dilation or early stenosis. The pathogenesis of AVF nonmaturation may be related to pre-existing vascular pathologic states: medial fibrosis or microcalcification may limit arterial dilation, and intimal hyperplasia may cause stenosis. STUDY DESIGN Observational study. SETTING & PARTICIPANTS Patients with chronic kidney disease (N = 50) undergoing AVF placement. PREDICTORS Medial fibrosis, microcalcification, and intimal hyperplasia in arteries and veins obtained during AVF creation. OUTCOME & MEASUREMENTS AVF nonmaturation. RESULTS AVF nonmaturation occurred in 38% of patients despite attempted salvage procedures. Preoperative arterial diameter was associated with upper-arm AVF maturation (P = 0.007). Medial fibrosis was similar in patients with nonmaturing and mature AVFs (60% ± 14% vs 66% ± 13%; P = 0.2). AVF nonmaturation was not associated with patient age or diabetes, although both variables were associated significantly with severe medial fibrosis. Conversely, AVF nonmaturation was higher in women than men despite similar medial fibrosis in both sexes. Arterial microcalcification (assessed semiquantitatively) tended to be associated with AVF nonmaturation (1.3 ± 0.8 vs 0.9 ± 0.8; P = 0.08). None of the arteries or veins obtained at AVF creation had intimal hyperplasia. However, repeated venous samples obtained in 6 patients during surgical revision of an immature AVF showed venous neointimal hyperplasia. LIMITATIONS Single-center study. CONCLUSION Medial fibrosis and microcalcification are frequent in arteries used to create AVFs, but do not explain AVF nonmaturation. Unlike previous studies, intimal hyperplasia was not present at baseline, but developed de novo in nonmaturing AVFs.

West Nile virus encephalitis in organ transplant recipients: another high-risk group for meningoencephalitis and death.

West Nile virus infection has been spreading westward across the continental United States since 1999. Although it often presents as a mild, self-limiting viral illness, it can result in a devastating meningoencephalitis in some patient populations, particularly the elderly. We report in this article on two immunosuppressed transplant patients who developed a severe meningoencephalitis caused by mosquito-borne West Nile virus infection. Suggestions for the prevention, diagnosis, and treatment of West Nile virus infection in this patient population are described.

Hand‐Assisted Laparoscopic Living‐Donor Nephrectomy as an Alternative to Traditional Laparoscopic Living‐Donor Nephrectomy

The benefits of laparoscopic living‐donor nephrectomy (LDN) are well described, while similar data on hand‐assisted laparoscopic living‐donor nephrectomy (HALDN) are lacking. We compare hand‐assisted laparoscopic living‐donor nephrectomy with open donor nephrectomy. One hundred consecutive hand‐assisted laparoscopic living‐donor nephrectomy (10/98–8/01) donor/recipient pairs were compared to 50 open donor nephrectomy pairs (8/97– 1/00). Mean donor weights were similar (179.6 ± 40.8 vs. 167.4 ± 30.3 lb; p = NS), while donor age was greater among hand‐assisted laparoscopic living‐donor nephrectomy (38.2 ± 9.5 vs. 31.2 ± 7.8 year; p < 0.01). Right nephrectomies was fewer in hand‐assisted laparoscopic living‐donor nephrectomy [17/100 (17%) vs. 22/50 (44%); p < 0.05]. Operative time for hand‐assisted laparoscopic living‐donor nephrectomy (3.9 ± 0.7 vs. 2.9 ± 0.5 h; p < 0.01) was longer; however, return to diet (6.9 ± 2.8 vs. 25.6 ± 6.1 h; p < 0.01), narcotics requirement (17.9 ± 6.3 vs. 56.3 ± 6.4 h; p < 0.01) and length of stay (51.7 ± 22.2 vs. 129.6 ± 65.7 h; p < 0.01) were less than open donor nephrectomy. Costs were similar (

Laparoscopic donor nephrectomy vs. open live donor nephrectomy: a quality of life and functional study

11 072 vs. 10 840). Graft function and 1‐week Cr of 1.4 ± 0.9 vs. 1.6 ± 1.1 g/dL (p = NS) were similar. With the introduction of HALDN, our laparoscopic living‐donor nephrectomy program has increased by 20%. Thus, similar to traditional laparoscopic donor nephrectomy, hand‐assisted laparoscopic living‐donor nephrectomy provides advantages over open donor nephrectomy without increasing costs.