Marlon F. Levy
Baylor University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Marlon F. Levy.
Diabetes Care | 2012
Franca B. Barton; Michael R. Rickels; Rodolfo Alejandro; Bernhard J. Hering; Stephen Wease; Bashoo Naziruddin; José Oberholzer; Jon S. Odorico; Marc R. Garfinkel; Marlon F. Levy; François Pattou; Thierry Berney; Antonio Secchi; Shari Messinger; Peter A. Senior; Paola Maffi; Andrew M. Posselt; Peter G. Stock; Dixon B. Kaufman; Xunrong Luo; Fouad Kandeel; Enrico Cagliero; Nicole A. Turgeon; Piotr Witkowski; Ali Naji; Philip J. O'Connell; Carla J. Greenbaum; Yogish C. Kudva; Kenneth L. Brayman; Meredith J. Aull
OBJECTIVE To describe trends of primary efficacy and safety outcomes of islet transplantation in type 1 diabetes recipients with severe hypoglycemia from the Collaborative Islet Transplant Registry (CITR) from 1999 to 2010. RESEARCH DESIGN AND METHODS A total of 677 islet transplant-alone or islet-after-kidney recipients with type 1 diabetes in the CITR were analyzed for five primary efficacy outcomes and overall safety to identify any differences by early (1999–2002), mid (2003–2006), or recent (2007–2010) transplant era based on annual follow-up to 5 years. RESULTS Insulin independence at 3 years after transplant improved from 27% in the early era (1999–2002, n = 214) to 37% in the mid (2003–2006, n = 255) and to 44% in the most recent era (2007–2010, n = 208; P = 0.006 for years-by-era; P = 0.01 for era alone). C-peptide ≥0.3 ng/mL, indicative of islet graft function, was retained longer in the most recent era (P < 0.001). Reduction of HbA1c and resolution of severe hypoglycemia exhibited enduring long-term effects. Fasting blood glucose stabilization also showed improvements in the most recent era. There were also modest reductions in the occurrence of adverse events. The islet reinfusion rate was lower: 48% by 1 year in 2007–2010 vs. 60–65% in 1999–2006 (P < 0.01). Recipients that ever achieved insulin-independence experienced longer duration of islet graft function (P < 0.001). CONCLUSIONS The CITR shows improvement in primary efficacy and safety outcomes of islet transplantation in recipients who received transplants in 2007–2010 compared with those in 1999–2006, with fewer islet infusions and adverse events per recipient.
Transplantation | 1997
Osman Abbasoglu; Marlon F. Levy; Mohan S. Vodapally; Robert M. Goldstein; B. S. Husberg; T A Gonwa; Goran B. Klintmalm
Little is known about hepatic artery (HA) patency and patient clinical course when the nonthrombosed HA has been revised. We undertook this study to evaluate the risk factors in the development of HA stenosis and to assess the impact of HA revision on the outcome. A total of 857 adult consecutive OLT in 780 patients performed over a 6-year period were studied. Patients who underwent revision of their nonthrombosed but stenotic HA were reviewed for patient/graft survival, method of HA revision, incidence of biliary strictures, and long-term HA patency. Overall 39 patients (5%) with 41 allografts underwent HA revision for stenosis. Median time to diagnosis was 100 days posttransplant (range 1-1220 days). HA flow at the time of OLT was found to be the only significant variable of an anastomotic stenosis. No risk factor could be identified for the graft HA stenosis. Treatment methods included resection of the stenotic segment with primary reanastomosis (n = 17), aortohepatic iliac artery graft (n = 11), interposition vein graft (n = 4), vein patch angioplasty (n = 2), interposition artery graft (n = 1), and percutaneous transluminal balloon angioplasty (n = 6). Postrevisional HA patency was demonstrated in 32 (78%) cases. At a median follow-up of 25 months, 26 patients (67%) were asymptomatic with good liver function. Nine patients had developed biliary strictures. Seven patients had undergone retransplantation and 8 patients had died. The actuarial patient and graft survivals at 4 years in the patients with revised HA were 65% and 56%, respectively. HA stenosis requiring revision is an infrequent occurrence after OLT. Long-term patency of the revised HA is good. Revision of the HA may help prevent biliary strictures and allow for good long-term graft function in the majority of patients.
Liver Transplantation | 2009
Yousri M. Barri; Edmund Q. Sanchez; Linda W. Jennings; Larry Melton; Steven R. Hays; Marlon F. Levy; Goran B. Klintmalm
The incidence of acute kidney injury (AKI) has been reported to vary between 17% and 95% post–orthotopic liver transplantation. This variability may be related to the absence of a uniform definition of AKI in this setting. The purpose of this study was to identify the degree of AKI that is associated with long‐term adverse outcome. Furthermore, to determine the best definition (for use in future studies) of AKI not requiring dialysis in post–liver transplant patients, we retrospectively reviewed the effect of 3 definitions of AKI post–orthotopic liver transplantation on renal and patient outcome between 1997 and 2005. We compared patients with AKI to a control group without AKI by each definition. AKI was defined in 3 groups as an acute rise in serum creatinine, from the pretransplant baseline, of >0.5 mg/dL, >1.0 mg/dL, or >50% above baseline to a value above 2 mg/dL. In all groups, the glomerular filtration rate was significantly lower at both 1 and 2 years post‐transplant. Patient survival was worse in all groups. Graft survival was worse in all groups. The incidence of AKI was highest in the group with a rise in creatinine of >0.5 mg/dL (78%) and lowest in patients with a rise in creatinine of >50% above 2.0 mg/dL (14%). Even mild AKI, defined as a rise in serum creatinine of >0.5 mg/dL, was associated with reduced patient and graft survival. However, in comparison with the other definitions, the definition of AKI with the greatest impact on patients outcome post–liver transplant was a rise in serum creatinine of >50% above baseline to >2 mg/dL. Liver Transpl 15:475–483, 2009.
American Journal of Transplantation | 2011
Greg J. McKenna; James F. Trotter; E. Klintmalm; Nicholas Onaca; Richard Ruiz; Linda W. Jennings; Michael A. Neri; J. G. O’Leary; Gary L. Davis; Marlon F. Levy; Robert M. Goldstein; Goran B. Klintmalm
Hepatitis C virus (HCV) causes progressive liver fibrosis in liver transplant recipients and is the principal cause of long‐term allograft failure. The antifibrotic effects of sirolimus are seen in animal models but have not been described in liver transplant recipients. We reviewed 1274 liver recipients from 2002 to 2010 and identified a cohort of HCV recipients exposed to sirolimus as primary immunosuppression (SRL Cohort) and an HCV Control Group of recipients who had never received sirolimus. Yearly protocol biopsies were done recording fibrosis stage (METAVIR score) with biopsy compliance of >80% at both year one and two. In an intent‐to‐treat analysis, the SRL Cohort had significantly less advanced fibrosis (stage ≥2) compared to the HCV Control Group at year one (15.3% vs. 36.2%, p < 0.0001) and year two (30.1% vs. 50.5%, p = 0.001). Because sirolimus is sometimes discontinued for side effects, the SRL Cohort was subgroup stratified for sirolimus duration, showing progressively less fibrosis with longer sirolimus duration. Multivariate analysis demonstrated sirolimus as an independent predictor of minimal fibrosis at year one, and year two. This is the first study among liver transplant recipients with recurrent HCV to describe the positive impact of sirolimus in respect of reduced fibrosis extent and rate of progression.
Liver Transplantation | 2007
Richard Ruiz; Yousri M. Barri; Linda W. Jennings; Srinath Chinnakotla; Robert M. Goldstein; Marlon F. Levy; Greg J. McKenna; Henry B. Randall; Edmund Q. Sanchez; Goran B. Klintmalm
Hepatorenal syndrome (HRS) is a well‐recognized complication of end‐stage liver disease. Once thought to be a reversible condition with liver transplantation (LT) alone, HRS may directly contribute to the requirement for long‐term dialysis posttransplant. As a result, discussion has now focused on whether or when a kidney allograft should be considered for these patients. Using the International Ascites Club guidelines with a pretransplant serum creatinine (SCr) >2.0 mg/dL to define HRS, 130 patients undergoing LT over a 10‐yr period were identified, for an overall incidence of 9%. Patient survival rates at 1, 3, and 5 yr were 74%, and 68%, and 62%, respectively. Survival was significantly worse when compared to non‐HRS patients undergoing LT over the same study period (P = 0.0001). For patients presenting with type 2 HRS, 7 patients (6%) developed irreversible kidney failure posttransplant compared to 0.34% in the non‐HRS population (P < 0.0001). Five of these patients died within 1 yr with a median survival time of 139 days. Combined liver and kidney transplantation (CLKT) for patients with HRS is not recommended. However, an improvement in outcome can be accomplished by addressing those patients who require dialysis greater than 60 days posttransplant. We propose a role for kidney after liver transplantation (KALT) in select HRS patients. Liver Transpl 13:838–843, 2007.
Cell Transplantation | 2011
Shinichi Matsumoto; Morihito Takita; Damien Chaussabel; Hirofumi Noguchi; Masayuki Shimoda; Koji Sugimoto; Takeshi Itoh; Daisuke Chujo; Jeff A. SoRelle; Nicholas Onaca; Bashoo Naziruddin; Marlon F. Levy
Poor efficacy is one of the issues for clinical islet transplantation. Recently, we demonstrated that pancreatic ductal preservation significantly improved the success rate of islet isolation; however, two transplants were necessary to achieve insulin independence. In this study, we introduced iodixanol-based purification, thymoglobulin induction, and double blockage of IL-1β and TNF-α as well as sirolimus-free immunosuppression to improve the efficacy of clinical islet transplantation. Nine clinical-grade human pancreata were procured. Pancreatic ductal preservation was performed using ET-Kyoto solution in all cases. When the isolated islets met the clinical criteria, they were transplanted. We utilized two methods of immunosuppression and anti-inflammation. The first protocol prescribed daclizumab for induction, then sirolimus and tacrolimus to maintain immunosuppression. The second protocol used thymoglobulin for induction and tacrolimus and mycophenolate mofetil to maintain immunosuppression. Eternacept and anakinra were administered as anti-inflammatory drugs. The total amount of insulin required, HbA1c, and the SUITO index were determined to analyze and compare the results of transplantation. All isolated islet preparations (9/9) met the criteria for clinical transplantation, and they were transplanted into six type 1 diabetic patients. All patients achieved insulin independence with normal HbA1c levels; however, the first protocol required two islet infusions (N = 3) and the second protocol only required a single infusion (N = 3). The average SUITO index, at 1 month after a single-donor islet transplantation, was significantly higher in the second protocol (49.6 ± 8.3 vs. 19.3 ± 6.3, p < 0.05). Pancreatic ductal preservation, iodixanol-based purification combined with thymoglobulin induction, and blockage of IL-1β and TNF-α as well as sirolimus-free immunosuppression dramatically improved the efficacy of clinical islet transplantations. This protocol enabled us to perform successful single-donor islet transplantations. Further large-scale studies are necessary to confirm these results and clarify the mechanism of each component.
Cell Transplantation | 2010
Shinichi Matsumoto; Hirofumi Noguichi; Masayuki Shimoda; Tetsuya Ikemoto; Bashoo Naziruddin; Andrew Jackson; Yoshiko Tamura; Greg Olson; Yasutaka Fujita; Daisuke Chujo; Morihito Takita; Naoya Kobayashi; Nicholas Onaca; Marlon F. Levy
Inconsistent islet isolation is one of the issues of clinical islet transplantation. In the current study, we applied ductal injection to improve the consistency of islet isolation. Seven islet isolations were performed with the ductal injection of ET-Kyoto solution (DI group) and eight islet isolations were performed without the ductal injection (standard group) using brain-dead donor pancreata. Isolated islets were evaluated based on the Edmonton protocol for transplantation. The DI group had significantly higher islet yields (588,566 ± 64,319 vs. 354,836 ± 89,649 IE, p < 0.01) and viability (97.3 ± 1.2% vs. 92.6 ± 1.2%, p < 0.02) compared with the standard group. All seven isolated islet preparations in the DI group (100%), versus only three out of eight isolated islet preparations (38%) in the standard group met transplantation criteria. The islets from the DI group were transplanted into three type 1 diabetic patients and all three patients became insulin independent. Ductal injection significantly improved quantity and quality of isolated islets and resulted in high success rate of clinical islet transplantation. This simple modification will reduce the risk of failure of clinical islet isolation.
Liver Transplantation | 2006
Takehisa Ueno; Greg Jones; Adrian Martin; Toru Ikegami; Edmund Q. Sanchez; Srinath Chinnakotla; Henry B. Randall; Marlon F. Levy; Robert M. Goldstein; Goran B. Klintmalm
Hepatic artery stenosis after liver transplantation may affect liver function and result in hepatic artery thrombosis. Surgical reconstruction has been the first choice for treatment. Interventional radiologic technique can be used, but there is no report on long‐term outcome. The aim of this paper is to assess current outcome and complications of hepatic artery stenting. Twenty‐six adult patients were stented for hepatic artery stenosis between 1998 and 2003. Nine patients had previous surgical reconstruction for hepatic artery stenosis. Seventeen patients suffered newly developed hepatic artery stenosis. Three patients were retransplanted. After stenting, the patients were followed by Doppler ultrasound at day 1, 1 month, and 6 months. Angiography was scheduled in 6 months. Four patients died within 2 months. The other 22 patients were followed for mean 31 ± 14 months (8‐71 months). One of 22 patients died from renal failure 2 years later. Twelve patients hepatic arteries looked normal after stenting. Restenosis was seen in 8 patients (36%). Other complications were artery thrombosis (n = 1) and long segment stricture (n = 1). In 2 patients (25%) restenosis resulted in thrombosis. Six of the 8 patients who developed recurrent stenosis were successfully treated interventionally: restent (n = 5) and balloon dilation (n = 3). However, 3 patients (38%) restenosed. Kaplan‐Meier complication‐free survival was 54% at 1 year after stenting. In conclusion, hepatic artery stenting is a viable treatment for hepatic artery stenosis with reasonable results. Stenting is useful as adjuvant treatment after surgical revision. Liver Transpl 12:422–427, 2006.
Critical Care Medicine | 2001
Marlon F. Levy; Lonnie Greene; Michael Ramsay; Linda W. Jennings; Ba Kirsten J. Ramsay; Jin Meng; H. A. Tillmann Hein; Robert M. Goldstein; B. S. Husberg; T A Gonwa; Goran B. Klintmalm
ObjectiveWe undertook this study to understand the factors at our transplant center that contribute to patients’ return to the ICU after their liver transplant and their initial discharge from that unit. Patients who, after liver transplantation, fail discharge from the Intensive Care Unit (ICU) and must be readmitted to that unit may well utilize many more resources than those patients who are well enough to stay out of the ICU. DesignA retrospective review of a prospectively maintained liver transplant research database followed by a retrospective review of (a subgroup) patient charts and contemporaneous controls. SettingA large metropolitan tertiary care center and adult liver transplant center. PatientsA total of 1,197 consecutive adult patients who underwent their initial liver transplantation from 1984 to 1996. InterventionReadmission to the intensive care unit after adult liver transplantation and discharge from that unit. Main ResultsOnly recipient age, pretransplant synthetic function labs (protime and albumin), bilirubin levels, and intraoperative blood product requirements could be statistically linked to the group requiring ICU readmission. The primary etiology for ICU readmission was cardiopulmonary deterioration. Readmission was associated with significantly lower patient and graft survivals. A detailed review of 23 patients transplanted from October 1994 to June 1996 was made, with special emphasis on cardiopulmonary status (hemodynamics, respiratory variables, and chest radiograph findings). This subgroup was compared with 30 temporally matched controls who were not readmitted to the ICU. Intravascular fluid overload and lower inspiratory capacity were significant factors related to ICU readmission. Readmitted patients had a longer hospitalization with higher hospital charges than the control group. ConclusionsWe conclude that the most important means of preventing ICU readmission in liver transplantation patients is to optimize cardiopulmonary function and status. Close monitoring of fluid balance to avoid hypervolemia is essential. Readmitted patients have a greater resource utilization and have lower survival rates.
Cell Transplantation | 2009
Hirofumi Noguchi; Koichi Oishi; Michiko Ueda; Hiroshi Yukawa; Shuji Hayashi; Naoya Kobayashi; Marlon F. Levy; Shinichi Matusmoto
β-Cell replacement therapy via islet transplantation is a promising possibility for the optimal treatment of type 1 diabetes. However, such an approach is severely limited by the shortage of donor organs. Pancreatic stem/progenitor cells could become a useful target for β-cell replacement therapy in diabetic patients because the cells are abundantly available in the pancreas of these patients and in donor organs. In this study, we established a mouse pancreatic stem cell line without genetic manipulation. The duct-rich population after islet isolation was inoculated into 96-well plates in limiting dilution. From over 200 clones, 15 clones were able to be cultured for over 3 months. The HN#13 cells, which had the highest expression of insulin mRNA after induction, expressed PDX-1 transcription factor, glucagon-like peptide-1 (GLP-1) receptor, and cytokeratin-19 (duct-like cells). These cells continue to divide actively beyond the population doubling level (PDL) of 300. Exendin-4 treatment and transduction of PDX-1 and NeuroD proteins by protein transduction technology in HN#13 cells induced insulin and pancreas-related gene expression. This cell line could be useful for analyzing pancreatic stem cell differentiation. Moreover, the isolation technique might be useful for identification and isolation of human pancreatic stem/progenitor cells.