Los Angeles, CA, United States
Los Angeles, CA, United States

Time filter

Source Type

Ellingson K.,Centers for Disease Control and Prevention | Seem D.,Centers for Disease Control and Prevention | Nowicki M.,Mendez National Institute of Transplantation | Nowicki M.,University of Southern California | And 2 more authors.
American Journal of Transplantation | Year: 2011

To prevent unintentional transmission of bloodborne pathogens through organ transplantation, organ procurement organizations (OPOs) screen potential donors by serologic testing to identify human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection. Newly acquired infection, however, may be undetectable by serologic testing. Our objective was to estimate the incidence of undetected infection among potential organ donors and to assess the significance of risk reductions conferred by nucleic acid testing (NAT) versus serology alone. We calculated prevalence of HIV and HCV-stratified by OPO risk designation-in 13 667 potential organ donors managed by 17 OPOs from 1/1/2004 to 7/1/2008. We calculated incidence of undetected infection using the incidence-window period approach. The prevalence of HIV was 0.10% for normal risk potential donors and 0.50% for high risk potential donors; HCV prevalence was 3.45% and 18.20%, respectively. For HIV, the estimated incidence of undetected infection by serologic screening was 1 in 50 000 for normal risk potential donors and 1 in 11 000 for high risk potential donors; for HCV, undetected incidence by serologic screening was 1 in 5000 and 1 in 1000, respectively. Projected estimates of undetected infection with NAT screening versus serology alone suggest that NAT screening could significantly reduce the rate of undetected HCV for all donor risk strata. Results from this study suggest that the risk of undetected HCV infection among potential organ donors can be significantly reduced by screening with Nucleic Acid Testing as opposed to serology testing for both normal- and high-risk donors. See editorial by Pruett on page 1115. © 2011 The American Society of Transplantation and the American Society of Transplant Surgeons.


Chin-Hong P.V.,University of California at San Francisco | Schwartz B.S.,University of California at San Francisco | Bern C.,Centers for Disease Control and Prevention | Montgomery S.P.,Centers for Disease Control and Prevention | And 6 more authors.
American Journal of Transplantation | Year: 2011

Donor-derived transmission of Trypanosoma cruzi, the etiologic agent of Chagas disease, has emerged as an issue in the United States over the past 10 years. Acute T. cruzi infection causes substantial morbidity and mortality in the posttransplant setting if not recognized and treated early. We assembled a working group of transplant infectious disease specialists, laboratory medicine specialists, organ procurement organization representatives and epidemiologists with expertise in Chagas disease. Based on review of published and unpublished data, the working group prepared evidence-based recommendations for donor screening, and follow-up testing and treatment of recipients of organs from infected donors. We advise targeted T. cruzi screening of potential donors born in Mexico, Central America and South America. Programs can consider transplantation of kidneys and livers from T. cruzi-infected donors with informed consent from recipients. However, we recommend against heart transplantation from infected donors. For other organs, we recommend caution based on the anticipated degree of immunosuppression. Our recommendations stress the need for systematic monitoring of recipients by polymerase chain reaction, and microscopy of buffy coat and advance planning for immediate antitrypanosomal treatment if recipient infection is detected. Data on management and outcomes of all cases should be collected to inform future guidelines and to assist in coordination with public health authorities. © 2011 The Authors.


Sampaio M.S.,Mendez National Institute of Transplantation | Cho Y.W.,Mendez National Institute of Transplantation | Shah T.,Mendez National Institute of Transplantation | Shah T.,Saint Vincent Medical Center | And 3 more authors.
Nephrology Dialysis Transplantation | Year: 2012

Background Post-transplant lymphoproliferative disorder (PTLD) is a serious complication of transplantation. Methods Using the OPTN/UNOS database, primary kidney recipients (20002009) were stratified according to transplant type (deceased donor, DD or living donor, LD), donor (D) and recipient (R) EpsteinBarr virus (EBV) serostatus (R+; D/R-and D-/R-) and recipient age. Incidence and adjusted risk of PTLD and death were compared. Results Of the 137 939 primary kidney recipients transplanted between 2000 and 2009, 913 subsequently developed PTLD. In 90 208 recipients with known EBV serostatus, we found a trend toward a decrease in PTLD incidence in years 20072009 when compared to 20002003. This was due to a significant decrease in PTLD incidence in EBV-recipients. Of those, 61 273 had a known donor serostatus and were further examined. In adults, PTLD incidence (in 1000 person-years) in DD and LD was 7.0 and 7.0 in D +R-; 3.0 and 2.5 in D-/R-and 1.2 and 1.0 in R+, respectively. The hazard ratio (HR) for PTLD (R+ as reference) in D +R-(6.2 in DD and 7.2 in LD) was double to thrice than for D-/R-transplants (2.4 in both DD and LD). In pediatric recipients, PTLD incidence in DD and LD was 15.9 and 17.3 in D +R-; 12 and 18 in D-/R-and 1.2 and 2.2 in R+, respectively. The HR for PTLD was 17.4 and 6.9 in D +R-and 15.9 and 7.6 in D-/R-in DD and LD, respectively. Conclusion A D/R-, compared with a D-/R-transplant, may contribute to an increase in PTLD incidence of 35 and 42% in adult DD and LD transplants, respectively. © 2012 The Author.


Sampaio M.S.,University of California at Los Angeles | Sampaio M.S.,State University of Rio de Janeiro | Poommipanit N.,University of California at Los Angeles | Cho Y.W.,Mendez National Institute of Transplantation | And 2 more authors.
Clinical Transplantation | Year: 2010

Living donor kidney transplantation (LDKT) in type 1 diabetic recipients (T1DM) may be followed by a pancreas after living donor kidney (PALK). The impact of the PALK is largely unknown. Adult T1DM living donor kidney recipients (1997-2007) listed for pancreas transplantation were divided into those who subsequently received pancreas transplantation and those who did not (living donor kidney transplant alone [LDKA]). Outcomes were compared. A sub-analysis was performed in recipients with at least one yr of kidney graft survival and limiting PALK to those who underwent pancreas transplantation in the first year. Of 4554 recipients, 23% received PALK. PALK had more favorable baseline characteristics. At the end of eight yr, we found significantly superior patient (85% vs. 75%) and kidney graft survival (75% vs. 62%) in PALK group. The adjusted hazard ratios of PALK (LDKA as reference) were 0.65 (95%CI: 0.52-0.81) for death and 0.63 (0.54-0.76) for renal graft loss. In sub-group analysis, there was a trend toward decreased death in PALK (HR = 0.78: 0.57-1.07). In conclusion, only 23% of those wait-listed received a pancreas with patient and kidney survival superior to LDKA. Pancreas transplant in the first year after kidney transplant was associated with a trend toward better long-term patient survival. © 2009 John Wiley & Sons A/S.


Sampaio M.S.,Mendez National Institute of Transplantation | Cho Y.W.,Mendez National Institute of Transplantation | Cho Y.W.,University of Southern California | Qazi Y.,University of Southern California | And 5 more authors.
Transplantation | Year: 2012

Background: De novo posttransplant malignancy (PTM) is a serious complication of transplantation. Incidences may vary among solid organ transplantations (SOTs) and may take to particular screening recommendations and posttransplantation care. Methods: Adult recipients, from the U.S. Organ Procurement Transplant Network/United Network for Organ Sharing database (data as of September 3, 2010), of a primary kidney transplantation (KT), liver transplantation (LT), heart transplantation (HT) or lung transplantation (LuT) performed in the United States between 1999 and 2008 were selected. Multiple-organ recipients and those whose grafts failed within 2 weeks after transplantation were excluded. The incidence of PTM (in 1000 person-years) was estimated using the Kaplan-Meier product-limit method and compared with SOT and the general population. Results: The cohort included 193,905 recipients (123,380 KT; 43,106 LT; 16511 HT; and 10,908 LuT). PTM incidence was 8.03, 11.0, 14.3, and 19.8 in KT, LT, HT, and LuT, respectively. In general, PTM recipients were 3 to 5 years older, mostly whites, and are males in all SOTs. In KT, the type of cancer with the highest incidence was posttransplant lymphoproliferative disorder (PTLD, 1.58%), followed by lung (1.12%), prostate (0.82%), and kidney (0.79%) cancers; in LT, PTLD (2.44%), lung and bronchial (2.18%), primary hepatic (0.91%), and prostate (0.88%) cancers; in HT, lung and bronchial (3.24%) and prostate (3.07%) cancers, and PTLD (2.24%); and in LuT, lung and bronchial cancers (5.94%), PTLD (5.72%), and colorectal cancer (1.38%). PTLD, Kaposi sarcoma, and lung and bronchial cancers were increased in all SOTs, when compared with an older (55-to 59-year-old) population. Conclusions: Cancer incidence is different among solid organ transplantations, and ratios may be higher than those in the 55-to 59-year-old population. © 2012 Lippincott Williams & Wilkins.


Sampaio M.S.,Mendez National Institute of Transplantation | Cho Y.W.,Mendez National Institute of Transplantation | Shah T.,Mendez National Institute of Transplantation | Shah T.,Saint Vincent Medical Center | And 3 more authors.
Transplantation | Year: 2012

BACKGROUND.: The association of immunosuppressive regimens (ISRs) with posttransplant lymphoproliferative disorder (PTLD) may be related with the Epstein-Barr virus (EBV) recipient serostatus. METHODS.: We selected primary kidney transplant recipients from Organ Procurement Transplant Network/United Network for Organ Sharing database (2000-2009) who were discharged with a functioning graft and were receiving an ISR including an antiproliferative drug and a calcineurin inhibitor as follows: mycophenolate mofetil (MMF)/mycophenolate sodium+tacrolimus (TAC), MMF+cyclosporine A (CsA); mammalian target of rapamycin inhibitor (mTORi)+TAC; and mTORi+CsA. Adjusted risks of PTLD, rejection, death, and graft failure were examined in all recipients and compared between EBV+ and EBV- recipients. RESULTS.: Of 114,025 recipients, 754 developed PTLD (5-year incidence of 0.84%). Adjusted hazard ratio for PTLD was 4.39 (95% CI: 3.60-5.37) for EBV- versus EBV+ recipients; and 1.40 (95% CI: 1.03-1.90) for mTORi+TAC, 0.80 (95% CI: 0.65-0.99) for MMF+CsA, and 0.90 (95% CI: 0.57-1.42) for mTORi+CsA, versus MMF+TAC users. In EBV- recipients, hazard ratio for PTLD was 1.98 (95% CI: 1.28-3.07) for mTORi+TAC, 0.45 (95% CI: 0.28-0.72) for MMF+CsA, and 0.84 (95% CI: 0.39-1.80) for mTORi+CsA users versus MMF+TAC. No difference was seen in EBV+ recipient groups. Rejection rates were higher among MMF+CsA recipients in both EBV groups. Death and graft failure risk were increased in all EBV+ISR groups, while in EBV- these risks were only increased in mTORi+TAC group versus MMF+TAC. CONCLUSIONS.: In EBV- recipients, immunosuppression with mTORi+TAC was associated with increased risk of PTLD, death, and graft failure, while MMF+CsA use was associated with a trend to increased risk of rejection, lower PTLD risk, and similar risk for graft failure when compared with MMF+TAC.


Chen Y.,Mendez National Institute of Transplantation | Chen Y.,University of Southern California | Sampaio M.S.,Mendez National Institute of Transplantation | Yang J.W.,University of Kansas | And 4 more authors.
Transplantation | Year: 2012

Transcription factors of the nuclear factor of activated T cells (NFAT) family regulate both immune activation and insulin production. Calcineurin inhibitors (CNIs) target NFAT activation. Hence, CNIs not only prevent organ transplant rejection but also contribute to the development of new-onset diabetes after transplantation (NODAT). Given individual variation in the susceptibility to NODAT, we hypothesized that polymorphisms in the cytoplasmic NFAT (NFATc)4 gene, which is expressed in pancreatic islets, may be associated with NODAT. Haplotype-tagging single-nucleotide polymorphisms (SNPs) of the NFATc4 gene were genotyped in Hispanic renal transplant patients. Cumulative incidences of NODAT were compared between recipients of different NFATc4 genotypes and haplotypes. The Cox proportional hazard model was used to examine risks for NODAT. Nongenetic and genetic characteristics were included in the multivariate risk model. The SNP (rs10141896) T allele was associated with a lower cumulative incidence of NODAT (P=0.02). This is a tagging SNP for one of the five dominant NFATc4 haplotypes, T-T-T-T-G, and CNI-treated recipients with this haplotype had a reduced adjusted risk for NODAT (hazard ratio: 0.45; 95% confidence interval: 0.19-1.01). Conversely, patients homozygous for the C-C-C-G-G haplotype were at an increased risk (hazard ratio: 2.13; 95% confidence interval: 1.01-4.46) for NODAT in subanalysis. Of the nongenetic factors, use of tacrolimus, sirolimus, and older age were associated with increased risk for NODAT. Polymorphisms in the NFATc4 gene may confer certain protection or predisposition for NODAT. © 2012 by Lippincott Williams & Wilkin.


Yang J.,University of Kansas | Hutchinson I.I.,University of Southern California | Hutchinson I.I.,Mendez National Institute of Transplantation | Shah T.,University of Southern California | And 4 more authors.
Transplantation | Year: 2011

Background: New-onset diabetes after transplantation (NODAT) is one of the major complications after transplantation and is associated with reduced overall patient and graft survival. The objective of this study was to determine the genetic and clinical risk factors for NODAT in Hispanic kidney transplant recipients. Methods: Hispanic kidney allograft recipients without evidence of preexisting diabetes who developed NODAT (n=133) were studied using Hispanic kidney transplant recipients with no evidence of diabetes as a control group (n=170). NODAT was defined as fasting glucose levels â‰1 126 mg/dL on two or more occasions or patients taking any insulin or oral hypoglycemic agents 1 month or later after kidney transplantation. Fourteen alleles in nine genes were genotyped and other patientsÊ clinical data with genotype data were analyzed by logistic regression. Results: Among 14 alleles, hepatocyte nuclear factor 4 alpha (HNF4A) AA (rs2144908, odds ratio [OR]=1.96, confidence interval [CI]=1.08-3.50, P=0.010), HNF4A TT (rs1884614, OR=2.44, CI=1.42-4.48, P=0.002), and insulin receptor substrate 1 AA+AG (rs1801278, OR=2.71, CI=1.16-6.89, P=0.021) remained significant after logistic regression. Among the clinical factors, average age (OR=1.01, CI=1.00-1.08, P=0.048), sirolimus (OR=5.36, CI=3.02-10.4, P=0.001), deceased donor (OR=1.96, CI=1.16-2.94, P=0.015), and acute rejection (OR=2.92, CI=1.31-5.77, P=0.009) remained significant after logistic regression. Conclusion: This study indicates that polymorphism of two alleles of HNF-4A gene (rs2144908 and rs1884614) and insulin receptor substrate 1 (rs1801278) are significantly associated with NODAT in kidney transplant patients with Hispanic ethnicity. In the case of clinical factors, older age (>50 year), deceased donor type, acute rejection, and sirolimus use are associated with NODAT in Hispanic kidney transplant recipients. © 2011 by Lippincott Williams & Wilkins.


Fong T.-L.,University of Southern California | Khemichian S.,University of Southern California | Shah T.,Mendez National Institute of Transplantation | Hutchinson I.V.,Mendez National Institute of Transplantation | And 2 more authors.
Transplantation | Year: 2012

BACKGROUND: The role of combined liver-kidney transplantation (CLKT) for cirrhotic patients with renal failure (RF) is controversial. Since the model for end-stage liver disease era, there has been a rise in the number of CLKT. Using the Organ Procurement Transplant Network/United Network for Organ Sharing database, this study was undertaken to compare outcomes of cirrhotic patients with RF who received either liver transplant alone (LTA) or CLKT between 2002 and 2008. METHODS: Analysis was limited to cirrhotic patients 18 years old or older, with serum creatinine level 2.5 mg/dL or higher at the time of orthotopic liver transplantation (OLT) or who received dialysis at least twice during the week before OLT. Patients who received CLKT were categorized based on the cause of their underlying RF. RESULTS: Overall liver allograft and patient survival rates of LTA patients were significantly lower compared with CLKT patients (P<0.001). CLKT patients with hepatorenal syndrome showed significantly higher patient and liver allograft survival rates. Liver allograft survival was superior among CLKT patients irrespective of whether they received dialysis. Prevalence of posttransplantation RF was higher for LTA patients at 6 months and 3 years of follow-up (P<0.001). LTA was a significant risk factor both for graft loss and mortality. Recipient hepatitis C virus seropositivity, donor age, donor cause of death, and life support at the time of OLT were also risk factors for graft loss and death. CONCLUSIONS: Cirrhotic patients with RF, in particular with hepatorenal syndrome, CLKT is preferable to LTA because it improves liver allograft and patient survival. Copyright © 2012 by Lippincott Williams &Wilkins.


Fong T.-L.,University of Southern California | Cho Y.W.,University of Southern California | Cho Y.W.,Mendez National Institute of Transplantation | Hou L.,University of Southern California | And 3 more authors.
Transplantation | Year: 2011

Background: The estimated prevalence of hepatitis C virus (HCV) infection among lung transplant (LT) recipients is 1.9%. Many thoracic transplant programs are reluctant to transplant HCV-seropositive patients due to concerns of hepatic dysfunction caused by immunosuppression. The aims of this study are to survey current practices of US LT programs regarding HCV-seropositive patients and using the Organ Procurement and Transplantation Network/United Network for Organ Sharing database and to assess the clinical outcomes of HCV-positive compared with HCV-negative LT recipients. Methods: A survey of US transplant centers that have performed more than 100 LTs was conducted. In addition, 170 HCV-seropositive and 9259 HCV-seronegative recipients who received HCV-seronegative donor organs between January 1, 2000, to December 31, 2007, were identified from the Organ Procurement and Transplantation Network/United Network for Organ Sharing database. Outcome variables including patient survival were compared between the two groups. Results: A total of 64.4% centers responded to the survey. Ten of 29 (34.5%) programs would not consider HCV-seropositive patients for LT. Among the 19 programs that will consider HCV-seropositive patients, only five centers would transplant actively viremic patients. Overall patient survival rates of HCV-seropositive patients were similar to HCV-seronegative patients (84.7% at 1 year, 63.9% at 3 years, 49.4% at 5 years for HCV-seropositive group vs. 82.0% at 1 year, 65.0% at 3 years, 51.4% at 5 years for HCV-seronegative group, P=0.712). Relative risk of recipients for death remained statistically insignificant after adjusting for recipient age, donor age, obesity, sensitization, serum creatinine, and medical condition at time of transplant (relative risk [RR]=1.07 [0.84-1.38], P=0.581). Conclusions: Since 2000, patient survival rates of HCV-positive patients are identical to those who are HCV-negative. However, most of these HCV-seropositive patients were probably nonviremic. © 2011 by Lippincott Williams & Wilkins.

Loading Mendez National Institute of Transplantation collaborators
Loading Mendez National Institute of Transplantation collaborators