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1.
Transpl Infect Dis ; 20(2): e12858, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29427406

ABSTRACT

BACKGROUND: Clostridium difficile is the most common cause of healthcare-associated infectious diarrhea. Risk factors for C. difficile infections (CDI) in intestinal transplant recipients (ITR) are not well-defined. The aim of our study was to assess specific risk factors for CDI in ITR. METHODS: This is a 1:3 case-control study that included 29 ITR who developed CDI (cases) and 87 ITR without CDI (controls) observed during the first year post-transplantation. Wilcoxon rank sum and Fisher's exact tests were used to compare variables. Univariate and multivariable conditional logistic regressions analysis were performed to identify risk factors for CDI. RESULTS: The multivariable conditional logistic regression analysis showed that proton pump inhibitors (PPI) administration (odds ratio [OR] = 0.06; 95% confidence interval [CI]: 0.007-0.52; P = .01) was the only factor associated with lower rates of CDI. Outcomes for cases vs controls: rejection episodes 24.14% vs 20.69% (P = .7), graft loss 0% vs 2.3% (P = .99), and survival rate 1 year post-transplantation 79.3% (59.6-90.1%) vs 87.2% (78.1-92.7%) (P = .38). CONCLUSIONS: Proton pump inhibitor administration might be protective for CDI in ITR. Risks factors for CDI might be different in ITR compared to other populations; anatomical differences and medications administered in the post-transplantation period may affect intestinal microbiota.


Subject(s)
Clostridium Infections/drug therapy , Clostridium Infections/etiology , Intestines/transplantation , Organ Transplantation/adverse effects , Transplant Recipients , Adolescent , Case-Control Studies , Child , Child, Preschool , Female , Humans , Infant , Male , Postoperative Complications , Retrospective Studies , Risk Factors
2.
Am J Transplant ; 15(5): 1173-9, 2015 May.
Article in English | MEDLINE | ID: mdl-25833653

ABSTRACT

The American Society of Transplantation (AST) and American Society of Transplant Surgeons (ASTS) convened a workshop on June 2-3, 2014, to explore increasing both living and deceased organ donation in the United States. Recent articles in the lay press on illegal organ sales and transplant tourism highlight the impact of the current black market in kidneys that accompanies the growing global organ shortage. We believe it important not to conflate the illegal market for organs, which we reject in the strongest possible terms, with the potential in the United States for concerted action to remove all remaining financial disincentives for donors and critically consider testing the impact and acceptability of incentives to increase organ availability in the United States. However, we do not support any trials of direct payments or valuable considerations to donors or families based on a process of market-assigned values of organs. This White Paper represents a summary by the authors of the deliberations of the Incentives Workshop Group and has been approved by both AST and ASTS Boards.


Subject(s)
Motivation , Tissue and Organ Procurement/methods , Transplantation/methods , Humans , Kidney Failure, Chronic/surgery , Kidney Transplantation/economics , Kidney Transplantation/methods , Living Donors , Medical Tourism , Tissue Donors , Transplantation/economics , United States
3.
Am J Transplant ; 15(3): 601-5, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25693472

ABSTRACT

Compensation models for physicians are currently based primarily on the work relative value unit (wRVU) that rewards productivity by work volume. The value-based payment structure soon to be ushered in by the Centers for Medicare and Medicaid Services rewards clinical quality and outcomes. This has prompted changes in wRVU value for certain services that will result in reduced payment for specialty procedures such as transplantation. To maintain a stable and competent workforce and achieve alignment between clinical activity, growth imperatives, and cost effectiveness, compensation of transplant physicians must evolve toward a matrix of measures beyond the procedure-based activity. This personal viewpoint proposes a redesign of transplant physician compensation plans to include the "virtual RVU" to recognize and reward meaningful clinical integration defined as hospital-physician commitment to specified and measurable metrics for current non-RVU-producing activities. Transplantation has been a leader in public outcomes reporting and is well suited to meet the challenges ahead that can only be overcome with a tight collaboration and alignment between surgeons, other physicians, support staff, and their respective institution and leadership.


Subject(s)
Income , Models, Economic , Physicians/economics , Transplantation , Centers for Medicare and Medicaid Services, U.S. , Humans , United States
4.
Am J Transplant ; 15(1): 210-9, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25438622

ABSTRACT

The Registry has gathered information on intestine transplantation (IT) since 1985. During this time, individual centers have reported progress but small case volumes potentially limit the generalizability of this information. The present study was undertaken to examine recent global IT activity. Activity was assessed with descriptive statistics, Kaplan-Meier survival curves and a multiple variable analysis. Eighty-two programs reported 2887 transplants in 2699 patients. Regional practices and outcomes are now similar worldwide. Current actuarial patient survival rates are 76%, 56% and 43% at 1, 5 and 10 years, respectively. Rates of graft loss beyond 1 year have not improved. Grafts that included a colon segment had better function. Waiting at home for IT, the use of induction immune-suppression therapy, inclusion of a liver component and maintenance therapy with rapamycin were associated with better graft survival. Outcomes of IT have modestly improved over the past decade. Case volumes have recently declined. Identifying the root reasons for late graft loss is difficult due to the low case volumes at most centers. The high participation rate in the Registry provides unique opportunities to study these issues.


Subject(s)
Global Health , Graft Rejection/mortality , Intestinal Diseases/surgery , Intestines/transplantation , Registries , Tissue Transplantation/standards , Tissue Transplantation/trends , Tissue and Organ Procurement/organization & administration , Adolescent , Adult , Child , Child, Preschool , Female , Follow-Up Studies , Graft Survival , Humans , Immunosuppression Therapy , Infant , Infant, Newborn , Male , Middle Aged , Prognosis , Survival Rate , Tissue Donors , Young Adult
5.
Am J Transplant ; 14(11): 2645-50, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25179206

ABSTRACT

Aplastic anemia (AA) has been observed in nearly a third of patients undergoing liver transplantation (LT) for non-A-E fulminant hepatic failure (FHF). Few of these patients have been successfully managed with sequential LT and bone marrow transplantation (BMT). No causative agent has been identified for the FHF or AA in these reported cases. At our center, two patients, aged 15 years and 7 years, respectively, underwent sequential living-related LT and living-unrelated BMT. These patients are 10/9 years and 5/4 years post-LT/BMT. Human parvovirus B19 (HPV-B19) was established as the causative agent for FHF in both these patients by polymerase chain reaction. This report presents the first two cases associating HPV-B19 with FHF and AA who underwent sequential LT and BMT with excellent outcomes.


Subject(s)
Anemia, Aplastic/surgery , Bone Marrow Transplantation , Liver Failure, Acute/surgery , Liver Transplantation , Parvovirus B19, Human/pathogenicity , Adolescent , Base Sequence , Child , DNA Primers , DNA, Bacterial/genetics , Humans , Liver Failure, Acute/virology , Male , Parvovirus B19, Human/genetics , Parvovirus B19, Human/isolation & purification
6.
S Afr Med J ; 104(11 Pt 2): 799-802, 2014 Nov.
Article in English | MEDLINE | ID: mdl-26038792

ABSTRACT

BACKGROUND: A paediatric liver transplant programme was started at the Wits Donald Gordon Medical Centre, Johannesburg, South Africa (SA), in November 2005. We reported on the first 29 patients in 2012. Since then we have performed a further 30 transplants in 28 patients, having met the major challenge of donor shortage by introducing a living related donor programme and increasing the use of split liver grafts. OBJECTIVE: To review the Wits Donald Gordon Medical Centre paediatric liver transplant programme to date. We describe how the programme has evolved and specifically compare the outcomes of the first cohort with the most recent 28 patients. METHODS: Case notes of all paediatric liver transplants performed between 14 November 2005 and 30 June 2014 were retrospectively reviewed. Data were analysed for age and weight at transplantation, indication and type of graft. Morbidity and mortality were documented, specifically biliary and vascular complications. Comparison was made between Era 1 (November 2005 - October 2012) and Era 2 (November 2012 - June 2014). RESULTS: A total of 59 transplants were performed in 57 patients. Age at transplantation ranged from 9 months to 213 months (mean 82.39 months) and weight ranged from 5 kg to 62 kg (mean 21 kg). A total of 23 whole livers, 10 reduced-size grafts, 14 split liver grafts and 12 living donor liver transplants (LDLTs) were performed. Eight patients were referred with fulminant hepatic failure (FHF), all in Era 2. Of these, three patients were successfully transplanted. Of the 57 patients, 45 are alive and well with actuarial 1-year patient and graft survival of 85% and 84% and 5-year patient and graft survival of 78% and 74%, respectively. Sixteen (25.42%) biliary complications occurred in 15 of our 59 transplants. Seven patients developed significant vascular complications. Comparing Era 1 with Era 2, mean age at transplant decreased from 100.86 months to 64.73 months, mean weight from 25.2 kg to 16.9 kg, and type of graft utilised changed with a trend away from the use of whole livers and reduced-sized grafts to split livers and segment 2,3 LDLT grafts. CONCLUSION: Initially limited by a shortage of donor organs, we aggressively explored optimal utilisation, splitting liver grafts from deceased donors as often as possible and establishing an LDLT programme. This increased access to donor livers allowed us to include patients with FHF and to perform retransplantation in recipients with early graft failure. It remains to offer liver transplantation to the entire paediatric community in SA, in conjunction with the only other established paediatric liver transplant unit, at Red Cross War Memorial Children's Hospital in Cape Town.


Subject(s)
Liver Diseases , Liver Transplantation , Living Donors , Postoperative Complications , Child , Child, Preschool , Female , Hospitals, Pediatric/statistics & numerical data , Humans , Infant , Liver Diseases/classification , Liver Diseases/epidemiology , Liver Diseases/surgery , Liver Transplantation/adverse effects , Liver Transplantation/methods , Liver Transplantation/statistics & numerical data , Male , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Program Evaluation/statistics & numerical data , Retrospective Studies , South Africa/epidemiology , Treatment Outcome
7.
Pediatr Transplant ; 16(3): 294-301, 2012 May.
Article in English | MEDLINE | ID: mdl-22212495

ABSTRACT

Despite improved prophylaxis, monitoring, and more efficient immunosuppression, CMV infection remains a common opportunistic infection in transplant recipients. We assessed the incidence of CMV disease in pediatric SBT recipients, the timing of CMV disease after transplantation, and its impact on patient outcome. The medical records of 98 SBT recipients were reviewed. We performed descriptive analysis, regression analysis, and Kaplan-Meier curves to determine the time-to-event after transplantation. Fifty-three percent patients were male and 47% female, with a mean age of 38.3 months. Thirty-five percent of patients received prophylactic VGC, 55% GCV, 10% a combination of GCV/VGC, and 99% CMV immunoglobulins. A total of 24.5% recipients were CMV D+/R- (CMV serostatus donor positive/recipient negative). Seven (c. 7%) patients developed CMV disease. CMV disease was associated with 2.5 times (0.52-12.1; p = 0.25) higher rate of CMV mismatch and 11.1 times (1.3-95.9; p = 0.03) higher risk of death. CMV prophylaxis increased time-to-death (p = 0.074). Time-to-CMV disease was shorter in patients with enteritis (p < 0.0001), and CMV disease was associated with shorter time-to-death after transplantation (p = 0.001). CMV disease in SBT recipients was associated with an 11-fold mortality increase and a fourfold faster time-to-death. Time-to-death was significantly shorter with CMV enteritis.


Subject(s)
Cytomegalovirus Infections/epidemiology , Cytomegalovirus Infections/etiology , Cytomegalovirus/metabolism , Transplantation/adverse effects , Child, Preschool , Cytomegalovirus Infections/therapy , Female , Humans , Immunosuppressive Agents/pharmacology , Incidence , Infant , Intestines/transplantation , Intestines/virology , Male , Models, Statistical , Retrospective Studies , Risk Factors , Time Factors , Treatment Outcome
8.
Infection ; 40(3): 263-9, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22124952

ABSTRACT

BACKGROUND: More data on the risk factors and outcomes after Staphylococcus aureus infections in liver transplantation are needed. METHODS: Liver recipients with S. aureus infections (cases) were retrospectively identified and compared to gender-, age-, and transplant type-matched (1:2) non-S. aureus-infected controls. Risk factors associated with S. aureus infections were identified by conditional logistic regression analysis. RESULTS: We evaluated 51 patients (median age 52 years). First S. aureus infections developed at a median time of 29 days after transplantation, with 52.94% of them in the first month; 88.24% were nosocomial, 41.18% were polymicrobial, and 47.06% were caused by methicillin-resistant S. aureus (MRSA). Surgical site infections represented 58.82% and bacteremia 23.53%. By univariate analysis, patients with S. aureus infections were intubated more frequently (odds ratio [OR] 26.92, 95% confidence interval [CI] 3.23-3,504.15, p = 0.0006), had a central line (OR 11.69, 95% CI 1.42-95.9, p = 0.02), or recent surgery (OR 26.92, 95% CI 3.23-3,504.15, p = 0.0006) compared with controls. By multivariate analysis, subjects who underwent surgery within 2 weeks prior to infection had a 26.9 times higher risk of developing S. aureus infection (95% CI 3.23-3,504.15, p = 0.0006); these results were adjusted for matched criteria. S. aureus infections did not affect graft or patient survival, but the study was not powered for such outcomes. CONCLUSION: Only recent surgical procedure was found to be a significant independent risk factor for S. aureus infections after liver transplantation.


Subject(s)
Liver Transplantation/adverse effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Postoperative Complications/epidemiology , Staphylococcal Infections/epidemiology , Staphylococcus aureus/isolation & purification , Adolescent , Bacteremia/epidemiology , Bacteremia/microbiology , Case-Control Studies , Child , Cross Infection/epidemiology , Cross Infection/microbiology , Female , Humans , Immunosuppressive Agents/administration & dosage , Immunosuppressive Agents/adverse effects , Logistic Models , Male , Middle Aged , Multivariate Analysis , Nebraska , Postoperative Complications/mortality , Retrospective Studies , Risk Factors , Staphylococcal Infections/mortality , Steroids/administration & dosage , Steroids/adverse effects , Survival Analysis , Time Factors
9.
Am J Transplant ; 11(1): 13-7, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21199345

ABSTRACT

Like all other areas of transplantation, vascularized composite allografts (VCA) has the capacity to transform the lives of patients, for the better or for the worse. It is this duality that mandates VCA be performed in centers prepared for the intricacies accompanying other transplant procedures. Similarly, the complexities of VCA require that the procedures be driven by surgeons and physicians with experience in the multidisciplinary management of immunocompromised postsurgical patients. Furthermore, the grafts should be considered as organs rather than tissues from a regulatory and a biological standpoint. The ASTS supports the field of VCA and has demonstrated its support and leadership by actively formulating a strategy for its systematic development. The goal of this document is to provide a framework for the prospective, thoughtful realization of VCA in the United States from the American Society of Transplant Surgeons (ASTS) perspective.


Subject(s)
Blood Vessel Prosthesis , Humans , Informed Consent , Tissue Donors , Transplantation, Homologous
10.
Transpl Infect Dis ; 12(6): 497-504, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20626710

ABSTRACT

BACKGROUND: Data on the incidence, timing, and outcome of fungal infections in pediatric small bowel transplantation (SBT) are lacking. METHODS: Cases of pediatric SBT from January 2003 through December 2007 were collected. Standard induction was with thymoglobulin and/or basiliximab and maintenance immunosuppression was a tacrolimus-based regimen. Chi-square was used for categorical variables and Kaplan-Meier for survival analyses. RESULTS: A total 98 recipients were included; 25 patients developed 59 episodes of Candida infections and 4 episodes of invasive aspergillosis (incidence 25.5%, 95% confidence interval [CI] 17%, 34%). Of the Candida species, 37.3% were Candida albicans and 62.7% non-albicans Candida. Of all yeast infections, 66.1% were fungemia, 28.8% intra-abdominal infections, 1.7% empyema, and 3.4% urinary tract infection. Of the Candida intra-abdominal infections, 41.2% developed in the first month post transplantation, while 79.5% of candidemia developed after >6 months. Median time from transplantation to fungal infection was significantly shorter for abdominal infections compared with fungemia (9 versus 163 days; P=0.004). All-cause mortality was not significantly different between patients with and without fungal infections (32.3% versus 29.8%; odds ratio=1.12, 95% CI 0.45, 2.8). CONCLUSION: Fungal infections occurred in 25% of SBT recipients and C. albicans was the most common species. Intra-abdominal fungal infections occurred earlier (<1 month) than fungemia (>6 months) post transplantation.


Subject(s)
Fungemia/epidemiology , Fungemia/mortality , Intestine, Small/transplantation , Mycoses/epidemiology , Mycoses/mortality , Transplants/adverse effects , Antifungal Agents/therapeutic use , Aspergillosis/epidemiology , Aspergillosis/microbiology , Aspergillosis/mortality , Aspergillus/classification , Aspergillus/isolation & purification , Candida/classification , Candida/isolation & purification , Candida albicans/isolation & purification , Candidemia/epidemiology , Candidemia/microbiology , Candidemia/mortality , Candidiasis, Invasive/epidemiology , Candidiasis, Invasive/microbiology , Candidiasis, Invasive/mortality , Female , Fungemia/microbiology , Humans , Immunosuppression Therapy/adverse effects , Immunosuppressive Agents , Incidence , Infant , Male , Mycoses/microbiology , Treatment Outcome
11.
Am J Transplant ; 10(4 Pt 2): 1020-34, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20420650

ABSTRACT

Improving short-term results with intestine transplantation have allowed more patients to benefit with nearly 700 patients alive in the United States with a functioning allograft at the end of 2007. This success has led to an increase in demand. Time to transplant and waiting list mortality have significantly improved over the decade, but mortality remains high, especially for infants and adults with concomitant liver failure. The approximately 200 intestines recovered annually from deceased donors represent less than 3% of donors who have at least one organ recovered. Consent practice varies widely by OPTN region. Opportunities for improving intestine recovery and utilization include improving consent rates and standardizing donor selection criteria. One-year patient and intestine graft survival is 89% and 79% for intestine-only recipients and 72% and 69% for liver-intestine recipients, respectively. By 10 years, patient and intestine survival falls to 46% and 29% for intestine-only recipients, and 42% and 39% for liver-intestine, respectively. Immunosuppression practice employs peri-operative antibody induction therapy in 60% of cases; acute rejection is reported in 30%-40% of recipients at one year. Data on long-term nutritional outcomes and morbidities are limited, while the cause and therapy for late graft loss from chronic rejection are areas of ongoing investigation.


Subject(s)
Donor Selection/standards , Adult , Graft Survival , Humans , Immunosuppression Therapy , Infant , Intestines/surgery , Liver Failure/surgery , Patient Selection , Tissue Donors/statistics & numerical data , Tissue Donors/supply & distribution , United States/epidemiology , Waiting Lists
12.
Am J Transplant ; 9(11): 2466-9, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19843028

ABSTRACT

The American Society of Transplant Surgeons (ASTS) was asked to endorse the 'The Declaration of Istanbul on Organ Trafficking and Transplant Tourism.' The document has been reviewed by the ASTS Ethics Committee and their ensuing report was presented, discussed and approved by the ASTS Council. The ASTS vigorously supports the principles outlined in the Declaration and details specific current obstacles to implementation of some of its proposals in the United States.


Subject(s)
Codes of Ethics , Organ Transplantation/ethics , Tissue Donors/ethics , Tissue and Organ Procurement/ethics , Crime , Humans , Turkey , United States
13.
Am J Transplant ; 6(6): 1422-9, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16686766

ABSTRACT

Inflammatory bowel disease (IBD) is associated with primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) and can recur or develop de novo after orthotopic liver transplantation (OLT). The aim of this study was to investigate the incidence and severity of IBD after liver transplantation and to perform a multivariate analysis for possible risk factors. In this retrospective study, 91 patients transplanted for PSC or AIH, without prior colectomy, were included. Sixty patients were transplanted for PSC, 31 for AIH. IBD activity before and after OLT and other possible risk factors were analysed in a multivariate model. Forty-nine patients (54%) had IBD before OLT. Forty patients (44%) had active IBD after transplantation: recurrence in 32 and de novo in 8. Cumulative risk for IBD after OLT was 15, 39 and 54% after 1, 5 and 10 years, respectively. In 59% of patients with IBD prior to OLT the disease was more active after transplantation. Risk factors for recurrent disease were: symptoms at time of OLT, short interval of IBD before OLT and use of tacrolimus. 5-aminosalicylates were protective. A cytomegalovirus positive donor/negative recipient combination increased the risk for de novo IBD.


Subject(s)
Cholangitis, Sclerosing/surgery , Hepatitis, Autoimmune/surgery , Inflammatory Bowel Diseases/epidemiology , Liver Transplantation/adverse effects , Adult , Cholangitis, Sclerosing/complications , Cytomegalovirus Infections/epidemiology , Follow-Up Studies , Hepatitis, Autoimmune/complications , Humans , Immunosuppressive Agents/adverse effects , Inflammatory Bowel Diseases/etiology , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Recurrence , Retrospective Studies , Risk Factors , Time Factors , Tissue Donors
14.
J Pediatr Surg ; 39(3): 340-4; discussion 340-4, 2004 Mar.
Article in English | MEDLINE | ID: mdl-15017549

ABSTRACT

BACKGROUND/PURPOSE: Parenteral nutrition (PN) is life saving in short bowel syndrome. However, long-term parenteral nutrition is frequently complicated by a syndrome of progressive cholestatic liver disease that is considered to be irreversible beyond the early stages of cholestasis, particularly in the presence of any degree of fibrosis in the liver. The purpose of this study was to examine apparent improvement in PN-associated liver dysfunction in a cohort of children with short bowel syndrome. METHODS: A retrospective case-record review of all patients managed within a dedicated Intestinal Rehabilitation Program (IRP) identified 13 patients with short bowel who had PN-associated liver dysfunction, defined for this purpose as hyperbilirubinemia or an abnormal liver biopsy. RESULTS: At referral, 12 of the 13 patients were exclusively on PN, and one was on 50% PN. At current follow-up, 3 patients have achieved complete enteral autonomy from PN, and 7 patients have had smaller decrements in PN requirements. Specific operative procedures to improve intestinal function were undertaken in 11 patients; 4 patients also underwent cholecystectomies with biliary irrigation at the time of intestinal reconstruction. The median highest bilirubin level in these 13 patients was 10.7 mg% (range, 3.2 to 24.5 mg%). Liver biopsy results indicated that 5 patients were cirrhotic, 3 had bridging fibrosis, and 4 had severe cholestasis or lesser degrees of fibrosis. Of 10 survivors in this series, 9 patients currently have a serum bilirubin less than 1 mg% with a median bilirubin in the group of 0.6 mg% (range, 0.3 to 6.4 mg%). Twelve of the 13 patients in this series were initially referred for liver-small bowel transplantation. CONCLUSIONS: This preliminary experience suggests that PN-dependent patients with advanced liver dysfunction in the setting of the short bowel syndrome may, in some instances, experience functional and biochemical liver recovery. The latter appears to parallel autologous gut salvage in most cases. As a corollary, the authors believe that even advanced degrees of liver dysfunction should not preclude attempts at autologous gut salvage in very carefully selected patients. Such a policy of "aggressive conservatism" may help avoid the need for liver/intestinal transplantation in some patients who appear to be not responding to PN.


Subject(s)
Cholestasis, Intrahepatic/physiopathology , Intestine, Small/transplantation , Liver Cirrhosis/physiopathology , Liver Regeneration , Parenteral Nutrition, Total/adverse effects , Short Bowel Syndrome/therapy , Adolescent , Child , Child, Preschool , Cholestasis, Intrahepatic/etiology , Humans , Infant , Liver/physiology , Liver Cirrhosis/etiology , Recovery of Function , Retrospective Studies
15.
Scand J Immunol ; 58(1): 59-66, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12828559

ABSTRACT

Mouse T cells fail to respond to xenogeneic pig and human antigens using the direct antigen-presenting pathway. The poor response by mouse CD8 cells is because of multiple defects in the molecular interactions between mouse CD8 cells and xenogeneic antigen-presenting cells (APCs). Using human CD4/DR3+, mouse CD4-/major histocompatibility complex (MHC) class II - mice, we investigated the defects in molecular interaction responsible for the poor response to xenogeneic antigens by naïve mouse CD4+ cells. Mouse CD4 cells failed to respond to human leucocyte antigen (HLA)-DR3 expressed on mouse APCs but developed a strong response to alloantigens, indicating a defect in the interaction between mouse CD4 and HLA-DR3 molecules. Human CD4+/mouse CD4- mouse T cells respond poorly to human and pig APCs but not allogeneic APCs, indicating that accessory molecular interactions are deficient across highly separated species. Adding mouse interleukin-2 (IL-2) to the mixed lymphocyte reaction system did not improve the poor response to human or pig antigens by mouse or human CD4+/mouse CD4- mouse T cells. Therefore, multiple molecular interactions deficient between mouse CD4 cells and human or pig APCs may lead to the poor response to xenogeneic antigens by naïve mouse CD4 cells.


Subject(s)
Antigen-Presenting Cells/physiology , Antigens/immunology , CD4-Positive T-Lymphocytes/immunology , Animals , Histocompatibility Antigens Class II/immunology , Humans , Lymphocyte Activation , Lymphocyte Culture Test, Mixed , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Swine
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