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1.
Am Surg ; 89(9): 3732-3738, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37148273

ABSTRACT

INTRODUCTION: Despite a high prevalence of retained bullet fragments (RBFs) after firearm related injury (FRI) there is limited data on the full spectrum of their consequences, particularly the psychological impacts on those injured. Further, the experiences of FRI survivors with RBFs are missing from existing literature. The objective of this study was to explore the psychological impacts of RBFs on individuals who have experienced recent FRI. METHODS: Adult (18-65 years) survivors of FRI with radiographically confirmed RBFs were purposively selected from an urban Level 1 trauma center in Atlanta, Georgia, to participate in an in-depth interview. Interviews were conducted between March 2019 and February 2020. Thematic analysis was used to identify a range of psychological effects from RBFs. RESULTS: Interviews from 24 FRI survivors were analyzed: the majority of participants were Black males (N = 22, 92%) with a mean age of 32 years whose FRI occurred ∼8.6 months prior to data collection. The psychological effects of RBFs were grouped into four categories: physical health (eg, pain, limited mobility), emotional well-being (eg, anger, fear), social isolation, and occupational welfare (eg, disability leading to inability to work). A range of coping mechanisms were also identified. CONCLUSION: Survivors of FRI with RBFs experience a range of psychological impacts that are far-reaching and affect daily activities, mobility, pain and emotional wellbeing. Study results indicate a need for enhanced resources to support those with RBFs. Further, changes to clinical protocols are warranted on removal of RBFs and communication about the effects of leaving RBFs in situ.


Subject(s)
Adaptation, Psychological , Pain , Adult , Male , Humans , Fear , Social Isolation , Survivors/psychology
2.
Gen Hosp Psychiatry ; 81: 46-50, 2023.
Article in English | MEDLINE | ID: mdl-36764261

ABSTRACT

OBJECTIVE: Predicting risk of posttraumatic stress disorder (PTSD) in the acute care setting is challenging given the pace and acute care demands in the emergency department (ED) and the infeasibility of using time-consuming assessments. Currently, no accurate brief screening for long-term PTSD risk is routinely used in the ED. One instrument widely used in the ED is the 27-item Immediate Stress Reaction Checklist (ISRC). The aim of this study was to develop a short screener using a machine learning approach and to investigate whether accurate PTSD prediction in the ED can be achieved with substantially fewer items than the IRSC. METHOD: This prospective longitudinal cohort study examined the development and validation of a brief screening instrument in two independent samples, a model development sample (N = 253) and an external validation sample (N = 93). We used a feature selection algorithm to identify a minimal subset of features of the ISRC and tested this subset in a predictive model to investigate if we can accurately predict long-term PTSD outcomes. RESULTS: We were able to identify a reduced subset of 5 highly predictive features of the ISRC in the model development sample (AUC = 0.80), and we were able to validate those findings in the external validation sample (AUC = 0.84) to discriminate non-remitting vs. resilient trajectories. CONCLUSION: This study developed and validated a brief 5-item screener in the ED setting, which may help to improve the diagnostic process of PTSD in the acute care setting and help ED clinicians plan follow-up care when patients are still in contact with the healthcare system. This could reduce the burden on patients and decrease the risk of chronic PTSD.


Subject(s)
Stress Disorders, Post-Traumatic , Humans , Stress Disorders, Post-Traumatic/diagnosis , Stress Disorders, Post-Traumatic/epidemiology , Prospective Studies , Longitudinal Studies , Emergency Service, Hospital
4.
Am J Surg ; 225(6): 948-952, 2023 06.
Article in English | MEDLINE | ID: mdl-36182595

ABSTRACT

INTRODUCTION: Patients with Non-English Language Preferences (NELP) experience challenges navigating the US healthcare system which can lead to disparate outcomes. This study sought to investigate injury patterns and outcomes in hospitalized trauma patients with NELP. METHODS: A retrospective review was performed at a trauma center from January 2019-December 2020. An institutional database of all emergency department video consultations for interpreter services was cross-referenced with the trauma registry and comparisons were made between NELP and English-preferred (EP) speaking patients. RESULTS: During the study, 257 NELP patients were hospitalized after traumatic injury. Twenty-two percent had work related injuries compared to only 3.0% in the EP cohort (p < 0.001). When propensity score matched, there were no significant differences in ICU and hospital length of stay or mortality between NELP and EP patients. DISCUSSION: Trauma patients are linguistically diverse and understanding their injury patterns and outcomes is crucial for guiding culturally and linguistically appropriate injury prevention.


Subject(s)
Language , Trauma Centers , Humans , Emergency Service, Hospital , Retrospective Studies , Hospital Mortality , Injury Severity Score , Length of Stay
5.
Am J Surg ; 224(1 Pt B): 607-611, 2022 07.
Article in English | MEDLINE | ID: mdl-35534294

ABSTRACT

BACKGROUND: This study investigated the impact of COVID-19 infection on hospitalized trauma patients. METHODS: A retrospective review of hospitalized trauma patients at a level I trauma center was performed from March-December 2020. Data pertaining to patient demographics, presentation and hospital course was compared between COVID positive and negative trauma patients. RESULTS: There were 4,912 patients and 179 (3.64%) were COVID-19 positive. Demographics and clinical presentation did not differ significantly between those with and without concomitant COVID-19. However, COVID positive trauma patients had higher rates of acute kidney injury (p = 0.016), sepsis (p = 0.016), unplanned intubation (p = 0.002) and unplanned return to the ICU (p = 0.01). The COVID positive cohort also had longer hospital stays (p < 0.01) with no significant difference in mortality. CONCLUSIONS: In the setting of an ongoing pandemic, awareness of the complications COVID positive trauma patients are predisposed to is important for providers.


Subject(s)
COVID-19 , COVID-19/complications , Humans , Length of Stay , Pandemics , Retrospective Studies , Trauma Centers
6.
BMC Med Genomics ; 14(1): 86, 2021 03 19.
Article in English | MEDLINE | ID: mdl-33740956

ABSTRACT

BACKGROUND: RNA gene expression of renal transplantation biopsies is commonly used to identify the immunological patterns of graft rejection. Mostly done with microarrays, seminal findings defined the patterns of gene sets associated with rejection and non-rejection kidney allograft diagnoses. To make gene expression more accessible, the Molecular Diagnostics Working Group of the Banff Foundation for Allograft Pathology and NanoString Technologies partnered to create the Banff Human Organ Transplant Panel (BHOT), a gene panel set of 770 genes as a surrogate for microarrays (~ 50,000 genes). The advantage of this platform is that gene expressions are quantifiable on formalin fixed and paraffin embedded archival tissue samples, making gene expression analyses more accessible. The purpose of this report is to test in silico the utility of the BHOT panel as a surrogate for microarrays on archival microarray data and test the performance of the modelled BHOT data. METHODS: BHOT genes as a subset of genes from downloaded archival public microarray data on human renal allograft gene expression were analyzed and modelled by a variety of statistical methods. RESULTS: Three methods of parsing genes verify that the BHOT panel readily identifies renal rejection and non-rejection diagnoses using in silico statistical analyses of seminal archival databases. Multiple modelling algorithms show a highly variable pattern of misclassifications per sample, either between differently constructed principal components or between modelling algorithms. The misclassifications are related to the gene expression heterogeneity within a given diagnosis because clustering the data into 9 groups modelled with fewer misclassifications. CONCLUSION: This report supports using the Banff Human Organ Transplant Panel for gene expression of human renal allografts as a surrogate for microarrays on archival tissue. The data modelled satisfactorily with aggregate diagnoses although with limited per sample accuracy and, thereby, reflects and confirms the modelling complexity and the challenges of modelling gene expression as previously reported.


Subject(s)
Kidney Transplantation , Formaldehyde , Graft Rejection , Humans
7.
S Afr Med J ; 109(3): 154-158, 2019 Feb 26.
Article in English | MEDLINE | ID: mdl-30834870

ABSTRACT

BACKGROUND: Low-cost, portable fingertip pulse oximeters are widely available to health professionals and the public. They are often not tested to International Organization for Standardization standards, or only undergo accuracy studies in healthy volunteers under ideal laboratory conditions. OBJECTIVES: To pragmatically evaluate the agreement between one such device and a conventional bedside pulse oximeter in a clinical setting, in patients with varied comorbidities and skin pigmentations. METHODS: A single-centre equipment comparison study was conducted. Simultaneous measurements were obtained in 220 patients with both a Contec CMS50D Fingertip Pulse Oximeter and a Nihon Kohden Life Scope MU-631 RK conventional bedside monitor. Peripheral oxygen saturations (SpO2) and pulse rates were documented, and patients' skin tone was recorded using the Fitzpatrick scale. Data were assessed using a Bland-Altman analysis with bias, precision and limits of agreement (LOA) calculated with 95% confidence intervals (CIs). A priori acceptability for LOA was determined to be 3%, in keeping with international standards. RESULTS: The mean difference (therefore bias) between the conventional and fingertip oximeters for all data was -0.55% (95% CI -0.73 - -0.36). Upper and lower limits of agreement were 2.16% (95% CI 1.84 - 2.47) and -3.25% (95% CI -3.56 - -2.94). Regression analysis demonstrated worsening agreement with decreasing SpO2. When samples were separated into 'normal' (SpO2≥93%) and 'hypoxaemic' (SpO2 <93%) groups, the normal range displayed acceptable agreement between the two oximeters (bias -0.20% with LOA 2.20 - -2.27), while the hypoxaemic group fell outside the study's a priori limits. Heart rate measurements had a mean difference of -0.43 bpm (LOA -5.61 - 4.76). The study was not powered to detect differences among the skin tones, but demonstrated no trend for this parameter to alter the SpO2measurements. CONCLUSIONS: During normoxia, portable fingertip pulse oximeters are reliable indicators of SpO2and pulse rates in patients with various comorbidities in a pragmatic clinical context. However, they display worsening agreement with conventional pulse oximeters during hypoxaemia. Skin tones do not appear to affect measurements adversely.


Subject(s)
Equipment Design , Oximetry/instrumentation , Perioperative Care/instrumentation , Point-of-Care Systems , Adolescent , Adult , Aged , Aged, 80 and over , Female , Fingers , Healthy Volunteers , Humans , Male , Middle Aged , Prospective Studies , Young Adult
8.
Am J Transplant ; 18(6): 1328-1339, 2018 06.
Article in English | MEDLINE | ID: mdl-29288556

ABSTRACT

Tolerance induction to prevent allograft rejection is a long-standing clinical goal. However, convincing and dependable tolerance identification remains elusive. Hypothesizing that intragraft RNA expression is informative in both rejection and tolerance, we profile intrarenal allograft RNA expression in a mixed chimerism renal allograft model of cynomolgus monkeys and identify biologically significant tolerance. Analysis of 67 genes identified 3 dominant factors, each with a different pattern of gene expressions, relating to T cell-mediated rejection (TCMR), chronic antibody-mediated rejection (CAMR), or Tolerance. Clustering these 3 factors created 9 groups. One of the 9 clustered groups, the Tolerance cluster, showed the lowest probability of terminal rejection, the longest duration of allograft survival, and the lowest relative risk of terminal rejection. The Tolerance factor consists of a novel set of gene expressions including cytokine and immunoregulatory genes adding mechanistic insights into tolerance. The Tolerance factor could not be identified within current pathologic diagnostic categories. The TCMR and CAMR factors are dominant to the Tolerance factor, causing rejection even if the Tolerance factor is present. These 3 factors determine the probability of terminal rejection or tolerance. This novel a posteriori approach permits identification of pathways of rejection, including tolerance.


Subject(s)
Gene Expression Profiling , Graft Rejection/immunology , Kidney Transplantation , Primates/immunology , RNA/genetics , Transplantation Tolerance , Animals , Graft Survival/immunology , Immunosuppressive Agents/therapeutic use , Macaca fascicularis
9.
Am J Transplant ; 18(6): 1340-1350, 2018 06.
Article in English | MEDLINE | ID: mdl-29286578

ABSTRACT

RNA transcript expression estimates are a promising method to study the mechanisms and classification of renal allograft rejections. Here we use the Nanostring platform to profile RNA expression in renal allografts in a nonhuman primate (NHP), the Cynomolgus monkey. We analyzed protocol and indication 278 archival renal allograft samples, both protocol and indication from 76 animals with diagnoses of chronic antibody-mediated rejection (CAMR), acute cellular rejection (TCMR), and MIXED (both CAMR and TCMR), plus normals and samples with no pathological rejection using a Cynomolgus-specific probe set of 67 genes. Analysis identified RNA expression heterogeneity of endothelial and NK genes within CAMR and TCMR, including the stages of CAMR. Three factors were partitioned into additional groups. One group with the longest allograft survival time is pure CAMR without NK or CD3. Three mixed groups show variation in NK and CD3. TCMR was split into 2 groups with variation in NK genes. Additional validation of the complete gene-set correlated many of the genes with diagnoses of CAMR, MIXED, and TCMR rejections and with Banff histologic criteria defined in human subjects. These NHP data demonstrate the utility of RNA expression profiling to identify additional heterogeneity of endothelial and NK RNA gene expressions.


Subject(s)
Endothelium/metabolism , Gene Expression Profiling , Kidney Transplantation , Killer Cells, Natural/metabolism , Animals , Graft Rejection , Graft Survival , Macaca fascicularis , Transplantation, Homologous
10.
Am J Transplant ; 17(11): 2841-2850, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28444814

ABSTRACT

Molecular testing represents a promising adjunct for the diagnosis of antibody-mediated rejection (AMR). Here, we apply a novel gene expression platform in sequential formalin-fixed paraffin-embedded samples from nonhuman primate (NHP) renal transplants. We analyzed 34 previously described gene transcripts related to AMR in humans in 197 archival NHP samples, including 102 from recipients that developed chronic AMR, 80 from recipients without AMR, and 15 normal native nephrectomies. Three endothelial genes (VWF, DARC, and CAV1), derived from 10-fold cross-validation receiver operating characteristic curve analysis, demonstrated excellent discrimination between AMR and non-AMR samples (area under the curve = 0.92). This three-gene set correlated with classic features of AMR, including glomerulitis, capillaritis, glomerulopathy, C4d deposition, and DSAs (r = 0.39-0.63, p < 0.001). Principal component analysis confirmed the association between three-gene set expression and AMR and highlighted the ambiguity of v lesions and ptc lesions between AMR and T cell-mediated rejection (TCMR). Elevated three-gene set expression corresponded with the development of immunopathological evidence of rejection and often preceded it. Many recipients demonstrated mixed AMR and TCMR, suggesting that this represents the natural pattern of rejection. These data provide NHP animal model validation of recent updates to the Banff classification including the assessment of molecular markers for diagnosing AMR.


Subject(s)
Graft Rejection/etiology , Graft Survival/immunology , Isoantibodies/adverse effects , Kidney Transplantation/adverse effects , Allografts , Animals , Biomarkers/analysis , Chronic Disease , Gene Expression Profiling , Graft Rejection/diagnosis , Humans , Macaca fascicularis , Phenotype , ROC Curve , Retrospective Studies
11.
Eur J Trauma Emerg Surg ; 43(2): 265-272, 2017 Apr.
Article in English | MEDLINE | ID: mdl-26869519

ABSTRACT

PURPOSE: Surgical disease is being increasingly recognized as a significant health burden in Africa. Efforts have been made to describe surgical disease and capacity at the district hospital level. Little is known about patterns seen at regional hospitals supporting the district hospital network. METHODS: This retrospective study was conducted at Uganda's Soroti Regional Referral Hospital, serving eight districts. Data were collected from July 2010 to March 2012 using operative and inpatient records as available. Univariate and bivariate analyses were performed to explore patterns of procedures performed and in-patient diagnoses. RESULTS: There were 8511 procedures recorded in the operative log between July 2010 and June 2011, averaging 709 per month. Caesarian sections (41 %), dilation and evacuations (28 %), and laparotomies (19 %) were most frequent. Referrals to Soroti averaged 260 per month, while transfers out averaged 5 patients per month. Inpatient records documented 2949 surgically related diagnoses between July 2010 and May 2011. In patients >4 years old, 21 % of mortality was due to surgical disease, 29 % of which was trauma-related. Women comprised 80 % of violent injury. Common hospital record elements, such as demographic data, important clinical information, and operative notes were absent from these data sources. CONCLUSIONS: The World Health Assembly recently recognized strengthening of first referral hospitals as a crucial element to achieving universal health coverage. Inconsistencies in recordkeeping despite the large volume of surgical disease suggest that sustainable surveillance systems and capacity building at the referral hospital level are potential building blocks to improving access to surgical care.


Subject(s)
Health Services Accessibility/organization & administration , Health Services Research , Hospitals, Rural/statistics & numerical data , Referral and Consultation/organization & administration , Surgical Procedures, Operative/statistics & numerical data , Age Distribution , Child, Preschool , Developing Countries , Female , Health Services Needs and Demand , Hospitals, District , Hospitals, Rural/organization & administration , Humans , Infant , Infant, Newborn , Male , Referral and Consultation/statistics & numerical data , Retrospective Studies , Surgery Department, Hospital , Uganda/epidemiology , Workforce
12.
Am J Transplant ; 17(7): 1791-1801, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28009476

ABSTRACT

One of the key unmet needs to improve long-term outcomes of heart transplantation is to develop accurate, noninvasive, and practical diagnostic tools to detect transplant rejection. Early intragraft inflammation and endothelial cell injuries occur prior to advanced transplant rejection. We developed a novel diagnostic imaging platform to detect early declines in microvascular perfusion (MP) of cardiac transplants using contrast-enhanced ultrasonography (CEUS). The efficacy of CEUS in detecting transplant rejection was tested in a murine model of heart transplants, a standard preclinical model of solid organ transplant. As compared to the syngeneic groups, a progressive decline in MP was demonstrated in the allografts undergoing acute transplant rejection (40%, 64%, and 92% on days 4, 6, and 8 posttransplantation, respectively) and chronic rejection (33%, 33%, and 92% on days 5, 14, and 30 posttransplantation, respectively). Our perfusion studies showed restoration of MP following antirejection therapy, highlighting its potential to help monitor efficacy of antirejection therapy. Our data suggest that early endothelial cell injury and platelet aggregation contributed to the early MP decline observed in the allografts. High-resolution MP mapping may allow for noninvasive detection of heart transplant rejection. The data presented have the potential to help in the development of next-generation imaging approaches to diagnose transplant rejection.


Subject(s)
Disease Models, Animal , Graft Rejection/diagnosis , Heart Transplantation/adverse effects , Ultrasonography/methods , Animals , Contrast Media , Graft Rejection/diagnostic imaging , Graft Rejection/etiology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Transplantation, Homologous
13.
Am J Transplant ; 17(1): 42-53, 2017 01.
Article in English | MEDLINE | ID: mdl-27862968

ABSTRACT

The 13th Banff Conference on Allograft Pathology was held in Vancouver, British Columbia, Canada from October 5 to 10, 2015. The cardiac session was devoted to current diagnostic issues in heart transplantation with a focus on antibody-mediated rejection (AMR) and small vessel arteriopathy. Specific topics included the strengths and limitations of the current rejection grading system, the central role of microvascular injury in AMR and approaches to semiquantitative assessment of histopathologic and immunophenotypic indicators, the role of AMR in the development of cardiac allograft vasculopathy, the important role of serologic antibody detection in the management of transplant recipients, and the potential application of new molecular approaches to the elucidation of the pathophysiology of AMR and potential for improving the current diagnostic system. Herein we summarize the key points from the presentations, the comprehensive, open and wide-ranging multidisciplinary discussion that was generated, and considerations for future endeavors.


Subject(s)
Graft Rejection/pathology , Isoantibodies/immunology , Organ Transplantation/adverse effects , Practice Guidelines as Topic/standards , Graft Rejection/etiology , Humans , Isoantibodies/blood , Research Report , Transplantation, Homologous
14.
Am J Transplant ; 17(3): 646-656, 2017 03.
Article in English | MEDLINE | ID: mdl-27501203

ABSTRACT

The lack of a reliable immunosuppressive regimen that effectively suppresses both renal and islet allograft rejection without islet toxicity hampers a wider clinical application of simultaneous islet-kidney transplantation (SIK). Seven MHC-mismatched SIKs were performed in diabetic cynomolgus monkeys. Two recipients received rabbit antithymocyte globulin (ATG) induction followed by daily tacrolimus and rapamycin (ATG/Tac/Rapa), and five recipients were treated with anti-CD40 monoclonal antibody (mAb) and rapamycin (aCD40/Rapa). Anti-inflammatory therapy, including anti-interleukin-6 receptor mAb and anti-tumor necrosis factor-α mAb, was given in both groups. The ATG/Tac/Rapa recipients failed to achieve long-term islet allograft survival (19 and 26 days) due to poor islet engraftment and cytomegalovirus pneumonia. In contrast, the aCD40/Rapa regimen provided long-term islet and kidney allograft survival (90, 94, >120, >120, and >120 days), with only one recipient developing evidence of allograft rejection. The aCD40/Rapa regimen was also tested in four kidney-alone transplant recipients. All four recipients achieved long-term renal allograft survival (100% at day 120), which was superior to renal allograft survival (62.9% at day 120) with triple immunosuppressive regimen (tacrolimus, mycophenolate mofetil, and steroids). The combination of anti-CD40 mAb and rapamycin is an effective and nontoxic immunosuppressive regimen that uses only clinically available agents for kidney and islet recipients.


Subject(s)
Antilymphocyte Serum/therapeutic use , Diabetes Mellitus/surgery , Graft Survival/drug effects , Islets of Langerhans Transplantation , Kidney Transplantation , Sirolimus/therapeutic use , Animals , CD40 Ligand/antagonists & inhibitors , Drug Therapy, Combination , Immune Tolerance , Immunosuppressive Agents/therapeutic use , Macaca fascicularis , Rabbits , Transplantation, Homologous
15.
Am J Transplant ; 15(12): 3055-66, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26190648

ABSTRACT

Tolerance of allografts achieved in mice via stable mixed hematopoietic chimerism relies essentially on continuous elimination of developing alloreactive T cells in the thymus (central deletion). Conversely, while only transient mixed chimerism is observed in nonhuman primates and patients, it is sufficient to ensure tolerance of kidney allografts. In this setting, it is likely that tolerance depends on peripheral regulatory mechanisms rather than thymic deletion. This implies that, in primates, upsetting the balance between inflammatory and regulatory alloimmunity could abolish tolerance and trigger the rejection of previously accepted renal allografts. In this study, six monkeys that were treated with a mixed chimerism protocol and had accepted a kidney allograft for periods of 1-10 years after withdrawal of immunosuppression received subcutaneous injections of IL-2 cytokine (0.6-3 × 10(6) IU/m(2) ). This resulted in rapid rejection of previously tolerated renal transplants and was associated with an expansion and reactivation of alloreactive pro-inflammatory memory T cells in the host's lymphoid organs and in the graft. This phenomenon was prevented by anti-CD8 antibody treatment. Finally, this process was reversible in that cessation of IL-2 administration aborted the rejection process and restored normal kidney graft function.


Subject(s)
Graft Rejection/etiology , Interleukin-2/administration & dosage , Kidney Failure, Chronic/surgery , Kidney Transplantation , Postoperative Complications , Transplantation Chimera/immunology , Transplantation Tolerance/immunology , Animals , Bone Marrow Transplantation , Chimerism , Glomerular Filtration Rate , Graft Rejection/drug therapy , Graft Survival , Injections, Subcutaneous , Kidney Function Tests , Macaca fascicularis , Mice , Risk Factors , Transplantation Conditioning , Transplantation, Homologous
16.
Am J Transplant ; 15(10): 2739-49, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26014796

ABSTRACT

The full potential of islet transplantation will only be realized through the development of tolerogenic regimens that obviate the need for maintenance immunosuppression. Here, we report an immunotherapy regimen that combines 1-ethyl-3-(3'-dimethylaminopropyl)-carbodiimide (ECDI)-treated donor lymphoid cell infusion (ECDI-DLI) with thymoglobulin, anti-interleukin-6 receptor antibody and rapamycin to achieve prolonged allogeneic islet graft survival in a nonhuman primate (NHP) model. Prolonged graft survival is associated with Treg expansion, donor-specific T cell hyporesponsiveness and a transient absence of donor-specific alloantibody production during the period of graft survival. This regimen shows promise for clinical translation.


Subject(s)
Graft Rejection/prevention & control , Graft Survival/immunology , Immunosuppressive Agents/therapeutic use , Islets of Langerhans Transplantation/immunology , Isoantigens/immunology , Lymphocyte Transfusion/methods , T-Lymphocytes, Regulatory/immunology , Animals , Drug Therapy, Combination , Graft Rejection/immunology , Pilot Projects , Primates
17.
Am J Transplant ; 15(8): 2231-9, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25904524

ABSTRACT

While the induction of transient mixed chimerism has tolerized MHC-mismatched renal grafts in nonhuman primates and patients, this approach has not been successful for more immunogenic organs. Here, we describe a modified delayed-tolerance-induction protocol resulting in three out of four monkeys achieving long-term lung allograft survival without ongoing immunosuppression. Two of the tolerant monkeys displayed stable mixed lymphoid chimerism, and the other showed transient chimerism. Serial biopsies and post-mortem specimens from the tolerant monkeys revealed no signs of chronic rejection. The tolerant recipients also exhibited T cell unresponsiveness and a lack of alloantibody. This is the first report of durable mixed chimerism and successful tolerance induction of MHC-mismatched lungs in primates.


Subject(s)
Chimerism , Hematopoiesis , Lung Transplantation , Animals , Macaca fascicularis , Transplantation, Homologous
18.
Am J Transplant ; 15(5): 1415-20, 2015 May.
Article in English | MEDLINE | ID: mdl-25772308

ABSTRACT

Despite advances in surgical technique and clinical care, lung transplantation still remains a short-term solution for the treatment of end-stage lung disease. To date, there has been limited experience in experimental lung transplantation using nonhuman primate models. Therefore, we have endeavored to develop a long-term, nonhuman primate model of orthotopic lung transplantation for the ultimate purpose of designing protocols to induce tolerance of lung grafts. Here, we report our initial results in developing this model and our observation that the nonhuman primate lung is particularly prone to rejection. This propensity toward rejection may be a consequence of 1) upregulated nonspecific inflammation, and 2) a larger number of pre-existing alloreactive memory T cells, leading to augmented deleterious immune responses. Our data show that triple-drug immunosuppression mimicking clinical practice is not sufficient to prevent acute rejection in nonhuman primate lung transplantation. The addition of horse-derived anti-thymocyte globulin and a monoclonal antibody to the IL-6 receptor allowed six out of six lung recipients to be free of rejection for over 120 days.


Subject(s)
Lung Diseases/surgery , Lung Transplantation , Animals , Antilymphocyte Serum/chemistry , Histocompatibility Testing , Horses , Immune Tolerance , Immunologic Memory/immunology , Immunosuppression Therapy , Inflammation/immunology , Lung/pathology , Macaca fascicularis , Major Histocompatibility Complex , Models, Animal , Receptors, Interleukin-6/metabolism , T-Lymphocytes/cytology , Transplantation, Autologous , Transplantation, Homologous
19.
Am J Transplant ; 14(12): 2704-12, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25394378

ABSTRACT

We have previously reported successful induction of renal allograft tolerance via a mixed chimerism approach in nonhuman primates. In those studies, we found that costimulatory blockade with anti-CD154 mAb was an effective adjunctive therapy for induction of renal allograft tolerance. However, since anti-CD154 mAb is not clinically available, we have evaluated CTLA4Ig as an alternative agent for effecting costimulation blockade in this treatment protocol. Two CTLA4Igs, abatacept and belatacept, were substituted for anti-CD154 mAb in the conditioning regimen (low dose total body irradiation, thymic irradiation, anti-thymocyte globulin and a 1-month posttransplant course of cyclosporine [CyA]). Three recipients treated with the abatacept regimen failed to develop comparable lymphoid chimerism to that achieved with anti-CD154 mAb treatment and these recipients rejected their kidney allografts early. With the belatacept regimen, four of five recipients developed chimerism and three of these achieved long-term renal allograft survival (>861, >796 and >378 days) without maintenance immunosuppression. Neither chimerism nor long-term allograft survival were achieved in two recipients treated with the belatacept regimen but with a lower, subtherapeutic dose of CyA. This study indicates that CD28/B7 blockade with belatacept can provide a clinically applicable alternative to anti-CD154 mAb for promoting chimerism and renal allograft tolerance.


Subject(s)
Bone Marrow Transplantation , Chimerism , Immunoconjugates/administration & dosage , Immunosuppressive Agents/administration & dosage , Kidney Diseases/immunology , Kidney Transplantation , Transplantation Tolerance/immunology , Abatacept , Animals , Antibodies, Monoclonal/administration & dosage , Flow Cytometry , Graft Rejection/immunology , Graft Rejection/prevention & control , Graft Survival/immunology , Kidney Diseases/therapy , Kidney Function Tests , Macaca fascicularis , Tissue Donors , Transplantation Chimera/immunology , Transplantation Conditioning , Transplantation, Homologous , Whole-Body Irradiation
20.
Am J Transplant ; 14(7): 1599-611, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24903438

ABSTRACT

We report here the long-term results of HLA-mismatched kidney transplantation without maintenance immunosuppression (IS) in 10 subjects following combined kidney and bone marrow transplantation. All subjects were treated with nonmyeloablative conditioning and an 8- to 14-month course of calcineurin inhibitor with or without rituximab. All 10 subjects developed transient chimerism, and in seven of these, IS was successfully discontinued for 4 or more years. Currently, four subjects remain IS free for periods of 4.5-11.4 years, while three required reinstitution of IS after 5-8 years due to recurrence of original disease or chronic antibody-mediated rejection. Of the 10 renal allografts, three failed due to thrombotic microangiopathy or rejection. When compared with 21 immunologically similar living donor kidney recipients treated with conventional IS, the long-term IS-free survivors developed significantly fewer posttransplant complications. Although most recipients treated with none or two doses of rituximab developed donor-specific antibody (DSA), no DSA was detected in recipients treated with four doses of rituximab. Although further revisions of the current conditioning regimen are planned in order to improve consistency of the results, this study shows that long-term stable kidney allograft survival without maintenance IS can be achieved following transient mixed chimerism induction.


Subject(s)
Bone Marrow Transplantation , Graft Survival/immunology , Immunosuppression Therapy , Kidney Diseases/surgery , Kidney Transplantation , Postoperative Complications , Transplantation Tolerance/immunology , Adult , Female , Follow-Up Studies , Humans , Immunosuppressive Agents/therapeutic use , Isoantibodies/blood , Kidney Diseases/immunology , Male , Middle Aged , Prognosis , Transplantation Chimera , Transplantation Conditioning , Transplantation, Homologous , Young Adult
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