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ABSTRACT: The role of non-complement activating antibodies (ncAbs) to mismatched donor human leukocyte antigen (HLA) in the pathogenesis of chronic lung rejection is not known. We used a murine model of obliterative airway disease (OAD) induced by Abs to major histocompatibility major histocompatibility complex (MHC) class I and serum from donor-specific Abs developed in human lung transplant (LTx) recipients to test the role of ncAbs in the development of OAD and bronchiolitis obliterans syndrome (BOS).
Anti-MHC ncAbs were administered intrabronchially in B.10 mice or in C3 knockout (C3KO) mice. Lungs were analyzed by histopathology. Lymphocytes secreting interleukin (IL)-17, interferon-γ, or IL-10 to collagen V and K-α1 tubulin (Kα1T) were enumerated by enzyme-linked immunospot assay. Serum antibodies to collagen V and Kα1T were determined by enzyme-linked immunosorbent assay. Cytokine and growth factor expression in lungs was determined by real-time polymerase chain reaction. Donor-specific Abs from patients with BOS and control BOS-negative LTx recipients were analyzed by C1q assay.
Administration of ncAbs in B.10 mice or C3KO resulted in OAD lesions. There were significant increases in IL-17- and interferon-γ-secreting cells to collagen V and Kα1T, along with serum Abs to these antigens. There was also augmented expression of monocyte chemotactic protein-1, IL-6, IL-1β, vascular endothelial growth factor, transforming growth factor-β, and fibroblastic growth factor in mice administered ncAbs by Day 3. Among 5 LTx recipients with BOS, only 1 had C1q binding donor-specific Abs.
Complement activation by Abs to MHC class I is not required for development of OAD and human BOS. Therefore, anti-MHC binding to epithelial and endothelial cells can directly activate pro-fibrotic and pro-inflammatory cascades leading to immune response to self-antigens and chronic rejection.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 09/2012; 31(11):1214-22. · 3.54 Impact Factor
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ABSTRACT: Alloimmune-induced immune responses to self-antigens are involved in the development of chronic lung allograft rejection. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) have been shown to modulate autoimmune diseases. This study investigated the effect of modulation of the renin angiotensin aldosterone system (RAAS) a murine model of obliterative airways disease (OAD).
Major histocompatibility complex (MHC) class I antibodies were administered intrabronchially to C57Bl/6 mice on Days 1, 2, 3, and 6, and weekly thereafter. ACEI/ARB (10 mg/kg/day) were administered in water 5 days before antibody administration. Antibodies were analyzed by enzyme-linked immunosorbent assay, cytokines by Luminex, Th-frequency by enzyme-linked immunosorbent spot, and transcription factors by Western blotting and real-time polymerase chain reaction.
Significant decreases (50%-70%) in airway lesions and fibrous deposition were noted in lungs at Day 30 in the animals administered ACEI and ARB vs controls. Antibody concentrations to self-antigens also decreased from 14 ± 21 to 62 ± 18 μg/ml for collagen V and from 263 ± 43 to 84 ± 28 μg/ml for K-α1 tubulin. Th-precursor frequency and cytokine analysis showed increased interleukin (IL)-10 (3-fold increase) and decreased levels of IL-6 (3.4-fold) and IL-17 (4-fold decrease; p < 0.05) in ACEI and ARB groups. There was also messenger RNA level downregulation of tumor necrosis factor-α (8.6-fold) and p38/mitogen-activated protein (MAP)kinase (3.1-fold) in the treatment groups.
Our results demonstrate that modulation of RAAS leads to downregulation of IL-17 through tumor necrosis factor-α-dependant IL-6 through p38/MAPKinase pathway and thus abrogation of anti-MHC-induced OAD.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 01/2012; 31(4):419-26. · 3.54 Impact Factor
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Deepti Saini,
Joseph Weber,
Sabarinathan Ramachandran,
Donna Phelan,
Venkataswarup Tiriveedhi,
Michael Liu,
Nancy Steward,
Aviva Aloush, Ramsey Hachem,
Elbert Trulock,
Bryan Meyers,
G Alexander Patterson,
Thalachallour Mohanakumar
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ABSTRACT: Bronchiolitis obliterans syndrome (BOS) is a major cause of morbidity and mortality after lung transplantation (LTx). We sought to better understand the relationship between alloimmune responses and autoimmunity and, subsequently, how autoimmunity leads to chronic rejection.
We analyzed the development of donor-specific antibodies (Abs) in LTx by flow PRA and the development of Abs to K-α1 tubulin (K-α1T) and collagen V (ColV) by ELISA. The frequency of K-α1T- and ColV-specific T cells that secrete IFN-γ, IL-17 and IL-10 in LTx recipients was measured by ELISPOT.
In a retrospective analysis of 42 LTx recipients, we demonstrated a strong correlation between development of donor-specific anti-HLA Abs, Abs to self-antigens and BOS (p < 0.05). To test the hypothesis that alloimmunity is related to an immune response to self-antigens, we analyzed 103 LTx patients prospectively for the development of donor-specific Abs (DSA) and Abs to self-antigens. A total of 42.7% of recipients developed DSA and 30.1% developed Abs to K-α1T and ColV. Development of DSA preceded development of Abs to self-antigens. BOS(+) patients had higher frequency of T cells secreting IL-17 (p < 0.01) and IFN-γ (p < 0.05) with decreased IL-10 (p < 0.05) when compared with BOS(-) patients.
Based on these results we propose that alloimmune responses to donor HLA can induce autoimmune responses to airway epithelial self-antigens, characterized by activation of the IL-17 pathway. These immune responses to self-antigens along with alloimmunity contribute to the pathogenesis of BOS. Strategies to prevent development of autoimmunity may be play a key role in preventing the development of chronic rejection.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 03/2011; 30(6):624-31. · 3.54 Impact Factor
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ABSTRACT: This study aims to determine the role of antibodies to donor-mismatched human leukocyte antigen (HLA) developed during the post-transplant period in inducing defensins and their synergistic role in the pathogenesis of chronic rejection, bronchiolitis obliterans syndrome (BOS), after human lung transplantation (LTx).
Bronchoalveolar lavage (BAL) and serum from 21 BOS+ LTx patients were assayed for β-defensins human neutrophil peptides (HNP) 1-3 (enzyme-linked immunosorbent assay [ELISA]) and anti-HLA antibodies (Luminex, Luminex Corp, Austin, TX). Human airway epithelial cells (AEC) were treated with anti-HLA antibodies, HNP-1/2, or both, and the levels of β-defensin were measured by ELISA. Using a mouse model of obliterative airway disease induced by anti-major histocompatibility (MHC) class-I antibodies, we quantitatively and qualitatively determined neutrophil infiltration by myeloperoxidase (MPO) staining and activity by MPO assay, and defensin levels in the BAL.
In human LTx patients, higher defensin levels correlated with presence of circulating anti-HLA antibodies (p < 0.05). AEC treated with anti-HLA antibodies or HNP-1/2, produced β-defensin with synergistic effects in combination (612 ± 06 vs 520 ± 23 pg/ml anti-HLA antibody, or 590 ± 10 pg/ml for HNP treatment; p < 0.05). Neutrophil numbers (6-fold) and activity (5.5-fold) were higher in the lungs of mice treated with anti-MHC antibodies vs control. A 2-fold increase in α-defensin and β-defensin levels was also present in BAL on Day 5 after anti-MHC administrations.
Anti-HLA antibodies developed during the post-transplant period and α-defensins stimulated β-defensin production by epithelial cells, leading to increased cellular infiltration and inflammation. Chronic stimulation of epithelium by antibodies to MHC and resulting increased levels of defensins induce growth factor production and epithelial proliferation contributing to the development of chronic rejection after LTx.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 12/2010; 29(12):1330-6. · 3.54 Impact Factor
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ABSTRACT: Lower respiratory viral infections predispose to bronchiolitis obliterans syndrome (BOS). In addition, there is emerging evidence to support the role of autoimmunity in the pathogenesis of BOS. Because CD4(+)CD25(+)Foxp3(+) regulatory T-cells (Treg) control autoimmunity, we tested the hypothesis that respiratory virus-induced Treg dysfunction leads to BOS.
Treg frequency was monitored using flow cytometry. Apoptosis, cytokines, and antibodies were analyzed using annexin V assay, LUMINEX, and enzyme-linked immunosorbent assay, respectively. Murine studies were performed using the orthotopic tracheal transplant model.
(A) Human studies: Treg troughs (decrease >50% of baseline) were found in 13 (43.3%) of 30 lung transplant recipients. Treg isolated during troughs revealed increased apoptosis (37.8%). Patients with Treg troughs had increased prevalence of antibodies to self-antigens collagen type I (23.1% vs 5.8% pretrough), collagen V (7.7% vs 0%), and k-alpha tubulin (30.7% vs 11.7%, p < 0.01) at 6 months post-trough. Increased number of Treg troughs correlated with more rapid onset of BOS. (B) Murine studies: Infection of tracheal transplant recipients with murine parainfleunza sendai virus led to increased Treg apoptosis (50.5%) in the draining lymph nodes. Vaccination against sendai virus prior to transplant abrogated apoptosis of Treg. In vitro, sendai virus-infected, but not naive, tracheal epithelial cells demonstrated upregulation of FasL (>3.5-fold) and induction of co-cultured Treg apoptosis (5.6-fold increase).
Respiratory viral infections cause Treg apoptosis which leads to the development of de novo autoimmunity that may play a role in the pathogenesis of BOS.
The Annals of thoracic surgery 11/2010; 90(5):1637-44; discussion 1644. · 3.74 Impact Factor
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ABSTRACT: Primary graft dysfunction (PGD) is a known risk factor for bronchiolitis obliterans syndrome (BOS) after lung transplantation. Here, we report that preformed antibodies to self-antigens increase PGD risk and promote BOS.
Adult lung transplant recipients (n = 142) were included in the study. Primary graft dysfunction and BOS were diagnosed based on International Society for Heart and Lung Transplantation guidelines. Antibodies to self-antigens k-alpha-1 tubulin, collagen type V, and collagen I were quantitated using standardized enzyme-linked immunosorbent assays, and cytokines were analyzed using Luminex immunoassays (Biosource International, Camirillo, CA). Human leukocyte antigen (HLA) antibodies were measured using Flow-PRA (One Lambda, Canoga Park, CA).
Lung transplant recipients with pretransplant antibodies to self-antigens had increased risk of PGD (odds ratio 3.09, 95% confidence interval: 1.2 to 8.1, p = 0.02) compared with recipients without. Conversely, in patients with PGD, 34.7% were positive for pretransplant antibodies whereas in the PGD negative group, only 14.6% had antibodies (p = 0.03). Antibody positive patients demonstrated high levels of proinflammatory cytokines interleukin (IL)-1β (2.1-fold increase), IL-2 (3.0), IL-12 (2.5), IL-15 (3.0), and chemokines interferon-inducible protein-10 (3.9) and monocyte chemotactic protein-1 (3.1; p < 0.01 for all). On 5-year follow-up, patients without antibodies showed greater freedom from development of HLA antibodies compared with patients who had antibodies (class I: 67% versus 38%, p = 0.001; class II: 71% versus 41%, p < 0.001). Patients with pretransplant antibodies were found to have an independent relative risk of 2.3 (95% confidence interval: 1.7 to 4.5, p = 0.009) for developing BOS.
Presence of antibodies to self-antigens pretransplant increases the risk of PGD immediately after transplant period and BOS on long-term follow-up. Primary graft dysfunction is associated with an inflammatory cascade that augments the alloimmune (anti-HLA) response that predisposes to BOS.
The Annals of thoracic surgery 10/2010; 90(4):1094-101. · 3.74 Impact Factor
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ABSTRACT: The development of antibodies (Abs) to major histocompatibility (MHC) class I-related chain A (MICA) and human leukocyte antigen (HLA) and their role in the immunopathogenesis of chronic rejection (bronchiolitis obliterans syndrome [BOS]) after human lung transplantation (LTx) was analyzed. Sera from 80 LTx recipients were analyzed for anti-MICA and anti-HLA Abs using Luminex and flow PRA (panel reactive assay). Development of Abs either to MICA alone or MICA and HLA together significantly correlated (p < 0.01) with development of BOS. Kinetic analysis in the post-LTx period revealed that development of anti-HLA Abs (7.6 +/- 4.7 months) preceded the development of anti-MICA Abs (10.0 +/- 3.5 months). Abs to MICA alleles (*001 and *009) developed approximately 6 months after LTx and peak titers were present at the time of clinical diagnosis of BOS (16.3 +/- 2.7 months). The development of Abs to both MICA and HLA was strongly associated with the development of BOS thereby suggesting a synergistic effect. Furthermore, immune response to mismatched HLA can lead to development of Abs to other MHC related antigens expressed on the airway epithelial cells. Cumulatively, these immune responses contribute to the pathogenesis of chronic rejection following human LTx.
Human immunology 03/2010; 71(6):560-5. · 2.55 Impact Factor
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ABSTRACT: Lung donation after cardiac death (DCD) can enlarge the donor pool. Single-center reports have shown comparable outcomes after lung transplantation using conventional donors versus DCD in small numbers of patients.
We performed a retrospective review of DCD experience at a single lung transplant program using a prospective database.
Between January 2003 and April 2008, 293 lung transplantations were performed, including 11 bilateral transplantations (3.7%) using DCD lungs. Similar criteria were used to assess donor quality. The hospital mortality for DCD recipients was 2 of 11 (18%) and overall mortality was 4 of 11 (36%) by 18 months of follow-up. Seven DCD patients (64%) are alive with a median follow-up of 32 months. The DCD group was comparable to the control group in age and ischemic times. The 4 deaths, when compared with 7 DCD survivors, had longer ischemic time (293 minutes versus 232 minutes) and a higher incidence of nonlocal donors (3 of 4 versus 1 of 7).
At our center, early outcomes after DCD lung transplantations are somewhat inferior to those of series from other centers but approach national averages for conventional lung transplantation. Thus, DCD lung transplantation has the potential to increase the donor pool but must be offered cautiously.
The Annals of thoracic surgery 11/2009; 88(5):1609-14; discussion 1614-5. · 3.74 Impact Factor
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Ramsey R Hachem
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ABSTRACT: Rejection remains a common complication after lung transplantation and has adversely affected long-term outcomes. This manuscript reviews the various manifestations of rejection after lung transplantation and provides an update of recent developments.
The grading scheme for lymphocytic bronchiolitis was updated in 2007, and recent studies demonstrate that this disease is an important and independent risk factor for chronic rejection. Furthermore, a role for humoral immunity has become more apparent in recent years, although this role remains enigmatic in lung transplantation. Finally, a new subtype of bronchiolitis obliterans syndrome, termed neutrophilic reversible allograft dysfunction, has been proposed based on the response to treatment with azithromycin.
Acute rejection and lymphocytic bronchiolitis are major risk factors for chronic rejection, which remains the primary obstacle to better outcomes after lung transplantation.
Current opinion in organ transplantation 08/2009; 14(5):477-82. · 1.22 Impact Factor
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ABSTRACT: Diagnosis and therapy of chronic inflammatory lung disease is limited by the need for individualized biomarkers that provide insight into pathogenesis. Herein we show that mouse models of chronic obstructive lung disease exhibit an increase in lung chitinase production but cannot predict which chitinase family member may be equivalently increased in humans with corresponding lung disease. Moreover, we demonstrate that lung macrophage production of chitinase 1 is selectively increased in a subset of subjects with severe chronic obstructive pulmonary disease, and this increase is reflected in plasma levels. The findings provide a means to noninvasively track alternatively activated macrophages in chronic lung disease and thereby better differentiate molecular phenotypes in heterogeneous patient populations.
American Journal of Respiratory Cell and Molecular Biology 07/2009; 41(4):379-84. · 5.13 Impact Factor
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Chest 01/2009; 134(6):1340-3. · 5.25 Impact Factor
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ABSTRACT: Primary graft dysfunction (PGD) in the immediate post-lung transplant period strongly increases the risk of chronic rejection (broncholitis obliterans syndrome). Here, we hypothesized that PGD-induced inflammation augments alloimmunity, thereby predisposing to broncholitis obliterans syndrome.
Primary graft dysfunction and broncholitis obliterans syndrome were diagnosed according to the established International Society for Heart and Lung Transplantation criteria. Anti-human leukocyte antigen (HLA) alloantibodies were analyzed using Flow-PRA. Donor HLA class II-specific T cells were analyzed using interferon (IFN)-gamma ELISPOT. Serum levels of 25 cytokines and chemokines were measured using LUMINEX.
Of the 127 subjects, 29 (22.8%) had no PGD (grade 0), 42 (33.2%) had PGD-1, 36 (28.3%) had PGD-2, and 20 (15.7%) had PGD-3. Patients with PGD grades 1 to 3 (PGD(1-3)) had elevated proinflammatory mediators MCP-1, IP-10, interleukin (IL)-1 beta, IL-2, IFN-gamma, and IL-12 in the sera during the early posttransplant period compared with patients with PGD grade 0 (PGD(0)). On serial analysis, PGD(1-3) patients revealed increased development of de novo anti-HLA-II (5 years: 52.2% versus PGD(0) 13.5%, p = 0.008). However, no difference was found in anti-HLA-I alloantibody development (PGD(1-3) patients 48% versus PGD(0) 39.6%, p = 0.6). Furthermore, PGD(1-3) patients had increased frequency of donor HLA class II-specific CD4(+) T cells [(91.4 +/- 19.37) x 10(-6) versus (23.6 +/- 15.93) x 10(-6), p = 0.003].
Primary graft dysfunction induces proinflammatory cytokines that can upregulate donor HLA-II antigens on the allograft. Increased donor HLA-II expression along with PGD-induced allograft inflammation promotes the development of donor specific alloimmunity. This provides an important mechanistic link between early posttransplant lung allograft injury and reported association with broncholitis obliterans syndrome.
The Annals of thoracic surgery 08/2008; 86(1):189-95; discussion 196-7. · 3.74 Impact Factor
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Ramsey R Hachem
Southern medical journal 07/2008; 101(7):683-4. · 0.92 Impact Factor
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Chest 06/2008; 133(5):1256-9. · 5.25 Impact Factor
