Acute Rejection Therapy Research Articles

Lung Transplantation and Extracorporeal Photopheresis as Induction Therapy in Cystic Fibrosis Patients: Immune System Profile Changes

<h3>Purpose</h3> Acute rejection (AR), common during the first year after lung transplantation (LuTx), can trigger chronic rejection (CR), the leading cause of late morbidity and mortality of LuTx. Extracorporeal photopheresis (ECP) has emerged as a promising treatment for chronic rejection. Only few studies are focus on ECP as prophylactic therapy of AR and CR. This study aims to verify, in recipients affected by cystic fibrosis (CF), whether the induction therapy with ECP can decrease the rate of AR, in order to impact positively on CR (primary end point: survival, AR). The expected results are the reduction of AR episodes in its clinical and histopathological manifestations. <h3>Methods</h3> This is a pilot clinical trial on 20 CF lung-transplanted patients, randomize, 2 parallel arms: standard immunosuppressive therapy and ECP (ECP) vs standard immunosuppressive therapy alone (CTR). We investigated the effect of ECP by the evaluation of lymphocyte immunophenotype by multiplex essay (CD4 + and CD25 +), the cytokine profile, the leukocytes subsets (by flow cytometry) in blood and BAL at different time points. AR episodes and infections were recorded, as far as ECP-related adverse events. <h3>Results</h3> No differences were detected in terms of AR episodes. Treg cells were significantly increased in the ECP group at 3 weeks post LuTx, and this difference was more evident 1 year post LuTx . Th17 cells were diminished in the ECP group. The anti-inflammatory IL10-producing NKs were significantly increased in the ECP group. Cytokine profile, both in BAL and plasma obtained at defined time points shows that in ECP group pro-inflammatory cytokines were early reduced and anti-inflammatory cytokines were upregulated. <h3>Conclusion</h3> In FC lung transplanted patients ECP was well tolerated without increasing in opportunistic infections. Its tolerogenic effect was not pointed out in terms of AR episodes, but has been confirmed in the immunological setting of ECP patients vs control: it prevents decline in Treg and NK observed with standard immunosuppressive drugs, with higher expression of anti-inflammatory cytokines (Il10, Il1RA) and less pro-inflammatory ones (Il1beta, Il6). Its effect is more evident months after the end of ECP treatment. The schedule of ECP prophylactic treatment has to be tested in an ampler cohort in order to reach its best immunomodulatory effect.

Extracorporeal Photopheresis With Low-Dose Immunosuppression in High-Risk Heart Transplant Patients-A Pilot Study.

In severely ill patients undergoing urgent heart transplant (HTX), immunosuppression carries high risks of infection, malignancy, and death. Low-dose immunosuppressive protocols have higher rejection rates. We combined extracorporeal photopheresis (ECP), an established therapy for acute rejection, with reduced-intensity immunosuppression. Twenty-eight high-risk patients (13 with high risk of infection due to infection at the time of transplant, 7 bridging to transplant via extracorporeal membrane oxygenation, 8 with high risk of malignancy) were treated, without induction therapy. Prophylactic ECP for 6 months (24 procedures) was initiated immediately postoperatively. Immunosuppression consisted of low-dose tacrolimus (8–10 ng/ml, months 1–6; 5–8 ng/ml, >6 months) with delayed start; mycophenolate mofetil (MMF); and low maintenance steroid with delayed start (POD 7) and tapering in the first year. One-year survival was 88.5%. Three patients died from infection (POD 12, 51, 351), and one from recurrence of cancer (POD 400). Incidence of severe infection was 17.9% (n = 5, respiratory tract). Within the first year, antibody-mediated rejection was detected in one patient (3.6%) and acute cellular rejection in four (14.3%). ECP with reduced-intensity immunosuppression is safe and effective in avoiding allograft rejection in HTX recipients with risk of severe infection or cancer recurrence.

MO995DO THE TIMELINE AND SPECTRUM OF INFECTIONS CHANGE AFTER ANTI-REJECTION THERAPY IN KIDNEY TRANSPLANT RECIPIENTS?

Abstract Background and Aims The infections in kidney transplant recipients has been well defined. The timeline of infections and type of infection among patients who received anti-rejection therapy for acute rejection when compared to the patients who did not develop an acute rejection. Method Renal transplant recipients with post-transplant median follow up of four years from July 2009-June 2018 were included in a retrospective cohort study at a tertiary care hospital. Demographic characteristics, biopsy proven rejections, infections and graft and patient outcome were collected from transplant records and the hospital clinical workstation. Early and late acute rejections were defined as less than and more than 3 months respectively. The rates of various infections, type and time to develop an infection in the acute rejection group were compared with the patients who did not develop any rejection. Results A total of 794 patients underwent kidney transplant during the study with mean age of 35.5±12 years and 78% being male. Two hundred and eight four patients (35.8 %) had one or more biopsy proven rejections during the median follow up of 48 months (IQR 28,77). 213 patients (75%) developed early acute rejection (less than 3 months) while the remainder developed late acute rejection. The median time to develop the first acute rejection was 12 days (IQR 6,93.3). Majority of the patients (176, 62%) developed biopsy proven acute cellular rejection, 77 patients (27.1%) acute antibody mediated rejection and rest (10.9%) either mixed or borderline rejection who were treated. The proportion of BKV infection and infective diarrhea were more in rejection group when compared to no rejection group which was statistically significant (refer Table 1). At follow up, the patients who developed rejection had more graft loss (p value 0.010) but no increase in mortality. The predictors of infection among the patients who received anti-rejection therapy were identified. The median time to develop any infection in both groups were also compared. The spectrum of infections and outcome following early and late rejections were compared. Subgroup analysis was done to look at the eGFR, proteinuria trend, graft outcomes in patients with no rejection, rejection without any infection at follow up and rejection with any infection at follow up. The effect of type of anti-rejection therapy on spectrum of infections was also studied. Conclusion This is one of the few studies which looked at the effect of anti-rejection therapy in kidney transplant recipients. Anti-rejection treatment received post kidney transplant resulted in increased rates of BKV infection and infective diarrhea. Patients with acute rejection had more graft loss during follow up with no significant effect on mortality.

The Role of Tacrolimus Nanomicelles in Acute Rejection After Liver Transplantation in Rats.

Although there is some progress in immunosuppressive therapy of acute rejection, there is still a lack of standardized diagnosis and treatment. For the acute rejection after liver transplantation, there is still a lack of an exact treatment at this stage. Tacrolimus (TAC) side effects will also affect the survival rate and quality of life of recipients after transplantation to a large extent. Rat orthotopic liver transplantation model was established and divided into three groups. In the tolerance group, Brown Norway (BN) to Lewis liver transplantation was used; in the rejection group, Lewis to BN liver transplantation was used; in the TAC group, TAC was injected after operation on the basis of establishing rejection model. The expression of GITRL in Kupffer cells and the change of cytokines were detected 7 days after operation. In this study, the animal model of acute rejection of rat liver transplantation was established to simulate the clinical allogeneic liver transplantation, and the important role of TAC in the acute rejection of rat liver transplantation was evaluated.

Immunosuppressive Management of Pediatric Kidney Transplant Recipients.

Kidney transplantation is a preferable treatment of children with end-stage kidney disease. All kidney transplant recipients, including pediatric need immunosuppressive medications to prevent rejection episodes and graft loss. Induction therapy is used temporarily only immediately following transplantation while maintenance immunosuppressive drugs are started and given long-term. There is currently no consensus regarding the use of induction therapy in children; its use should be decided based on the immunological risk of the child. The recent progress shows that the recommended strategy is to use as maintenance immunosuppressive therapy a combination of a calcineurin inhibitor (preferably tacrolimus) with an antiproliferative drug (preferably mycophenolate mofetil) with steroids that can be withdrawn early or late in low-risk children. The mTOR-inhibitors (sirolimus, everolimus) are used rarely in pediatrics because of common side effects and no evidence of a benefit over calcineurin inhibitors. The use of calcineurin inhibitors, mycophenolate, and mTOR-inhibitors should be followed by therapeutic drug monitoring. Immunosuppressive therapy of acute rejection consists of high-dose steroids and/or anti-lymphocyte antibodies (T-cell mediated rejection) or plasma exchange, intravenous immunoglobulines and/or rituximab (antibodymediated rejection). The future strategies for research are mainly precise characterisation of children needing induction therapy, more specific indications for mTOR-inhibitors and for the far future, the possibility to reach the immuno tolerance.

Mesenchymal stem cells transfected with sFgl2 inhibit the acute rejection of heart transplantation in mice by regulating macrophage activation

BackgroundMesenchymal stem cells (MSCs) have become a promising candidate for cell-based immune therapy for acute rejection (AR) after heart transplantation due to possessing immunomodulatory properties. In this study, we evaluated the efficacy of soluble fibronectin-like protein 2 (sFgl2) overexpressing mesenchymal stem cells (sFgl2-MSCs) in inhibiting AR of heart transplantation in mice by regulating immune tolerance through inducing M2 phenotype macrophage polarization.Methods and resultsThe sFgl2, a novel immunomodulatory factor secreted by regulatory T cells, was transfected into MSCs to enhance their immunosuppressive functions. After being co-cultured for 72 h, the sFgl2-MSCs inhibited M1 polarization whereas promoted M2 of polarization macrophages through STAT1 and NF-κB pathways in vitro. Besides, the sFgl2-MSCs significantly enhanced the migration and phagocytosis ability of macrophages stimulated with interferon-γ (IFN-γ) and lipopolysaccharide (LPS). Further, the application potential of sFgl2-MSCs in AR treatment was demonstrated by heterotopic cardiac transplantation in mice. The tissue damage and macrophage infiltration were evaluated by H&E and immunohistochemistry staining, and the secretion of inflammatory cytokines was analyzed by ELISA. The results showed that sFgl2-MSCs injected intravenously were able to locate in the graft, promote the M2 polarization of macrophages in vivo, regulate the local and systemic immune response, significantly protect tissues from damaging, and finally prolonged the survival time of mice heart grafts.ConclusionsFgl2-MSCs ameliorate AR of heart transplantation by regulating macrophages, which provides a new idea for the development of anti-AR treatment methods after heart transplantation.

P1773BENEFITS OF CONTROL RENAL BIOPSIES IN THE ASSESSMENT OF ANTI-REJECTION THERAPY EFFICACY IN PATIENTS WITH HISTOLOGICAL LESIONS DIAGNOSED EITHER BY PROTOCOL OR BY “FOR CAUSE” BIOPSIES

Abstract Background and Aims Efficacy of acute rejection (AR) therapy has always been evaluated based upon improvement of renal function. On the contrary, the degree of histological lesion (HL) regression has rarely been considered for this purpose. The main goal of this study was to evaluate the percentage of failures in HLs regression after treatment aimed at both “subclinical” and “clinical” AR. Treatment efficacy was therefore evaluated with control renal biopsies (CBs) performed 30-60 days after anti-rejection therapy. In addition, the correlation between graft function and histological data was assessed. The results of treatment for “subclinical" and "clinical” AR were considered separately. Method Real-time ultrasound-guided CBs were performed in an outpatient setting using 16G tru-cut needles. The HLs considered were: interstitial inflammation (i), tubulitis (t), glomerulitis (g), arteritis (v), capillaritis (ptc). Each lesion was graded from 0 to 3 (sec Banff 2013-2017). For this study, only HLs with a score ≥2 were considered. Therapy failure was determined both by the percentage of patients (pts) with persistence of HLs and by the change of HLs score after treatment, in the control biopsies. Anti-rejection therapy varied according to AR type and severity. In patients failing AR therapy, serum creatinine was evaluated before and after the treatment. Results 111 BCs were performed after treatment either for subclinical (n = 47) or for clinical (n = 64) AR. Before therapy, HLs (with score ≥2) present in subclinical and clinical AR were: i: 23% and 52%; t: 30% and 30%; g: 34% and 41%; ptc: 11% and 28%; v: 15% and 19%. After therapy, in the setting of subclinical AR, HLs were still present with a range between 29% (v) and 81% (g) with stable or improved histological score. In this scenario, renal function resulted stable and satisfactory (Tab 1). In the case of clinical AR, the persistence of histological lesions ranged from 25% (v) to 92% (g), also with stable or improved histological scores. In this case, therapy was always followed by an improvement in renal function (Tab 2). Conclusion After AR therapy, only the morphological data obtained with histological analysis can disclose failures of anti-rejection therapy, both in presence of subclinical and clinical AR. The high rate of treatment failure may explain the correlation between AR and worse graft survival. Our results could lead us to consider the need for a more aggressive anti-rejection treatment. Control renal biopsies after AR therapy should always be considered on clinical grounds.

Surface Antigens on Plasma Extracellular Vesicles of Cystic Fibrosis Patients Treated by Extracorporeal Photopheresis as Induction Therapy after Lung Transplantation: Preliminary Results of a Pilot Randomized Trial

Acute rejection (AR) is common during the first year after lung transplantation (LuTx) and can trigger chronic rejection (CR), the leading cause of late morbidity and mortality of LuTx. Extracorporeal photopheresis (ECP) is a promising treatment for chronic rejection. Few studies focus on ECP as prophylactic therapy of AR and CR. Microvesicles and exosomes (i.e.extracellular vesicles EV) are released into the blood and in bronchoalveolar lavage (BAL) and their role in cell-to-cell communication has been assessed in several studies; EV have been proposed as non-invasive biomarkers to assess lung injury and monitor clinical outcome. We conduct a pilot clinical trial on 24 cystic fibrosis patients undergoing LuTx, randomly allocated in 2 parallel arms: standard immunosuppressive therapy and ECP (ECP) vs standard immunosuppressive therapy alone (CTR). EV concentration was assessed at different time points in blood and BAL in the first year after LuTx (analyzed by nanoparticle tracking analysis Nanosight NS300, Malvern). EV were analyzed for antigen expression with MACSplex bead-based assay. AR episodes and infections were recorded, as far as ECP-related adverse events. Preliminary data on the first 18 patients (9 ECP and 9 CTR) are reported RESULTS: ECP was well tollerated and no adverse events or AR occurred in either groups. EV presented highly polydispersed size distributions in a 50-1000 nm range. The expression of EV-associated markers CD63, CD9 and CD81 was detected. Upregulation of platelets (CD62p; p<0.05 by t-test), lymphocytes (CD3, CD24) markers and integrins (CD29, CD49e) was observed in ECP-treated patient compared to the control group. The underlying mechanism of ECP remains unresolved. The identification of specific EV antigen signatures may represent a promising approach to better understand the immunomodulatory effects of ECP, both at molecular and cellular level.

Bone marrow stem cells modified with human interleukin 10 attenuate acute rejection in rat lung allotransplantation.

The aim of this study was to investigate new therapeutic options to attenuate acute rejection in a rat lung allograft model. Cell-based gene therapies have recently been reported as a novel curative option in acute and chronic diseases for which conventional treatments are not available. We studied the effect of human interleukin 10 (hIL-10) on expressing bone marrow-derived mesenchymal stem cells (BMSCs) in combination with cyclosporine A (CsA) on acute rejection of lung allografts in the rat. Lung allotransplantation was performed from male Brown Norway donor to male Fisher (F344) rats. Rat BMSCs were transfected with hIL-10 in vitro and introduced in the graft prior to implantation. Group A (n = 5) received CsA intraperitoneally (2.5 mg/kg body weight) for 5 days post-transplant; Group B (n = 5) received BMSC and CsA and Group C (n = 5) received hIL-10-BMSC before implantation and CsA. Graft function was assessed by blood gas levels only from the graft on day 5; tissue was sampled for histological grading of rejection and measurement of the wet-to-dry ratio. All Group A control animals showed severe signs of rejection. On Day 5, all grafts in Group C showed improved gas exchange (mean arterial partial pressure of oxygen 222.2 ± 40.38 mmHg vs 92.36 ± 20.92 mmHg in Group B and 42.72 ± 18.07 mmHg in Group A). Histological examination revealed moderate-to-severe rejection in all animals in Group A [International Society for Heart and Lung Transplantation Level III B (ISHLT)] in contrast to low-to-moderate rejection in Group B (II-IIIA) and much improved histological grade in Group C (I-IIA). Moreover, the wet-to-dry ratio was also reduced in Group C (4.8 ± 1.19 compared with 4.78 ± 0.62 in Group B and 9.36 ± 0.90 in Group A). The hIL-10 BMSC represent a promising novel method for localized cell-based gene therapy for acute rejection in a rat lung allograft model.

(511) - The Number of Human Leukocyte Antigen DR Mismatch Is Associated with Early Post-Transplant Acute Cellular Rejection Among Heart Transplantation Recipients

s S193 The purpose of the study was to evaluate T2, T1 and extracellular volume (ECV) quantification as novel tissue markers to diagnose acute cardiac rejection. Methods: CMR was prospectively performed in heart transplant patients before or just after routine EMB and before acute rejection therapy. Images were acquired on a 1.5 Tesla scanner including T2 mapping (T2 preparedSSFP) and T1 mapping using a modified look locker inversion recovery sequence ( MOLLI) at basal, mid and apical level in short axis view. T2 and T1 values were measured before and 15 minutes (for T1 mapping) after contrast administration. The results are expressed by the median and the 5th and the 95th percentiles. Results: twenty six patients (age 52±14 years) were included providing 40 comparisons CMR/EMB. Acute rejection (cellular, humoral or clinical symptoms) was diagnosed in 13 patients. Patients with AR had significantly higher global T2 values at 3 levels (58 ms [52-61] vs 55ms [49-55], P= 0.0049 at basal; 57 ms [54-61] vs 51 ms [5054], P= 0.0010 at median and 60 ms [54-66] vs 54 ms [50-57], P= 0.0119 at apical level). The area under the curve (AUC) for each level was: 0.78; 0.84 and 0.77 respectively. Patients with AR had significantly higher ECV at basal and median level: 35% [33-41] vs 27% [25-31] P= 0.0021 and 33% [28-38] vs 27%[24-31], P= 0.015 respectively. The AUC for each level was; 0.83 and 0.75 respectively. The sensitivity, specificity and diagnosis accuracy for basal T2 (cutoff : 58 ms) were 70%, 96 % and 79% respectively; basal ECV: (cutoff 31%) 89%, 77% and 81% respectively. The best AUC ( 0.88) was obtained when we combined basal T2 and basal ECV. Conclusion: In heart transplant patients, a combined CMR approach using T2 mapping and ECV quantification provides a high diagnostic accuracy for acute rejection diagnosis and could potentially decrease the number of routine EMB. Further studies are required to confirm these data.

(514) - Organ Preservation and Reperfusion Influence on Outcome after Heart Transplantation

s S193 The purpose of the study was to evaluate T2, T1 and extracellular volume (ECV) quantification as novel tissue markers to diagnose acute cardiac rejection. Methods: CMR was prospectively performed in heart transplant patients before or just after routine EMB and before acute rejection therapy. Images were acquired on a 1.5 Tesla scanner including T2 mapping (T2 preparedSSFP) and T1 mapping using a modified look locker inversion recovery sequence ( MOLLI) at basal, mid and apical level in short axis view. T2 and T1 values were measured before and 15 minutes (for T1 mapping) after contrast administration. The results are expressed by the median and the 5th and the 95th percentiles. Results: twenty six patients (age 52±14 years) were included providing 40 comparisons CMR/EMB. Acute rejection (cellular, humoral or clinical symptoms) was diagnosed in 13 patients. Patients with AR had significantly higher global T2 values at 3 levels (58 ms [52-61] vs 55ms [49-55], P= 0.0049 at basal; 57 ms [54-61] vs 51 ms [5054], P= 0.0010 at median and 60 ms [54-66] vs 54 ms [50-57], P= 0.0119 at apical level). The area under the curve (AUC) for each level was: 0.78; 0.84 and 0.77 respectively. Patients with AR had significantly higher ECV at basal and median level: 35% [33-41] vs 27% [25-31] P= 0.0021 and 33% [28-38] vs 27%[24-31], P= 0.015 respectively. The AUC for each level was; 0.83 and 0.75 respectively. The sensitivity, specificity and diagnosis accuracy for basal T2 (cutoff : 58 ms) were 70%, 96 % and 79% respectively; basal ECV: (cutoff 31%) 89%, 77% and 81% respectively. The best AUC ( 0.88) was obtained when we combined basal T2 and basal ECV. Conclusion: In heart transplant patients, a combined CMR approach using T2 mapping and ECV quantification provides a high diagnostic accuracy for acute rejection diagnosis and could potentially decrease the number of routine EMB. Further studies are required to confirm these data.

Hyperosmolar nonketotic hyperglycemic coma induced by methylprednisolone pulse therapy for acute rejection after liver transplantation: a case report and review of the literature

Hyperosmolar nonketotic hyperglycemic coma induced by methylprednisolone pulse therapy for acute rejection after liver transplantation: a case report and review of the literature Jian Zhou,* Weiqiang Ju,* Xiaopeng Yuan, Xiaofeng Zhu, Dongping Wang, Xiaoshun HeOrgan Transplant Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, People&#39;s Republic of China *These authors contributed equally to this work Abstract: Hyperosmolar nonketotic hyperglycemic coma (HNKHC) is a serious, rare complication induced by methylprednisolone (MP) pulse therapy for acute rejection after orthotopic liver transplantation (OLT). Herein, we report an unusual case of a 58-year-old woman who experienced acute rejection at 30 months after OLT, only one case in which HNKHC resulted in MP pulse therapy for acute rejection in all 913 recipients in our center. The general morbidity of HNKHC was 1.09&permil; in this study. HNKHC is characterized by rapid onset, rapid progression, and a lack of specific clinical manifestations. High-dose MP management was a clear risk factor. The principle of treatment included rapid rehydration, low-dose insulin infusion, and correcting disorders of electrolytes and acidosis. In conclusion, clinicians considering MP pulse therapy after OLT should be alert to the occurrence of HNKHC. Keywords: liver transplantation, complications, hyperosmolar nonketotic hyperglycemic coma, methylprednisolone pulse therapy, principle of treatment

Cytomegalovirus infection after acute rejection therapy in seropositive kidney transplant recipients.

Acute rejection (AR) after solid organ transplantation has been known to be a risk factor for cytomegalovirus (CMV) infection. However, data regarding the risk for CMV infection during and after anti-rejection therapy are limited. This study investigated whether the risk of CMV infection and disease within 6 months of kidney transplantation (KT) increases in CMV-seropositive KT recipients who develop AR. A total of 992 seropositive KT recipients, including 75 patients (8%) who developed AR within 6 months after KT and 917 patients (92%) who did not, were recruited between May 2007 and April 2012. No significant difference was found in the incidence of CMV infection between the groups (AR group, 13% [10/75] vs. non-AR group, 10% [92/917], P = 0.37). The number of KT recipients in each group receiving preemptive therapy for CMV was similar (5% [4/75] vs. 6% [53/917], P > 0.99). While the incidence of CMV syndrome was comparable (0% [0/75] vs. 1% [12/917], P > 0.99), the incidence of tissue-invasive CMV disease (8% [6/75] vs. 3% [27/917], P = 0.04), particularly gastrointestinal CMV disease, was significantly greater in patients who experienced AR. No CMV-related mortality occurred in either group. AR (odds ratio, 2.81; 95% confidence interval, 1.08-7.29; P = 0.03) was an independent risk factor for tissue-invasive CMV disease within 6 months of KT. A high index of suspicion and active evaluation for tissue-invasive CMV disease in KT recipients suffering AR may be necessary to ensure appropriate treatment.

Incidence and risk factors for new‐onset diabetes in living‐donor liver transplant recipients

With the increased number of long-term survivors after liver transplantation, new-onset diabetes after transplantation (NODAT) is becoming more significant in patient follow-up. However, the incidence of new-onset diabetes after living-donor liver transplantation (LDLT) has not been well elucidated. The aim of this study was to evaluate the incidence and risk factors for NODAT in adult LDLT recipients at a single center in Japan. A retrospective study was performed on 161 adult patients without diabetes who had been followed up for ≥threemonths after LDLT. NODAT was defined according to the 2003 American Diabetes Association/World Health Organization guidelines. The recipient-, donor-, operation-, and immunosuppression-associated risk factors for NODAT were assessed. Overall, the incidence of NODAT was 13.7% (22/161) with a mean follow-up of 49.8months. In a multivariate analysis, the identified risk factors for NODAT were donor liver-to-spleen (L-S) ratio (hazard ratio [HR]=0.022, 95% confidence interval [CI]=0.001-0.500, p=0.017), and steroid pulse therapy for acute rejection (HR=3.320, 95% CI=1.365-8.075, p=0.008). In conclusion, donor L-S ratio and steroid pulse therapy for acute rejection were independent predictors for NODAT in LDLT recipients. These findings can help in screening for NODAT and applying early interventions.

Simultaneous Diagnosis and Gene Therapy of Immuno-Rejection in Rat Allogeneic Heart Transplantation Model Using a T-Cell-Targeted Theranostic Nanosystem

As the final life-saving treatment option for patients with terminal organ failure, organ transplantation is far from an ideal solution. The concomitant allograft rejection, which is hardly detectable especially in the early acute rejection (AR) period characterized by an intense cellular and humoral attack on donor tissue, greatly affects the graft survival and results in rapid graft loss. Based on a magnetic resonance imaging (MRI)-visible and T-cell-targeted multifunctional polymeric nanocarrier developed in our lab, effective co-delivery of pDNA and superparamagnetic iron oxide nanoparticles into primary T cells expressing CD3 molecular biomarker was confirmed in vitro. In the heart transplanted rat model, this multifunctional nanocarrier showed not only a high efficiency in detecting post-transplantation acute rejection but also a great ability to mediate gene transfection in T cells. Upon intravenous injection of this MRI-visible polyplex of nanocarrier and pDNA, T-cell gathering was detected at the endocardium of the transplanted heart as linear strongly hypointense areas on the MRI T(2)*-weighted images on the third day after cardiac transplantation. Systematic histological and molecular biology studies demonstrated that the immune response in heart transplanted rats was significantly suppressed upon gene therapy using the polyplex bearing the DGKα gene. More excitingly, the therapeutic efficacy was readily monitored by noninvasive MRI during the treatment process. Our results revealed the great potential of the multifunctional nanocarrier as a highly effective imaging tool for real-time and noninvasive monitoring and a powerful nanomedicine platform for gene therapy of AR with high efficiency.

Post‐transplantation lymphoproliferative disorder in pediatric kidney‐transplant recipients – A national study

PTLD is the most common malignancy in pediatric kidney-transplant recipients. We examined the prevalence, clinical features, and outcome of PTLD in Israel. Twelve (4.4%) of 272 pediatric (<19 yr) kidney-transplant recipients retrieved from a search of the NIKTR for 1991-2008 had acquired PTLD at a median of 3.2 yr post-transplantation. PTLD-affected patients were younger at transplantation (4.2 vs. 12.5 yr, p = 0.02), had a higher rate of OKT3 therapy for acute rejection (25% vs. 4%, p = 0.015), and 5/12 were EBV-seropositive at transplantation. Graft dysfunction was the presenting sign in six (50%). PTLD was predominantly abdominal (83%) and B-cell type (67%); T-cell PTLD occurred exclusively in EBV-seropositive patients. Treatment consisted of immunosuppression cessation (6/12, 50%), antiviral agents (7/12, 58%), anti-CD20 monoclonal antibodies (4/12, 33%), and chemotherapy (6/12, 50%). Survival was 100% in the EBV-naïve patients and 40% in the EBV-seropositive patients. Graft loss occurred in three of eight survivors (37.5%). PTLD-associated mortality risk was older age: 11.2 vs. 3.4 yr, longer dialysis: 15 vs. 6.5 months, T-cell type disease (75%), later PTLD onset: 6.35 vs. 1.9 yr post-transplantation and era of transplantation (43% mortality before vs. 20% after 2001). Pretransplantation EBV-seronegative status might confer a survival benefit with early detected PTLD. EBV-seropositive patients are at risk for aggressive late-onset lethal PTLD.

Basiliximab as therapy for acute rejection after liver transplantation for hepatitis C virus cirrhosis

Steroid bolus therapy for acute rejection after liver transplantation for hepatitis C virus (HCV) cirrhosis often results in graft loss due to adverse effects. The efficacy and safety of basiliximab for the treatment of acute cellular rejection (ACR) in adult liver transplantation has not been adequately evaluated. Three patients received basiliximab as rescue therapy for acute rejection. The outcome and biochemical parameters were recorded before and after treatment with basiliximab. These results were compared to 11 patients who received steroid therapy for ACR. The median time from transplantation to the development of ACR was 19 days (range, 9-49 days). The degree of ACR was mild or moderate. Resolution of rejection was obtained in all patients and the median time from the onset to resolution of ACR was 16 days (range, 6-41 days). A steroid resistant reaction occurred in 2 of 11 patients and OKT3 was used, and the rejection eventually resolved in all patients. Five patients died within 2 to 22 months after transplantation and four of them died from graft failure. In the basiliximab group, there were no significant immediate adverse effects. One patient died from pneumonia 8 months after transplantation. Basiliximab can be safely used as rescue therapy for ACR without significant adverse effects in patients who underwent liver transplantation for HCV cirrhosis.

Overview of immunosuppression in liver transplantation

Continued advances in surgical techniques and immunosuppressive therapy have allowed liver transplantation to become an extremely successful treatment option for patients with end-stage liver disease. Beginning with the revolutionary discovery of cyclosporine in the 1970s, immunosuppressive regimens have evolved greatly and current statistics confirm one-year graft survival rates in excess of 80%. Immunosuppressive regimens include calcineurin inhibitors, anti-metabolites, mTOR inhibitors, steroids and antibody-based therapies. These agents target different sites in the T cell activation cascade, usually by inhibiting T cell activation or via T cell depletion. They are used as induction therapy in the immediate peri- and post-operative period, as long-term maintenance medications to preserve graft function and as salvage therapy for acute rejection in liver transplant recipients. This review will focus on existing immunosuppressive agents for liver transplantation and consider newer medications on the horizon.

The significance of metabolic syndrome in the setting of recurrent hepatitis C after liver transplantation

Although hyperinsulinemia and its associated metabolic syndrome (MS) have been implicated in the progression of hepatic fibrosis in hepatitis C virus (HCV) patients, little is known about the consequences of MS after orthotopic liver transplantation (OLT). The aim of this study was to assess the association between MS and fibrosis progression in patients with recurrent HCV after OLT. We identified all OLT/HCV patients (1998-2005) with at least 2 post-OLT liver biopsies. MS was defined with Adult Treatment Panel III criteria at 1 year post-OLT. The Ludwig-Batts scoring system was used to stage all biopsies (408 biopsies from 95 patients). The first biopsy that showed progression post-OLT was used for the time-to-progression analysis. Univariable and multivariable logistic regression analysis was performed to identify factors associated with fibrosis progression. MS was present in 50% of patients. Average follow-up to last available biopsy was 24 +/- 17 months, during which 72% of subjects had fibrosis progression. The overall median rate of fibrosis progression was 0.08 units per month (Q25, Q75: 0.0, 0.17). By univariable analysis, high HCV RNA at 4 months post-OLT (P < 0.001), diabetes (P = 0.046), cytomegalovirus infection (P = 0.006), and MS (P = 0.049) were associated with progression of fibrosis. In multivariable analysis, MS was independently associated with progression of fibrosis beyond 1 year after OLT (odds ratio = 6.3, P = 0.017). A high viral load at 4 months post-OLT (odds ratio = 1.1, P = 0.004) and steroid therapy for acute rejection (odds ratio = 1.9, P = 0.05) were independently associated with fibrosis progression. In conclusion, MS, a potentially modifiable disease, is common and is strongly associated with long-term fibrosis progression in the setting of recurrent HCV after OLT.

Low incidence of adverse events in outpatient pediatric renal allograft biopsies

In 1999, our center implemented a policy of outpatient protocol biopsies as standard practice for the clinical management of pediatric renal allograft recipients. In order to determine the safety of this procedure, we conducted a retrospective chart audit of all outpatient renal allograft biopsies performed at our center. Biopsies were performed under conscious (midazolam) or procedural (propofol/fentanyl) sedation. Localization of the lower pole of the renal allograft was achieved with renal ultrasound. Using a Biopty gun with a 16-gauge needle, two cores were obtained. Patients were discharged four h post-biopsy. Patient demographics, hospital length of stay (LOS), specimen adequacy (per Banff criteria) and major and minor adverse events were recorded in a central database. Data were expressed as mean +/- SD. From June 1999 to July 2004, we performed 162 biopsies in 43 pediatric renal allograft recipients. Most patients underwent extraperitoneal transplantation (42/43, 97.7%) and were greater than five yr of age at biopsy (129/131 biopsies, 98.5%). The majority of these procedures (131/162, 80.9%) were conducted in the outpatient department, with 113 of 131 (86.3%) being obtained for protocol (n = 89) and one-month follow-up acute rejection therapy (n = 24) indications. Patients underwent 3.7 +/- 2.7 biopsies (range = 1-11). Specimen adequacy was achieved in 119 of 124 (96.0%) of documented cases. The overall incidence of adverse events was 12 of 131 (9.2%) biopsies, all of which were minor in severity. Macroscopic hematuria was the most common minor adverse event, occurring after 11 of 131 (8.4%) biopsies. While macroscopic hematuria prolonged LOS (adverse events vs. no adverse events: 23.0 +/- 26.0 vs. 8.6 +/- 4.1 h, p = 0), none of these episodes required major surgical or radiographic interventions. We conclude that in patients greater than five yr of age with extraperitoneal renal allografts, outpatient protocol biopsies using a 16-gauge needle are sufficiently safe to justify their inclusion in the routine clinical management of pediatric renal allograft recipients and in pediatric clinical trials.