Treatment Of Graft Rejection Research Articles

Preparing the Heart for a New Baby: Management of Pregnancy in Heart Transplant Recipients.

Heart transplant (HT) recipients are more frequently reaching childbearing age given improvement in median survival and outcomes after HT. Although most pregnancies in HT recipients have favorable outcomes, poor fetal outcomes and maternal complications such as hypertensive disorders of pregnancy are more common in HT recipients than in the general population. In this review, we summarize the current evidence to guide the management of pregnancy in HT recipients. Preconception counseling, focused on risk stratification and optimal timing of conception, is the first important step to optimize pregnancy outcomes. During pregnancy and in the postpartum period, frequent monitoring of graft function and immunosuppressive levels is recommended. Calcineurin inhibitors and corticosteroids should be the mainstay of treatment for both prevention and treatment of graft rejection. Delivery planning should follow usual obstetric indications, preferably with vaginal delivery at term using regional anesthesia. A multidisciplinary care team should be involved in management through all stages of pregnancy to ensure success.

Nanoparticle-assisted Targeting Delivery Technologies for Preventing Organ Rejection.

Although organ transplantation is a life-saving medical procedure, the challenge of posttransplant rejection necessitates safe and effective immune modulation strategies. Nanodelivery approaches may have the potential to overcome the limitations of small-molecule immunosuppressive drugs, achieving efficacious treatment options for transplant tolerance without compromising overall host immunity. This review highlights recent advances in biomaterial-assisted formulations and technologies for targeted nanodrug delivery with transplant organ- or immune cell-level precision for treating graft rejection after transplantation. We provide an overview of the mechanism of transplantation rejection, current clinically approved immunosuppressive drugs, and their relevant limitations. Finally, we discuss the targeting principles and advantages of organ- and immune cell-specific delivery technologies. The development of biomaterial-assisted novel therapeutic strategies holds considerable promise for treating organ rejection and clinical translation.

Potential Roles of Long Noncoding RNAs as Therapeutic Targets in Organ Transplantation.

Organ transplantation is the most preferred treatment option for end-stage organ diseases; however, allograft rejection is the major hurdle in successful long-term transplant survival. In spite of developing better HLA matching and more effective immunosuppressive regimen, one-year graft survival has been increased by nearly 90% and the incidence of acute rejection by one-year post-transplantation has been decreased by 12.2% in the last decades, chronic allograft rejection has remained as one of the major obstacles to the long-lasting survival of the transplanted allograft. Therefore, seemingly preventing the allograft rejection and inducing immunological tolerance against transplanted allografts is one of the primary goals in transplantation research to enable long-lasting graft survival. Various mechanisms such as long noncoding RNAs (lncRNAs) have been proposed that induce immune tolerance by modulating the gene expression and regulating innate and adaptive immune responses during transplantation. Besides, because of involvement in regulating epigenetic, transcriptional, and post-translational mechanisms, lncRNAs could affect allograft status. Therefore, these molecules could be considered as the potential targets for prediction, prognosis, diagnosis, and treatment of graft rejection. It is suggested that the noninvasive predictive biomarkers hold promise to overcome the current limitations of conventional tissue biopsy in the diagnosis of rejection. Hence, this review aims to provide a comprehensive overview of lncRNAs and their function to facilitate diagnosis, prognosis, and prediction of the risk of graft rejection, and the suggestive therapeutic choices after transplantation.

Immunogenic and immunotolerogenic effects of extracorporeal photopheresis in high immunological risk kidney recipients. A single center case series

The immunomodulatory effects of extracorporeal photopheresis (ECP) have been used for the treatment of T-cell mediated disorders, such as rejection in organ transplantation. Currently, it is an established therapy for heart and lung rejection, but not for kidney transplantation (KT), where experience is limited. In addition, some data suggest that ECP could generate an immune response against infections, thus being an alternative for the treatment of rejection in case of active or high-risk of infection. In the present study, we analyze four cases of use of ECP as concomitant therapy in patients with KT and high risk of opportunistic infections due to the high burden of immunosuppression throughout their renal diseases. Two patients had concomitant viral infection (cytomegalovirus and BK virus, respectively) and three patients were on treatment for graft rejection. In the two patients with active viral infection, the infection was successfully controlled during ECP treatment. In all cases, ECP has been shown to be a safe procedure, without complications.

Chronic everolimus treatment of high-fat diet mice leads to a reduction in obesity but impaired glucose tolerance.

Everolimus, which inhibits mTOR kinase activity and is clinically used in graft rejection treatment, may have a two‐sided influence on metabolic syndrome; its role in obesity and hyperglycemic in animals and humans, however, has been explored insufficiently. This study further determined how continual everolimus treatment affects glucose homeostasis and body weight control in C57BL6/J mice with obesity. An obesity mouse model was developed by administering a high‐fat diet (HFD) to C57BL6/J mice over 12 weeks. The experimental group, while continuing their HFD consumption, were administered everolimus daily for 8 weeks. Metabolic parameters, glucose tolerance, fatty liver score, endocrine profile, insulin sensitivity index (ISI), insulin resistance (IR) index, and Akt phosphorylation, GLUT4, TNF‐α, and IL‐1 levels were measured in vivo. Compared with the control group, the everolimus group gained less body weight and had smaller adipocytes and lower fat pad weight; triglyceride (serum and hepatic), patatin‐like phospholipase domain‐containing 3, and fatty acid synthase levels; fatty liver scores; and glucose tolerance test values—all despite consuming more food. However, the everolimus group exhibited decreased ISI and muscle Akt phosphorylation and GLUT4 expression as well as impaired glucose tolerance and serum TNF‐α and IL‐1β levels—even when insulin levels were high. In conclusion, continual everolimus treatment may lead to diabetes with glucose intolerance and IR.

Pulmonary complications within the first year after renal transplantation

Background The lungs are commonly involved after renal transplantation, with many complications, either infectious or noninfectious. The infectious complications significantly increased morbidity and mortality. Several risk factors were involved, such as old age, smoking status, comorbid diseases, pretransplant peritoneal dialysis, cadaveric renal transplantation, heavy immunosuppression, and treatment of graft rejection. Aim To study the predisposing risk factors, etiologic factors, and the timeline of pulmonary complications within the first year after renal transplantation (either infectious or noninfectious complications). Patients and methods We conducted this prospective observational study in the Organ Transplant Center in Kuwait from March 2016 to October 2019. The kidney recipients were followed up for 1 year after transplantation. For suspected infectious pulmonary complications, the patients were subjected to blood, sputum, and or bronchoalveolar lavage within the first 24 h after admission; all samples were subjected to microbiological and serological examinations. Results We had 60 patients who developed postrenal transplant pulmonary complications. A total of 42 patients developed infectious pulmonary complications and 54 patients developed noninfectious complications. The most common infectious pulmonary complications were bacterial pneumonia (42 patients), opportunistic fungal infection (47 patients), and viral pneumonia (37 patients). The most common noninfectious pulmonary complications were pulmonary congestion (51 patients), pleural effusion (29 patients), and pulmonary embolism (16 patients). In the first 6 months, surgery-related complications and opportunistic fungal infection predominated owing to heavy immunosuppression. After 6 months, infections were due to community-acquired pathogens. The mortality rate was 38%. Bacterial pneumonia was the main cause of death (39%) followed by viral pneumonia (26%) and Pneumocystis jiroveci pneumonia (13%). Septic shock and respiratory failure were the leading causes of death. Conclusion Renal transplant was associated with infectious and noninfectious pulmonary complications. Infections were highly prevalent in the first year after transplantation. Old age, smoking status, comorbid diseases, pretransplant peritoneal dialysis, cadaveric renal transplantation, heavy immunosuppression, and treatment of graft rejection were the main risk factors for posttransplant pulmonary complications. Sepsis and respiratory failure represented the commonest causes of death.

Combined therapy of infusion of DC from rats with higher expression of IDO and CD40L on rejection post heart transplantation.

Indoleamine 2, 3-dioxygenase (IDO) can inhibit rejection of graft via inducing T cell apoptosis. CD40L monoclonal antibody (mAb) inhibits T cell activation. However, the effects of the combination of infusion of dendritic cell (DC) from IDO over-expressed donor mice and CD40L mAb on the treatment of graft rejection after heart transplantation have not been reported. Allogeneic heart transplantation mouse model was established. Recipient mice were divided into three groups, including control group, IDO group (in which DC donors received adenoviral vector of IDO) and combined therapy group (which received both IDO over-expressed DC infusion and CD40L mAb injection post transplantation). Survival time and cardiac function were observed, with IDO expression being quantified. Flow cytometry (FCM) was used to analyze T cell apoptosis, while enzyme linked immunosorbent assay (ELISA) was adopted to test the levels of interferon-γ (IFN-γ), interleukin-2 (IL-2), interleukin-10 (IL-10) and interleukin-6 (IL-6). IDO expression was significantly elevated in both IDO and combined therapy groups, with enhanced T cell apoptosis compared to control group (p < 0.05). Both groups had better survival time and cardiac functions compared to control group, along with increased IL-10/IL-6 expression and suppressed INF-γ and IL-2 expression (p < 0.05). However, combined therapy had a better efficiency compared to IDO group (p < 0.05). Combined therapy of high IDO expressed mouse DC perfusion with CD40L mAb can elongate the survival time of recipient heart and inhibit rejection reaction via facilitating T cell apoptosis. Meanwhile, combined therapy could also regulate the expression of some immune suppressant factors and mediate the Th1/Th2 cytokine balance.

Liver transplantation: post-transplant management.

Medical care for patients following liver transplantation is complex and requires a holistic approach to management. Patients and clinicians are faced with multiple challenges: immunosuppressive regimens must be optimized to avoid and treat graft rejection, the risk and atypical features of sepsis in the immunocompromised patient must be recognized, steps are required to reduce the recurrence of liver disease and the long-term increased risks of malignancy, renal failure and metabolic complications need managing. Despite the benefits of liver transplantation there are additional concerns regarding the impact upon quality of life. This review will focus upon the care of patients following liver transplantation. As these patients will present to a broad range of clinicians, an understanding of the common drugs used post-transplantation and general approach to management of these patients will be of benefit to the general clinical audience.

Experimental study on inhibiting graft rejection following high-risk cornea transplatation by resolvinE1 in mice

Background The conventional drugs for preventing and treating graft rejection have the risks of inducing adverse responses.Researches showed that resolvinE1 (RvE1) can regulate Th1 cell-mediated immunoreaction.However, whether RvE1 has an inhibit effect on high-risk corneal graft is unclear now. Objective This study was to investigate the effects of RvE1 on immune rejection in high-risk corneal grafting mouse models. Methods SPF BALB/c mice were used as recipients, C57BL/6 mice were as donors.Ninety BALB/c mice were divided into corneal allograft group, corneal allograft+ RvE1 group and corneal autograft group according to random number table.High-risk corneal graft models were established by corneal suturing for 14 days and followed by penetrating keratoplasty in recipients.Allograft keratoplasty was performed on the right eyes in the mice of corneal allograft group and corneal allograft+ RvE1 group, and self-corneal graft rotated 180°was transplanted on the right eyes in the mice of autograft group.Normal saline solution of 10 μl was subconjunctivally injected after surgery once per day for 7 days in the corneal allograft group and corneal autograft group, and 10 μl RvE1 (1 μg) was used in the same way in the corneal allograft+ RvE1 group.The recipient eyes were examined for potential rejection signals with slit lamp microscope and calculated the mean survival time and rejection index (RI). The histopathology was examined 21 days after modeling by hemotoxylin and eosin staining.The expressions of CD4 and interferon-γ (IFN-γ) in the corneas were detected by immunohistochemistry.Th1 cell (CD3+ CD8a-IFN-γ+ ) percentage in draining lymph nodes were measured by flow cytometry.The mRNA expression levels of interleukin-2 (IL-2), tumor mecrosis factor-α (TNF-α), IFN-γ and T-bet were detected by real-time fluorescence quantitative PCR. Results The mean survival time of grafts was (28.5±1.7) days in the corneal allograft group, and that in the corneal allograft+ RvE1 group was (14.0±1.6) days, showing a significant difference between them (t=4.14, P<0.001), while the survival rate was 100% at 50 days after modeling in the corneal autograft group.Corneal edema and inflammatory cell infiltration were slight in the corneal allograft+ RvE1 group and corneal autograft group compared with corneal allograft group.CD4 was positively expressed in corneal tissue, and IFN-γ was expressed in corneal epithelium.The CD4+ and IFN-γ+ cell number was decreased in the corneal allograft+ RvE1 group and corneal autograft group compared with corneal allograft group under the fluorescence microscope.The percentages of Th1 cells in lymph cells of corneal allograft + RvE1 group and corneal autograft group were (1.07±0.25)%, (0.85±0.12)%, respectively, which were significnatly lower than (1.56±0.20)% in the corneal allograft group (both at P<0.05). The expressions of IL-2, TNF-α, IFN-γ and T-bet mRNA in the corneal tissue in the corneal allograft group were higher than those in the corneal allograft+ RvE1 group and corneal autograft group (all at P<0.05). Conclusions RvE1 inhibits graft rejection in high-risk allograft mouse models probably by down-regulating the Th1 cell percentage in lymph cells and the expression of inflammation-related cytokines in corneal grafts. Key words: Cornea/immunology; Corneal transplantation/immunology; Graft rejection; Eicosapentaenoic acid/analogs & derivatives; ResolvinE1; T helper cell 1; Cytokines; Disease models, animal; Mice, inbred BALB/c; Mice, inbred C57BL/6

MicroRNA expression analysis during FK506-induced osteogenic differentiation in rat bone marrow stromal cells.

FK506 (also known as tacrolimus) is a potent immunosuppressive agent that is widely used in the treatment of graft-rejection and autoimmune diseases. FK506 has attracted additional attention owing to its potential role in osteogenic differentiation and bone formation. MicroRNAs (miRNAs) have been demonstrated to serve important roles in the regulation of osteogenic differentiation; however, identification of specific miRNAs and their roles in regulating FK506-induced osteogenic differentiation have been poorly examined. In the present study, osteodifferentiation of rat bone marrow stromal cells (BMSCs) was induced with varying concentrations of FK506 (5–5,000 nM) for 3, 7 and 14 days. Differentially expressed miRNAs were profiled using miRNA array, verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and subjected to gene ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Results from the present study identified a subset of miRNAs that were differentially expressed, of which five upregulated miRNAs (miR-106b-5p, miR-101b-3p, miR-193a-3p, miR-485-3p and miR-142-3p) and four downregulated miRNAs (miR-27a-3p, miR-207, miR-218a-2-3p and let-7a-5p) were confirmed by RT-qPCR. GO and KEGG analysis revealed that the predicted target genes of these miRNAs are involved in multiple biological processes and signaling pathways, including cell differentiation and the mitogen-activated protein kinase (MAPK) signaling pathway. Verification of the miRNA-target genes revealed that Smad5, Jagged 1 and MAPK9 were significantly upregulated, whereas Smad7, BMP and activin membrane-bound inhibitor, and dual-specificity phosphatase 2 were significantly downregulated during FK506-induced osteodifferentiation. The present study may provide an experimental basis for further research on miRNA functions during FK506-induced osteogenic differentiation in rat BMSCs.

P072 De novo anti-HLA-class II donor specific antibodies are associated with patient mortality after lung transplant failure

Aim The development of donor-specific HLA antibodies (DSA) after lung transplantation has been implicated in acute and chronic rejection. The diagnosis of lung antibody mediated rejection (AMR) is based upon histology, DSA testing and clinical assessment of graft function. Post-transplant DSA monitoring has become more and more common as a guide toward diagnosis and sometimes institution of AMR treatment. In this study, we aimed to assess DSA with biopsy surveillance and associate with patient mortality after lung transplant failure (MLTF). Methods We retrospectively selected 127 patients, transplanted between Jan, 2004 and July, 2015 whose DSA were tested for clinical indications post-transplantation. Protocol biopsies were performed for these patients at 1, 3, 6, 9, and 12-months after transplant for clinical suspicions. DSA were monitored using LabScreen single antigen bead assays. Biopsy HE however, no association was found for Class I DSA. No significant relationship between DSA and histological changes of AMR in lung transplant biopsies was found in this cohort. Conclusion HLA Class II DSA is associated with graft dysfunction and mortality in pulmonary transplant patients although we did not find the correlation with biopsy findings. Our study suggests that post-transplant protocol DSA surveillance may add value to assess allograft function and to treat graft rejection at the early stage.

The effect of immunosuppressive drug cyclosporine A on myeloid-derived suppressor cells in transplanted mice.

Myeloid-derived suppressor cells (MDSCs) play important roles in preventing graft rejection. Immunosuppressive drug cyclosporine A (CsA) is widely used in clinics to treat patients with allografts and autoimmune diseases. However, the effect of CsA on CD11b(+)Gr1(+) MDSCs has not been studied. The subjects of the study include BALB/c skin-grafted C57BL/6 mice and the in vitro MDSCs induction system. Skin-grafted mice were treated with CsA (30mg/kg, i.p.) or control buffer daily. 0.01μg/ml CsA was added during MDSC induction. Flow cytometry was used to check cell phenotypes and proliferation. Real-time PCR was used for gene expressions. Inducible nitric oxide synthase iNOS-knockout mice were used for the role of iNOS in the immunosuppression of MDSCs. CsA in MDSC-induction system significantly increased the number of CD11b(+)Gr1(+)MDSCs without detectable effects on the expressions of CD31, CD115 and CD274. However, GM-CSF+CsA-induced MDSCs express higher iNOS than control MDSCs. Blocking iNOS activity by inhibitor or gene deletion significantly reversed the inhibitory effects of GM-CSF+CsA-induced MDSCs on T cell proliferation. Importantly, CsA treatment significantly increased the number and the immunosuppressive ability of CD11b(+)Gr1(+)MDSCs in allogeneic skin-grafted mice. CsA promotes MDSC induction and immunosuppressive function, which might be of clinical importance in treating graft rejection and autoimmune diseases.

MTOR masters monocytic myeloid-derived suppressor cells in mice with allografts or tumors.

CD11b+ Gr1+ myeloid-derived suppressor cells (MDSCs) play critical roles in controlling the processes of tumors, infections, autoimmunity and graft rejection. Immunosuppressive drug rapamycin (RPM), targeting on the key cellular metabolism molecule mTOR, is currently used in clinics to treat patients with allo-grafts, autoimmune diseases and tumors. However, the effect of RPM on MDSCs has not been studied. RPM significantly decreases the cell number and the immunosuppressive ability on T cells of CD11b+ Ly6Chigh monocytic MDSCs (M-MDSCs) in both allo-grafts-transplanted and tumor-bearing mice respectively. Mice with a myeloid-specific deletion of mTOR have poor M-MDSCs after grafting with allo-skin tissue or a tumor. Grafting of allo-skin or tumors significantly activates glycolysis pathways in myeloid precursor cells in bone marrow, which is inhibited by RPM or mTOR deletion. 2-deoxyglucose (2-DG), an inhibitor of the glycolytic pathway, inhibits M-MDSC differentiation from precursors, while enhancing glycolysis by metformin significantly rescues the RPM-caused deficiency of M-MDSCs. Therefore, we offer evidence supporting that mTOR is an intrinsic factor essential for the differentiation and immunosuppressive function of M-MDSCs and that these metabolism-relevant medicines may impact MDSCs-mediated immunosuppression or immune tolerance induction, which is of considerable clinical importance in treating graft rejection, autoimmune diseases and cancers.

DYNAMICS OF IRIG IN TREATMENT OF HEART TRANSPLANT REJECTIONS

In cardiac recipients non-invasive monitoring will identify the risk of acute rejection, as well as reduce the number of routine biopsies. The relation between the development of the transplanted heart rejection and the change of elastic properties of common carotid artery has been proved. Aim: to analyze dynamics of iRIG in treatment of graft rejection in heart recipients.Materials and methods. 59 heart recipients were examined: 21 patients (pts)without rejection, 20 pts – with rejection after 1st biopsy, 15 pts – with rejection after 1st and 2 biopsies, 3 pts – with persistent rejection after all biopsies. iRIG was estimated using empirical equation.Results. Dynamics of iRIG in pts. without rejection according to all biopsies over time was not signifi cantly changed 6280 ± 2143, 6083 ± 2388, 6362 ± 1984 and 6188 ± 3012 cm/sec2 (p = 0.11, p = 0.13, p = 0.17 between the 1st and 2nd, 2nd and 3rd, 3rd and 4th values, respectively). In pts. with rejection iRIG decreased during treatment, but was signifi cantly higher even after successful treatment. In patients with persistent rejection iRIG did not decrease and tended to increase (17 459 ± 9702 cm/sec2 on the results of the 1st biopsy to 21 305 ± 10 448 cm/sec2 on the results of the 4th biopsy).Conclusions. In patients with heart transplant iRIG does not change signifi cantly with the time after transplantation. iRIG increases in all types of rejection, followed by its decrease in the course of therapy; in patients with persistent rejection iRIG remains high. Evaluation of iRIG can be used for non-invasive monitoring of patients after heart transplantations (HTx) and to identify patients at high risk of transplant rejection.

Rapamycin impairs HPD-induced beneficial effects on glucose homeostasis.

Rapamycin, which is used clinically to treat graft rejection, has also been proposed to have an effect on metabolic syndrome; however, very little information is available on its effects in lean animals/humans. The purpose of this study was to characterize further the effects of the continuous use of rapamycin on glucose homeostasis in lean C57BL6/J mice. Mice were fed a high-protein diet (HPD) for 12 weeks to develop a lean model and then were treated daily with rapamycin for 5 weeks while remaining on a HPD. Metabolic parameters, endocrine profiles, glucose tolerance tests, insulin sensitivity index, the expression of the glucose transporter GLUT4 and chromium distribution were measured in vivo. Lower body weight gain as well as a decreased caloric intake, fat pads, fatty liver scores, adipocyte size and glucose tolerance test values were observed in HPD-fed mice compared with mice fed a high-fat or standard diet. Despite these beneficial effects, rapamycin-treated lean mice showed greater glucose intolerance, reduced insulin sensitivity, lower muscle GLUT4 expression and changes in chromium levels in tissues even with high insulin levels. Our findings demonstrate that continuous rapamycin administration may lead to the development of diabetes syndrome, as it was found to induce hyperglycaemia and glucose intolerance in a lean animal model.

Induction of PD-L1 on monocytes: A new mechanism by which IVIg inhibits mixed lymphocyte reactions

Allograft rejection and graft-versus-host disease (GvHD) are frequent complications following solid organ or stem cell transplantation in which T cell activation plays a central role. Despite the development of new immunosuppressive drugs that improve the success rate of transplantation, allograft survival continues to be a challenge. Recently, intravenous immunoglobulin (IVIg) has been proposed as prophylaxis and post-transplant treatment to reduce acute rejection episodes. IVIg is a therapeutic agent that is known to down-modulate T cell functions in patients with autoimmune disorders. To test the hypothesis that this immunomodulatory effect could be beneficial in the context of transplantation, we used mixed lymphocyte reactions (MLR) as an in vitro model of allograft rejection and GvHD. Our results show that IVIg strongly inhibits the MLR as evaluated by IL-2 secretion, a well-known marker of T cell activation. IVIg also modulates the secretion of other pro-(IL-6, IFN-γ) and anti-inflammatory (IL-1RA) cytokines. More importantly, we show that IVIg induces monocytes with a CD80low PD-L1high phenotype and that blockade of PD-L1 partially abrogates the inhibitory effect of IVIg. We have thus identified a new mechanism by which IVIg inhibits T cell functions in the context of transplantation, supporting the potential usefulness of IVIg in the prevention or treatment of graft rejection and GvHD.

Invasive Mold Infection in Kidney Transplant Recipients: Observation of Early-Onset Mucormycosis

From the Division of Infectious Diseases and Tropical Medicine (M.C.), Division of Nephrology (A.V.), Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. Methee Chayakulkeeree and Attapong Vongwiwatana receive the Chalermphrakiat grant from the Faculty of Medicine Siriraj Hospital, Mahidol University. Address reprint requests to Attapong Vongwiwatana, MD, Division of Nephrology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Prannok Road, Bangkoknoi, Bangkok, 10700, Thailand. E-mail: siavw@hotmail. com INVASIVE FUNGAL DISEASE (IFD) is a major complication in solid organ transplant (SOT) recipients, resulting in allograft damage, morbidity, and mortality [1]. The overall incidence of IFD during the first year posttransplantation is about 3% and it varies by type of organ transplantation [2]. Although IFD is rare after 2 years posttransplantation, it can occur many years after transplantation, especially in those receiving high-dose immunosuppressive agents for treatment of graft rejection [3]. Yeasts such as Candida and Cryptococcus and molds such as Aspergillus and Mucorales are the most important pathogens that cause IFD in SOT recipients [4]. According to the Transplant-Associated Infection Surveillance Network report, the most prevalent fungal infection in SOT is candidiasis, followed by aspergillosis and cryptococcosis [2]. Non-Aspergillus mold infection in SOT is relatively rare, but difficult to treat [5]. The mortality of IFD in SOT is reported approximately 40% for aspergillosis, 34% for candidiasis, and 27% for cryptococcosis [2]. IFD was reported at 1.3% among kidney transplant (KT) recipients, which was relatively uncommon compared with other types of organ transplantation [2]. Small bowel and lung transplantation are among the highest risks for fungal infection [2]. Fungal infection in organ transplantation usually occurs after 3 months posttransplantation, when the immunosuppressive agents take greatest effect [3]. However, different fungal pathogens exhibit different onsets of diseases, and geographical factors may affect the epidemiology and manifestations of IFD in such patients. We hypothesize that the prevalence and characteristics of invasive mold infections (IMI) in KT recipients in tropical countries may be different from those in Western countries.

Aggressive Pulmonary Calcification Developed After Living Donor Kidney Transplantation in a Patient With Primary Hyperparathyroidism

Metastatic pulmonary calcification, defined as calcium deposition in the intact lung, is commonly seen in patients with chronic renal failure, and it is known to be a benign clinical condition when detected by chance in an asymptomatic patient. Here we report the case of a 33-year-old woman who developed rapid and aggressive metastatic pulmonary calcification shortly after a living donor kidney transplantation, which induced acute antibody-mediated rejection. The patient's metastatic pulmonary calcification was successfully improved by extensive treatment for graft rejection, the correction of her accompanying primary hyperparathyroidism, and medical treatment with a bisphosphonate and sodium thiosulfate. Aggressive pulmonary calcification is reported as a rare complication seen in patients who have undergone a failed renal transplantation. A failed renal graft and accompanying secondary hyperparathyroidism seem to accelerate metastatic calcification. Most of the patients who develop aggressive pulmonary calcification suffer from the rapid progression of dyspnea and occasionally fever, and they die of respiratory failure. Pulmonary calcification should be considered in a patient developing dyspnea and unexplained pulmonary infiltrate, especially in the context of renal graft rejection; otherwise the prognosis of the patient will be very poor.

53: Inhibition of interleukin-15 dependent cytotoxic T-cell proliferation by the action of adenosine on dendritic cells

Dendritic cells (DCs) regulate the immune response through production of various cytokines and signaling molecules, among which is IL-15, an important NK and cytotoxic T-cell (CTL) activator and survival factor. At the site of immune reaction, adenosine is produced from ATP by CD39 and CD73, ecto-enzymes expressed on regulatory T-cells (Treg). The aim of this present study was to examine the effect of adenosine on IL-15 production by DCs and the implication of this effect on CTL proliferation. Bone marrow derived DCs (BMDCs) were isolated from ICR mice. BMDCs were exposed to various adenosine receptor agonists/antagonist prior to stimulation with LPS and interferon- γ (IFN- γ ). Levels of cAMP, IL-15 and IL-15 receptor α chain (IL-15R α ) were measured using QPCR and/or ELISA. To assess the effect on CTL proliferation BMDCs were gamma-radiated and co-cultured with CTLL-2, a cytotoxic T-cell line, in the presence or absence of adenosine. Stimulation of BMDCs with LPS and IFN- γ increased IL-15 and IL-15R α levels. Treatment of stimulated BMDCs with adenosine significantly reduced IL-15/IL-15R α mRNA and protein levels. This down-regulatory effect was blocked by the combination of ZM 241385, an A 2 A R antagonist, and MRS1754, an A 2 B R antagonist, while addition of only one of them separately yielded a partial inhibitory effect. Treatment of BMDCs with adenosine receptor agonists increased cAMP levels, and di-butirilic-cAMP, a stable cAMP analog, effectively reduced IL-15R α levels. Finally, treatment of BMDCs with adenosine, before stimulation and co-culture, significantly reduced PBMC-dependent CTLL-2 proliferation. Our data indicate that adenosine acting through A 2 A R and A 2 B R by elevation of cAMP suppresses IL-15 and IL-15R α levels in activated DCs and restrains CTL proliferation. These finding can set a pharmacological base for CTL dependent pathologies such as graft rejection treatment.

Cognate antigen directs CD8+ T cell migration to vascularized transplants

The migration of effector or memory T cells to the graft is a critical event in the rejection of transplanted organs. The prevailing view is that the key steps involved in T cell migration - integrin-mediated firm adhesion followed by transendothelial migration - are dependent on the activation of Gαi-coupled chemokine receptors on T cells. In contrast to this view, we demonstrated in vivo that cognate antigen was necessary for the firm adhesion and transendothelial migration of CD8+ effector T cells specific to graft antigens and that both steps occurred independent of Gαi signaling. Presentation of cognate antigen by either graft endothelial cells or bone marrow-derived APCs that extend into the capillary lumen was sufficient for T cell migration. The adhesion and transmigration of antigen-nonspecific (bystander) effector T cells, on the other hand, remained dependent on Gαi, but required the presence of antigen-specific effector T cells. These findings underscore the primary role of cognate antigen presented by either endothelial cells or bone marrow-derived APCs in the migration of T cells across endothelial barriers and have important implications for the prevention and treatment of graft rejection.