Clinical Signs Of Acute Rejection Research Articles

427.1: Donor Dendritic Cell Depletion Allows Novel Insights Into the Alloimmune Response Following Murine Composite Tissue and Skin Transplantation

Background: Cell-based therapies in vascularized composite tissue allotransplantation (VCA) have demonstrated promising results with the potential to modify life-long conventional immunosuppression. Dendritic cells (DCs) promote pro-inflammatory, alloimmune responses. Of particular interest is the role of DCs as antigen-presenting cells and potential tolerogenic effects as immature DCs. Material and Methods: Diphteria Toxin Receptor (DTR) transgenic or wild-type (WT) donor mice were used to deplete subsets of DCs or APCs respectively in a fully histoincompatible murine hind limb and skin transplant models; prior to procurement, all donors were either treated with diphteria toxin (DT; at -15 hours) or with clodronate (CL; 8 days prior to Tx). DBA/2J mice served as recipients. Study endpoint was on POD 6. Alloimmune response was assessed sequentially; graft survival, intragraft structural and inflammatory changes were tested serially. Results: The total number of dendritic cells (CD11b- CD11c+ DC) had markedly increased in recipients of skin WT grafts compared to recipients of VCA WT grafts (p<0.0001). The treatment with CL or DT significantly reduced the numbers of maturated and activated DC in the spleen, blood, and LN of mice receiving a skin graft, whereas numbers of CD11b-CD11c+MHCII+ and CD11b-CD11c+CD40+ DC were exclusively reduced in the spleen of VCA recipients after donor pretreatment with DT. cDC 1 subtypes were significantly higher in VCA WT vs. skin WT recipients (p<0.001). Donor pretreatment with DT decreased cDC1 counts only in recipients of VCA grafts (p<0.001).Luminex analysis revealed significantly higher TNF-alpha serum levels in the VCA WT vs. skin WT group (p<0.01). TNF-beta serum levels were significantly decreased in VCA depletion groups vs VCA WT group (p<0.001). Clinical signs of acute rejection among the VCA groups revealed higher rejection grades in the WT compared to the DC depletion group according to the BANFF criteria (grade III vs. grade II). Additional injection of immature DCs did not show any difference in allograft survival (p=ns).Conclusion: This is to our knowledge the first systematic study delineating the role of mature and immature DCs tested across and skin transplants. Those data may help explaining split-tolerance phenomenon in VCA while providing a basic concept for the utilization of mature and immature DCs in modifying alloimmune responses in VCA transplants.

The Evolving Clinical Presentation of Acute Rejection in Facial Transplantation.

Acute rejection is one of the most frequent complications in facial transplantation, with potentially severe consequences for the recipient if overlooked. Clinical signs, such as erythema or edema, are helpful to diagnose acute rejection in the early follow-up stage; however, it is not well known whether these clinical signs remain reliable markers of acute rejection beyond the second posttransplant year. To determine the diagnostic value of clinical signs of acute rejection after facial transplantation over time. A retrospective, single-center cohort study was conducted of patients who underwent facial transplantation at Brigham and Women's Hospital between April 2009 and October 2014, with up to an 8-year follow-up. Medical records were reviewed until September 30, 2017. The medical records from 104 encounters with 7 patients who underwent partial or full facial transplantation were analyzed for symptoms of rejection, immunosuppressive therapy, and histopathologic findings. The occurrence of 5 clinical signs of acute rejection were evaluated: erythema, edema, exanthema, suture line erythema, and mucosal lesions. Odds ratios (ORs) were calculated to determine the statistically significant association of these signs with the histopathologic diagnosis of rejection. In addition, tacrolimus blood levels, as a surrogate marker of immunosuppressive therapy, were evaluated. Of the 7 patients included in the study, 5 were men. The mean follow-up was 66 months (range, 35-101). Of 104 clinical encounters, 46 encounters (44.2%) represented rejection episodes and 58 encounters (55.8%) represented no-rejection episodes. Beyond 2 years posttransplantation, only erythema (OR, 6.53; 95% CI, 1.84-20.11; P = .004) and exanthema (OR, ∞; 95% CI, 2.2-∞; P = .004) were demonstrated to be reliable clinical signs of acute rejection in facial transplantation. There was also a statistically significant association of subtherapeutic tacrolimus levels with late rejection episodes (OR, 3.79; 95% CI, 1.25-12.88; P = .03). In addition, the occurrence of subclinical rejection was more frequent during later follow-up times (7 [24.1%] late rejections vs 1 [5.9%] early rejection). Five of 8 subclinical rejections (62.5%) were associated with subtherapeutic tacrolimus levels. Clinical signs of acute rejection in facial transplantation appear to be of limited diagnostic value, particularly after the second postoperative year. Until alternative biomarkers for rejection are identified, protocol skin biopsies will remain necessary for guiding assessments of allograft rejection. 3.

Successful Liver Transplantation for Glycogen Storage Disease Type 1b

Glycogen storage disease type 1b is a rare metabolic inborn disease, caused by a defect of glucose-6-phosphatase-translocase that leads to an inadequate glucose metabolism in the liver with severe hypoglycemia and metabolic acidosis. Other clinical manifestations might include hyperuricemia, growth retardation, liver adenomas, neutropenia and neutrophil dysfunction. We present on a 37 year old female patient with glycogen storage disease type 1b, leukocytopenia and multiple liver adenomas. The patients quality of life was extremely poor due to frequent control of glucose concentrations at day and especially during night. Therefore, liver transplantation was indicated to correct the metabolic defect. Liver transplantation was performed in standard technique on 17.01.2010 using a postmortal full-size graft (CMV D−/R-, CIT 9h 42 min). The postoperative course was complicated by a reoperation to remove a hematoma on pod 5. Initial immunosuppression was converted from cyclosporine to tacrolimus due to clinical signs of acute rejection at the end of the first week. A wound infection required readmission from 04.-06.02.2010. The further clinical course after transplantation was uneventful. The patient is currently in an excellent condition with normal liver function tests and dramatically improved quality of life. In the literature, only three other reports have been published on adult patients undergoing liver transplantation for glycogen storage disease type 1b. Glycogen storage disease type 1b is a very rare indication for liver transplantation, which can dramatically improve quality of life in selected patients.

Immunological Issues in Clinical Composite Tissue Allotransplantation

Composite tissue allografts are made of histogenetically different tissues and although skin seems to be the most antigenic of them, it is unknown whether the dominant immune response is really directed against the skin or we have insufficient information on the involvement of the other components of these allografts. The first clinical signs of acute rejection manifest on the skin and microscopically the earliest lesions consist in a dermal perivascular lymphocytic infiltrate, predominantly made of CD3+/CD4+ T cells. On the basis of the histological changes, a specific score (Banff score 2007) has been established to assess the severity of rejection. Despite the high incidence of acute rejection episodes, they can be completely reversed when promptly diagnosed and treated. C4d deposits in the skin and circulating donor-specific antibodies are rarely detected, suggesting that humoral rejection does not play a significant role in composite tissue allotransplantation. Chronic rejection features are still unknown. The majority of recipients have been maintained on an immunosuppressive regimen consisting of tacrolimus, steroids, and mycophenolate mofetil. The complications in composite tissue allotransplantation are similar to those usually reported after solid organ transplantation and have prompted different strategies to minimize the maintenance immunosuppression or to induce donor-specific tolerance. Furthermore, to what extent the immunosuppression can be tapered is unknown, as well as the influence of donor bone-marrow infusion in tolerance and chronic rejection. The increasing number of patients and the longer follow-up hopefully will allow answering these questions.

HHV-6 infection in a pediatric kidney transplant patient

Human herpesvirus 6 (HHV-6) infection can induce unusual complications in transplant patients, such as interstitial pneumonitis, encephalitis and marrow aplasia. We describe the clinical course of HHV-6 infection in a girl with renal transplantation. She presented with diarrhea and poor feeding on day 36 post-transplantation (Tx), after a 5-day steroid pulse for clinical signs of acute rejection. A week later she developed fever and had elevated plasma creatinine and lactic dehydrogenase levels, but a physical examination did not reveal any anomalies with respect to suggest rash, pneumonitis, encephalitis or lymphadenopathy. Two weeks later, the patient developed anemia and leucopenia. HHV-6 was the only pathogen detected by the PCR assay of the serum and marrow aspiration. The patient had a successful recovery without specific treatment. This case report highlights the wide spectrum of complications resulting from HHV-6 infection in immunosuppressed patients.

MYCOPHENOLATE MOFETIL IN PEDIATRIC RENAL TRANSPLANTATION WITHOUT INDUCTION THERAPY: RESULTS AFTER 12 MONTHS OF TREATMENT1,2

Acute rejection episodes (ARE) of kidney transplants are considered as risk factor in the development of chronic rejection. In adult renal transplantation (RTx), ARE have been significantly reduced by mycophenolate mofetil (MMF) in combination with cyclosporin (CyA) and steroids (Pred). Reports of pediatric RTx on a maintenance immunosuppression with MMF are restricted to patients (P) after antibody induction therapy. The efficacy and safety of MMF combined with CyA and Pred in pediatric RTx without induction therapy were evaluated in an open-labeled multicenter study. From 10/1996 to 6/1999, 65 pediatric P (MMF group) were followed for at least 6 months, 58 of 65 for 12 months. These P were compared with 54 retrospectively analyzed pediatric P who were transplanted between 1990 and 1996 and had received CyA, Pred, and azathioprine for immunosuppression (historic AZA group). Within the first 6 months after RTx, 18 of 65 (MMF group) and 32 of 54 (historic AZA group) P showed clinical signs of acute rejection (P<0.01). Thereafter only one further P in the MMF group developed a first ARE. Graft loss due to rejection occurred in one MMF- and seven AZA-treated P (P<0.05). The creatinine-clearance 3 and 6 months after RTx was higher in the MMF group. Major adverse events (MMF group) included infections of the urinary and the upper respiratory tract, diarrhea, and leukopenia. Cytomegalovirus-infection occurred in 13 P and 2 P developed cytomegalovirus disease. One P developed PTLD 10 months after RTx and recovered after the reduction of immunosuppression. The combination of MMF, CyA, and Pred reduced ARE in pediatric RTx without incurring major side effects.

Perforin expression in peripheral blood lymphocytes in rejecting and tolerant kidney transplant recipients.

Perforin (P) is a cytolytic molecule expressed in the granules of cytolytic T cells and natural killer cells. Although cytotoxic cells have been implicated in graft rejection, no prospective clinical study has been published that examines the dynamics of perforin expressing cells in peripheral blood lymphocytes of transplanted patients. The cytofluorimetric assay developed in our laboratory previously for the simultaneous detection of intracellular perforin together with cell surface molecules was used for posttransplantation monitoring of patients, for the assessment of the efficiency of immunosuppressive treatment, and for the prediction of acute kidney transplant rejection and the stability of tolerance to long lived kidney transplants. Immunosuppression for the purpose of allotransplantation causes a decline in the number of perforin-expressing cells in peripheral blood. In contrast, in patients with clinical signs of acute rejection, the total number of perforin-expressing lymphocytes was increased in comparison with nonrejecting patients. Analyzing perforin-expressing subsets, rejection crises were accompanied by a relative decrease of perforin expression in the CD4+ subpopulation while increasing in the CD8+ subset. In the CD56+ and CD16+ NK subpopulations changes in perforin expression were mixed. In nonrejecting patients the ratio of perforin expression in CD4+ cells was high compared with CD8+ cells. Intensive therapy of acute rejection episodes with high doses of corticosteroids (methylprednisolonet [Solumedrol] bolus) strongly and significantly decreased the percentage of both, the subpopulations of perforin-positive T cells and the subpopulation of CD56+P+ NK cells. The lowest level of perforin expression, including low frequencies of perforin among CD8+ and CD4+ cells, was found in the group of patients tolerating transplanted kidneys for several years. These changes in perforin protein expression in peripheral blood can be used to discriminate between immunosuppressed patients who are immunologically quiescent and those who undergo transplant rejection. Our results confirm the hypothesis that cytotoxicity mediated by perforin may be an important effector mechanism in the rejection of allografted kidneys.

IMMUNOHISTOCHEMICAL STUDY OF THE CELLS INFILTRATING HUMAN RENAL ALLOGRAFTS BY THE ABC AND THE IGSS METHOD USING MONOCLONAL ANTIBODIES

Sixty renal allograft tissues obtained from 29 patients were stained with hematoxylin and eosin. These tissues were histologically classified into 4 patterns according to the distribution pattern of the infiltrating cells: normal, focal, focal-diffuse, and diffuse types. Clinical signs of acute rejection were observed in 88% of the patients with the diffuse type infiltration, and 83% of those with the focal-diffuse type infiltration but in only 13% of those with the focal type infiltration. Twenty-four renal allografts were analyzed by the ABC and the IGSS methods using monoclonal antibodies. The number of T cells (Leu 1) accounted for about 80% of the total number of infiltrating cells; 2-8% of the cells were B cells (Leu 12); about 10% were NK/K cells (Leu 7); and 4-6% were monocytes/macrophages (Leu M3). As to helper/inducer T cell (Leu3a) and killer/suppressor T cell (Leu2a), which are T lymphocyte subsets, there were more Leu3a- than Leu2a-positive cells in focal type tissue, but there were more Leu2a- than Leu3a-positive cells in focal-diffuse and diffuse type tissue. In most cases that developed clinical signs of acute rejection, there were more Leu2a- than Leu3a-positive cells. The Leu3a/Leu2a ratio in most of the AZA-administered cases dropped immediately after the transplantation and maintained a low value, but in the CSA-administered cases it decreased gradually post-transplant.

Immunogenicity of human amniotic epithelial cells after transplantation into volunteers.

Human amniotic epithelial cells do not express on their surfaces HLA-A, B, C, and DR antigens, or beta 2-microglobulin. In vitro these cells synthesise the enzymes lacking in patients with selected enzymatic deficiencies: the survival of a transplanted monolayer of human amniotic epithelial cells was therefore investigated in seven volunteers. None of the volunteers showed clinical signs of acute rejection, and amniotic epithelial cells were demonstrated by biopsy up to 7 weeks after implantation. HLA antibodies were not detected in samples of serum from four volunteers thoroughly investigated, and there was no in-vitro lymphocyte reaction to the amniotic cells in two of them. The results suggest that acute immune rejection does not occur after the transplantation of human amniotic epithelial cells.