Giovanbattista Ippoliti

Neoplastic disease after heart transplantation: single center experience

OBJECTIVES Mandatory use of prolonged immunosuppression in organ transplantation is complicated by an increased incidence of cancer. The current study represents a retrospective analysis of the incidence of neoplasms in our heart transplantation program. METHODS Four-hundred and seventy-four patients (403 male and 71 female; mean age, 48.6+/-12.1 years), with at least 30 days of follow-up, were enrolled in this study. Patients received triple immunosuppression with cyclosporin A, azathioprine and steroids. Moreover, as a prophylactic anti-lymphocyte therapy, 388 patients (82%) were administered RATG, 67 patients (14%) received ALG and 19 patients (4%) OKT3. The mean follow-up time was 71.1+/-43.0 months. RESULTS Fifty-five patients (11.6%) developed malignant neoplasms. The cancer frequencies were: solid tumors, 55%; non-Hodgkin lymphomas (NHL), 20%; Kaposis sarcomas, 11%; skin cancers, 9%; undifferentiated sarcomas and myelomas, 5%. Solid tumors mainly affected the lung (39%), bowel (16%), stomach (6.5%), liver (6.5%), pancreas (6.5%) and oral cavity (6.5%). The times to the onset of cancer from transplantation were: Kaposis sarcoma, 12.7+/-16.8 months; skin cancers, 34.5+/-23.8 months; solid tumors, 54.3+/-38.7 months; NHL, 60.1+/-36.4 months; undifferentiated sarcomas and myelomas, 90.0+/-15.6 months. As determined by univariate and multivariate analyses, sex, number of treated rejections, previous history of tumor, average dose of cyclosporine and prednisone and cyclosporine blood levels did not increase the incidence of malignancies. Univariate analysis suggests a significant correlation between the type of prophylactic immunoglobulins and the average dose of azathioprine with the incidence of neoplasms. Both univariate and multivariate analyses demonstrated a significant correlation between patients age at the time of transplantation and risk of cancer occurrence (risk increased by 1.074/year; P=0.0056 with multivariate Cox regression). CONCLUSIONS Cancer is a strong limitation for long-term survival after heart transplantation. The only risk factor recognized is the patients age at the time of transplant. Furthermore, the type of prophylactic globulins used for induction therapy and some specific immunosuppressant agent (azathioprine) may play a significant role in the development of malignancies after transplantation.

EBV Positive Primary Cutaneous CD30+ Large T‐Cell Lymphoma in a Heart Transplanted Patient: Case Report

Most post‐transplant lymphoproliferative disorders (PTLDs) are of B‐cell origin, whereas T‐cell lymphomas rarely occur. We detail the clinicopathological features of the first case of Epstein–Barr virus (EBV)‐associated primary cutaneous CD30+ anaplastic large cell lymphoma (ALCL) in the setting of heart transplant. A 71‐year‐old patient, 111 months after transplant, presented with multiple cutaneous lesions on the left thigh; histological and immunohistochemical examinations led to diagnosis of T‐cell CD30+ ALCL. In situ hybridization demonstrated the presence of EBV‐positive tumour cells. The patient received radiotherapy, but he relapsed at the same cutaneous site with loco‐regional nodal spread. Chemotherapy was administered resulting in complete remission; four years later the patient is alive and well. Our findings indicate that primary cutaneous EBV+ CD30+ ALCLs should be included within the T‐cell PTLDs spectrum; further studies are required to confirm whether they may be also considered, in transplantation settings, a distinct lymphoma subset with relatively favourable outcome.

Clodronate treatment of established bone loss in cardiac recipients: a randomized study.

Background. Bone loss has been reported as a complication after heart transplantation (HTx), and the increase in bone fractures is an effective problem. Treatment of osteoporosis has obtained mixed results. In this study we evaluate the effect of treatment with an oral bisphosphonate. Methods. Sixty-four patients with low mineral density 6 months after HTx were randomized as follows: Group A received oral clodronate (1600 mg/day in two divided doses), and Group B received placebo. Every patient was also treated with 2000 mg/day of oral calcium carbonate. Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry at the lumbar spine, 1/3 and 1/10 of the distal nondominant forearm before and after 12 months of treatment. Laboratory tests were performed at 3, 6, and 12 months of treatment. Results. All patients demonstrated manifest bone loss 6 months after HTx compared with normal non-HTx controls (P =0.0001). After 1 year of clodronate therapy, BMD at the lumbar spine increased from 0.77±1.4 g/cm2 to 0.86 g/cm2 (P =0.02). Laboratory tests did not show any significant variation, except for the bone isoenzyme of alkaline phosphatase, which showed a significant decrease after 1 year of treatment. The incidence of new fractures was 9.3% in the placebo group and 0% in the clodronate group. Therapy was well tolerated without impact on graft function. Conclusions. One year of clodronate therapy induced a significant increase in BMD at the lumbar spine in our HTx patients. Treatment was well tolerated without onset of new bone fractures.

B-cell posttransplant lymphoproliferative disorders in heart and/or lungs recipients: clinical and molecular-histogenetic study of 17 cases from a single institution.

Background. Posttransplantation lymphoproliferative disorders (PTLDs) are heterogeneous lymphoid proliferations representing a major complication of solid organ transplant. This study details the clinicopathological and molecular features of 17 B-cell PTLDs observed in a single center series of 988 heart and/or lung transplant recipients. Methods. Cases were classified according to World Health Organization lymphoma classification and tested for Epstein-Barr Virus (EBV), clonality, histogenetic phenotypic (CD10, Bcl-6, MUM1, CD138), and genotypic (immunoglobulin and BCL-6 genes somatic hypermutation) markers. Results. This series of 17 PTLDs included: two B-cell monoclonal polymorphic PTLDs and 15 B-cell monomorphic PTLDs (13 diffuse large B-cell lymphomas [DLBCL] and 2 Burkitt lymphomas [BL]). EBV was detected in 9/17 cases. A monoclonal immunoglobulin variable (IGV) genes rearrangement was documented in 17/17 cases; IGV somatic hypermutation was found in 88% of cases, indicating a prevalent origin from germinal center (GC)-experienced B cells. Using immunophenotypic markers, three histogenetic profiles were identified: a) CD10+/bcl-6+/MUM1−/CD138−, mimicking GC B-cells; b) CD10-/bcl-6+/MUM1+/CD138−, reminiscent of B-cells at the latest phases of GC reaction; and c) CD10−/bcl-6−/MUM1+/CD138±, consistent with preterminally differentiated B-cells. Conclusions. Correlation between morphology, histogenesis, and EBV status demonstrated a high degree of homogeneity in the two GC-related groups, mostly including EBV-negative cases with BL and DLBCL-centroblastic features; the third group, consisting of post GC EBV-positive cases, was histologically less homogeneous, as it included polymorphic PTLDs and DLBCL with immunoblastic and anaplastic features. The EBV-negative cases with GC histogenetic phenotype showed a slightly better outcome; however, such less aggressive prognostic trend was not confirmed by statistical analysis.

Functional effects of a monoclonal antibody directed against a distinct epitope on 4F2 molecular complex in human peripheral blood mononuclear cell activation

The 4F2 antigenic complex is expressed on most human cell lines in culture, on monocytes and activated lymphocytes, but not on resting T and B lymphocytes. Monoclonal antibody (mAb) CB43 recognizes an epitope of the 4F2 heterodimer either located on the light chain or dependent on the conformation of the molecule. The binding of CB43 mAb to peripheral blood mononuclear cells (PBMC) induced a dose-dependent comitogenic effect in the presence of submitogenic concentrations of anti-CD3 mAb. Significant amounts of interleukin (IL)-1 beta but not IL-2 or interferon-gamma were released in the supernatant. Pretreatment of monocytes with CB43 mAb increased the phytohemagglutinin-induced T lymphocyte proliferation. However, CB43 mAb did not exert agonistic effects on activated T lymphocytes. Depletion of CB43+ cells from PBMC decreased the proliferation and generation of cytotoxic effector cells induced by a mannoprotein (MP) derived from Candida albicans cell wall but not by recombinant IL-2. Furthermore, depletion of CB43+ cells from PBMC preactivated with MP or rIL-2 led to a significant decrease in their cytotoxic activity. CB43 mAb did not inhibit the growth of cell lines nor the proliferation of T cells. Thus CB43 mAb identifies a distinct functional epitope on the 4F2 molecular complex and might be useful in further studying the role of this molecule in cellular activation.

Fetal erythroblast isolation up to purity from cord blood and their culture in vitro

BACKGROUND Erythroblasts have been the most encouraging candidate cell type for noninvasive prenatal genetic investigation. We previously showed that human erythroblasts can be recovered from bone marrow and blood bank buffy coats by a physical cell separation. In the present study, we modified our previous methodology, taking into account the peculiar behavior of erythroblasts in response to modifications of pH and osmolality of the separation medium. METHODS Twenty to forty milliters of cord blood were initially centrifuged on Ficoll/diatrizoate (1.085 g/ml). The interphase cells were further separated on a continuous density gradient (1.040-1.085 g/ml). Two different gradients were initially compared: the first was iso-osmolar and neutral, whereas the second also contained an ionic strength gradient and a pH gradient (triple gradient). A subsequent monocyte depletion was performed by using magnetic microbeads coated with anti-CD14 monoclonal antibody (mAb), and erythroblasts were purified by sedimentation velocity. Purified cells were investigated by analyses with fluorescence-activated cell sorting (FACS) and fluorescence in situ hybridization (FISH) and immunocytochemistry with mAb against fetal hemoglobin and were cultured in vitro. RESULTS When nucleated cells were spun on an iso-osmolar and neutral continuous density gradient, two separated bands of nucleated red blood cells (NRBCs) were obtained: a light fraction banding at 1.062 g/ml and an heavy fraction banding at 1.078 g/ml. Conversely, when cells were spun in the triple gradient, NRBCs were shifted to the low-density region. Monocyte depletion by immunomagnetic microbeads and velocity sedimentation provided a pure erythroblast population. FACS and FISH analyses and immunocytochemistry substantiated the purity of the isolated cell fraction, which was successfully cultured in vitro. CONCLUSIONS We have shown that fetal erythroblasts can be purified up to homogeneity from cord blood, but further refinements of the isolation procedure are necessary before the same results can be obtained from maternal peripheral blood.

Introduction to the use of belatacept: a fusion protein for the prevention of posttransplant kidney rejection

The development of new immunosuppressive drugs for kidney transplantation resulted both in better short-term outcomes and in decreased metabolic, cardiovascular, and nephrotoxicity risk. Belatacept belongs to a new class of immunosuppressive drugs that selectively inhibits T-cell activation by preventing CD28 activation and by binding its ligands B7-1 and B7-2. The result is an inactivation of costimulatory pathways. A comparative analysis of the BENEFIT and BENEFIT-EXT datasets showed belatacept regimens resulted in better cardiovascular and metabolic risk profiles than did cyclosporin A (CsA) regimens: belatacept likewise outperformed CsA in terms of lower blood pressure and serum lipids and less new onset diabetes after transplantation. About 20% of belatacept-treated patients developed adverse effects which included anemia, pyrexia, neutropenia, diarrhea, urinary tract infection, headache, and peripheral edema. At present, belatacept does not seem to predispose patients to a higher rate of infection than CsA maintenance immunosuppression. The risk of posttransplant lymphoproliferative diseases was higher in Epstein–Barr virus (EBV)-seronegative patients than in EBV-seropositive patients, but the risk may be reduced by use of a less intensive regimen and avoidance of EBV-negative patients and of patients whose pretransplant EBV serology is unknown. Belatacept provides a new option for immunosuppressive therapy in kidney transplantation, but needs further evaluation in terms of the late effects that may derive from prolonged blockage of the costimulatory system and the induction of tolerance status.

Immunocytochemical detection of factor XIII A--subunit in acute leukemia.

Factor XIII (FXIII) is a plasma pro-transglutaminase consisting of A and B subunits in a tetrameric structure. A cellular form of FXIII consisting exclusively of A subunits exists in platelets and monocytes: monocyte FXIII may be involved in connective tissue organization. To evaluate the expression and diagnostic significance of FXIII A subunit (FXIIIA) in acute leukemia, we performed an immunocytochemical study (PAP technique) with rabbit antiserum against FXIIIA on leukemic blasts of 48 cases. FXIIIA was detected only in myelomonocytic (M4), monocytic (M5) and megakaryocytic (M7) cases: in M4 and M5 samples the amount of blast cytoplasmic FXIIIA was closely correlated with the expression of monocyte-specific antigenic and cytochemical markers. Our data show immunocytochemical detection of FXIIIA to be useful for acute leukemia characterization.

Immunomodulation with rabbit anti-thymocyte globulin in solid organ transplantation

Rabbit anti-thymocyte globulins manifold mechanisms of action may be attribuited to its polyclonal nature. Its T-cell depleting effect on lymphoid cells is well established: Occurring in the blood and secondary lymphoid tissues, depletion proceeds through complement-dependent lysis, opsonization and apoptotic pathways. Clinical studies have shown that rabbit anti-thymocyte globulins immunomodulatory effect extends beyond the initial T-cell depletion and up to the period during which lymphocyte populations begin to recover. The drug is able to mediate immunomodulation and graft tolerance by functionally inactivating cell surface receptors involved in antigen recognition, leukocyte trafficking and leukocyte endothelium adhesion. The complex and prolonged immunomodulation induced by this drug contributes to its efficacy in solid organ transplantation, mainly by reducing the incidence of acute graft rejection.

Leukocytoclastic Vasculitis as a Complication of Recombinant Granulocyte Colony-Stimulating Factor Therapy in a Heart Transplant Patient

Recombinant granulocyte colony-stimulating factor (rG-CSF) is a myeloid growth factor that is widely used in haematology to recover neutropenia secondary to myelosuppressive chemotherapy. Leukocytoclastic vasculitis is an acknowledged side effect of the above therapy. Its pathogenesis involves many mechanisms that collectively induce an increase in neutrophil function and a subsequent release of cytokines. Here, we report a case of leukocytoclastic vasculitis proven by skin biopsy, following the use of rG-CSF in a heart transplant patient with leukopenia secondary to immunosuppressive therapy.