New strategies for prevention and treatment of graft-versus-host disease and for induction of graft-versus-leukemia effects

Graft-versus-host disease in paediatric solid organ transplantation: A review of the literature

GvHD is a rare and serious complication of organ transplantation. The literature is sparse following solid organ transplantation. The aim of this report was to review the literature of GvHD in paediatric solid organ transplantation. We searched PubMed for English-language full-text manuscripts between 1990 and 2015 for eligible studies. A total of 28 publications were found pertaining to paediatric GvHD following solid organ transplantation. GvHD had a mean incidence of 11% (range 8.3-13.4%) following SBTx and 1.5% following liver transplantation. Where described, the most common sites for presentation of GvHD were the skin (87%), the native GI tract (43%), the lungs (7%), the eyes (4%), HA (4%), and the kidneys (1%). Diagnosis was confirmed with biopsy (93%) and/or chimerism (41%). Treatments used include steroids (80%), of which 75% showed partial or complete resolution. Mortality was 33.3% (range 0-100%). Novel therapies include ECP and MSC therapy. GvHD is a rare but serious disease with high mortality. Novel therapies may offer hope in the future, but currently there is limited evidence for their efficacy in the context of intestinal or liver transplantation.

[Intraabdominal infection in inmunodepressed patients]

Diseases of the gastrointestinal system frequently complicate immunosuppressed patients. Endogenous flora is the principal source of infection in humans, especially in patients with dysfunction of the digestive epithelial barrier due to various factors. Bacterial translocation, traumatisms, ischemia and surgery are frequent events in the general population. In addition, important risk factors for abdominal infections in specific patients include tumoral infiltration, mucositis complicating chemotherapy and/or radiotherapy, hypoproteinemia, neutropenia and lymphocyte deficiency. Clinical pictures vary according to patients' baseline condition and the environmental setting, including nosocomial infections. The differential clinical characteristics of abdominal infections observed in distinct types of immunosuppressed patients are reviewed.

Hematopoietic stem cell transplantation: implications for critical care nurses

Hematopoietic stem cell transplantation (HSCT) is being used increasingly in the treatment of malignant and nonmalignant diseases. The treatment modality has been proven effective but is not without risks. Studies consistently have identified the need for advanced supportive care (e.g., multiple organ dysfunction, vasopressor use, mechanical ventilation) as a negative prognostic indicator in patients who have received HSCT. Among patients who have received HSCT, 15%-40% require critical care monitoring or advanced support. Nurses on intensive care units can positively impact outcomes for transplant recipients when they possess the specialized skills to recognize and promptly intervene when transplant-related complications arise. This article will provide a basic overview of the HSCT process and outline the complications that may necessitate transfer to a higher level of care for specialized skills and equipment in the intensive care setting.

T cell-mediated immunotherapy of metastases: state of the art in 2005

Advances in cellular and molecular immunology have led to the development of strategies for effective augmentation of antitumour immune responses in cancer patients. This review focuses on the manipulation of T cell immunity either by active specific immunotherapy (ASI) using tumour vaccines, or by adoptive immunotherapy (ADI) with immune T cells. Such therapies offer exquisite specificity of tumour recognition based on the ability of the T cell to distinguish single amino acid differences in any protein from any compartment of the tumour cell. Examples are presented of clinical survival benefits for cancer patients by postoperative ASI with a modified autologous tumour vaccine of high quality. Furthermore, clinical studies employing ADI with T cells activated and expanded ex vivo have demonstrated 'proof of principle' that tumour-specific T cells are capable of mediating anticancer activity in vivo, as measured by regression of metastatic tumours. Translation of these findings into a standardised immunotherapy is, however, not easy and will require coordination and cooperation among academic, private and federal sectors.

Hematologic aspects of myeloablative therapy and bone marrow transplantation

The transplantation of bone marrow cells or isolated hematopoietic stem cells from the bone marrow or peripheral blood is a widely utilized form of therapy for patients with incurable diseases of the hematopoietic and immune systems. Successful engraftment of the transplanted stem cells in an adequately prepared recipient normally leads to bone marrow reconstitution over a period of several weeks, accompanied by more gradual reconstitution of the immune system. Since the recipient is profoundly ill during the initial treatment period, laboratory data is critical for monitoring engraftment, detecting residual/recurrent disease, and identifying problems that may delay bone marrow reconstitution or lead to other medical complications. Accurate blood cell counts are imperative, and most bone marrow transplantation patients undergo periodic monitoring with bone marrow aspirates and biopsies with cytogenetic, molecular, and multiparametric flow cytometric studies. The potential complications of bone marrow transplantation include engraftment failure and delayed engraftment, infection, residual bone marrow disease, acute and chronic graft versus host disease, myelofibrosis, therapy-related acute leukemia, post-transplant lympho-proliferative disorders, and toxic myelopathy.

Target Antigens Determine Graft-versus-Host Disease Phenotype

Chronic graft-vs-host disease (cGVHD) is an increasingly frequent complication of allogeneic stem cell transplantation. Phenotypically, cGVHD differs from patient to patient; in particular, a subset of patients develops extensive cutaneous fibrosis. Similarly, graft-vs-host disease (GVHD) is distinct in inbred murine donor:recipient pairings, indicating a genetic component to disease phenotype. The B10.D2 -->BALB/c (H-2d) strain pairing uniquely recapitulates key pathologic features of fibrotic human cutaneous cGVHD. To distinguish whether this genetic component is due to differences in genes that modulate immune responses or to the specific Ags targeted, we asked whether skin-dominant cGVHD also develops in the B10 -->BALB.B (H-2b) and B10.BR -->BALB.K (H-2k) MHC-congenic pairings. Because each MHC haplotype presents different peptides and selects different T cell repertoires, GVHD in each donor:recipient pair undoubtedly targets different Ags. We found that, in contrast to BALB/c recipients, BALB.B mice never manifested skin disease while BALB.K mice developed a modified form of skin disease. Instead, BALB.B and BALB.K recipients developed systemic GVHD which was absent in BALB/c mice. Moreover, in (B10 x B10.D2)F1 -->(BALB.B x BALB/c)F1 H-2b/d transplants, recipients developed both cutaneous and systemic disease. Thus, the selection of immunodominant Ags determines the target and character of GVHD, providing insight into the genetic basis for different forms of GVHD.

Graft versus host disease in intestinal transplantation

Our aim was to analyze the clinical course and outcome of patients with graft vs. host disease (GVHD) after intestinal transplantation (ITx). All patients receiving ITx between May, 1990 and December, 2003 were retrospectively reviewed for evidence of GVHD. Two hundred and fifty patients underwent ITx during the study period. Graft vs. host disease was suspected clinically in 23 patients on the clinical basis of presentation such as skin rash, ulceration of oral mucosa, diarrhea, lymphadenopathy, or native liver dysfunction. Fourteen (eight children and six adults) patients (5.6% of total patient population) had GVHD confirmed by histopathological criteria including keratinocyte necrosis (n = 9), epithelial apoptosis of the native gastrointestinal tract (n = 4), and epithelial cell necrosis of oral mucosa (n = 1). Donor-cell tissue infiltration or extensive peripheral blood donor-cell chimerism was documented on seven occasions. The majority of cases of GVHD resolved with steroid administration and optimization of tacrolimus immunosuppression. The incidence of histologically proven GVHD after clinical intestinal transplantation is 6.5% (8/122) in children and 4.7% (6/128) in adults. Successful clinical management requires a high index of suspicion to minimize morbidity and mortality. Diagnostic and treatment strategies based on this experience are proposed.

Minor histocompatibility antigens: allo target molecules for tumor-specific immunotherapy

Minor histocompatibility antigens have to be considered as key molecules in the stem cell-based immunotherapy of malignancies. Allogeneic stem cell transplantation (SCT) is a well-established and effective therapy for advanced hematologic malignancies. The apparent powerful graft-versus-leukemia effect of SCT led clinicians to apply SCT for the treatment of metastatic solid tumors. The SCT-based graft-versus-tumor reaction in the allogeneic human leukocyte antigen-matched SCT setting is mediated by allo-immune effectorcells directed against tumor-related target antigens. The target molecules involved in the allo-immune graft-versus-tumor reaction are tumor-specific antigens, tumor-associated antigens, and tissue- and cell-specific minor histocompatibility antigens. The power of the minor histocompatibility antigens in the human leukocyte antigen-identical, stem cell-based immunotherapy for malignancies is their "allo-ness." As opposed to tumor-associated self antigens, the complexes of MHC and allo-target peptide are likely to be more immunogeneic than the major histocompatibility complex and self-target peptide complexes. Moreover, minor histocompatibility allo-antigens are not subject to self tolerance. Earlier minor histocompatibility antigens were seen as alien entities, disturbing the success of the so ideally matched organ and SCT donor-recipient combinations. To date, minor histocompatibility antigens can be set in the favorable light of useful tools for immunotherapy for cancer. The first clinical application of the hematopoietic minor histocompatibility antigens HA-1 and HA-2 is currently being explored in a stem cell-based setting for hematologic malignancies. Because HA-1 is also expressed on carcinoma cells, a stem cell-based vaccination trial for patients with metastatic breast or renal cancer is about to start as well. The immunotherapeutic potential of minor histocompatibility antigens demands serious searches for new minor histocompatibility antigens and analyses of their phenotype frequency, tissue distribution, and functional membrane expression. The minor histocompatibility antigens meeting the prerequisites for specific immunotherapy for malignancies, such as membrane expression and tissue and/or cell specificity, may offer the curative tools for stem cell-based immunotherapy for various hematologic and nonhematologic malignancies.