Posttransplant Malignancy

Post-transplant lymphoproliferative disorder presenting with skin ulceration in a renal transplant recipient who achieved sustained remission with rituximab therapy: A case report

Post-transplant lymphoproliferative disorder (PTLD) is associated with a variety of clinical presentations, but rarely involves the skin. We herein report a case of PTLD presenting with skin ulceration in a renal transplant recipient. A biopsy of the ulcer confirmed the diagnosis of diffuse large B-cell lymphoma. The patient was initially treated with immunosuppression reduction, but the skin ulcer persisted. He was then treated with two courses of chemotherapy, but his condition was complicated with cryptococcal infection. Antifungal agents were administered to control the fungal infection. The patient later developed lymphoma recurrence and was successfully treated with single-agent rituximab. The patient remains well 6 years after treatment, with no evidence of disease relapse. Therefore, PTLD may manifest as skin lesions and physicians must be aware of this rare presentation.

Ethics at the end of life in transplant recipients

The field of transplantation is intended to try to save or improve people's lives. In some situations though, the length of a person's life is not as vital as the quality of that life. As a member of a transplant team, one must recognize the differences between quality and quantity and apply the ethical principles of autonomy, justice, nonmaleficence, and beneficence. When a lung transplant recipient became ill with posttransplant lymphoproliferative disease 10 months after her surgery, these ethical principles came to the foreground. This dynamic, vibrant woman, recently engaged, faced her own mortality with grace. There is a time for everything. When death is a long time coming, many people are referred to hospice care and the death is viewed as a blessing. This situation rarely occurs in the transplant field. Many people, whether professionals or laypersons, have a difficult time letting go. Our team and this very special woman all knew when it was time. Creating a warm and open environment in the intensive care unit helped her through the rhythms of transition in dying.

Ethics at the End of Life in Transplant Recipients

The field of transplantation is intended to try to save or improve people's lives. In some situations though, the length of a person's life is not as vital as the quality of that life. As a member of a transplant team, one must recognize the differences between quality and quantity and apply the ethical principles of autonomy, justice, nonmaleficence, and beneficence. When a lung transplant recipient became ill with posttransplant lymphoproliferative disease 10 months after her surgery, these ethical principles came to the foreground. This dynamic, vibrant woman, recently engaged, faced her own mortality with grace. There is a time for everything. When death is a long time coming, many people are referred to hospice care and the death is viewed as a blessing. This situation rarely occurs in the transplant field. Many people, whether professionals or laypersons, have a difficult time letting go. Our team and this very special woman all knew when it was time. Creating a warm and open environment in the intensive care unit helped her through the rhythms of transition in dying.

Hematopoietic stem cell transplantation after posttransplant lymphoproliferative disorder

A 16-yr-old girl received liver transplantation for fulminant hepatitis. Aplastic anemia developed, and she received hematopoietic stem cell transplantation (HSCT). Eleven months after liver transplantation, abdominal lymph node enlargement and colon ulcers were observed, and colon biopsy showed posttransplant lymphoproliferative disorder (PTLD). Immunosuppression reduction was attempted, but it produced no therapeutic effect. Fourteen months after liver transplantation, she received a second HSCT due to engraftment failure, and PTLD resolved completely. The second HSCT can serve as cellular therapy for PTLD.

Autologous tumor rejection in humans: trimming the myths

There is overwhelming evidence that the human immune system can keep in check the growth of autologous tumors. Yet, this phenomenon is rare and most often tumors survive striking a balance with the host's immune system. The well-documented coexistence of immune cells that can recognize cancer and their targets within the same host is reminiscent of chronic allograft rejection well-controlled by immune suppression or of a lingering tissue-specific autoimmune reaction. In this review, we argue that autologous tumor rejection represents a distinct form of tissue-specific rejection similar to acute allograft rejection or to flares of autoimmunity. Here we discuss similarities within the biology of these phenomena that may converge into a common immunological constant of rejection. The purpose is to simplify the basis of immune rejection to its bare bones critically dissecting the significance of those components proposed by experimental models as harbingers of this final outcome.

Interleukin-10-secreting type 1 regulatory T cells in rodents and humans

Interleukin-10 (IL-10)-secreting T regulatory type 1 (Tr1) cells are defined by their specific cytokine production profile, which includes the secretion of high levels of IL-10 and transforming growth factor-beta(TGF-beta), and by their ability to suppress antigen-specific effector T-cell responses via a cytokine-dependent mechanism. In contrast to the naturally occurring CD4+ CD25+ T regulatory cells (Tregs) that emerge directly from the thymus, Tr1 cells are induced by antigen stimulation via an IL-10-dependent process in vitro and in vivo. Specialized IL-10-producing dendritic cells, such as those in an immature state or those modulated by tolerogenic stimuli, play a key role in this process. We propose to use the term Tr1 cells for all IL-10-producing T-cell populations that are induced by IL-10 and have regulatory activity. The full biological characterization of Tr1 cells has been hampered by the difficulty in generating these cells in vitro and by the lack of specific marker molecules. However, it is clear that Tr1 cells play a key role in regulating adaptive immune responses both in mice and in humans. Further work to delineate the specific molecular signature of Tr1 cells, to determine their relationship with CD4+ CD25+ Tregs, and to elucidate their respective role in maintaining peripheral tolerance is crucial to advance our knowledge on this Treg subset. Furthermore, results from clinical protocols using Tr1 cells to modulate immune responses in vivo in autoimmunity, transplantation, and chronic inflammatory diseases will undoubtedly prove the biological relevance of these cells in immunotolerance.

Inhibitory effects of B cells on antitumor immunity

B-cell functions in antitumor immunity are not well understood. In this study, we evaluated the role of B cells in the development of antitumor immunity using Friend murine leukemia virus gag-expressing mouse EL-4 (EL-4 gag), D5 mouse melanoma, or MCA304 mouse sarcoma cells. To screen tumors for susceptibility to B-cell-deficient immune environments, spleen cells from naive C57BL/6 [wild-type (WT)] and B-cell knockout (BKO) mice were cultured with irradiated tumor cells in vitro. When cells were stimulated with EL-4 gag or D5 (but not MCA304 tumors), IFN-gamma production from CD8 T cells and natural killer cells was markedly decreased in WT compared with BKO cultures. IFN-gamma production was correlated with CD40 ligand expression on the tumor and inversely with interleukin-10 (IL-10) production by B cells. Sorted WT B cells produced more IL-10 than CD40 knockout (CD40KO) B cells when cocultured with EL-4 gag or D5 (but not MCA304). IFN-gamma production by BKO cells was reduced by the addition of sorted naive WT B cells (partially by CD40KO B cells) or recombinant mouse IL-10. In vivo tumor progression mirrored in vitro studies in that WT mice were unable to control tumor growth whereas EL-4 gag and D5 tumors (but not MCA304) were eliminated in BKO mice. Robust in vivo antitumor CTLs developed only in BKO tumor-challenged mice. Our studies provide the first mechanistic basis for the concept that B-cell depletion could therapeutically enhance antitumor immune responses to certain tumors by decreasing IL-10 production from B cells.