Blood stem cell transplantation for breast cancer: new approaches using pre- peri- post-transplant immunotherapy

Review of evidence that posttransplantation psychiatric treatment commonly affects prolactin levels and thereby influences graft fate

Delirium, depression and other psychiatric difficulties are commonly encountered by posttransplantation patients, and antipsychotic medicines are frequently used to treat these difficulties. This article reviews previous research data concerning the immunological effects of these medicines, with particular focus on the consequences of prolactin elevation. Unproven but of concern is that these effects may influence graft fate. Older antipsychotic medicines such as haloperidol and chlorpromazine have a high likelihood of elevating prolactin. Prolactin is an immunologically active molecule generally promoting bone marrow function. This may be of benefit post-stem-cell transplant, helping engraftment, but could further rejection of solid-organ transplants. Elevated prolactin is implicated in the facilitation of graft-versus-host disease. Aripiprazole is the antipsychotic medicine least likely to increase prolactin (and may actually decrease prolactin); risperidone, the most likely to increase prolactin. Olanzapine, quetiapine and ziprazadone are antipsychotic medicines with a lower likelihood of elevating prolactin. Older ("neuroleptic") antipsychotics, such as chlorpromazine, droperidol and haloperidol, perphenazine and many others, are likely to elevate serum prolactin. Among antidepressants, most serotonin reuptake inhibitors, with the exception of sertraline, can slightly elevate prolactin. The atypical (i.e., alone in their class) antidepressants bupropion and mirtazapine are prolactin neutral. The immunological consequences of psychiatric medicines should be considered when treating transplant patients for delirium, depression and thought disorders; in addition, if elevation of prolactin is thought to be of immunological importance during psychiatric treatment, then it should be monitored and treated. The dopamine agonists used to treat Parkinson's disease--bromocriptine, pergolide, pramipexole, ropinerole--usually reverse antipsychotic-induced prolactin increases without compromising psychiatric effectiveness.

Immunotherapy of cancer by active vaccination: does allogeneic bone marrow transplantation after non-myeloablative conditioning provide a new option?

The critical role of antigen-specific T cells in cancer immunotherapy has been amply demonstrated in many model systems. Though success of clinical trials still remains far behind expectation, the continuous improvement in our understanding of the biology of the immune response will provide the basis of optimized cancer vaccines and allow for new modalities of cancer treatment. This review focuses on the current status of active therapeutic vaccination and future prospects. The latter will mainly be concerned with allogeneic bone marrow cell transplantation after non-myeloablative conditioning, because it is my belief that this approach could provide a major breakthrough in cancer immunotherapy. Concerning active vaccination protocols the following aspects will be addressed: i) the targets of immunotherapeutic approaches; ii) the response elements needed for raising a therapeutically successful immune reaction; iii) ways to achieve an optimal confrontation of the immune system with the tumor and iv) supportive regimen of immunomodulation. Hazards which one is most frequently confronted with in trials to attack tumors with the inherent weapon of immune defense will only be briefly mentioned. Many question remain to be answered in the field of allogeneic bone marrow transplantation after non-myeloablative conditioning to optimize the therapeutic setting for this likely very powerful tool of cancer therapy. Current considerations to improve engraftment and to reduce graft versus host disease while strengthening graft versus tumor reactivity will be briefly reviewed. Finally, I will discuss whether tumor-reactive T cells can be "naturally" maintained during the process of T cell maturation in the allogeneic host. Provided this hypothesis can be substantiated, a T cell vaccine will meet a pool of virgin T cells in the allogeneically reconstituted host, which are tolerant towards the host, but not anergised towards tumor antigens presented by MHC molecules of the host.