Immunological monitoring of the tumor immunoenvironment for clinical trials

Monitoring of immunotherapeutic clinical trials has undergone a considerable change in the last decade resulting in a general agreement that immune monitoring should guide the development of cancer vaccines. The emphasis on immune cell functions and quantitation of antigen-specific T cells have been playing a major role in the attempts to establish meaningful correlations between therapy-induced alterations in immune responses and clinical endpoints. However, one significant unresolved issue in modern immunotherapy is that when a tumor-specific cellular immune response is observed following the course of immunotherapy, it does not always lead to clinically proven cancer regression. This disappointing lack of a correlation between the tumor-specific cytotoxic immune responses and the clinical efficacy of immunotherapy may be explained, among other reasons, by the notion that the analysis of any single immunological parameter is not sufficient to provide clinically feasible information about the complex interactions between different cell subsets in the peripheral blood and immune, tumor, and stromal cells in the tumor milieu. By contrast, a systemic approach is required for improving the quality of a serial monitoring to ensure that it adequately and reliably measures potential changes induced in patients by administered vaccines or immunomodulators. Comprehensive evaluation of the balance between the immunostimulatory and immunosuppressive compartments of the immune system could be critical for a better understanding of how a given immunotherapy works or does not work in a particular clinical trial. New approaches to characterize tumor-infiltrating leukocytes, their phenotypic, biochemical, and genetic characteristics within the tumor microenvironment need to be developed and validated and should complement current monitoring techniques. These immune-monitoring assays for the local tumor immunoenvironment should be developed, validated, and standardized for reliability and consistency in order to establish the overall performance standards.

The current trend of induction and maintenance treatment in patient of different PRA levels: a report on OPTN/UNOS Kidney Transplant Registry data

We investigate the status of sensitization in kidney transplant recipients and analyze the trend of induction and maintenance therapy in patients of different PRA levels. Despite the fact of the decreased percentages of kidney transplant recipients with presensitization history, the mean PRA levels of all kidney recipients has been increasing in the last 7 years, which is possibly due to the introduction of more sensitive antibody testing techniques or the tendency for kidney allocation organization and clinicians to give priority to patients with elevated PRA once a compatible donor kidney becomes available. The percentage of patients with treated rejection episodes within one year post-transplant were significantly higher in sensitized patients (PRA = 50-100:14.3%, and PRA = 1-49%: 13.9%) than in non-sensitized patients (12.4%). Both 1- and 5-yr graft survival rates have improved in the last 10 years; this was more significant in high PRA patients. Thymoglobulin was the most commonly used induction agent in last 10 years. Its users increased from 10% to 46% in non-sensitized patients, from 12% to 57% in PRA = 1-49% patients, and from 19% to 63% in PRA = 50-100% patients. The users of Campath, IVIg, and Rituximab have been increasing and reached 16%, 20%, and 11% in highly sensitized patients. In the last 5 years, steroid-free patients were 33-36%, 30-37%, and 10-25% for patients with PRA levels of 0, 1-49, and 50-100 respectively. Almost 90% of patients were on Prograf at discharge. Myfortic users have been increasing since 2005 and it may soon replace MMF if long-term follow-up study confirms its safety and efficacy.

Monitoring of minimal residual disease in leukemia, advantages and pitfalls

The term 'minimal residual disease' (MRD) defines the level of disease detectable in patients in clinical remission during therapy, below the detection limit of conventional methods. Very sensitive methods can be used, able to identify one leukemic cell out of 10,000 normal lymphocytes. In vivo measurements of leukemia cytoreduction reflect the combined effect of clinical and biological variables, thus providing direct information on the effectiveness of treatment in each patient. Thus, these methods can potentially be used for tailoring treatment and personalize the cure. Although MRD studies are becoming an integral part of the modern management of patients with leukemia, several parameters are critical for the application and interpretation of MRD studies, including therapeutic context, timing of sampling, target genes and sensitivity of the polymerase chain reaction (PCR) assay, inter-laboratory standardization (particularly relevant in multicenter studies), selection of patients, retrospective or prospective nature of the study. Methodologies and pitfalls as well as results of clinical uses of MRD will be reviewed in this article by selecting significant examples of its clinical impact in the management of patients with leukemia.

Mechanisms of immune evasion by tumors

In the past decade, basic studies in animal models have begun to elucidate the physiological barriers which impede a successful antitumor immune response. These barriers operate at a number of levels, and involve the tumor, the tumor microenvironment and various components of the innate and adaptive immune systems. In this review, we discuss the multiple mechanisms by which tumors evade an immune response, with an emphasis on clinically relevant strategies to overcome these inhibitory checkpoints.

Cancer Immunosurveillance and Immunoediting: The Roles of Immunity in Suppressing Tumor Development and Shaping Tumor Immunogenicity

Cellular transformation and tumor development result from an accumulation of mutational and epigenetic changes that alter normal cell growth and survival pathways. For the last 100 years, there has been a vigorous debate as to whether the unmanipulated immune system can detect and eliminate such altered host derived cells despite the fact that cancer cells frequently express either abnormal proteins or abnormal levels of normal cellular proteins that function as tumor antigens. In this review, we discuss the current state of this argument and point out some of the recent key experiments demonstrating that immunity not only protects the host from cancer development (i.e., provides a cancer immunosurveillance function) but also can promote tumor growth, sometimes by generating more aggressive tumors. The terminology "cancer immunoediting" has been used to describe this dual host protective and tumor promoting action of immunity, and herein we summarize the ever-increasing experimental and clinical data that support the validity of this concept.

18th Annual Scientific Meeting of the International Society for Biological Therapy of Cancer. 30 October-2 November 2003, Bethesda, Maryland, USA

The 18th Annual Scientific Meeting of the International Society for Biological Therapy of Cancer (iSBTc) was held at the Hyatt Regency, Bethesda, MD, close to the National Institutes of Health (NIH) campus. The meeting was organised on behalf of the society by Neil Berinstein from Aventis Pasteur, Toronto, Canada, Janice P Dutcher from Our Lady of Mercy Medical Center, Bronx, NY and Francesco M Marincola from the NIH, Bethesda, MD. The 2003 meeting included 57 oral presentations and > 100 poster presentations. There were > 800 registrants to the Annual Meeting and the multiple satellite symposia. The iSBTc, formerly the Society of Biological Therapy (SBT), was founded by R Oldham in 1984. Its membership has been rapidly growing of late, with > 500 members at present. The purpose of the iSBTc is to bring together those diverse individuals actively investigating biologic agents and biological response modifiers in the treatment of cancer, including clinicians and basic scientists from industry, government and academia. The President of the Society is Dr Michael B Atkins from Beth Israel Deaconess Medical Center, Boston, MA and the Vice President is Ulrich Keilholz from UKBF, Free University Berlin, Germany.

Immune profiling: molecular monitoring in renal transplantation

Molecular techniques have become a mainstay for most biomedical research. In particular, sensitive methods for gene transcript detection and advanced flow cytometry have been crucial in fostering our understanding of the basic mechanisms promoting allosensitization and adaptive immune regulation. These technologies have been validated in vitro, and in pre-clinical settings, and as such their clinical application is now clearly appropriate. It is becoming increasingly clear that these robust techniques hold much promise to better elucidate human transplant biology, and more importantly, guide clinical decision making with mechanistically-based information. This article will discuss our laboratory's use of several novel technologies, including gene polymorphism analysis, real-time polymerase chain reaction transcript quantification, and multi-color flow cytometry in clinical human renal transplantation. Specific technical methodology will be presented outlining keys for effective clinical application. Clinical correlations will be presented as examples of how these techniques may have clinical relevance. Suggestions for the adaptation of these methods for therapeutic intervention will be given. We propose that clinical transplantation should proceed in close step with modern molecular diagnostics.

Monitoring early inflammation in CF. Infant pulmonary function testing

Infant pulmonary function tests (iPFTs) have primarily been used as research tools to further define physiologic pulmonary abnormalities in infants and young children with cystic fibrosis (CF). Methodologies used to measure pulmonary function in infants are described, with particular relevance to CF. A comprehensive review of studies and findings in CF infants using iPFTs is presented. Further goals in improving methodologies and in defining pulmonary disease in CF are presented.