Antitumor vaccination: where we stand.

BACKGROUND AND OBJECTIVES: Vaccination is an effective medical procedure of preventive medicine based on the induction of a long-lasting immunologic memory characterized by mechanisms endowed with high destructive potential and specificity. In the last few years, identification of tumor-associated antigens (TAA) has prompted the development of different strategies for antitumor vaccination, aimed at inducing specific recognition of TAA in order to elicit a persistent immune memory that may eliminate residual tumor cells and protect recipients from relapses. In this review characterization of TAA, different potential means of vaccination in experimental models and preliminary data from clinical trials in humans have been examined by the Working Group on Hematopoietic Cells. EVIDENCE AND INFORMATION SOURCES: The method employed for preparing this review was that of informal consensus development. Members of the Working Group met four times and discussed the single points, previously assigned by the chairman, in order to achieve an agreement on different opinions and approve the final manuscript. Some of the authors of the present review have been working in the field of antitumor immunotherapy and have contributed original papers to peer-reviewed journals. In addition, the material examined in the present review includes articles and abstracts published in journals covered by the Science Citation Index and Medline. STATE OF THE ART: The cellular basis of antitumor immune memory consists in the generation and extended persistence of expanded populations of T- and B-lymphocytes that specifically recognize and react against TAA. The efficacy of the memory can be modulated by compounds, called "adjuvants", such as certain bacterial products and mineral oils, cytokines, chemokines, by monoclonal antibodies triggering co-stimulatory receptors. Strategies that have been shown in preclinical models to be efficient in protecting from tumor engraftment, or in preventing a tumor rechallenge, include vaccination by means of soluble proteins or peptides, recombinant viruses or bacteria as TAA genes vectors, DNA injection, tumor cells genetically modified to express co-stimulatory molecules and/or cytokines. The use of professional antigen-presenting cells, namely dendritic cells, either pulsed with TAA or transduced with tumor-specific genes, provides a useful alternative for inducing antitumor cytotoxic activity. Some of these approaches have been tested in phase I/II clinical trials in hematologic malignancies, such as lymphoproliferative diseases or chronic myeloid leukemia, and in solid tumors, such as melanoma, colon cancer, prostate cancer and renal cell carcinoma. Different types of vaccines, use of adjuvants, timing of vaccination as well as selection of patients eligible for this procedure are discussed in this review. PERSPECTIVES: Experimental models demonstrate the possibility of curing cancer through the active induction of a specific immune response to TAA. However, while pre-clinical research has identified several possible targets and strategies for tumor vaccination the clinical scenario is far more complex for a number of possible reasons. Since experimental data suggest that vaccination is more likely to be effective on small tumor burden, such as a minimal residual disease after conventional treatments, or tumors at an early stage of disease, better selection of patients will allow more reliable clinical results to be obtained. Moreover, a poor correlation is frequently observed between the ability of TAA to induce a T-cell response in vitro and clinical responses. Controversial findings may also be due to the techniques used for monitoring the immune status. Therefore, the development of reliable assays for efficient monitoring of the state of immunization of cancer patients against TAA is an important goal that will markedly improve the progress of antitumor vaccines. (ABSTRACT TRUNCATED)

The SMile Card: a computerised data card for multiple sclerosis patients. SMile Card Scientific Board.

The SMile Card was developed as a means for computerising clinical information for the purpose of transferability, accessibility, standardisation and compilation of a national database of demographic and clinical information about multiple sclerosis (MS) patients. In many European countries, centres for MS are organised independently from one another making collaboration, consultation and patient referral complicated. Only the more highly advanced clinical centres, generally located in large urban areas, have had the possibility to utilise technical possibilities for improving the organisation of patient clinical and research information, although independently from other centres. The information system, developed utilising the Visual Basic language for Microsoft Windows 95, stores information via a 'smart card' in a database which is initiated and updated utilising a microprocessor, located at each neurological clinic. The SMile Card, currently being tested in Italy, permits patients to carry with them all relevant medical information without limitations. Neurologists are able to access and update, via the microprocessor, the patient's entire medical history and MS-related information, including the complete neurological examination and laboratory test results. The SMile Card provides MS patients and neurologists with a complete computerised archive of clinical information which is accessible throughout the country. In addition, data from the SMile Card system can be exported to other database programs.

Cell therapy: achievements and perspectives.

BACKGROUND AND OBJECTIVE: Cell therapy can be considered as a strategy aimed at replacing, repairing, or enhancing the biological function of a damaged tissue or system by means of autologous or allogeneic cells. There have been major advances in this field in the last few years. This has prompted the Working Group on Hematopoietic Cells to examine the current utilization of this therapy in clinical hematology. EVIDENCE AND INFORMATION SOURCES: The method employed for preparing this review was that of informal consensus development. Members of the Working Group met three times, and the participants at these meetings examined a list of problems previously prepared by the chairman. They discussed the single points in order to reach an agreement on different opinions and eventually approved the final manuscript. Some of the authors of the present review have been working in the field of cell therapy and have contributed original papers in peer-reviewed journals. In addition, the material examined in the present review includes articles and abstracts published in journals covered by the Science Citation Index and Medline. STATE OF THE ART: Lymphokine-activated killer (LAK) and tumor-infiltrating lymphocytes (TIL) have been used since the '70s mainly in end-stage patients with solid tumors, but the clinical benefits of these treatments has not been clearly documented. TIL are more specific and potent cytotoxic effectors than LAK, but only in few patients (mainly in those with solid tumors such as melanoma and glioblastoma) can their clinical use be considered potentially useful. Adoptive immunotherapy with donor lymphocyte infusions has proved to be effective, particularly in patients with chronic myeloid leukemia, in restoring a state of hematologic remission after leukemia relapse occurring following an allograft. The infusion of donor T-cells can also have a role in the treatment of patients with Epstein-Barr virus (EBV)-induced post-transplant lymphoproliferative disorders. However, in this regard, generation and infusion of donor-derived, virus specific T-cell lines or clones represents a more sophisticated and safer approach for treatment of viral complications occurring in immunocompromised patients. Whereas too few clinical trials have been performed so far to draw any firm conclusion, based on animal studies dendritic cell-based immunotherapy holds promises of exerting an effective anti-tumor activity. Despite leukemic cells not being immunogenic, induction on their surface of co-stimulatory molecules or generation of leukemic dendritic cells may induce antileukemic cytotoxic T-cell responses. Tumor cells express a variety of antigens and can be genetically manipulated to become immunogenic. The main in vitro and in vivo functional characteristics of marrow mesenchymal stem cells (MSCs) with particular emphasis on their hematopoietic regulatory role are reviewed. In addition, prerequisites for clinical applications using culture-expanded mesenchymal cells are discussed PERSPECTIVES: The opportuneness of using LAK cells or activated natural killer (NK) cells in hematologic patients with low tumor burden (e.g. after stem cell transplantation) should be further explored. Moreover the role of new cytokines in enhancing the antineoplastic activity of NK cells and the infusion of selected NK in alternative to CTL for graft versus leukemia (GVL) disease (avoiding graft versus host disease (GvHD) seems very promising. Separation of GVL from GvHD through generation and infusion of leukemia-specific T-cell clones or lines is one of the most intriguing and promising fields of investigations for the future. Likewise, strategies devised to improve immune-reconstitution and restore specific anti-infectious functions through either induction of unresponsiveness to recipient alloantigens or removal of alloreactive donor T-cells might increase the applicability and success of hematopoietic stem cell transplantation. (ABSTRACT TRUNCATED)

Ex vivo expansion of hematopoietic cells and their clinical use.

BACKGROUND AND OBJECTIVE: Hematopoietic stem cells are being increasingly used for treatment of malignant and nonmalignant disorders. Various attempts have been made in recent years to expand and manipulate these cells in order to increase their therapeutic potential. A Working Group on Hematopoietic Cells has analyzed the most recent advances in this field. EVIDENCE AND INFORMATION SOURCES: The method used for preparing this review was an informal consensus development. Members of the Working Group met three times, and the participants at these meetings examined a list of problems previously prepared by the chairman. They discussed the single points in order to achieve an agreement on different judgments, and eventually approved the final manuscript. Some authors of the present review have been working in the field of stem cell biology, processing and transplantation, and have contributed original papers in peer-reviewed Journals. In addition, the material examined in the present review includes articles and abstracts published in Journals covered by the Science Citation Index and Medline. STATE OF ART: Over the last decade, recombinant DNA technology has allowed the large scale production of cytokines controlling the proliferation and differentiation of hemo-lymphopoietic cells. Thus, in principle, ex vivo manipulation of hemopoiesis has become feasible. The present review covers three major area of interest in experimental and clinical hematology: manipulation of hematopoietic stem/progenitor cells, cytotoxic effector cells and antigen presenting dendritic cells. Preliminary data demonstrate the possibility of using, in a clinical setting, ex vivo expanded hematopoietic cells with the aim of reducting, and perhaps abrogating, the myelosuppression after high-dose chemotherapy. Concurrently, other important potential applications for ex vivo manipulation of hematopoietic cells have recently been investigated such as the generation and expansion of cytotoxic cells for cancer immunotherapy, and the large scale production of professional antigen presenting cells capable of initiating the process of immune response. CONCLUSIONS AND PERSPECTIVES: Present and future challenges in this field are represented by the expansion of true human stem cells without maturation, to extend this strategy to allogeneic stem cell transplantation as well as the manipulation of cycling of primitive progenitors for gene therapy programs. The selective outgrowth of normal progenitor cells over neoplastic cells to achieve tumor-free autografts may ameliorate the results of autologous transplantation. The selective production of cellular subsets to manipulate the graft versus-host and graft versus-tumor effects and anti-tumor vaccination strategies may be important to improve cellular adoptive immunotherapy.

Clinical use of allogeneic hematopoietic stem cells from sources other than bone marrow.

BACKGROUND AND OBJECTIVE: Peripheral blood stem cells (PBSC) are being increasingly used as an alternative to conventional allogeneic bone marrow (BM) transplantation. This has prompted the Working Group on CD34-Positive Hematopoietic Cells to evaluate the current utilization of allogeneic PBSC in clinical hematology. EVIDENCE AND INFORMATION SOURCES: The method employed for preparing this review was that of informal consensus development. Members of the Working Group met three times, and the participants at these meetings examined a list of problems previously prepared by the chairman. They discussed the single points in order to reach an agreement on different opinions and eventually approved the final manuscript. Some of the authors of the present review have been working in the field of stem cell transplantation and have contributed original papers in peer-reviewed journals. In addition, the material examined in the present review includes articles and abstracts published in journals covered by the Science Citation Index and Medline. STATE OF THE ART: Review of the current literature shows that unmanipulated allogeneic PBSC give prompt and stable engraftment in HLA-identical sibling recipients. Despite the much higher number of T-cells infused, the incidence and severity of acute GVHD after PBSC transplant seems comparable to that observed with bone marrow (BM) cells. In comparison to the latter, PBSC probably ensure faster immunologic reconstitution in the early post-transplant period. Controversial results on the incidence and severity of acute-GVHD have been reported when CD34+ selection methods are used. Prospective randomized trials are underway to compare the results of PBSC and BM allogeneic transplantation. In mismatched family donor transplants, T-cell depleted PBSC successfully engraft immune-myeloablated recipients through a megacell-dose effect able to overcome the HLA barrier. Experience with PBSC in the context of unrelated donor transplants is currently anecdotal and prospective trials should be completed before that practice becomes routine. Finally, there is also limited evidence that, following induction chemotherapy, the addition of PBSC to donor lymphocyte infusion (DLI) for treatment of leukemia relapse after BMT may improve the safety and effectiveness of DLI itself. Concerning cord blood (CB) transplants, the most interesting aspects are the ease of CB collection and storage, the low risk of viral contamination and the low immune reactivity of CB cells. This last property has its clinical counterpart in an apparently reduced incidence and severity of acute GVHD both in sibling and unrelated CB transplants, probably making the level of donor/recipient HLA disparity acceptable a greater degree with respect to what is required for transplants from other sources.

Allogeneic hematopoietic stem cells from sources other than bone marrow: biological and technical aspects.

BACKGROUND AND OBJECTIVE: Identification and characterization of hematopoietic stem cells in peripheral blood (PB) and cord blood (CB) have suggested feasible alternatives to conventional allogeneic bone marrow (BM) transplantation. The growing interest in this use of allogeneic stem cells has prompted the Working Group on CD34-positive Hematopoietic Cells to review this subject by analyzing its biological and technical aspects. EVIDENCE AND INFORMATION SOURCES: The method used for preparing this review was informal consensus development. Members of the Working Group met three times, and the participants at these meetings examined a list of problems previously prepared by the chairman. They discussed the individual points in order to reach an agreement on the various concepts, and eventually approved the final manuscript. Some of the authors of the present review have been working in the field of hematopoietic stem cell biology and processing, and have contributed original papers published in peer-reviewed journals. In addition, the material examined in the present review includes articles and abstracts published in journals covered by the Science Citation Index and Medline. STATE OF ART: Several studies have now shown that hematopoietic stem cells collected from peripheral blood after the administration of G-CSF, or from cord blood upon delivery, are capable of supporting rapid and complete reconstitution of BM function in allogeneic recipients. Perhaps more importantly, reinfusion of large numbers of HLA-matched T-cells from PB collections or T-cells with various degrees of HLA disparity from CB did not result in a higher incidence or greater severity of acute graft-versus-host disease than expected with BM. Based on the data reviewed, operative guidelines for mobilization, collection and graft processing are provided. PERSPECTIVES: It should be remembered that despite the growing interest, these procedures must be still considered as advanced clinical research and should be included in formal clinical trials aimed at demonstrating their definitive role in stem cell transplantation. In this regard, a large European randomized study is currently comparing PB and BM allografts. However, the possibility of collecting large quantities of hematopoietic progenitor-stem cells, perhaps with reduced allo-reactivity, offers an exciting perspective for widening the number of potential stem cell donors and greater leeway for graft manipulation than is possible with BM.

Glutathione prevents ethanol induced gastric mucosal damage and depletion of sulfhydryl compounds in humans.

Whether parenteral administration of reduced glutathione prevented ethanol induced damage to and depletion of sulfhydryl compounds in the human gastric mucosa was investigated. Ten healthy volunteers underwent endoscopy on three separate occasions. Gastric mucosal damage was induced by spraying 80% ethanol on to the gastric mucosa through the biopsy channel of the endoscope. The gastric mucosal score, total sulfhydryls, glutathione, and cysteine were evaluated in basal conditions and after ethanol administration with and without pretreatment with parenteral glutathione. Glutathione significantly decreased the extent of ethanol induced macroscopic injury to the mucosa of the gastric body and antrum. Glutathione's protective effect is associated with appreciable inhibition of ethanol induced depletion of gastric sulfhydryl compounds. This is the first report of protection against ethanol induced gastric mucosal damage by a sulfhydryl containing agent in humans.

Crystalline lactulose in the therapy of hepatic cirrhosis. Evaluation of clinical and immunological parameters. Preliminary results.

Crystalline lactulose (Laevolac Cristalli, CAS 4618-18-2), a pure form of the disaccharide widely employed in the therapy of complications of liver cirrhosis, was administered, after a pharmacological wash-out of 10 days and following a randomized design, to 10 cirrhotic patients for 30 days at the dosage of 60 g/d, while another 10 subjects with similar characteristics received no treatment. Besides the parameters usually monitored for the evaluation of liver function and state of hepatic encephalopathy, immunological patterns such as lymphocyte subpopulations CD3, CD4, CD8, CD16(NK), CD25 and antibacterial activity against Ty2 strain of Salmonella typhi were evaluated. At the end of the study (day 30) a significant decrease of blood ammonia was observed, as expected, only in the group treated with lactulose with respect to the control group, as well as a significant increase of CD16 and antibacterial activity (1/3); an enhanced level of CD25, although not significant, was also noticed in the treated group with respect to the control group. These findings seem to show an effect of activation on cell-mediated immune system depressed during liver cirrhosis, produced by lactulose. Further studies are needed to confirm these data and to clarify the possible mechanisms involved.

[Evaluation of the effects of reduced glutathione in subjects with acquired and congenital changes in heme biosynthesis]. / Valutazione degli effetti del glutatione ridotto in soggetti con alterazioni acquisite e congenite della biosintesi dell'eme.

In order to evaluate the possible therapeutical effects of reduced glutathione in subjects affected by acquired or congenital heme biosynthesis alterations, two groups of subjects have been considered: the first, of 5 subjects with abnormal lead absorption, the second of 10 patients suffering from porphyria cutanea tarda (PCT). The drug was administered i.v. at the dosage of 600-1200 mg for a variable period of 3-5 days in the first group, for 7-10 days in the patients with PCT. In the lead-exposed subjects an increase in the activity of ALA-dehydratases enzyme was observed, with a decrease in the urinary excretion of delta-aminolevulinic acid, and a decrease in the percentage of urinary coproporphyrins as well. In the patients with PCT, after the therapy, a relevant reduction of urinary excretion of porphyrins, prevalently uro- and heptaporphyrins, was noticed. The results of this preliminary study suggest that glutathione can exert an effect of "normalization" on heme biosynthesis when altered in acquired and/or congenital conditions.

Anemia and chronic renal failure: a therapeutical approach by reduced glutathione parenteral administration.

Authors report on the effect of reduced glutathione parenterally administered on the anemic status in patients suffering from chronic renal failure and undergoing hemodialysis. Twenty patients were studied for 180 days and were divided into two age- and sex-matched groups. The first group (10 patients) received placebo, the second group (10 patients) received the treatment (1,200 mg of reduced glutathione). Reduced glutathione and placebo were given for 120 days in a randomized double-blind fashion and the following measurements were performed: red blood cells reduced and oxidized glutathione, plasma reduced and oxidized glutathione, hematocrit, hemoglobin, reticulocytes, serum iron, transferrin, indirect bilirubin, urea, creatinine, calcium, phosphate, parathyroid hormone and alkaline phosphatase. In the treated group, during the supplementation period, there was an increase in the levels of red blood cells and plasma reduced glutathione, hematocrit and hemoglobin and a concomitant decrease in plasma oxidized glutathione and reticulocytes with a maximum effect on the 120th day of therapy. In the placebo-treated group there were no significant variations of the parameters considered during the study period. When the therapy, on patients undergoing treatment, was terminated there was a drop in the analyzed parameters, which fell to pretreatment values at the subsequent controls. These findings seem to indicate that reduced glutathione could represent a useful drug in the treatment and management of anemia in patients affected by chronic renal failure.

[Crystalline lactulose and oral preparations of micro-organisms for the treatment of chronic aspecific diarrhea in children. A controlled clinical study]. / Lattulosio cristallino e preparazioni orali di microorganismi quale trattamento della diarrea cronica aspecifica dell'infanzia. Studio clinico controllato.

Aspecific chronic diarrhea is one of the most common causes of protracted diarrhea in infancy. The pathology is characterised by an increased frequency of daily bowel movement with half-formed feces; it is not associated to malabsorption syndrome or enteric infections and appears to be correlated to an unbalanced diet and changes in microflora involved in the fermentation processes. A controlled randomised single-blind clinical trial was performed, using commercially available crystalline lactulose and lactic enzymes, in order to normalise the modified intestinal ecosystem. Twenty-four children (mean age 21.76 months) affected by aspecific chronic diarrhea were studied; weight and height parameters were not influenced. Patients were first divided by age and then randomly divided into two groups of 12. Group 1 received treatment with crystalline lactulose (Laevolac crystals, BBR) and Group 2 received lyophilised Lactipan. In both cases treatment continued for 15 days. At the end of the trial all subjects showed a complete remission of intestinal disorders. Children in Group 1 showed more fully formed feces following treatment. Fecal pH values were considerably reduced only in those subjects treated with crystalline lactulose. In the latter subjects H2 excretion diminished during the trial, a fact which may probably be attributed to reduced colic pH values. On the basis of these results, it is possible to conclude that both treatments proved efficacious. The re-establishment of a balanced intestinal ecosystem remains the choice treatment for subjects affected by aspecific chronic diarrhea.