OFLOXACIN VERSUS TRIMETHOPRIM AND CO-TRIMOXAZOLE IN THE TREATMENT OF UNCOMPLICATED URINARY TRACT INFECTION IN GENERAL PRACTICE

A large-scale, randomised, multicentre single-blind clinical trial was conducted to assess the comparative efficacy and tolerance of ofloxacin, trimethoprim and co-trimoxazole in the treatment of uncomplicated urinary tract infection in general practice. A total of 1,069 patients from 76 centres across the UK were enrolled in the study, and randomised to one of the following treatment groups: ofloxacin (200 mg od), trimethoprim (200 mg bd) or co-trimoxazole (trimethoprim 160 mg and sulphamethoxazole 800 mg bd). Each patient received five days of medication. Clinically, ofloxacin was as effective as trimethoprim and co-trimoxazole. However, the bacteriological cure rate was significantly better for ofloxacin, with eradication of the initial causative pathogen by the end of treatment in 92% of patients in the ofloxacin group, compared with 81% for trimethoprim and co-trimoxazole (P = 0.0002). There was also a lower relapse rate for ofloxacin. Ofloxacin was well tolerated: adverse events were reported by 67 (12.4%) patients in the ofloxacin group, compared with 48 (18.7%) patients in the co-trimoxazole group and 37 (13.6%) patients in the trimethoprim group. Ofloxacin can therefore be considered a suitable alternative for the treatment of uncomplicated urinary tract infection.     

Direct demonstration that autologous bone marrow transplantation for solid tumors can return a multiplicity of tumorigenic cells

Patients with solid tumors are increasingly being treated by autologous bone marrow transplantation (BMT). Although response rates appear to be increased, disease recurrence is the commonest cause of treatment failure. Whether relapse is entirely due to residual disease in the patient or arises also from infiltrating malignant cells contained in the autologous marrow transplant has not been resolved. If the latter explanation is correct, then purging would be required as part of the transplantation procedure. We used retrovirally mediated transfer of the neomycin-resistance gene to mark BM harvested from eight patients with neuroblastoma in clinical remission. The marked marrow cells were subsequently reinfused as part of an autologous BMT. At relapse, we sought the marker gene in malignant cell populations. Three patients have relapsed, and in each the marker gene was detected by phenotypic and genetic analyses of resurgent malignant cells at medullary and extramedullary sites. Analysis of neuroblast DNA for discrete marker gene integration sites suggested that at least 200 malignant cells, each capable of tumor formation, were introduced with the autologous marrow transplant and contributed to relapse. Thus, autologous BMTs administered to patients with this solid tumor may contain a multiplicity of malignant cells that subsequently contribute to relapse. The marker-gene technique we describe should permit evaluation of the mechanisms of relapse and the efficacy of purging in patients receiving autologous marrow transplantation for other solid tumors that infiltrate the marrow.     

Leaders in Hematology Review Series: T-cell and natural killer cell therapies for hematologic malignancies after hematopoietic stem cell transplantation: enhancing the graft-versus-leukemia effect

Hematopoietic stem cell transplantation has revolutionized the treatment of hematologic malignancies, but infection, graft-versus-host disease and relapse are still important problems. Calcineurin inhibitors, T-cell depletion strategies, and immunomodulators have helped to prevent graft-versus-host disease, but have a negative impact on the graft-versus-leukemia effect. T cells and natural killer cells are both thought to be important in the graft-versus-leukemia effect, and both cell types are amenable to ex vivo manipulation and clinical manufacture, making them versatile immunotherapeutics. We provide an overview of these immunotherapeutic strategies following hematopoietic stem cell transplantation, with discussions centered on natural killer and T-cell biology. We discuss the contributions of each cell type to graft-versus-leukemia effects, as well as the current research directions in the field as related to adoptive cell therapy after hematopoietic stem cell transplantation.     

Treatment of progressive Hodgkin's disease with intensive chemoradiotherapy and autologous bone marrow transplantation

Twenty-six patients with progressive Hodgkin's disease after conventional chemotherapy received intensive chemoradiotherapy and autologous bone marrow transplantation (ABMT); 19 also received additional involved-field radiotherapy. Twenty-one patients [81%, 95% confidence intervals (CI) 61% to 94%] attained complete (n = 18) or partial responses. Ten patients (38%, 95% CI 20% to 59%) are disease- free a median of 4.5 years later (range 3.5 to 7.0 years), including seven patients with continuous complete responses. The likelihood of overall response was not significantly influenced by any clinical or treatment variable examined. However, there was a trend favoring patients with higher Karnofsky scores, and higher scores were associated with attainment of complete responses (P = .06 and P = .02, respectively, Mann-Whitney U test). Both higher Karnofsky scores and shorter durations of disease before transplantation were associated with improved survival in a stepwise Cox multivariate analysis. The chief cause of failure was progression at sites previously involved with Hodgkin's disease. No patient relapsed in the marrow, and two of three patients with a history of marrow involvement with Hodgkin's disease achieved durable complete responses after transplantation. These data suggest that inadequate pretransplant conditioning, and not the reinoculation of occult tumor cells in the autologous marrow, caused most relapses. Fatal treatment-related toxicity occurred in six patients. Three patients died of idiopathic interstitial pneumonitis; each had previously received local mediastinal irradiation before intensive chemoradiotherapy. Intensive chemoradiotherapy and ABMT produces durable responses in some patients with Hodgkin's disease incurable with conventional therapy. Use of such therapies at the first sign of failure with conventional chemotherapy and development of more effective conditioning regimens should further improve results.     

Broadly-specific Cytotoxic T Cells Targeting Multiple HIV Antigens Are Expanded From HIV+ Patients: Implications for Immunotherapy

Antiretroviral therapy (ART) is unable to eradicate human immunodeficiency virus type 1 (HIV-1) infection. Therefore, there is an urgent need to develop novel therapies for this disease to augment anti-HIV immunity. T cell therapy is appealing in this regard as T cells have the ability to proliferate, migrate, and their antigen specificity reduces the possibility of off-target effects. However, past human studies in HIV-1 infection that administered T cells with limited specificity failed to provide ART-independent, long-term viral control. In this study, we sought to expand functional, broadly-specific cytotoxic T cells (HXTCs) from HIV-infected patients on suppressive ART as a first step toward developing cellular therapies for implementation in future HIV eradication protocols. Blood samples from seven HIV+ patients on suppressive ART were used to derive HXTCs. Multiantigen specificity was achieved by coculturing T cells with antigen-presenting cells pulsed with peptides representing Gag, Pol, and Nef. All but two lines were multispecific for all three antigens. HXTCs demonstrated efficacy as shown by release of proinflammatory cytokines, specific lysis of antigen-pulsed targets, and the ability to suppress HIV replication in vitro. In conclusion, we are able to generate broadly-specific cytotoxic T cell lines that simultaneously target multiple HIV antigens and show robust antiviral function.     

The axon guidance molecule semaphorin 3F is a negative regulator of tumor progression and proliferation in ileal neuroendocrine tumors

Gastro-intestinal neuroendocrine tumors (GI-NETs) are rare neoplasms, frequently metastatic, raising difficult clinical and therapeutic challenges due to a poor knowledge of their biology. As neuroendocrine cells express both epithelial and neural cell markers, we studied the possible involvement in GI-NETs of axon guidance molecules, which have been shown to decrease tumor cell proliferation and metastatic dissemination in several tumor types. We focused on the role of Semaphorin 3F (SEMA3F) in ileal NETs, one of the most frequent subtypes of GI-NETs.SEMA3F expression was detected in normal neuroendocrine cells but was lost in most of human primary tumors and all their metastases. SEMA3F loss of expression was associated with promoter gene methylation. After increasing endogenous SEMA3F levels through stable transfection, enteroendocrine cell lines STC-1 and GluTag showed a reduced proliferation rate in vitro. In two different xenograft mouse models, SEMA3F-overexpressing cells exhibited a reduced ability to form tumors and a hampered liver dissemination potential in vivo. This resulted, at least in part, from the inhibition of mTOR and MAPK signaling pathways.This study demonstrates an anti-tumoral role of SEMA3F in ileal NETs. We thus suggest that SEMA3F and/or its cellular signaling pathway could represent a target for ileal NET therapy.     

Immunotherapy highlights from the 2011 meeting of the American Society of Hematology

The world's largest hematology society, the American Society for Hematology, meets annually, gathering physicians, scientists, administrators, medical students, graduate students, allied health professionals and exhibitors. The meeting this year was held in San Diego, CA, USA, and included a plethora of basic, translational and clinical research.     

Cytogenetic studies in patients with secondary leukemia/dysmyelopoietic syndrome after different treatment modalities

Cytogenetic studies of 68 patients who developed secondary leukemia (SL)/dysmyelopoietic syndrome (DMS) after extensive chemotherapy and/or radiation therapy as well as patients who developed SL/DMS without such treatment showed that those patients who received radiation alone or with chemotherapy had more extensive numerical and structural abnormalities than those who received only chemotherapy. In terms of the specific chromosomal abnormalities, there are no differences between the various treatment groups. Hypodiploidy is the most common form of aneuploidy in these patients, with the most common numerical abnormality being the loss of chromosome 7. The most common structural abnormalities involved chromosomes 3 and 5. When compared with patients with de novo leukemia and DMS, the chromosomal abnormalities in these patients are more complex and extensive. Serial studies revealed that cytogenetic abnormalities do not precede the development of hematologic changes by significant time periods.     

Monoclonal antibody BA-1 does not bind to hematopoietic precursor cells

Monoclonal antibody BA-1 binds to B lymphocytes, to cells from most cases of non-T acute lymphoblastic leukemia (ALL), and weakly to neutrophils. To determine whether BA-1 also reacts with hematopoietic progenitor cells (HPC), we studied the effect of removal of BA-1+ cells from human bone marrow on the proliferation in vitro of the trilineage precursor cell CFU-GEMM, and on the committed progenitor cells of granulopoiesis (CFU-C) and erythropoiesis (BFU-E/CFU-E). Complement- mediated cytotoxicity using BA-1 at concentrations far beyond those required to lyse BA-1+ bone marrow cells and ALL cells did not result in inhibition of colony formation in any of the assays. A rosette separation method, using ox red blood cells coated with BA-1, resulted in enrichment of HPC in the BA-1-depleted interface, whereas very few HPC were found in the BA-1-enriched pellet. Both methods indicate that BA-1 does not bind to HPC, although binding of the antibody to the lymphohematopoietic stem cell cannot be excluded yet. The high cytotoxic capacity of the IgM antibody BA-1, and the lack of reactivity with HPC, make the antibody particularly suitable for use in autologous bone marrow transplantation for patients with ALL.