Blast-derived microvesicles in sera from patients with acute myeloid leukemia suppress natural killer cell function via membrane-associated transforming growth factor-beta1.

BACKGROUND: Natural killer cell cytotoxicity is decreased in patients with acute myeloid leukemia in comparison to that in normal controls. Tumor-derived microvesicles present in patients' sera exert detrimental effects on immune cells and may influence tumor progression. DESIGN AND METHODS: We investigated the microvesicle protein level, molecular profile and suppression of natural killer cell activity in patients with newly diagnosed acute myeloid leukemia. RESULTS: The patients' sera contained higher levels of microvesicles compared to the levels in controls (P<0.001). Isolated microvesicles had a distinct molecular profile: in addition to conventional microvesicle markers, they contained membrane-associated transforming growth factor-ß1, MICA/MICB and myeloid blasts markers, CD34, CD33 and CD117. These microvesicles decreased natural killer cell cytotoxicity (P<0.002) and down-regulated expression of NKG2D in normal natural killer cells (P<0.001). Sera from patients with acute myeloid leukemia contained elevated levels of transforming growth factor-ß, and urea-mediated dissociation of microvesicles further increased the levels of this protein. Neutralizing anti-transforming growth factor-ß1 antibodies inhibited microvesicle-mediated suppression of natural killer cell activity and NKG2D down-regulation. Interleukin-15 protected natural killer cells from adverse effects of tumor-derived microvesicles. CONCLUSIONS: We provide evidence for the existence in acute myeloid leukemia of a novel mechanism of natural killer cell suppression mediated by tumor-derived microvesicles and for the ability of interleukin-15 to counteract this suppression.

The Development and Implementation of an Autopsy/ Tissue Donation for Breast Cancer Research.

There is growing interest in tissue procurement for cancer research through autopsy. Establishing an autopsy/tissue donation programme for breast cancer research within an academic medical centre in the United States requires consideration, planning, multi-departmental collaboration and labour-intensive maintenance. It is the purpose of this paper to outline the necessary considerations in implementing and maintaining a tissue donation and autopsy programme within a breast cancer centre at a comprehensive cancer centre. Considerations of programme planning include: patient engagement, the recruitment of patients and families into the programme, the role and scope of work of the clinical coordinator, regulatory issues and the coordination with both pathology and the research team at time of death and autopsy/tissue donation. All aspects of the tissue donation/rapid autopsy programme development and implementation are discussed and illustrated through case study. An Autopsy/ Tissue Donation for breast cancer research can be successfully developed and implemented.

Interleukin-15 enhances natural killer cell cytotoxicity in patients with acute myeloid leukemia by upregulating the activating NK cell receptors.

Interleukin-15 (IL-15) has a major role in NK-cell homeostasis. Modulation of the relative frequency and expression intensity of the NK-cell receptors by IL-15 may increase NK cell-mediated cytotoxicity in cancer patients. We investigated the receptor repertoire and measured NK-cell activity in newly diagnosed AML patients and evaluated the ex vivo effects of IL-15. The expression of the activating NK cell receptors was significantly decreased in the AML patients compared to that in NK cells of healthy donors. When NK cells obtained from AML patients were cultured with IL-15, expression of the activating receptors was significantly upregulated compared to pre-culture levels. Concomitantly, cytotoxic activity of NK cells against autologous leukemic blasts increased following IL-15 stimulation. This IL-15 induced increase in activity was blocked by neutralizing antibodies specific for the NK cell activating receptors. These pre-clinical data support the future use of IL-15 for NK cell- based therapies for AML patients.

Increased frequency and suppression by regulatory T cells in patients with acute myelogenous leukemia.

PURPOSE: Regulatory CD4(+)CD25(high)Foxp3(+) T cells (Treg) control peripheral immune tolerance. Patients with cancer, including those with hematologic malignancies, have elevated numbers of Treg in the peripheral circulation and in tumor tissues. However, mechanisms of suppression and clinical significance of Treg, especially in patients with acute myelogenous leukemia (AML), has not been well defined. EXPERIMENTAL DESIGN: We prospectively evaluated the phenotype, function, and mechanisms of suppression used by Treg in newly diagnosed untreated AML patients. The relationship between the frequency of circulating Treg and the disease status as well as treatment outcome was also evaluated. RESULTS: The percentage of circulating Treg was higher (P < 0.0001) and their phenotype was distinct in AML patients relative to normal controls. Suppression mediated by Treg coincubated with proliferating autologous responder cells was also higher (P < 0.001) in AML than that mediated by control Treg. Using Transwell inserts, we showed that interleukin-10 and transforming growth factor-beta1 production as well as cell-to-cell contact were necessary for Treg-mediated suppression. Also, the pretreatment Treg frequency predicted response to chemotherapy. Unexpectedly, patients who achieved complete remission still had elevated frequency of Treg, which mediated high levels of suppressor activity. CONCLUSIONS: Treg accumulating in the peripheral circulation of AML patients mediate vigorous suppression via contact-dependent and contact-independent mechanisms. Patients with lower Treg frequency at diagnosis have a better response to induction chemotherapy. During the post-induction period, the Treg frequency and suppressive activity remain elevated in complete remission, suggesting that Treg are resistant to conventional chemotherapy.

The Support, Education, and Advocacy (SEA) Program of Care for Women With Metastatic Breast Cancer: A Nurse-Led Palliative Care Demonstration Program.

BACKGROUND: Women with metastatic breast cancer (MBC) experience unique symptom management and psychosocial needs due to aggressive, yet palliative treatment with a progressive, chronic illness. OBJECTIVE: This article describes the effect of a quality improvement project for coordination of supportive care in MBC. Program evaluations included referral rates for supportive services, patient-reported outcomes of symptom distress, generalized anxiety, and overall well-being. DESIGN: An interdisciplinary Support, Education and Advocacy Program (MBC-SEA) was developed. The 1-hour, weekly, patient review included collaborative assessments to determine needs for social service, psychological counseling, and palliative care. A prospective pre- and postexperimental cohort design with convenience sampling was used. Analysis was conducted with paired t test analysis of pre- and postimplementation outcomes. SETTING/PARTICIPANTS: Program outcomes of 118 women with MBC visiting an urban outpatient breast cancer clinic during September 2016 to November 2016 (pre) and January 2017 to March 2017 (post) were evaluated. MEASUREMENTS: Referral rates to social work and palliative care, symptom, anxiety, and overall well-being scores. RESULTS: Following program implementation, referrals to palliative care and social work supportive services increased significantly including patient-reported outcomes symptom distress scores mean difference 1.4 (95% confidence interval [CI]: 0.4306-2.6428), P = .004; generalized anxiety scores mean difference 1.5 (95% CI: 0.5406-2.5781), P = .003; and overall well-being mean difference of -0.7 (95% CI: -1.3498 to -0.0570), P = .03. CONCLUSIONS: Purposeful nurse-led assessment for social service and palliative care needs increases referrals with improvement in patient-reported outcomes.

The Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of hematologic malignancies: multiple myeloma, lymphoma, and acute leukemia.

Increasing knowledge concerning the biology of hematologic malignancies as well as the role of the immune system in the control of these diseases has led to the development and approval of immunotherapies that are resulting in impressive clinical responses. Therefore, the Society for Immunotherapy of Cancer (SITC) convened a hematologic malignancy Cancer Immunotherapy Guidelines panel consisting of physicians, nurses, patient advocates, and patients to develop consensus recommendations for the clinical application of immunotherapy for patients with multiple myeloma, lymphoma, and acute leukemia. These recommendations were developed following the previously established process based on the Institute of Medicine's clinical practice guidelines. In doing so, a systematic literature search was performed for high-impact studies from 2004 to 2014 and was supplemented with further literature as identified by the panel. The consensus panel met in December of 2014 with the goal to generate consensus recommendations for the clinical use of immunotherapy in patients with hematologic malignancies. During this meeting, consensus panel voting along with discussion were used to rate and review the strength of the supporting evidence from the literature search. These consensus recommendations focus on issues related to patient selection, toxicity management, clinical endpoints, and the sequencing or combination of therapies. Overall, immunotherapy is rapidly emerging as an effective therapeutic strategy for the management of hematologic malignances. Evidence-based consensus recommendations for its clinical application are provided and will be updated as the field evolves.