Apparent mtDNA sequence heterogeneity in single human blood CD34+ cells is markedly affected by storage and transport.

Single CD34(+) cells from adult human peripheral blood show mtDNA sequence heterogeneity. In this study, we compared mtDNA sequence variation in single CD34(+) cells from peripheral blood (PB) mononuclear cells (MNCs) from the same donors but under different conditions of storage and transport: group I, MNCs from heparinized PB that inadvertently required six days to be transported to the testing laboratory; group II, MNCs which were isolated from PB within a day of phlebotomy and frozen prior to transportation and storage. We observed more cell death for MNCs of group I than group II. Concordantly, group I CD34(+) cells had a very low potential for hematopoietic colony formation in vitro compared with group II cells. CD34(+) cells of group II showed an unexpectedly higher level of mtDNA sequence heterogeneity than was present in group I cells. These observations suggest that reduced mtDNA sequence heterogeneity in single CD34(+) cells of group I was likely due to elimination of cells harboring mutations. CD34(+) cells that survive stress ex vivo may be more enriched in quiescent primitive hematopoietic stem cells, with fewer mtDNA mutations than are present in committed progenitors. Technically, attention is required to conditions of preparation of human blood samples for single cell mtDNA analysis.

Accumulation of mtDNA variations in human single CD34+ cells from maternally related individuals: effects of aging and family genetic background.

Marked sequence variation in the mtDNA control region has been observed in human single CD34(+) cells, which persist in vivo and are present also in differentiated hematopoietic cells. In this study, we analyzed 5071 single CD34(+) cells from 49 individuals (including 31 maternally related members from four families and 18 unrelated donors) in order to determine the mutation spectrum within the mtDNA control region in single cells, as related to aging and family genetic background. Many highly mutated sites among family members were hypervariable sites in the mtDNA control region. Further, CD34(+) cells from members of the same family also shared several unique mtDNA variants, suggesting pedigree-specific occurrence of these variants. Overall age-related accumulation of mtDNA mutations in CD34(+) cells varied in different families, suggesting a specific accumulation pattern, which might be modulated by family genetic background. Our current findings have implications for the occurrence of mtDNA mutations in hematopoietic stem cells and progenitors.

Physical contact with endothelial cells through ß1- and ß2- integrins rescues chronic lymphocytic leukemia cells from spontaneous and drug-induced apoptosis and induces a peculiar gene expression profile in leukemic cells.

BACKGROUND: Chronic lymphocytic leukemia B cells display prolonged survival in vivo, but when cultured in vitro rapidly undergo spontaneous apoptosis. We hypothesize that interactions with endothelial cells in infiltrated tissues and during recirculation may have a pathogenic role in chronic lymphocytic leukemia. DESIGN AND METHODS: We evaluated apoptosis of leukemic cells after co-culture on a monolayer of human umbilical vein endothelial cells with addition of fludarabine and antibodies that block adhesion. Then, we compared microarray-based gene expression profiles between leukemic cells at baseline and after co-culture. RESULTS: We found that the endothelial layer protected leukemic cells from apoptosis inducing a 2-fold mean decrement in apoptotic cells after 2 days of co-culture. Moreover, the endothelial layer decreased the sensitivity of chronic lymphocytic leukemia B cells to fludarabine-induced apoptosis. Physical contact with endothelium mediated by both ß(1)- and ß(2)- integrins is essential for the survival advantage of leukemic cells. In particular, blocking CD106 on endothelial cells or CD18 on leukemic B cells led to the almost complete abrogation of the survival advantage (>70% inhibition of viability). However, a reduction of apoptosis was also measured in leukemic cells cultured in conditioned medium collected after 2 days of co-culture, implying that survival is partially mediated by soluble factors. Overall, the contact with endothelial cells modulated 1,944 genes in chronic lymphocytic leukemia B cells, establishing a peculiar gene expression profile: up-regulation of angiogenesis-related genes, an increase of genes involved in TGFß and Wnt signaling pathways, secretion of cytokines recruiting stromal cells and macrophages and up-regulation of anti-apoptotic molecules such as Bcl2 and Survivin. CONCLUSIONS: Our study supports the notion that endothelial cells are major players in the chronic lymphocytic leukemia microenvironment. Adhesion to endothelium strongly supports survival, protects from drug-induced apoptosis and extensively modifies the gene expression profile of leukemic cells.

Cytogenetic abnormalities and clinical features in a patient cohort affected by three or more synchronous or metachronous primitive malignancies.

The multiple cancers (MC) phenotype represents an intriguing entity from both the clinical and the biomolecular points of view. Multiple cancers can arise in a patient either synchronously or metachronously and are frequently detected in hereditary disorders. Here we report the clinical and cytogenetic characterization of 48 patients developing at least three malignancies outside the context of a known genetic condition and 30 control individuals. Medical and pathology reports were registered, blood was collected for cytogenetic studies, and the standard G-banding technique was used for chromosomal analysis of the lymphocyte cultures. Chromosomal analysis of the peripheral blood cultures revealed high cytogenetic instability in 83% of patients' karyotypes that displayed structural rearrangements most often involving chromosomes X, 1, 6, and 7. Peculiar telomeric associations and marker chromosomes were detected in patients with a suspected cancer family history. The MC condition can be observed over a wide clinical range, which includes either apparently sporadic cases or families with a strong history of tumors. These findings indicate that Xq, 6p, and 7q are likely to harbor genes of importance in cancer development, and the present cytogenetic mapping may be crucial for further molecular genetic investigations to recognize a predictive cytogenetic signature useful to detect patients with a high risk of multiple malignancies.

Posttraumatic massive bleeding: a challenging multidisciplinary task.

Massive bleeding is a key issue in the treatment of trauma and surgery. It does in fact account for more than 50% of all trauma-related deaths within the first 48 h following hospital admission, and it can significantly raise the mortality rate of any kind of surgery. Despite this great clinical relevance, evidence on the management of massive bleeding is surprisingly scarce, and its treatment is often based on empirical grounds. Successful treatment of massive haemorrhage depends on better understanding of the associated physiological changes as well as on good team work between the different specialists involved in the management of such a complex condition. The aim of this article is to provide an overview of the pathophysiology as well as of current treatment options of such a condition, including the new concept of "damage control resuscitation", which integrates permissive hypotension, haemostatic resuscitation and damage control surgery.

Angiopoietin-2 plasma dosage predicts time to first treatment and overall survival in chronic lymphocytic leukemia.

The clinical relevance of angiopoietin-2 (Ang2) in chronic lymphocytic leukemia (CLL) was previously suggested by the association between high Ang2, and shorter progression-free survival reported in small series of patients. Here, we evaluated Ang2 glycoprotein levels in plasma samples collected from a multicentric cohort of CLL patients (n = 316) using an enzyme-linked immunosorbent assay method, and we investigated its prognostic role in relation to time to first treatment (TTFT) and overall survival. Based on a cutoff equal to 2459 pg/mL, we divided our cohort in 2 subsets (high and low Ang2) composing 100 (31.6%) and 216 (68.4%) patients, respectively. High Ang2 was predictive of reduced TTFT (P < .001) and overall survival (P = .002). Multivariate analysis confirmed that high Ang2 was an independent prognosticator for TTFT (hazard ratio = 1.739; 95% confidence interval, 1.059-2.857; P = .029). Significant associations were found between high Ang2 and advanced Binet stages (P < .001), high beta(2)-microglobulin (P < .001), unmutated variable region of immunoglobulin heavy chain gene status (P < .001), high CD38 and zeta-chain-associated protein kinase 70 expression (P < .001 and P = .003), and intermediate/high cytogenetic risk (P = .005). Moreover, Ang2 added prognostic power to other conventional prognosticators and helped to refine prognosis among CLL subsets with both high and low vascular endothelial growth factor plasma levels. Ang2 plasma level may be a useful independent prognosticator for CLL.

Immunological and inflammatory features of Kaposi's sarcoma and other Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8-associated neoplasias.

During the last 15 years, virologic and immunologic studies have provided a series of valuable clues on the modalities of gamma-herpesvirus-induced oncogenesis, which do not only consist of the direct subversion of intracellular signaling pathways, leading to a frank neoplastic molecular network in the infected cell, but also rely on viral manipulations of the cellular and cytokine microenvironment, especially in conditions of immunodeficiency in the host. At the virus-host interface, something iniquitous, strikingly favoring the aggressive expansion of human herpesvirus 8-infected lympho-endothelial clones, known as Kaposi's sarcoma, often occurs in different types of immunocompromised patients, able to establish a deleterious "pro-Kaposi's sarcoma" neo-angiogenic inflammatory network. However, these patients may control - or even resolve - the neoplastic burden as soon as an immunologic reassessment restores functional anti-Kaposi's sarcoma immune responses and reconstitutes a proper inflammatory environment. Indeed, the occurrence of iatrogenic Kaposi's sarcoma remissions, after the reduction or switch of immunosuppressive regimens, strongly suggests that the reset of immunologic constraints characterizing the Kaposi's sarcoma onco-pathogenic system may be sufficient to inhibit human herpesvirus 8-positive lympho-endothelial proliferations. Accordingly, immunologic reports all underline the pivotal protective role of anti-human herpesvirus 8 memory T-cells (harmonically, both CD8+ and CD4+ subsets), thus definitely implying a general requirement for an effective, antiviral immuno-inflammatory environment, based on correct and productive interactions between different compartments of dendritic, myeloid, and specific T-cells, in order to achieve and maintain optimal control on human herpesvirus 8-associated antigenic stimulations and Kaposi's sarcoma disease. In this review, we recapitulate some remarkable features about the outstanding immunologic issue raised by human herpesvirus 8-driven neoplastic outgrowths in immunodeficient patients, and in particular, we discuss the emerging view of Kaposi's sarcoma as an atypical neoplastic process, tightly dependent on immune system dynamics. It is conceivable that functional dissection of the specific immune responses, capable to cope with human herpesvirus 8, and further definitions of a global inflammatory profile with protective activity against Kaposi's sarcoma outbreaks, will eventually foster immunologic monitoring protocols during the follow-up of AIDS and posttransplant patients, either preventing or treating human herpesvirus 8-related tumors by multifunctional immunomodulation or prompt development of adoptive immunotherapeutic approaches.

Randomized trial of two schedules of low-dose gemtuzumab ozogamicin as induction monotherapy for newly diagnosed acute myeloid leukaemia in older patients not considered candidates for intensive chemotherapy. A phase II study of the EORTC and GIMEMA leukaemia groups (AML-19).

This study compared two schedules of low-dose gemtuzumab ozogamicin (GO) as induction monotherapy for untreated acute myeloid leukaemia in older patients unfit for intensive chemotherapy, to identify the more promising regimen for further study. Patients were randomized to receive either best supportive care or a course of GO according to one of two schedules: 3 mg/m(2) on days 1, 3 and 5 (arm A), or GO 6 mg/m(2) on day 1 and 3 mg/m(2) on day 8 (arm B). Primary endpoint was the rate of disease non-progression (DnP), defined as the proportion of patients either achieving a response or maintaining a stable disease following GO induction in each arm. Fifty-six patients were randomized in the two GO arms (A, n = 29; B, n = 27). The rate of DnP was 38% [90% confidence interval (CI), 23-55] in arm A, and 63% (90% CI, 45-78) in arm B. Peripheral cytopenias were the most common adverse events for both regimens. The all-cause early mortality rate was 14% in arm A and 11% in arm B. The day 1 + 8 schedule, which was associated with the highest rate of DnP, met the statistical criteria to be selected as the preferred regimen for phase III comparison with best supportive care.

Organising pneumonia mimicking invasive fungal disease in patients with leukaemia.

Clinical charts from 63 consecutive highly immunocompromised haematologic patients presenting with pulmonary nodular lesions on CT scan, classified as either probable or possible invasive fungal disease (IFD) according to the revised EORTC/MSG classification, were retrospectively studied. Histopathological analysis of lung tissues, available for 23 patients, demonstrated proven IFD in 17 cases (14 invasive aspergillosis and 3 invasive zygomycosis), diffuse alveolar damage in one and organising pneumonia (OP) in five cases. In the OP cases, three of which have been defined as probable IFD according to EORTC/MSG classification, extensive immunohistochemical, molecular and immunological analyses for fungi were negative. Our case descriptions extend the notion that OP may be encountered as a distinct histopathological entity in pulmonary nodular lesions in patients with leukaemia with probable/possible IFD.

Emergence of BCR-ABL-specific cytotoxic T cells in the bone marrow of patients with Ph+ acute lymphoblastic leukemia during long-term imatinib mesylate treatment.

Imatinib mesylate has been demonstrated to allow the emergence of T cells directed against chronic myeloid leukemia cells. A total of 10 Philadelphia chromosome-positive acute lymphoblastic leukemia patients receiving high-dose imatinib mesylate maintenance underwent long-term immunological monitoring (range, 2-65 months) of (p190)BCR-ABL-specific T cells in the bone marrow and peripheral blood. (p190)BCR-ABL-specific T lymphocytes were detected in all patients, more frequently in bone marrow than in peripheral blood samples (67% vs 25%, P < .01) and resulted significantly associated with lower minimal residual disease values (P < .001), whereas absent at leukemia relapse. Specific T cells were mainly effector memory CD8(+) and CD4(+) T cells, producing interferon-gamma, tumor necrosis factor-alpha, and interleukin-2 (median percentage of positive cells: 3.34, 3.04, and 3.58, respectively). Cytotoxic subsets able to lyse BCR-ABL-positive leukemia blasts also were detectable. Whether these autologous (p190)BCR-ABL-specific T cells may be detectable under other tyrosine-kinase inhibitors, expanded ex vivo, and exploited for immunotherapy remains to be addressed.

Increased angiogenesis induced by chronic lymphocytic leukemia B cells is mediated by leukemia-derived Ang2 and VEGF.

Emerging evidence suggests that angiogenic signalling pathways play important role in the patho-biology of chronic lymphocytic leukemia (CLL). Our goal was to investigate: (i) the spontaneous and hypoxia-induced production of pro-angiogenic factors, VEGF and Ang2, by Real-time PCR and ELISA, (ii) the degree of vascularization in CLL-infiltrated bone marrow (BM) compartment by CD34 immunohistochemical staining of microvessels and (iii) the direct angiogenic effect of CLL-derived VEGF and Ang2 by function-blocking experiments in Matrigel assays. The results demonstrated that CLL cells spontaneously express both VEGF and Ang2 and are able to secrete these factors in surrounding microenvironment. Full-length Ang2 mRNA and truncated form Ang2(443) were detectable. Moreover, CLL cells were shown to enhance secretion of both VEGF and Ang2 proteins when subjected to hypoxic condition. Furthermore, increased in vivo and in vitro angiogenesis was induced by CLL cells. Enhanced BM vascularity correlated with Ig-unmutated CLL subset and increased expression of Ang2. Then, we demonstrated that supernatants obtained from CLL cells significantly increase the HUVEC tube formation in Matrigel assays and that this enhanced angiogenic capacity is mediated by both CLL-derived VEGF and Ang2. Taken together, these results suggest that several simultaneous mechanisms may be involved in the CLL capacity to induce the disruption of pre-existing vessel structures to give rise to tumor neoangiogenesis. The preliminary studies in solid tumors, showing that the disruption of Ang2 function can inhibit tumor vessel density and growth, are encouraging and suggest the possibility of new future therapeutic options targeting CLL microenvironment.