Gianluca Viarengo

Extracorporeal photochemotherapy for treatment of acute and chronic GVHD in childhood.

BACKGROUND: Extracorporeal photochemotherapy (EPC) has recently been proposed for the treatment of adults with either acute or chronic GVHD. However, data on children given this therapy are scarce. A Phase I‐II study was carried out on EPC in children experiencing GVHD after allogeneic transplantation of HPCs.

Extracorporeal photochemotherapy in graft-versus-host disease: a longitudinal study on factors influencing the response and survival in pediatric patients.

BACKGROUND: Extracorporeal photochemotherapy (ECP) is a valid therapeutic option in the treatment of acute and chronic graft‐versus‐host disease (aGVHD and cGVHD, respectively). No standard clinical and laboratory criteria of response to ECP treatment are available at the moment.

Circulating CD34+, CD133+, and vascular endothelial growth factor receptor 2-positive endothelial progenitor cells in myelofibrosis with myeloid metaplasia.

PURPOSE Endothelial progenitor cells (EPCs) are present in circulation and contribute to vasculogenesis in adults. We measured the number of circulating EPCs in patients with myelofibrosis with myeloid metaplasia (MMM), and we examined the relationship between the number of EPCs and severity of the MMM disease process. PATIENTS AND METHODS The number of EPCs was measured by assaying the CD34+CD133+ vascular endothelial growth factor receptor 2 (VEGFR2) -positive cell phenotype in 110 MMM patients, 16 patients with other Philadelphia-negative chronic myeloproliferative disorders (Ph-negative CMPDs), and 14 healthy participants. In four MMM patients, the capacity of selected CD34+ cells to form endothelial colonies (CFU-End) in vitro was tested. RESULTS CD34+, CD133+, and VEGFR2-positive EPCs were detectable in unselected peripheral-blood cells of 50.9% MMM patients, 37.5% control patients, and 21% healthy participants. Patients with MMM had a median of 0.26% EPCs, significantly higher than that in healthy controls (median, 0%) and in patients with other Ph-negative CMPDs (median, 0.1%). In 14.5% of MMM patients, the numbers of EPCs were greater than the highest value found in patients with other Ph-negative CMPDs. CD34+ selected cells produced colony-forming unit-endothelial (CFU-End), which were vascular endothelial (VE) -cadherin positive, CD31+, von Willebrand factor positive, and CD45-. In MMM patients, the larger the number of EPCs, the smaller the number of circulating immature myeloid cells and circulating CD45+CD34+ hematopoietic progenitor cells. Increased numbers of EPCs were associated with younger age and a diagnosis of prefibrotic MMM. CONCLUSION Circulating EPCs are elevated in MMM patients in the early stage of the disease. Heightened mobilization of EPCs may represent an important mechanism for development of neoangiogenesis in MMM.

Evidence that prefibrotic myelofibrosis is aligned along a clinical and biological continuum featuring primary myelofibrosis.

Purpose In the WHO diagnostic classification, prefibrotic myelofibrosis (pre-MF) is included in the category of primary myelofibrosis (PMF). However, strong evidence for this position is lacking. Patients and Methods We investigated whether pre-MF may be aligned along a clinical and biological continuum in 683 consecutive patients who received a WHO diagnosis of PMF. Results As compared with PMF-fibrotic type, pre-MF (132 cases) showed female dominance, younger age, higher hemoglobin, higher platelet count, lower white blood cell count, smaller spleen index and higher incidence of splanchnic vein thrombosis. Female to male ratio and hemoglobin steadily decreased, while age increased from pre-MF to PMF- fibrotic type with early and to advanced bone marrow (BM) fibrosis. Likely, circulating CD34+ cells, LDH levels, and frequency of chromosomal abnormalities increased, while CXCR4 expression on CD34+ cells and serum cholesterol decreased along the continuum of BM fibrosis. Median survival of the entire cohort of PMF cases was 21 years. Ninety-eight, eighty-one and fifty-six percent of patients with pre-MF, PMF-fibrotic type with early and with advanced BM fibrosis, respectively, were alive at 10 years from diagnosis. Conclusion Pre-MF is a presentation mode of PMF with a very indolent phenotype. The major consequences of this contention is a new clinical vision of PMF, and the need to improve prognosis prediction of the disease.

Endothelial colony-forming cells from patients with chronic myeloproliferative disorders lack the disease-specific molecular clonality marker

Two putative types of circulating endothelial progenitor cells have been recently identified in vitro: (1) endothelial colony-forming cell (ECFC) and (2) colony-forming unit-endothelial cell (CFU-EC). Only the former is now recognized to belong to endothelial lineage. We have used the ECFC and CFU-EC assays to readdress the issue of the clonal relation between endothelial progenitor cells and hematopoietic stem cells in patients with Philadelphia-positive and Philadelphia-negative chronic myeloproliferative disorders. Both ECFCs and CFU-ECs were cultured from peripheral blood mononuclear cells, and either BCR-ABL rearrangement or JAK2-V617F mutation were assessed in both types of endothelial colonies. We found that ECFCs lack the disease-specific markers, which are otherwise present in CFU-ECs, thus reinforcing the concept that the latter belongs to the hematopoietic lineage, and showing that in chronic myeloproliferative disorders the cell that gives rise to circulating ECFC has a distinct origin from the cell of the hematopoietic malignant clone.

A new automated cell washer device for thawed cord blood units.

BACKGROUND:  The current available techniques to wash out DMSO from thawed umbilical cord blood (UCB) units are based essentially on standard centrifugation in an open system with various degrees of cell loss.

Conditioned Medium From Human Amniotic Mesenchymal Stromal Cells Limits Infarct Size and Enhances Angiogenesis

The paracrine properties of human amniotic membrane‐derived mesenchymal stromal cells (hAMCs) have not been fully elucidated. The goal of the present study was to elucidate whether hAMCs can exert beneficial paracrine effects on infarcted rat hearts, in particular through cardioprotection and angiogenesis. Moreover, we aimed to identify the putative active paracrine mediators. hAMCs were isolated, expanded, and characterized. In vitro, conditioned medium from hAMC (hAMC‐CM) exhibited cytoprotective and proangiogenic properties. In vivo, injection of hAMC‐CM into infarcted rat hearts limited the infarct size, reduced cardiomyocyte apoptosis and ventricular remodeling, and strongly promoted capillary formation at the infarct border zone. Gene array analysis led to the identification of 32 genes encoding for the secreted factors overexpressed by hAMCs. Among these, midkine and secreted protein acidic and rich in cysteine were also upregulated at the protein level. Furthermore, high amounts of several proangiogenic factors were detected in hAMC‐CM by cytokine array. Our results strongly support the concept that the administration of hAMC‐CM favors the repair process after acute myocardial infarction.

High Frequency of Endothelial Colony Forming Cells Marks a Non-Active Myeloproliferative Neoplasm with High Risk of Splanchnic Vein Thrombosis

Increased mobilization of circulating endothelial progenitor cells may represent a new biological hallmark of myeloproliferative neoplasms. We measured circulating endothelial colony forming cells (ECFCs) in 106 patients with primary myelofibrosis, fibrotic stage, 49 with prefibrotic myelofibrosis, 59 with essential thrombocythemia or polycythemia vera, and 43 normal controls. Levels of ECFC frequency for patients characteristics were estimated by using logistic regression in univariate and multivariate setting. The sensitivity, specificity, likelihood ratios, and positive predictive value of increased ECFC frequency were calculated for the significantly associated characteristics. Increased frequency of ECFCs resulted independently associated with history of splanchnic vein thrombosis (adjusted odds ratio = 6.61, 95% CI = 2.54–17.16), and a summary measure of non-active disease, i.e. hemoglobin of 13.8 g/dL or lower, white blood cells count of 7.8×109/L or lower, and platelet count of 400×109/L or lower (adjusted odds ratio = 4.43, 95% CI = 1.45–13.49) Thirteen patients with splanchnic vein thrombosis non associated with myeloproliferative neoplasms were recruited as controls. We excluded a causal role of splanchnic vein thrombosis in ECFCs increase, since no control had elevated ECFCs. We concluded that increased frequency of ECFCs represents the biological hallmark of a non-active myeloproliferative neoplasm with high risk of splanchnic vein thrombosis. The recognition of this disease category copes with the phenotypic mimicry of myeloproliferative neoplasms. Due to inherent performance limitations of ECFCs assay, there is an urgent need to arrive to an acceptable standardization of ECFC assessment.

A3669G polymorphism of glucocorticoid receptor is a susceptibility allele for primary myelofibrosis and contributes to phenotypic diversity and blast transformation

The frequency of A3669G single nucleotide polymorphism (SNP) of human glucocorticoid receptor has been reported increased in polycythemia vera. We investigated the frequency of A3669G SNP and its impact on disease phenotype and progression in 499 patients with primary myelofibrosis (PMF). The distribution of the A3669G allele differed between PMF patients and 2 healthy control populations (odds ratio, 1.6 and 1.8). The variant allele at the homozygous state (G/G) was associated with higher white blood cell count, larger spleen index, and higher frequency of circulating CD34(+) cells at diagnosis. The latter association remained significant after correction for the JAK2V617F genotype. In patients JAK2V617F mutated, the G/G genotype was associated with shorter overall survival (77.6 months vs 298 months, P = .049) and blast transformation (BT)-free survival (76.7 months vs 261 months; P = .018). The latter association remained significant after correction for the known BT risk factors, such as age, sex, white blood cell count, percentage of blasts, IPSS prognostic score, and homozygosity for JAK2V617F (hazard ratio = 3.3; P = .006). In conclusion, the glucocorticoid receptor A3669G is a susceptibility allele for PMF: it contributes to confer the phenotype of excess myeloproliferation, and it cooperates with the JAK2V617F mutation in determining BT.

Combination of miRNA499 and miRNA133 exerts a synergic effect on cardiac differentiation

Several studies have demonstrated that miRNA are involved in cardiac development, stem cell maintenance, and differentiation. In particular, it has been shown that miRNA133, miRNA1, and miRNA499 are involved in progenitor cell differentiation into cardiomyocytes. However, it is unknown whether different miRNA may act synergistically to improve cardiac differentiation. We used mouse P19 cells as a cardiogenic differentiation model. miRNA499, miRNA1, or miRNA133 were transiently over‐expressed in P19 cells individually or in different combinations. The over‐expression of miRNA499 alone increased the number of beating cells and the association of miRNA499 with miRNA133 exerted a synergistic effect, further increasing the number of beating cells. Real‐time polymerase chain reaction showed that the combination of miRNA499 + 133 enhanced the expression of cardiac genes compared with controls. Western blot and immunocytochemistry for connexin43 and cardiac troponin T confirmed these findings. Importantly, caffeine responsiveness, a clear functional parameter of cardiac differentiation, was increased by miRNA499 in association with miRNA133 and was directly correlated with the activation of the cardiac troponin I isoform promoter. Cyclic contractions were reversibly abolished by extracellular calcium depletion, nifedipine, ryanodine, and IP3R blockade. Finally, we demonstrated that the use of miRNA499 + 133 induced cardiac differentiation even in the absence of dimethyl sulfoxide. Our results show that the areas spontaneously contracting possess electrophysiological and pharmacological characteristics compatible with true cardiac excitation‐contraction coupling. The translational relevance of our findings was reinforced by the demonstration that the over‐expression of miRNA499 and miRNA133 was also able to induce the differentiation of human mesenchymal stromal cells toward the cardiac lineage. Stem Cells 2015;33:1187–1199