Maria Vittoria Gazzola

Mesenchymal stromal cells can be derived from bone marrow CD133+ cells: implications for therapy.

It is known that the bone marrow (BM) CD133(+) cells play an important role in the hematopoietic compartment, but this is not their only role. The cells indeed can take part in vascular reconstitution when they become endothelial cells (EC), in skeletal muscle fiber regeneration when there is a switch in muscle precursors, and to cardiomyocyte phenotypic conversion when differentiating in cardiomyocytes-like cells. While the role in hematopoiesis and vasculogenesis of the selected cells is well established, their ability to differentiate along multiple non-EC lineages has not yet been fully elucidated. The goal of this study is to assert whether human CD133(+)BM-derived cells are able to differentiate in vitro, besides to blood cells, cell lineages pertinent to the mesoderm germ layers. To this end, we isolated CD133(+) cells using a clinically approved methodology and compared their differentiation potential to that of hematopoietic progenitor cells (HPCs) and mesenchymal stem cells (MSCs) obtained from the same BM samples. In our culture conditions, CD133 expression was consistently decreased after passage 2, as well as the expression of the stemness markers c-kit and OCT4, whereas expression of Stage Specific Embryonic Antigen 4 (SSEA4) remained consistent in all different conditions. Expanded CD133 were also positive for HLA-ABC, but negative for HLA-DR, in accordance with what has been previously reported for MSCs. Moreover, CD133(+) cells from human BM demonstrated a wide range of differentiation potential, encompassing not only mesodermal but also ectodermal (neurogenic) cell lineages. CD133 antigen could be potentially used to select a cell population with similar characteristics as MSCs for therapeutic applications.

KIR/HLA‐I mismatching and risk of relapse in paediatric patients undergoing non‐haploidentical allogeneic haematopoietic stem cell transplantation

Scquizzato E, Zambello R, Teramo A, Baesso I, Varotto S, Albergoni MP, Boscaro E, Cesaro S, Pillon M, Calore E, Gazzola MV, Semenzato G, Messina C, Trentin L. KIR/HLA‐I mismatching and risk of relapse in paediatric patients undergoing non‐haploidentical allogeneic haematopoietic stem cell transplantation.
Pediatr Transplantation 2011: 15:198–204.

Non-T, non-B childhood acute lymphoblastic leukemia. Correlation between cytochemical markers and first complete remission

The positivity for four cytochemical reactions, acid phosphatase (AcP), alpha‐naphtyl acid acetate esterase (ANAE), beta‐glucuronidase (BG), and N‐acetyl beta‐glucosaminidase (NABG) was correlated to first remission duration in 120 children affected with non‐T, non‐B acute lymphoblastic leukemia (ALL). The percentages of patients remaining in complete remission at 72 months were always higher for children whose blasts lacked these enzymatic reactions; however, a statistical difference was found only between BG+ and BG− ALL. It also appears that more complete enzymatic patterns of leukemic cells are associated with a poorer prognosis. The percentage of patients still in their first remission was 89% for leukemias with no cytochemical markers, 59% when one reaction was present, but less than 39% when two or more enzymes were detected in the blasts. It is noteworthy that the blasts of patients with more severe prognosis demonstrated a simultaneous positivity for AcP–ANAE or BG–NABG cytochemical reactions. The possible usefulness of these cytochemical markers to detect subsets of patients with different prognostic significance among non‐T, non‐B ALL is discussed.

Differences in Aspergillus‐specific immune recovery between T‐cell‐replete and T‐cell‐depleted hematopoietic transplants

After hematopoietic stem cell transplantation, invasive aspergillosis remains one of the most lethal infections. Susceptibility may be due to prophylaxis and treatment of graft‐vs.‐host disease in T‐cell‐replete transplants, and delayed immune rebuilding due to T‐cell depletion in haploidentical transplantation.