Giancarlo Isacchi

Purified T-depleted, CD34+ peripheral blood and bone marrow cell transplantation from haploidentical mother to child with thalassemia.

Fetomaternal microchimerism suggests immunological tolerance between mother and fetus. Thus, we performed primary hematopoietic stem cell transplantation from a mismatched mother to thalassemic patient without an human leukocyte antigen-identical donor. Twenty-two patients with thalassemia major were conditioned with 60 mg/kg hydroxyurea and 3 mg/kg azathioprine from day -59 to -11; 30 mg/m(2) fludarabine from day -17 to -11; 14 mg/kg busulfan starting on day -10; and 200 mg/kg cyclophosphamide, 10 mg/kg thiotepa, and 12.5 mg/kg antithymocyte globulin daily from day -5 to -2. Fourteen patients received CD34(+)-mobilized peripheral blood and bone marrow progenitor cells; 8 patients received marrow graft-selected peripheral blood stem cells CD34(+) and bone marrow CD3/CD19-depleted cells. T-cell dose was adjusted to 2 x 10(5)/kg by fresh marrow cell addback at the time of transplantation. Both groups received cyclosporine for graft-versus-host disease prophylaxis for 2 months after transplantation. Two patients died (cerebral Epstein-Barr virus lymphoma or cytomegalovirus pneumonia), 6 patients reject their grafts, and 14 showed full chimerism with functioning grafts at a median follow-up of 40 months. None of the 14 patients who showed full chimerism developed acute or chronic graft-versus-host disease. These results suggest that maternal haploidentical hematopoietic stem cell transplantation is feasible in patients with thalassemia who lack a matched related donor.

Polymorphonuclear leukocyte transfusion for the treatment of sepsis in the newborn infant

A therapeutic trial of transfusions with polymorphonuclear leukocyte concentrates was performed in newborn infants with bacterial sepsis proven by blood culture. With each transfusion, 20 ml/kg of a preparation obtained by continuous flow filtration leukapheresis, and containing 0.5 to 1 x 10(9) WBC, with less than 6% lymphocytes, was administered. Twenty newborn infants with sepsis received from 2 to 15 PMN transfusions. Results were compared with findings in 18 newborn infants with sepsis admitted during the trial period, and not treated because of unavailability of the PMN preparation (Group B). Infants with fulminant illness were excluded from both groups. Groups A and B were similar with respect to clinical characteristics and to etiology (in the majority cases a highly antibiotic-resistant Klebsiella). The mortality rate was significantly lower in Group A than in Group B in the whole series (10% vs 72%, P < 0.001), and also in the subgroups with birth weight equal or below 1,500 gm (10% vs 91%, P < 0.001). Major complications and associated conditions (i.e., necrotizing enterocolitis, meningitis, pneumonia, peritonitis, osteoarthritis, disseminated intravascular coagulation) were observed in 12 patients of Group B, and in only three infants of Group A. Untoward effects attributable to PMN transfusions were never observed. PMN transfusion was a highly effective therapeutic tool in our population of infected newborn infants.

T cell-depleted hla-haploidentical stem cell transplantation in thalassemia young patients

The cure for thalassemia involves correcting the genetic defect in a hematopoietic stem cell that results in reduced or absent β-globin synthesis and an excess of α-globin dimers. Intracellular precipitation and accumulation of α- dimers results in ineffective erythropoiesis and hemolytic anemia. Replacing the abnormal thalassemic marrow with allogeneic normal or heterozygous stem cells carrying the functional gene restores appropriate β-globin chain synthesis.

Partial correction of chromosome instability in Fanconi anemia by desferrioxamine

SummaryThe action of the iron chelator desferrioxamine (DFO) on the cytogenetic pattern of cultured lymphocytes from Fanconi anemia (FA) patients was investigated. The addition of 10-4M DFO throughout the culture time resulted in a 50% reduction of the spontaneous chromosome breakage of FA cells. In addition, the clastogenic action of diepoxybutane on FA lymphocytes was also partly counteracted by DFO. The above findings support the assumption that one of the mechanisms involved in the pathogenesis of FA might be an impaired capacity of the cells from such patients to remove active oxygen species. The relationship between intraleukocyte chelatable iron pool and free radical formation in FA subjects is discussed.

Processing of hematopoietic stem cells from peripheral blood before cryopreservation: use of a closed automated system

BACKGROUND: Hematopoietic stem cell transplantation is commonly used to treat several oncohematologic diseases. The autologous hematopoietic progenitor cells collected through apheresis (HPC‐A) must be cryopreserved and stored before use in vivo. Cell processing that precedes cryopreservation of HPC‐A includes volume reduction aimed at reducing the amount of dimethyl sulfoxide used, as well as storage space.

Treg cells: Collection, processing, storage and clinical use

T regulatory cells are fundamental in the maintenance of immune homeostasis and self-tolerance. Experimental models suggest the existence of two functional types of T(reg) cells designated naturally occurring and induced. Interest in T(reg) cells increased with evidence from experimental mouse and human models demonstrating that the immunosuppressive potential of these cells can be utilized in the treatment of various pathological conditions. The existence of a subpopulation of suppressive T cells was the subject of significant controversy among immunologists for many years. T regulatory cells limit immune activation through a variety of direct and indirect interactions, many of which are yet to be determined. Fully understanding T(reg) cells biology will lead us to harnessing the capacity of these cells in order to develop strategies to prevent autoimmune disorders and tolerance to transplantation. Efficient isolation, expansion and cryopreservation strategies that comply with Good Manufacturing Practice (GMP) guidelines are prerequisites for the clinical application of human CD4+ CD25+ CD127(low) FOXP3+ regulatory T cells.

Positive immunomagnetic CD34+ cell selection in haplo-identical transplants in β-thalassemia patients: removal of platelets using an automated system

BACKGROUND AIMS Immunomagnetic CD34(+) cell selection (ICS) is utilized in autologous and allogeneic transplants. In the first case it is used to reduce the neoplastic contamination of concentrates, while in the second case it is needed to carry out a T-depletion of cell concentrates in order to reduce the incidence of graft-versus-host disease (GvHD) in patients who have undergone haplo-identical transplants. METHODS The efficacy of CliniMACS technology, after reduction of platelet contamination, incubation of monoclonal antibodies (MAb) and successive washings of concentrates, performed in 16 ICS using the standard method without reducing platelet content, was compared with the use of the automated system CytoMate, which was carried out in 46 ICS. RESULTS In the group of ICS carried out after automatic manipulation, a significant statistical difference in purity was noted (91.39% versus 83.57, P = 0.017) compared with the group of ICS carried out with the standard procedure. The same significant difference was noted in relation to the remaining percentages of CD3(+) and CD19(+) cells (2.31% versus 5.68%, P = 0.012, and 1.58% versus 2.71%, P = 0.014, respectively). Recovery of CD34+ cells overlapped in the two groups (70.49% versus 68.39%, P = 0.774). CONCLUSIONS Immunomagnetic selection carried out using the automated procedure was more efficient, producing a purer sample, more efficient T-depletion and optimal reduction of B cells, without influencing cell recovery. Furthermore, conforming to good manufacturing practice (GMP) guidelines, the entire procedure with CytoMate took place in a contamination-controlled environment.

Femoral catheters: safety and efficacy in peripheral blood stem cell collection

Central venous access is necessary in patients candidate for peripheral blood stem cell (PBSC) collection. We report our experience with a dual lumen femoral catheter (Gamcath, 11 french), initially designed for hemodialysis. We studied 147 patients and performed 488 collections after mobilization with either G-CSF alone or chemotherapy + G-CSF, when the white blood cell count exceeded 1 × 109 /L, or when a measurable population of CD34+ cells (20 / μL) was detected in peripheral blood. All patients received systemic anticoagulation with a low weight heparin and ultrasound examination was performed after the removal of the catheter. Seven patients developed thrombosis (4.7%), ten experienced hematomas at the site of catether placement (6.8%) despite prophylactic platelet transfusions, while only one patient (0.6%) had a catheter-related infection. In conclusion, the short-term use of large bore femoral catheters in setting up PBSC collection seems to be associated with minimal risk of infection and low thrombotic incidence.

Absence of chromosome heterogeneity between classical Fanconi's anemia and the Estren-Dameshek type

Abstract Chromosome investigations were carried out in 7 patients with Fanconis anemia, type Estren-Dameshek. The frequency and types of chromosome instability found in cultured lymphocytes were in accord with those detected in individuals with classical Fanconis anemia. The break-point distribution indicates a significant excess of breaks in chromosomes No. 1, 2, and 7 and a deficit in No. 18 and X and Y chromosomes. There was a clear clustering of breaks at certain locations in chromosomes No. 1, 2, 3, 7, 9, and 14. The location of the breaks with respect to the bands demonstrated an almost exclusive involvement of the lighter bands, regardless of the banding method used. These results suggest that most breaks take place in the interbands between the G and R bands. In all patients, chromosome instability was less frequent in direct bone marrow preparations than in lymphocyte cultures. However, cultured bone marrow cells showed a significant increase of chromosome aberrations. On the whole, the chromosome data derived from this series of patients are in agreement with those obtained in individuals with classical Fanconis anemia and give no support to the idea of cytogenetic heterogeneity between subjects affected by these two forms of childhood aplastic anemia.

Interleukin-2-dependent long-term cultures of low-density lymphocytes allow the proliferation of lymphokine-activated killer cells with natural killer, Tiγ/δ or TNK phenotype

SummaryWe have developed a culture system for “longterm” growth of human lymphokine-activated killer (LAK) cells exhibiting an elevated, wide-spectrum antitumor cytotoxicity. The system allows the exponential growth of monocyte-depleted low-density lymphocytes in the presence of human serum and recombinant human interleukin-2 (103 U/ml), alone or in combination with interleukin-1 α or β (both at 10 U/ml). Eighteen cultures were established from 18 normal adult donors. The membrane phenotypes of the final LAK cell population, assessed by a panel of monoclonal antibodies (mAb), consist of three main types: (a) NKH-1+, Tiα/β−, Tiγ/δ−, and CD3− lymphocytes; (b) NKH-1+, Tiα/β−, Tiγ/δ+, and CD3+ lymphocytes and (c) NKH-1+, Tiα/β+, Tiγ/δ− and CD3+ lymphocytes. Northern blot analysis showed that all these cell populations express relatively high levels of perforin RNA, particularly cells exhibiting the first phenotype. This culture system may provide a tool for cellular and molecular studies on the mechanisms of antitumor cytotoxicity, as well as the basis for new adoptive immunotherapy protocols in advanced cancer.