La célula dendrítica: biología y aplicaciones en inmunoterapia / The dendritic cell: biology and applications in immunology

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Controlled-rate versus uncontrolled-rate cryopreservation of peripheral blood progenitor cells: a prospective multicenter study. Group for Cryobiology and Biology of Bone Marrow Transplantation (CBTMO), Spain.

BACKGROUND AND OBJECTIVE: Cryopreservation of hemopoietic progenitors for transplantation has been traditionally performed by the use of a controlled-rate freezer. Several groups have reported successful cryopreservation of progenitor cells at -80 degrees C without a controlled-rate freezer. In an attempt to elucidate whether both methods are equally efficient, we compared controlled-rate versus uncontrolled cryopreservation of peripheral blood progenitor cells (PBPC) in a prospective, multicenter study. DESIGN AND METHODS: Apheresis products from patients undergoing PBPC mobilization were split into two aliquots, and cryopreserved simultaneously by both methods, in autologous plasma plus 10% dimethylsulfoxide. Controlled-rate samples were placed into a programmable freezer with a cooling rate of 1-2 degrees C/min. Uncontrolled-rate samples were directly introduced into a -80 degrees C mechanical freezer. After thawing, cell counts, assays for viability, clonogenic cultures and CD34+ cell enumeration were performed. RESULTS: A total of 105 cases were included. No significant differences were found in viability (mean 88.8 +/- 13% in the controlled-rate group vs. 89.7 +/- 12% in the uncontrolled-rate group), nucleated cell loss (23.5 +/- 23% vs. 23 +/- 22%), mononuclear cell loss (19 +/- 23% vs. 19.1 +/- 22%), and loss of CD34+ cells (34.3 +/- 33% vs. 28.6 +/- 34%). On the other hand, recovery of granulomonocytic colony-forming units (CFU-GM), was significantly better with the controlled-rate technique, than with the non-controlled-rate method (104.3 +/- 95 vs. 86.5 +/- 80, respectively; p = 0.048). INTERPRETATION AND CONCLUSIONS: Our results indicate that both techniques are suitable for cryopreservation of PBPC, although a better recovery of committed progenitors is achieved by the controlled-rate method. Therefore, the use of controlled-rate freezer should probably be recommended.

Mantle cell lymphoma with amyotrophic lateral sclerosis (motor neuron disease)

We describe a previously unreported case of mantle cell lymphoma (MCL) associated to amyotrophic lateral sclerosis (ALS) in a 63-year-old woman with a 1-year history of weakness of arm and leg muscles. The both molecular-genetic and flow cytometry analysis of lymphocytes of peripheral blood (PB) demonstrated leukemic phase of MCL.

Autologous bone marrow transplantation with monoclonal antibody purged marrow for children with acute lymphoblastic leukemia in second remission. Spanish Working Party for BMT in Children.

The purpose of this study was to evaluate the outcome of children with acute lymphoid leukemia (ALL) in second remission who have undergone high-dose chemotherapy and radiotherapy and autologous bone marrow transplantation (ABMT) with monoclonal antibody purged marrow, and to determine the main prognostic factors. From 1987 to 1992, 55 children with ALL in second remission underwent ABMT. The conditioning regimen consisted of total body irradiation (TBI) plus cyclophosphamide in 21 patients and TBI plus cyclophosphamide plus cytarabine or VP-16 in 28 patients; the remaining six patients were treated with chemotherapy alone (cyclophosphamide and busulfan, and/or VP-16). The marrow was purged using monoclonal antibodies and complement or magnetic microspheres in all cases. All patients engrafted. Three patients (5%) died early post transplant from infections. Twenty-six patients (47%) relapsed (median 150 days); 26 patients (47%) are alive and in complete remission (CR) at a median of 36 months. The Kaplan-Meier estimation showed a probability of event-free survival (EFS) of 46 +/- 0.007%. In the univariate analysis, first CR length and conditioning with TBI plus two or more cytotoxic drugs were found to be the most significant predictors of EFS. ABMT with purged marrow is a treatment modality which offers a chance of cure in children with ALL after relapse, including children who relapse early.

High-dose granulocyte-colony stimulating factor (G-CSF) in vitro induces the growth of high proliferative potential colony forming cells (HPP-CFC) in patients undergoing blood stem cell mobilization.

We evaluated the role of high-dose granulocyte colony stimulating factor (G-CSF) in vitro, in inducing the generation of high-proliferative potential colony forming cells (HPP-CFC), from either mononuclear cells or purified CD34+ cells. Both normal controls and patients undergoing peripheral blood stem cell (PBSC) mobilization and transplantation were studied. In serum-driven agar cultures, G-CSF stimulated the proliferation of HPP-CFC in a dose dependent manner (r = 0.92). The number of HPP-CFC was four-fold greater in mobilized patients than in normal controls. Purified CD34+ cells yielded 11-fold more colonies than mononuclear cells. HPP-CFC from mobilized patients showed replating capacity, giving rise to secondary colonies of more mature appearance. In serum-free cultures, the effect of G-CSF appeared to be mediated by synergistic interaction with stem cell factor. Our results suggest that G-CSF stimulates primitive hematopoietic cells that are detectable in increased amounts in patients receiving mobilization therapy. Therefore, determination of G-CSF induced HPP-CFC could be a useful tool in the evaluation of mobilization strategies.

Subcutaneous versus intravenous low-dose IL-2 therapy after autologous transplantation: results of a prospective, non-randomized study.

Use of IL-2 therapy after autologous transplantation is currently being explored to reduce relapse rate. Low doses of the cytokine induce significant immunomodulation avoiding the severe side-effects associated with high-dose IL-2 therapy. However, low-dose IL-2 is usually given by continuous infusion through central venous lines with the consequent risks of thrombosis and infections. Twenty-six consecutive patients who received autologous transplants received low-dose IL-2 after stable engraftment had been achieved. The first 13 patients (group A) were scheduled to receive 400,000/IU/m2/day for 3 months by continuous intravenous infusion. Ten of these patients suffered infectious episodes, mainly bacteriemias that often necessitated delaying IL-2 therapy (median delivered dose: 32% of planned). The next 13 patients were then assigned to receive IL-2 (800,000-1,000,000 IU/m2/day for 3 months) subcutaneously (group B). For group B patients, median dose intensity was 84% (P = 0.01 when compared with group A patients). Only one severe infectious episode was observed in these patients. Clinical toxicity in group B patients consisted mainly of s.c. nodules. Immunomodulation, measured as an increase in the absolute number of CD56+ cells and CD56+(bright) cells, was higher in patients who received the cytokine by the subcutaneous route (median peak increase of CD56+ cells: 160 and 220% for group A and B patients respectively; median peak increase of CD56+(bright) cells: 210% and 310% for group A and B respectively, P < 0.05 between groups A and B). No statistically significant increment of T lymphocytes was observed in any group. No hematologic toxicity was observed apart from eosinophilia, which was very marked in group B (P < 0.01). Our results show that low-dose s.c. IL-2 therapy is associated with low clinical and hematologic toxicity after autologous transplantation. The immunomodulation achieved is no less than that achieved with the i.v. approach.

IL-2 effects on allogeneic and autologous transplant haemopoietic progenitors in long-term cultures.

IL-2 therapy may be useful in situations with a low tumour burden, such as after autologous transplantation. However, conflicting reports about the deleterious effects of this cytokine on haemopoiesis have precluded its widespread use. To study IL-2 effects on haemopoietic transplant progenitors we established long-term cultures (Dexter-type) with cells from allogeneic marrow and marrow/peripheral blood cell infusates of autologous transplants with different concentrations of IL-2 (0-1000 IU/ml). Percentage of CD56+ cells was also determined in cultures. IL-2 induced an inhibitory effect on stroma and an increase in the percentage of CD56+ cells compared with controls. No deleterious effect either in the production of BFU-E or CFU-GM weekly or over the whole period of culture was observed. Our results suggest that IL-2 is able to induce an increase in CD56+ cells early after transplantation without a deleterious effect on long-term haemopoiesis.

Posttransfusion hepatitis after induction chemotherapy in acute nonlymphoblastic leukemia: implications for long-term management and outcome.

BACKGROUND: The purpose of this study was to evaluate 1) the incidence of hepatitis and its influence on the clinical management of and outcome in acute nonlymphoblastic leukemia (ANLL) patients in first complete remission and 2) the impact of routine hepatitis C virus screening on the incidence of hepatitis in these patients. STUDY DESIGN AND METHODS: Clinical and blood bank charts were reviewed for 65 consecutive ANLL patients between 1985 and 1993 who achieved complete remission after a course of daunomycin and cytarabine (cytarabine: 200 mg/m2/day x 7 days in continuous infusion; daunomycin: 60 mg/m2/day for the first 3 days of the 7, as a bolus). RESULTS: Only 43 percent of patients who developed hepatitis completed the scheduled therapy. Hepatitis did not decrease the probability of relapse (66 +/- 9% vs. 66 +/- 11%), but patients with changes in planned treatment, due to hepatitis or other causes, tended to have a higher relapse rate than patients without changes in consolidation therapy (56.5% vs. 40.4%; p = 0.10). This did not result in a decrease in disease-free survival, however, because of the higher number of treatment-related deaths in the patients without hepatitis (who completed the therapy). Over the period from 1985 through 1989, the 6-month actuarial probability of developing hepatitis was 42 percent. However, since 1989, when hepatitis C screening of blood donors was implemented, the incidence was reduced to 12.5 percent (p < 0.05), in spite of greater transfusion support (172 +/- 46 vs. 89 +/- 53, p < 0.01). No new cases of hepatitis were observed after the introduction of second-generation hepatitis C virus assays. CONCLUSION: Hepatitis precludes the use of consolidation therapy in about half of ANLL patients, resulting, in the experience described here, in a trend toward a higher rate of relapse. Hepatitis C virus screening of blood components reduces the incidence of hepatitis in ANLL patients.

Cardiovascular toxicities related to the infusion of cryopreserved grafts: results of a controlled study.

To evaluate cardiovascular toxicities associated with the infusion of cryopreserved grafts, we prospectively monitored the infusions of 29 autologous bone marrow transplant (BMT) recipients. Fifteen allogeneic BMT recipients served as a control group. Cardiac rhythm was recorded continuously with the Holter technique from at least 2 h before the start of graft infusion until 24 h after completion. Blood pressure was closely monitored during the same period. Graft infusions were performed through a standard transfusion filter with breaks between aliquots. When the infusion had commenced, diuretics were given frequently (40 and 40% of allogeneic BMT and autologous BMT recipients, respectively) to avoid fluid overload. Non-cardiovascular clinical toxicities were observed more frequently in autologous BMT patients (41% vs 6%, p = 0.02) and no significant differences were seen between autograft and allograft recipients in any of the measured cardiovascular parameters. The heart rate decreased slightly in both groups but no patient in either group had a heart rate of < 60 b.p.m. or heart block. No significant changes in blood pressure were detected in either group. Ventricular ectopic beats/atrial ectopic beats ratio increased in the autologous BMT group after graft infusion (0.7 vs 0, p = 0.1). Time to engraftment did not differ significantly from other published series. Our results suggest that increasing infusion time of cryopreserved material and using a standard filter may reduce toxicities associated with the infusion of cryopreserved grafts. Early administration of diuretics may contribute to better control of blood pressure.

[Pentoxifylline is not useful in the prevention of toxicity associated with bone marrow transplantation]. / La pentoxifilina no es útil en la prevención de la toxicidad asociada al trasplante de médula ósea.

BACKGROUND: To evaluate the possible beneficial effect of pentoxifylline (PTX) on both the decrease of toxicity related to bone marrow transplantation (BMT) and the acceleration of the hematopoietic graft. METHODS: Twenty consecutive patients treated with BMT received pentoxifylline (400 mg/6 hours, orally) up to day +50 to prevent toxicity derived from BMT. A previous group of 29 consecutive patients transplanted in the same center were used as controls. The different clinical toxicities (mucositis, kidney failure, hepatic venocclusive disease, graft versus host disease, number of days with fever, day of hospital discharge and survival at day +50), the time elapsed until the hematopoietic graft and the levels of tumoral necrosis factor alpha were evaluated. RESULTS: No significant differences were observed in any of the parameters studied in the two groups of patients. CONCLUSIONS: Treatment with pentoxifylline does not prevent the toxicity derived from BMT or accelerate the hematopoietic grafting.

[Pulmonary mucormycosis in leukemic patients. Apropos of 2 cases]. / Mucormicosis pulmonar en pacientes leucémicos. A propósito de dos casos.

Mucormycosis is a rare fungal infection that has been described mainly in oncologic and diabetic patients. We here report the cases of two leukaemic patients in whom pulmonary mucormycosis was diagnosed. Prompt diagnosis, therapy with amphotericin B and surgery when possible, are the cornerstones in the treatment of this fungal infection. Although infrequent, this infection must be suspected in oncohaematological patients with lung infiltrates.