Gelatin crosslinked with dehydroascorbic acid as a novel scaffold for tissue regeneration with simultaneous antitumor activity.

A porous scaffold was developed to support normal tissue regeneration in the presence of residual tumor disease. It was prepared by gelatin crosslinked with dehydroascorbic acid (DHA). A physicochemical characterization of the scaffold was carried out. SEM and mercury porosimetry revealed a high porosity and interconnection of pores in the scaffold. Enzymatic degradation provided 56% weight loss in ten days. The scaffold was also evaluated in vitro for its ability to support the growth of normal cells while hindering tumor cell development. For this purpose, primary human fibroblasts and osteosarcoma tumor cells (MG-63) were seeded on the scaffold. Fibroblasts attached the scaffold and proliferated, while the tumor cells, after an initial attachment and growth, failed to proliferate and progressively underwent cell death. This was attributed to the progressive release of DHA during the scaffold degradation and its cytotoxic activity towards tumor cells.

Selective apoptosis of monocytes and monocyte-derived DCs induced by bortezomib (Velcade).

Bortezomib, a proteasome inhibitor, has shown immunosuppressive activity in animal models of GVHD. In this study, we evaluated the effects of Bortezomib on the survival of monocytes, a major circulating source of DCs. PBMCs or purified CD14+ monocytes were cultured for 24 h with Bortezomib (0.1-100 ng/ml). Apoptosis was demonstrated on the basis of detection of phosphatydilserine. Bortezomib induced a significant dose-dependent depletion (P=0.008) of monocytes in PBMC preparations, with <1% CD14+ cells remaining at doses >or=5 ng/ml. Moreover, Bortezomib decreased the survival of purified monocytes within 24 h (P=0.004) (n=6). Monocyte loss was due to apoptosis (effective dose 50%, ED(50), 1-10 ng/ml). In addition, both immature and mature monocyte-derived DC underwent apoptosis following exposure to Bortezomib. Kinetic experiments showed that apoptosis increased at 16 h through 24 h of culture. However, short term (4 h) incubation with Bortezomib irreversibly committed monocytes to undergo apoptosis at 24, 72 and 144 h. Instead, Bortezomib induced no apoptosis of purified CD19+ B, CD3+ T lymphocytes and CD34+ progenitor cells (ED(50) >50 ng/ml). The inhibitory effect of Bortezomib on professional APCs, such as monocytes and DCs, suggests its possible use in GVHD prophylaxis.

Ureteral obstruction following allogeneic bone marrow transplantation in children.

Two patients with Ph + CML underwent URD-BMT after conditioning with Bu-Cy-LPAM. They developed hemorrhagic cystitis with an extremely complicated and painful course, caused by ureteral obstruction, requiring prolonged hospitalization. No virus other than cytomegalovirus was found and in both cases was attributed to Cy use. Treatment is usually conservative, but in the case of severe obstruction, a surgical approach should be considered and performed as early as possible to preserve renal function.

Mycophenolate mofetil (MMF) as therapy for refractory chronic GVHD (cGVHD) in children receiving bone marrow transplantation.

Mycophenolate mofetil (MMF) is an alternative immunosuppressant which inhibits the proliferation of T and B lymphocytes. The purpose of the present study was to evaluate the safety and efficacy of MMF as salvage therapy for chronic GVHD (cGVHD) in children receiving allogeneic bone marrow transplantation. Fifteen children, 3-16 years of age, who had received grafts from HLA-compatible siblings (n = 8), partially matched related donors (n= 2) or matched unrelated donors (n = 5), developed extensive cGVHD which had proved unresponsive to standard immunosuppressive therapy. Patients were treated with MMF at the dose of 15-40 mg/kg/day in combination with other immunosuppressive therapy for a median of 4 months (range 1-15 months). The overall response rate (complete or partial response) was 60%. Thirteen percent had only minor responses, whereas 27% of patients had progressive disease. Best responses were seen in patients with GI tract (60% of complete responses) or mouth (33% of complete responses) cGVHD and skin involvement (43% of complete responses) that did not include sclerodermatous manifestations. Once MMF was started, improvements in the clinical manifestations of cGVHD allowed a significant reduction of steroids in 45% of patients and discontinuation in 27% of cases. Six patients (40%) experienced adverse events, with gastrointestinal symptoms predominating. Five patients experienced opportunistic infections. MMF was discontinued after 35-180 days in six patients for the following reasons: parents choice (n = 2), liver toxicity (n = 1), poor compliance (n = 2), and no response (n = 1). In conclusion, these preliminary results suggest that MMF in combination with other immunosuppressive agents may have a role to play in patients with cGVHD. Prospective clinical trials are needed to establish exact indications for therapy and dosage scheduling. Bone Marrow Transplantation (2000).

Bone marrow transplantation for childhood hematological disorders: a global pediatric approach in a twelve year single center experience.

One hundred and 43 consecutive pediatric patients (June 1985-December 1996) with at least 18 months of follow-up, were considered: most of the patients (111/143, 77.6%) underwent allogeneic BMT. The median follow-up was 5.7 years. Overall survival and 5 years EFS were 48.6% and 46.9%, respectively. For patients who underwent allogeneic BMT from HLA-identical siblings, the 5 years EFS for ALL was 75% in 1st CR, 60.4% in 2nd CR, 22.3% in > 2nd CR and 86.7% for AML in 1st CR. The EFS for Allo-BMT in "good" and "poor" prognosis patients was 68.6% and 21.8%, respectively (p value = 0.001). Early mortality in Allo-BMT patients was 17.7% between 1985-1990 and 10.3% between 1991-1996. Early treatment-related organ complications occurred mostly in patients who underwent BMT from an unrelated or a mismatched family donor. Late toxicity was evaluated in 57 patients (median follow-up of 82 months): none of the patients complained of significant late cardiac or respiratory dysfunction. With regards to growth, 18/57 patients (31.6%) lost more than two height centile channels. Three cases of thyroid neoplasms were observed. Evaluation of psychosocial functioning, studied in 39 patients who had at least 2 years of follow-up in CR, did not reveal any evident quality of life impairment. The possibility of curing childhood hematological malignancies is based on a global pediatric and multidisciplinary approach. A continuous need to improve results in terms of EFS and quality of life suggests that further multicenter prospective studies should be carried out.

Mild pre-transplant cardiomyopathy may not impair long-term quality of life after bone marrow transplantation.

An 8-year-old child with acute myeloid leukemia (AML), underwent an allogeneic bone marrow transplant (BMT) from his HLA matched sister in spite of having a mild cardiomyopathy. We followed the patient with periodic electrocardiograms (ECG) and echocardiograms which have not worsened, and the patient's quality of life is not compromised 14 years after BMT. Bone Marrow Transplantation (2000) 25, 335-336.

A persistent severe autoimmune hemolytic anemia despite apparent direct antiglobulin test negativization.

BACKGROUND AND OBJECTIVE: Not all cases of autoimmune hemolytic anemia (AIHA) are diagnosed by the direct antiglobulin test (DAT). We present and discuss a simple method of enhancing the sensitivity of the standard DAT. DESIGN AND METHODS: We report the case of a five-month-old child diagnosed with a severe IgG-mediated AIHA, characterized by quick DAT negativization despite clinical worsening. Warm AIHA with negative DAT, possibly due to a low affinity autoantibody, unresponsive to conventional therapy, was hypothesized. RESULTS: The DAT resulted strongly positive with anti-IgG serum using a 4C saline for erythrocyte washing, to reduce the dissociation of the supposed low affinity autoantibody. Very intensive cytoreductive treatment was administered twice until clinical remission was obtained. INTERPRETATION AND CONCLUSIONS: The clinical course of AIHA can be dissociated by the DAT. Since autoantibody-mediated hemolysis with negative DAT rarely occurs, once other causes of high reticulocyte count anemia have been ruled out, the DAT after ice-cold saline washing could be a useful and easy means of corroborating the diagnosis of AHIA, when traditional methods fail.

The role of thalidomide in the treatment of refractory chronic graft-versus-host disease following bone marrow transplantation in children.

Chronic graft-versus-host disease (cGVHD) is a frequent complication of allogeneic bone marrow transplantation (BMT). Thalidomide was found to have immunosuppressive properties and it has been used in a limited number of children with cGVHD. We report our experience with refractory and/or high-risk cGVHD in 14 children. Six children showed complete clinical response to thalidomide in a median time of 2 months. Four children had partial responses and four failed. Side-effects were usually mild (somnolence, constipation) and only two patients developed sensory peripheral neuropathy. An increased incidence of infectious complications attributable to thalidomide was not observed. Nine out of 10 responding patients are alive 49-111 months post-BMT. Thalidomide can be effective particularly in children with prevailing mucocutaneous cGVHD. All patients should be carefully monitored to detect peripheral neuropathy early.

Long-term effects of bone marrow transplantation on dental status in children with leukaemia.

Minimal data about oral and dental health in long-term survivors after BMT are available. We studied the dental status of 27 children (19 males, eight females) with leukaemia, followed up with a routine oral examination, panoramic tomogram and, when necessary, an endoral radiograph at a median of 2 years (range 1-10) after BMT. Community periodontal index treatment necessity (CPITN), dental caries, missing or filled permanent teeth (DMFT) and dento-facial alterations according to WHO criteria were registered and evaluated. Median age of the patients at BMT was 9 years (range 1.1-17.9). The mean DMFT score ranged from 1.6 to 12.4 according to age at examination and was slightly higher than that which we previously reported in children who received chemotherapy alone. CPITN showed the presence of soft deposits in 77.7%, serious gingivitis in 59.2% and parodontal involvement in 3.7% of cases. Dento-facial abnormalities were found in 55.5% of patients, while 62.9% of the patients had tooth abnormalities or agenesis. Nine out of 27 patients (33%) had root hypoplasia. A negative impact on DMFT index due to multiple post-BMT factors was found. Age is the crucial factor in determining a developmental defect of enamel and root. The follow-up of long-term survivors after BMT should include regular dental examination.