Risks for infection of strawberry plants with an aerosolized inoculum of Xanthomonas fragariae.

Xanthomonas fragariae is the causative agent of angular leaf spot of strawberry, a quarantine organism in plant propagation material in the European Union. Field experiments were conducted to assess the risks for infection of strawberry plants through dispersal of an aerosolized inoculum. In practice, pathogen aerosols can be formed during mowing of an infected crop or by water splashing on symptomatic plants during overhead irrigation or rain. In our experiments, aerosols were generated by spraying suspensions of X. fragariae with a density of 108 cfu ml-1 or water under pressure vertically up into the air. In strawberry plants (cv Elsanta) placed at 1.3, 5 and 10 m distance downwind from the spray boom, infections were found, as evidenced with a combination of dilution-plating and molecular techniques, but more frequently in plants wetted prior to inoculation than in plants kept dry. A logarithmic decrease in infection incidence was found with the distance to the inoculum source. Symptomatic plants were found up to 5 m distance from the inoculum source. No infected plants were found in plants placed 4 m upwind or treated with water. In glasshouse studies, it was shown that under conditions favorable for disease development, spray-inoculation of strawberry plants with estimated densities of X. fragariae as low as 2000 cfu per plant were able to cause symptoms both in cv Elsanta and cv Sonata. Results indicate that there is a considerable risk on infections of strawberry plants exposed to aerosolized inoculum.

Haploidentical BMT and post-transplant Cy for severe aplastic anemia: a multicenter retrospective study.

Patients with refractory severe aplastic anemia (SAA) who lack a matched sibling or unrelated donor need new therapeutic approaches. Hematopoietic SCT (HSCT) using mismatched or haploidentical related donors has been used in the past, but was associated with a significant risk of GVHD and mortality. Recently, the use of post-transplant cyclophosphamide (Cy) has been shown to be an effective strategy to prevent GVHD in recipients of haploidentical HSCT, but the majority of reports have focused on patients with hematology malignancies. We describe the outcome of 16 patients who underwent haploidentical transplantation using a reduced-intensity conditioning regimen with post-transplant Cy. Stem cell sources were BM (N=13) or PBSCs (N=3). The rate of neutrophil engraftment was 94% and of platelet engraftment was 75%. Two patients had secondary graft failure and were successfully salvaged with another transplant. Three patients developed acute GVHD being grades 2-4 in two. Five patients have died and the 1-year OS was 67.1% (95% confidence interval: 36.5-86.4%). In our small series, the use of a reduced-intensity conditioning with post-transplant Cy in haploidentical BMT was associated with high rates of engraftment and low risk of GVHD in patients with relapsed/refractory SAA.

Bronchiolitis obliterans in patients undergoing allogeneic hematopoietic SCT.

Bronchiolitis obliterans (BO) is a severe pulmonary complication of allo-SCT. This study evaluated the incidence of BO in patients undergoing allo-SCT in Hospital Universitário da Universidade Federal do Paraná, risk factors for developing this complication and prognostic factors for those patients who developed this entity. The study included 1286 patients transplanted between 1979 and 2009 who survived for 100 days or more. We diagnosed 53 cases of BO. The cumulative incidence was 2.9% in 1 year and 3.7% in 3 years. Among patients with chronic GVHD, the cumulative incidence at the same intervals was 8.4% and 9.9%, respectively. The median time between transplantation and diagnosis of BO was 260 days (49-3877 days). In the multivariate analysis the risk factors for BO were female donor, older recipients and acute GVHD. The main prognostic factor was the severity of pulmonary impairment. Patients who developed BO earlier than 260 days had a worse prognosis than those who did so later. At least 80% of deaths were directly related to BO.

Imatinib mesylate versus allogeneic BMT for patients with chronic myeloid leukemia in first chronic phase.

Imatinib mesylate (IM) is now first-line treatment for CML. To study the results of treatment with IM after IFN failure/intolerance versus allogeneic BMT (allo-BMT), we retrospectively analyzed 264 patients treated for CML in first chronic phase in three different institutions. Over a 6-year period (2001-2006), 174 patients received IM after failure of or intolerance to IFN. During the same period of time, 90 patients received an allo-BMT from an HLA-matched sibling (n=83) or an unrelated donor (n=7). The IM group was older (41 versus 33 years, P<0.001). Five-year EFS was 62% among patients receiving IM and 52% among patients undergoing allo-BMT (P=0.0002). OS at 5 years was 93% for IM-treated patients and 59% for patients undergoing allo-BMT (P<0.0001). Allo-BMT cannot be considered as first-line treatment for CML patients in first chronic phase.

Allogeneic hematopoietic stem cell transplantation from an alternative stem cell source in Fanconi anemia patients: analysis of 47 patients from a single institution.

We transplanted 47 patients with Fanconi anemia using an alternative source of hematopoietic cells. The patients were assigned to the following groups: group 1, unrelated bone marrow (N = 15); group 2, unrelated cord blood (N = 17), and group 3, related non-sibling bone marrow (N = 15). Twenty-four patients (51%) had complete engraftment, which was not influenced by gender (P = 0.87), age (P = 0.45), dose of cyclophosphamide (P = 0.80), nucleated cell dose infused (P = 0.60), or use of anti-T serotherapy (P = 0.20). Favorable factors for superior engraftment were full HLA compatibility (independent of the source of cells; P = 0.007) and use of a fludarabine-based conditioning regimen (P = 0.046). Unfavorable factors were > or = 25 transfusions pre-transplant (P = 0.011) and degree of HLA disparity (P = 0.007). Intensity of mucositis (P = 0.50) and use of androgen prior to transplant had no influence on survival (P = 0.80). Acute graft-versus-host disease (GVHD) grade II-IV and chronic GVHD were diagnosed in 47 and 23% of available patients, respectively, and infections prevailed as the main cause of death, associated or not with GVHD. Eighteen patients are alive, the Kaplan-Meyer overall survival is 38% at approximately 8 years, and the best results were obtained with related non-sibling bone marrow patients. Three recommendations emerged from the present study: fludarabine as part of conditioning, transplant in patients with < 25 transfusions and avoidance of HLA disparity. In addition, an extended family search (even when consanguinity is not present) seeking for a related non-sibling donor is highly recommended.

Allogeneic hematopoietic stem cell transplantation from an alternative stem cell source in Fanconi anemia patients: analysis of 47 patients from a single institution

We transplanted 47 patients with Fanconi anemia using an alternative source of hematopoietic cells. The patients were assigned to the following groups: group 1, unrelated bone marrow (N = 15); group 2, unrelated cord blood (N = 17), and group 3, related non-sibling bone marrow (N = 15). Twenty-four patients (51 percent) had complete engraftment, which was not influenced by gender (P = 0.87), age (P = 0.45), dose of cyclophosphamide (P = 0.80), nucleated cell dose infused (P = 0.60), or use of anti-T serotherapy (P = 0.20). Favorable factors for superior engraftment were full HLA compatibility (independent of the source of cells; P = 0.007) and use of a fludarabine-based conditioning regimen (P = 0.046). Unfavorable factors were > or = 25 transfusions pre-transplant (P = 0.011) and degree of HLA disparity (P = 0.007). Intensity of mucositis (P = 0.50) and use of androgen prior to transplant had no influence on survival (P = 0.80). Acute graft-versus-host disease (GVHD) grade II-IV and chronic GVHD were diagnosed in 47 and 23 percent of available patients, respectively, and infections prevailed as the main cause of death, associated or not with GVHD. Eighteen patients are alive, the Kaplan-Meyer overall survival is 38 percent at ~8 years, and the best results were obtained with related non-sibling bone marrow patients. Three recommendations emerged from the present study: fludarabine as part of conditioning, transplant in patients with <25 transfusions and avoidance of HLA disparity. In addition, an extended family search (even when consanguinity is not present) seeking for a related non-sibling donor is highly recommended.

Therapy for severe refractory acute graft-versus-host disease with basiliximab, a selective interleukin-2 receptor antagonist.

Basiliximab is a chimeric monoclonal antibody that binds to the alpha chain of IL-2R on activated cytotoxic T-cells, inhibiting lymphocyte proliferation. We report 34 patients with refractory acute GVHD (grade III-IV) who received basiliximab from December 1998 to October 2003. Adults received 40 mg weekly (2-3 doses) and children received half of this dose. Median age was 13 years. Twenty-five donors were unrelated. The stem cell source was bone marrow in 30 and cord blood in four. Complete responses were seen in 27/32 patients (84%) with skin, 12/25 (48%) with gut and 6/23 (26%) with liver GVHD. Median duration of response was 38 days (5-1103). Overall survival at 5 years was 20%. Eleven patients (32%) are alive. The main causes of death were CMV (n=4), fungus (n=6), sepsis (n=8), hemorrhage (n=2), and relapse (n=2). Graft-versus-host disease flares were observed in 14 patients (41%), half being rescued by other therapies. In conclusion, basiliximab was able to induce complete responses in patients with refractory acute GVHD. Prospective studies are necessary to evaluate the optimal treatment schedule.

Low-dose cyclophosphamide conditioning for haematopoietic cell transplantation from HLA-matched related donors in patients with Fanconi anaemia.

Allogeneic haematopoietic cell transplantation (HCT) is effective therapy for Fanconi anaemia (FA). FA patients do not tolerate conditioning with 200 mg/kg of cyclophosphamide (Cy), typically used in aplastic anaemia. We previously published results of studies in which Cy doses were gradually reduced from 200 to 100 mg/kg. Here we update results of the initial studies and report data on 30 new patients conditioned with Cy either at 80 mg/kg (n = 7) or at 60 mg/kg (n = 23), given over 4 days before HCT from human leucocyte antigen-matched related donors. Methotrexate and cyclosporine were given for graft-versus-host disease (GVHD) prophylaxis. All seven patients given Cy at 80 mg/kg and 21 of 23 given Cy at 60 mg/kg had sustained engraftment, while two patients, both with clonal cytogenetics abnormalities, experienced graft failure. Grades 2-3 acute GVHD rates were 57% and 14% for patients given the higher and lower Cy doses, respectively (P = 0.001). Four patients given Cy at 80 mg/kg and 22 given Cy at 60 mg/kg were alive at a median of 47 (44-58) months and 16 (3-52) months, respectively. Cy at 60 mg/kg has acceptable toxicities, low rates of GVHD, and is sufficient for engraftment of related grafts in most FA patients.

Safety and potential efficacy of low-dose methotrexate for treatment of chronic graft-versus-host disease.

Low-dose methotrexate (MTX) is widely used in autoimmune diseases because of its anti-inflammatory activity. We report here the results of a retrospective study to review the outcomes of low-dose MTX used for treatment of refractory chronic graft-versus-host disease GVHD, with the goal of reducing the amount of prednisone needed to control the disease. In all, 14 patients with refractory chronic GVHD received MTX at a dose of 7.5 mg/m(2)/weekly for 3--0 weeks. Also, 11 patients had skin involvement, often with scleroderma or fasciitis. The median duration of chronic GVHD at the start of MTX was 38 (range 1--35) months. In this retrospective review, we found no grade 3-- toxicities, and none of the patients needed blood transfusion or growth factors. In 10 patients (71%), GVHD could be adequately controlled with prednisone at doses below 1 mg/kg every other day without the addition of other agents. Four patients decreased the amount of concomitant immunosuppressive treatment, five continued with the same regimen, four required an increase in immunosuppressive treatment, and one decided to discontinue all treatment. From this preliminary analysis, MTX appears to be a well-tolerated, inexpensive and possibly steroid-sparing agent that is worthy of further evaluation in prospective trials for treatment of chronic GVHD.

Effects of steroid hormones on replication of murine sarcoma virus in mouse embryo cultures.

The androgenic steroid hormone, testosterone, inhibited focus formation by the murine Moloney sarcoma virus in mouse embryo cells. The inhibition of focus formation was enhanced by cyclic AMP. Although focus formation was inhibited, there was no inhibition of viral replication. The glucogenic adrenal corticosteroids, cortisol and dexamethasone, and 17-beta-estradiol and progesterone did not affect focus formation by MuSV(M).

Effect of diethylaminoethyl-dextran on the replication of a murine sarcoma (Moloney)-leukemia virus complex in mouse embryo cultures (38577).

Isolates of a sarcoma (Moloney)-leukemia virus complex prepared as cell-free extracts from mouse tumors showed no enhancement in infectivity by DEAE-D either in the sarcoma moiety measured by focus formation or in the leukemia moiety measured by XC cell assay. The sarcoma moiety was not enhanced by DEAE-D in MEM and modified McCoy's 5a media or when varying amounts of FCS and glutamine were included in the media. Progressive enhancement of viral infectivity by DEAE-D was found when the viral preparations were passaged serially in MEF cells. DEAE-D ALSO ENHANCED TUMOR FORMATION IN VIVO BY TISSUE CULTURE PASSAGED VIRUS.