Sodium butyrate enhances fetal globin gene expression in erythroid progenitors of patients with Hb SS and beta thalassemia

Increasing the expression of the gamma globin genes is considered a useful therapeutic approach to the beta globin diseases. Because butyrate and alpha-amino-n-butyric acid (ABA) augment gamma globin expression in normal neonatal and adult erythroid progenitors, we investigated the effects of sodium butyrate and ABA on erythroid progenitors of patients with beta thalassemia and sickle cell anemia who might benefit from such an effect. Both substances increased fetal hemoglobin (Hb F) expression in Bfu-e from 7% to 30% above levels found in control cultures from the same subjects with sickle cell anemia. The fraction of cultured erythroblasts producing Hb F increased more than 20% with sodium butyrate treatment in 70% of cultures. In most cultures, this produced greater than 20% total Hb F and greater than 70% F cells, levels which have been considered beneficial in ameliorating clinical symptoms. Alpha: non-alpha (alpha-non-alpha) imbalance was decreased by 36% in erythroid progenitors of patients with beta thalassemia cultured in the presence of butyrate compared with control cultures from the same subjects. These data suggest that sodium butyrate may have therapeutic potential for increasing gamma globin expression in the beta globin diseases.     

Selective increase of potassium permeability in red blood cells exposed to acetylphenylhydrazine

Normal human red blood cells, when exposed briefly to acetylphenylhydrazine (APH), acquire Heinz bodies and a propensity for net ion and water loss upon subsequent incubation in an APH-free medium of physiologic sodium and potassium (K) content. The cells can be protected from APH damage by previous deoxygenation. The ion and water loss depend on the presence of a K gradient from cell to medium. In contradistinction to some other types of membrane perturbation in which K permeability is increased, the APH effect is not dependent on calcium. The meaning of these observations is discussed in relation to the vulnerability of the K permeability barrier.     

Analysis of interphase cells for the Philadelphia translocation using painting probe made by inter-Alu-polymerase chain reaction from a radiation hybrid

Fluorescence in situ hybridization (FISH) probe for the identification of the Philadelphia (Ph) translocation [t(9;22) (q34;q11)] in chronic myelogenous leukemia cells was developed by inter-Alu-polymerase chain reaction of DNA from an interspecific somatic cell hybrid containing approximately 5 Mb of human DNA covering the ABL gene region on human chromosome 9q34. This probe was large enough to be effective in identifying the genomic domains yet small enough to resolve them in more than 90% of bone marrow interphase cells. Combination of the probe with a cosmid contig probe for the BCR region of chromosome 22 in two- color FISH reduced the frequency of false-positive identification of the Ph chromosome to less than 1%. The procedure allows detection of as few as 1% Ph+ cells independent of the cycling status or BCR/ABL expression level of cells, and the quantitation of non-Ph chromosome- containing interphase nuclei in the marrow of patients judged 100% Ph+ by standard cytogenetics.     

High-dose chemotherapy with or without total body irradiation followed by autologous bone marrow and/or peripheral blood stem cell transplantation for patients with relapsed and refractory Hodgkin's disease: results in 85 patients with analysis of prognostic factors

Eight-five consecutive patients with relapsed or refractory Hodgkin's disease (HD) underwent high-dose chemotherapy or chemo/radiotherapy followed by autologous bone marrow (ABMT) and/or peripheral blood stem cell (PBSC) transplantation. Two preparative regimens were used. Twenty- two patients (26%) without prior radiation received fractionated total body irradiation (FTBI) 1,200 Gy in combination with high-dose etoposide (VP-16) 60 mg/kg and cyclophosphamide (CTX) 100 mg/kg. Sixty- three patients (74%) with prior radiotherapy received carmustine (BCNU) 450 mg/m2 instead of FTBI. The median age was 32 years (range, 16 to 56). The median number of prior chemotherapy regimens was three (range, 1 to 7). Forty-three patients (51%) received transplants in first relapse or second complete remission (CR), whereas 33 (39%) received transplants after second or subsequent relapse. All relapsed patients, except one, received conventional salvage chemotherapy and/or radiotherapy in an attempt to reduce tumor bulk before transplant. At the time of analysis in April 1994, fifty-seven patients (67%) are alive, including 44 (52%) in continuous CR, with a median follow-up for the surviving patients of 28 months (range, 7 to 66). Thirty patients (35%) relapsed at a median of 9 months (range, 1 to 43). Eleven patients (13%) died of transplant-related complications including veno- occlusive disease of the liver (VOD) in five, acute and late interstitial pneumonitis in three, graft failure in one, cerebral hemorrhage in one, and therapy-induced myelodysplasia (MDS)/acute leukemia in one patient. At a median follow-up of 25 months (range, 0.6 to 66), the cumulative probability of 2-year overall and disease-free survival (DFS) of all 85 patients is 75% (95% confidence interval [CI] 64% to 84%) and 58% (95% CI 47% to 69%), respectively. Three independent prognostic variables were identified by univariate analysis: number of prior chemotherapy regimens, prior radiotherapy, and extranodal disease at ABMT. Multivariate stepwise Cox regression identified the number of prior chemotherapy regimens as the only significant prognostic factor predicting for both relapse and DFS. There were no significant differences in the outcome of the treatment between the two preparative regimens. Our results confirm that high- dose therapy and ABMT is an effective therapy for patients with relapsed or refractory HD. Earlier transplantation is recommended before the development of drug resistance and end organ damage that results from repeated attempts of salvage therapy.     

Sirolimus-based graft-versus-host disease prophylaxis protects against cytomegalovirus reactivation after allogeneic hematopoietic stem cell transplantation: a cohort analysis

Sirolimus-based immunosuppressive regimens in organ transplantation have been associated with a lower than expected incidence of cytomegalovirus (CMV) disease. Whether sirolimus has a similar effect on CMV reactivation after allogeneic hematopoietic stem cell transplantation (HSCT) is not known. We evaluated 606 patients who underwent HSCT between April 2000 and June 2004 to identify risk factors for CMV reactivation 100 days after transplantation. The cohort included 252 patients who received sirolimus-tacrolimus for graft-versus-host disease (GVHD) prophylaxis; the rest received non-sirolimus-based regimens. An initial positive CMV DNA hybrid capture assay was observed in 225 patients (37.1%) at a median 39 days after HSCT for an incidence rate of 0.50 cases/100 patient-days (95% confidence interval [CI], 0.44-0.57). Multivariable Cox modeling adjusting for CMV donor-recipient serostatus pairs, incident acute GVHD, as well as other important covariates, confirmed a significant reduction in CMV reactivation associated with sirolimus-tacrolimus-based GVHD prophylaxis, with an adjusted HR of 0.46 (95% CI, 0.27-0.78; P = .004). The adjusted HR was 0.22 (95% CI, 0.09-0.55; P = .001) when persistent CMV viremia was modeled. Tacrolimus use without sirolimus was not significantly protective in either model (adjusted HR, 0.66; P = .14 and P = .35, respectively). The protective effect of sirolimus-containing GVHD prophylaxis regimens on CMV reactivation should be confirmed in randomized trials.     

Prognostic impact of elevated pretransplantation serum ferritin in patients undergoing myeloablative stem cell transplantation

Iron overload could be a significant contributor to treatment-related mortality (TRM) for patients with hematologic malignancies undergoing hematopoietic stem cell transplantation (HSCT). We studied 590 patients who underwent myeloablative allogeneic HSCT at our institution, and on whom a pretransplantation serum ferritin was available. An elevated pretransplantation serum ferritin level was strongly associated with lower overall and disease-free survival. Subgroup multivariable analyses demonstrated that this association was restricted to patients with acute leukemia or myelodysplastic syndrome (MDS); in the latter group, the inferior survival was attributable to a significant increase in TRM. There was also a trend toward an increased risk of veno-occlusive disease in patients with high ferritin. Our results argue that iron overload plays an important role in transplantation outcome for patients with acute leukemia or MDS, as it does in thalassemia. They also suggest future prospective trials to examine the potential benefit of chelation therapy in this setting.     

Emergence of a clinical daptomycin-resistant Staphylococcus aureus isolate during treatment of methicillin-resistant Staphylococcus aureus bacteremia and osteomyelitis

The emergence of a clinically daptomycin-resistant Staphylococcus aureus isolate occurred during treatment of methicillin-resistant S. aureus bacteremia and probable vertebral osteomyelitis. The breakthrough isolate was indistinguishable from pretreatment daptomycin-susceptible isolates by pulsed-field gel electrophoresis. Daptomycin nonsusceptibility was confirmed by MIC and time-kill curve analyses.