Adult human mesenchymal stem cells added to corticosteroid therapy for the treatment of acute graft-versus-host disease

The unique immunomodulatory properties of mesenchymal stem cells (MSCs) make them a rationale agent to investigate for graft-versus-host disease (GVHD). Human MSCs were used to treat de novo acute GVHD (aGVHD). Patients with grades II-IV GVHD were randomized to receive 2 treatments of human MSCs (Prochymal(R)) at a dose of either 2 or 8 million MSCs/kg in combination with corticosteroids. Patients received GVHD prophylaxis with tacrolimus, cyclosporine, (CsA) or mycophenolate mofetil (MMF). Study endpoints included safety of Prochymal administration, induction of response to Prochymal, and overall response of aGVHD by day 28, and long-term safety. Thirty-two patients were enrolled, with 31 evaluable: 21 males, 10 females; median age 52 years (range: 34-67). Twenty-one patients had grade II, 8 had grade III, and 3 had grade IV aGVHD. Ninety-four percent of patients had an initial response to Prochymal (77% complete response [CR] and 16% partial response [PR]). No infusional toxicities or ectopic tissue formations were reported. There was no difference with respect to safety or efficacy between the low and high Prochymal dose. In conclusion, Prochymal can be infused safely into patients with aGVHD and induces response in a high proportion of GVHD patients.

A knock-out model of paroxysmal nocturnal hemoglobinuria: Pig-a(-) hematopoiesis is reconstituted following intercellular transfer of GPI-anchored proteins

We created a "knockout" embryonic stem cell via targeted disruption of the phosphatidylinositol glycan class A (Pig-a) gene, resulting in loss of expression of cell surface glycosyl phosphatidylinositol-anchored proteins and reproducing the mutant phenotype of the human disease paroxysmal nocturnal hemoglobinuria. Morphogenesis of Pig-a- embryoid bodies (EB) in vitro was grossly aberrant and, unlike EB derived from normal embryonic stem cells, Pig-A EB produced no secondary hematopoietic colonies. Chimeric EB composed of control plus Pig-A- cells, however, appeared normal, and hematopoiesis from knock-out cells was reconstituted. Transfer in situ of glycosyl phosphatidylinositol-anchored proteins from normal to knock-out cells was demonstrated by two-color fluorescent analysis, suggesting a possible mechanism for these functional effects. Hematopoietic cells with mutated PIG-A genes in humans with paroxysmal nocturnal hemoglobinuria may be subject to comparable pathophysiologic processes and amenable to similar therapeutic protein transfer.

Single cycle of arsenic trioxide-based consolidation chemotherapy spares anthracycline exposure in the primary management of acute promyelocytic leukemia

PURPOSE Event-free survival following all-trans-retinoic acid (ATRA) -based therapy for acute promyelocytic leukemia (APL) averages 70% at 5 years. While arsenic trioxide (ATO) can induce remissions in 95% of relapsed patients, few studies have addressed the integration of ATO into the primary management of APL. This study examines the efficacy of a single cycle of ATO-based consolidation therapy in a treatment regimen designed to decrease exposure to other cytotoxic agents. PATIENTS AND METHODS After induction with ATRA and daunorubicin (DRN), untreated patients with APL received 3 days of cytarabine and DRN followed by 30 doses of ATO beginning on day 8. Molecular remitters received 2 years of risk-based maintenance therapy. Results Forty-one of 45 patients receiving induction therapy achieved remission; four patients died (one before treatment was initiated). Thirty-seven patients received consolidation and maintenance; of these one patient relapsed (CNS) and one died in remission during maintenance therapy (hepatic sickle cell crisis). With a median follow-up of 2.7 years, estimated disease-free survival was 90%; overall survival for all patients was 88%. Despite a total anthracycline dose of only 360 mg/m(2), cardiac ejection fraction decreased by > or = 20% in 20% of patients. CONCLUSION These data, combined with other recent studies using ATO in the primary management of APL, demonstrate the important role that ATO can play in the primary management of this curable disease. Future studies should continue to focus on reducing the toxicity of treatment without increasing the relapse rate.

Randomized phase II trial of the nucleolin targeting aptamer AS1411 combined with high-dose cytarabine in relapsed/refractory acute myeloid leukemia (AML)

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Background: Aptamers are small synthetic oligonucleotides that form stable nuclease-resistant 3D structures and bind target proteins with specificity and affinity similar to antibodies. These “chemical antibodies” represent a new class of therapeutics. The AS1411 aptamer binds nucleolin on the surface of cancer cells and induces apoptosis. AS1411 has synergistic effects in combination with cytarabine on AML cell lines in vitro and in vivo. A phase I trial of AS1411 monotherapy in 30 patients with advanced cancer showed objective responses without serious toxicities. Methods: This open-label randomized phase II trial compared AS1411 plus high-dose cytarabine (HiDAC) with HiDAC alone in patients with primary refractory or relapsed AML who had received up to 3 previous lines of chemotherapy. Patients in cohort I were randomized 2:1 to receive AS1411 10 mg/kg/day as continuous IVI on days 1–7 + HiDAC 1.5 g/m2/ twice daily on days 4–7 or HiDAC alone for 4 days. Following safety assessment, a second cohort was randomized in a similar manner, with AS1411 escalated to 40 mg/kg/day. Objectives were comparison of response rates (CR+CRp), safety and tolerability between treatment groups. Results: Accrual has been completed, with 71 patients randomized: 22 to AS1411 10 mg/kg/day + HiDAC (AS1411–10), 26 to AS1411 40 mg/kg/day + HiDAC (AS1411–40) and 23 to HiDAC alone (control). Safety findings are currently available for 44 patients (AS1411–10, 21; AS1411–40, 9; control, 14). The main grade 3/4 toxicities were hematologic, notably febrile neutropenia, neutropenia, and thrombocytopenia; and infections. Safety findings were similar across groups, except that grade 3 hypokalemia was more frequent with AS1411–40. Deaths within 28 days of treatment were: AS1411–10, 1/21; AS1411–40, 1/9; and control, 2/14. Response data are currently available for 39 patients; response rates were: AS1411–10, 16% (3/19); AS1411–40, 14% (1/7); and control, 0% (0/13). Conclusions: Data from this first phase II trial of an aptamer in oncology are encouraging. The combination of AS1411 at 10 or 40 mg/kg/day with HiDAC appears well tolerated and shows promising signs of activity in patients with relapsed/refractory AML.

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Hematopoietic cell transplantation: progress and obstacles

The use of hematopoietic cell transplantation has expanded and evolved substantially in the last decade. New stem cell sources and stem cell mobilizing agents have been introduced in clinical practice. The incidence of life-threatening complications following autologous stem cell transplant procedures has decreased dramatically. Understanding the immune mediated effect of allogeneic stem cell transplantation has resulted in the development of reduced intensity and non-myeloablative conditioning regimens, allowing transplantation of elderly patients. Long-term complications are starting to emerge, and will gain in importance in the near future.

Antiretroviral medication prescribing errors are common with hospitalization of HIV-infected patients

OBJECTIVES

Errors in prescribing antiretroviral therapy (ART) often occur with the hospitalization of HIV-infected patients. The rapid identification and prevention of errors may reduce patient harm and healthcare-associated costs.

METHODS

A retrospective review of hospitalized HIV-infected patients was carried out between 1 January 2009 and 31 December 2011. Errors were documented as omission, underdose, overdose, duplicate therapy, incorrect scheduling and/or incorrect therapy. The time to error correction was recorded. Relative risks (RRs) were computed to evaluate patient characteristics and error rates.

RESULTS

A total of 289 medication errors were identified in 146/416 admissions (35%). The most common was drug omission (69%). At an error rate of 31%, nucleoside reverse transcriptase inhibitors were associated with an increased risk of error when compared with protease inhibitors (RR 1.32; 95% CI 1.04-1.69) and co-formulated drugs (RR 1.59; 95% CI 1.19-2.09). Of the errors, 31% were corrected within the first 24 h, but over half (55%) were never remedied. Admissions with an omission error were 7.4 times more likely to have all errors corrected within 24 h than were admissions without an omission. Drug interactions with ART were detected on 51 occasions. For the study population (n = 177), an increased risk of admission error was observed for black (43%) compared with white (28%) individuals (RR 1.53; 95% CI 1.16-2.03) but no significant differences were observed between white patients and other minorities or between men and women.

CONCLUSION

Errors in inpatient ART were common, and the majority were never detected. The most common errors involved omission of medication, and nucleoside reverse transcriptase inhibitors had the highest rate of prescribing error. Interventions to prevent and correct errors are urgently needed.

The Fanconi anemia complementation group C gene (FAC) suppresses transformation of mutant fibroblasts by the SV40 virus

Fanconi anemia (FA) is a heterogeneous genetic syndrome manifested by bone marrow failure and consisting of at least five complementation groups (A, B, C, D, E). Mutations in a gene termed FAC are responsible for the C complementation group, but the function of the FAC protein remains obscure. FA patients are also highly cancer-prone; the molecular basis for this susceptibility is unclear but has led to the hypothesis that the wild-type FA gene may act as a tumor suppressor. In vitro, mutant FA primary fibroblasts are 3- to 50-fold more sensitive than normal fibroblasts to transformation in culture by the SV40 virus. We confirmed this marked susceptibility to transformation of a FAC-mutant primary fibroblast cell line, GM449. We then introduced a copy of the wild-type FAC cDNA into GM449 cells using a recombinant adeno-associated virus (rAAV) vector. We found that GM449 cells transduced with a copy of the normal FAC cDNA by a FAC-rAAV vector were at least 10-fold less prone to form transformed foci. Diminished transformation potential of transduced cells was a specific effect of the FAC cDNA since GM449 cells transduced with a rAAV vector not containing FAC retained marked susceptibility to SV40 transformation.

Effect of follow-up provider source on outcomes of patients with hematologic malignancies receiving hematopoietic stem cell transplantation

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Background: Studies have shown that involvement of trained physicians is associated with favorable outcomes of patients receiving hematopoietic stem cell transplantation (HSCT). At the University of Nebraska Medical Center (UNMC), most patients are shifted back to the care of their referring physicians in the first 100 days. We evaluated whether the practice of shifting care of patients from specialists to primary care providers (PCP), referred to as patient care oscillation, in HSCT results in optimal outcomes. Methods: Data from 666 patients who underwent HSCT for malignant hematologic disorders between 2000 and 2003 were analyzed. Cox proportional hazards regression analyses were done to compare the relative risk of relapse/progression and mortality at 100-days and 1-year between patients whose care remained with specialists (transplant MDs at UNMC or community oncologist) versus those who were transferred back to the care of referring PCPs while adjusting for patient and disease factors. Results: Rate of patient care oscillation varies according to type of transplant. In allo-HSCT, 50% of patients received follow-up care from PCPs, 30% from community oncologists, while 20% remain at UNMC for follow-up. In auto-HSCT, 70% of patients received follow-up care from PCPs, 20% from community oncologists, while 10% remain at UNMC for follow-up with transplanting physicians. Outcomes after HSCT according to type of transplant is shown in the table. Conclusions: These preliminary findings suggest that in both allogeneic and autologous HSCT, the risk of disease progression/relapse and mortality may be independent of the type of follow-up care provider. However, further studies are needed to determine whether the practice of shifting the care of HSCT patients results in similar medical care utilization, post-transplant complications, re-hospitalizations and patient satisfaction. Patients likely to benefit from specialized versus primary care should be identified.

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No significant financial relationships to disclose.

Overexpression of the fanconi anemia group C gene (FAC) protects hematopoietic progenitors from death induced by Fas-mediated apoptosis

Fanconi anemia is a rare, inherited disorder characterized by bone marrow failure, congenital malformations, and cancer susceptibility. The group C Fanconi anemia gene, FAC, identified by expression cloning methods, encodes a protein of unknown function that may be involved in the response to apoptotic stimuli. Hematopoietic progenitor cells from Fac knock-out mice are hypersensitive to IFN-gamma, a molecule that can induce apoptosis through up-regulation of the Fas death receptor. In this study, we used FAC-overexpressing transgenic mice to examine the relationship between FAC and Fas-triggered cell death. Hematopoietic progenitors from FAC-transgenic mice were up to 10-fold less sensitive to the cytolytic effect of Fas-ligation. Our experiments implicate FAC in the regulation of apoptosis mediated by the Fas death receptor.