Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease, with astrocytes implicated as contributing substantially to motor neuron death in familial (F)ALS (1-5). However, the proposed ...role of astrocytes in the pathology of ALS derives in part from rodent models of FALS based upon dominant mutations within the superoxide dismutase 1 (SOD1) gene, which account for <2% of all ALS cases (2,4,5). Their role in sporadic (S)ALS, which affects >90% of ALS patients, remains to be established. Using astrocytes generated from postmortem tissue from both FALS and SALS patients, we show that astrocytes derived from both patient groups are similarly toxic to motor neurons. We also demonstrate that SOD1 is a viable target for SALS, as its knockdown significantly attenuates astrocyte-mediated toxicity toward motor neurons. Our data highlight astrocytes as a non-cell autonomous component in SALS and provide an in vitro model system to investigate common disease mechanisms and evaluate potential therapies for SALS and FALS.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Proximal spinal muscular atrophy (SMA) is a debilitating neurological disease marked by isolated lower motor neuron death and subsequent atrophy of skeletal muscle. Historically, SMA pathology was ...thought to be limited to lower motor neurons and the skeletal muscles they control, yet there are several reports describing the coincidence of cardiovascular abnormalities in SMA patients. As new therapies for SMA emerge, it is necessary to determine whether these non-neuromuscular systems need to be targeted. Therefore, we have characterized left ventricular (LV) function of SMA mice (SMN2+/+; SMNΔ7+/+; Smn-/-) and compared it with that of their unaffected littermates at 7 and 14 days of age. Anatomical and physiological measurements made by electrocardiogram and echocardiography show that affected mouse pups have a dramatic decrease in cardiac function. At 14 days of age, SMA mice have bradycardia and develop a marked dilated cardiomyopathy with a concomitant decrease in contractility. Signs of decreased cardiac function are also apparent as early as 7 days of age in SMA animals. Delivery of a survival motor neuron-1 transgene using a self-complementary adeno-associated virus serotype 9 abolished the symptom of bradycardia and significantly decreased the severity of the heart defect. We conclude that severe SMA animals have compromised cardiac function resulting at least partially from early bradycardia, which is likely attributable to aberrant autonomic signaling. Further cardiographic studies of human SMA patients are needed to clarify the clinical relevance of these findings from this SMA mouse.
•The novel endpoint of graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) is achieved in a minority of allogeneic hematopoietic cell transplantation HCT recipients but is found to be ...highly prognostic for long term survival with major differences in the contribution of individual components.•Using statistical simulations, a modified form of GRFS (excluding death and chronic GVHD) that focuses on early severe events (grade III-IV acute GVHD and relapse) may serve as a useful surrogate endpoint in GVHD prevention studies given its strong associations with long-term overall survival.•Refinement of composite endpoints will necessarily occur depend on a priori assumptions of the study population as well as the intervention.
The overall composite of graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS), defined as survival free of grade III-IV acute GVHD (aGVHD), chronic GVHD (cGVHD) requiring systemic immunosuppressive therapy (IST), or relapse, has emerged as a useful composite in clinical trials and to capture clinically meaningful events that impact quantity and quality of survival after allogeneic hematopoietic cell transplantation (HCT). We reviewed 565 consecutive patients aged ≥18 years undergoing HCT for hematologic malignancy to analyze how baseline incidence, specifics of clinical definitions, and proposed reductions in any one individual event may dynamically alter the overall performance of the composite To determine the relative impact of each GRFS event (excluding death), we accounted for competing risks using Fine and Gray methods, and correlated each event with overall survival (OS) using Kaplan-Meier methods. The consequences of modulating individual or composite endpoints on OS, such as hypothesized reductions of events of an HCT interventional trial, were examined using Monte Carlo simulations. The median age of the cohort was 54 years (range, 18 to 73 years). The majority of patients received HLA-matched unrelated donor HCT (53%), consisting of peripheral blood stem cell grafts (90%) after myeloablative conditioning (68%). Relapse conferred the greatest risk for death (hazard ratio HR, 7.89; 95% confidence interval CI, 5.83 to 10.69), followed by grade III-IV aGVHD (HR, 6.16; 95% CI, 4.42 to 8.56) and cGVHD requiring IST (HR, 1.69; 95% CI, 1.16 to 2.46). The overall GRFS composite correlated with an HR of 4.81 (95% CI, 3.61 to 6.41), which was lower compared with either relapse or grade III-IV aGVHD. Statistical simulations found that modulating the combined risk of both relapse and grade III-IV aGVHD predicted the greatest change in 5-year OS. These simulations suggest that GRFS as currently defined may be less optimal for correlating with OS, and further refinement of composite endpoints is needed. Nonetheless, composite endpoints may be particularly helpful in mitigating potential difficulties in interpretation when competing risks are present, most commonly seen in HCT studies.
The composite endpoint of GVHD-free, relapse-free survival (GRFS), defined as survival free from grade 3–4 acute GVHD (aGVHD), chronic GVHD (cGVHD) requiring systemic immunosuppressive therapy (IST), ...or relapse has emerged as an outcome to capture clinically meaningful events. In the present study, we validated GRFS as a useful surrogate endpoint by examining the relative importance of individual events and the GRFS composite itself on overall survival (OS) at 5-years after allogeneic HCT.
We conducted an IRB-approved retrospective cohort study on 565 consecutive patients (age ≥18 years) undergoing first-time allogeneic HCT for hematologic malignancy (January 2007–March 2013). Data abstraction of GRFS events was performed through chart review of the EHR. To determine the impact of each event of the GRFS composite endpoint, we accounted for competing risks using Fine and Gray methods, and correlated each event with OS using Kaplan-Meier methods. Using statistical simulations, the relative consequences of successfully modulating individual or composite endpoints on OS were examined to further elucidate the role of GRFS in clinical trials research.
The median age of the cohort was 54 years (18–73 years), comprised predominantly of males (58%) and Caucasians (94%). The most common indication for transplant was AML (41%), followed by lymphoma (21%) and MDS/MPD (14%). Patients received HLA-matched related (47%), and matched unrelated (53%) donors, and mostly peripheral blood stem cells (90%) and myeloablative conditioning (68%). Relapse conferred the greatest risk for death (HR 7.89; 95% CI:5.83–10.69). Grade 3–4 aGVHD was associated with HR 6.16 (95%CI:4.42–8.56), while cGVHD requiring IST was associated with lower HR 1.69 (95%CI:1.16–2.46). Indeed, the GRFS composite correlated with less HR 4.81 (95% CI:3.61–6.41) compared with either relapse or grade 3–4 aGVHD events. To determine the impact of hypothetical improvements on individual events or combined events (composite) on OS, we next performed Monte Carlo simulations. Compared with individual events, modulating composite endpoints predicted the greatest change in 5-year OS (Figure 1). The greatest gain in OS was seen by proportionally reducing both grade 3–4 aGVHD and relapse (modified GRFS). Reducing chronic GVHD requiring IST proportionally with grade 3–4 aGVHD and relapse events (conventional GRFS) did not change 5-year OS.
These findings highlight the importance of influencing OS by targeting the major early adverse post-HCT events (i.e., grade 3–4 acute GVHD and relapse). Moreover, the simulations herein suggest that GRFS as currently defined may be less optimal for predicting OS than using early grade 3–4 aGVHD and relapse as composite endpoints. Importantly, further refinement of these endpoints will depend on the a priori defined study population as well as intervention.
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