Disabling Uncompetitive Inhibition of Oncogenic IDH Mutations Drives Acquired Resistance.

Mutations in IDH genes occur frequently in acute myeloid leukemia (AML) and other human cancers to generate the oncometabolite R-2HG. Allosteric inhibition of mutant IDH suppresses R-2HG production in a subset of patients with AML; however, acquired resistance emerges as a new challenge, and the underlying mechanisms remain incompletely understood. Here we establish isogenic leukemia cells containing common IDH oncogenic mutations by CRISPR base editing. By mutational scanning of IDH single amino acid variants in base-edited cells, we describe a repertoire of IDH second-site mutations responsible for therapy resistance through disabling uncompetitive enzyme inhibition. Recurrent mutations at NADPH binding sites within IDH heterodimers act in cis or trans to prevent the formation of stable enzyme-inhibitor complexes, restore R-2HG production in the presence of inhibitors, and drive therapy resistance in IDH-mutant AML cells and patients. We therefore uncover a new class of pathogenic mutations and mechanisms for acquired resistance to targeted cancer therapies. SIGNIFICANCE: Comprehensive scanning of IDH single amino acid variants in base-edited leukemia cells uncovers recurrent mutations conferring resistance to IDH inhibition through disabling NADPH-dependent uncompetitive inhibition. Together with targeted sequencing, structural, and functional studies, we identify a new class of pathogenic mutations and mechanisms for acquired resistance to IDH-targeting cancer therapies. This article is highlighted in the In This Issue feature, p. 1.

Epo-IGF1R cross talk expands stress-specific progenitors in regenerative erythropoiesis and myeloproliferative neoplasm.

We found that in regenerative erythropoiesis, the erythroid progenitor landscape is reshaped, and a previously undescribed progenitor population with colony-forming unit-erythroid (CFU-E) activity (stress CFU-E [sCFU-E]) is expanded markedly to restore the erythron. sCFU-E cells are targets of erythropoietin (Epo), and sCFU-E expansion requires signaling from the Epo receptor (EpoR) cytoplasmic tyrosines. Molecularly, Epo promotes sCFU-E expansion via JAK2- and STAT5-dependent expression of IRS2, thus engaging the progrowth signaling from the IGF1 receptor (IGF1R). Inhibition of IGF1R and IRS2 signaling impairs sCFU-E cell growth, whereas exogenous IRS2 expression rescues cell growth in sCFU-E expressing truncated EpoR-lacking cytoplasmic tyrosines. This sCFU-E pathway is the major pathway involved in erythrocytosis driven by the oncogenic JAK2 mutant JAK2(V617F) in myeloproliferative neoplasm. Inability to expand sCFU-E cells by truncated EpoR protects against JAK2(V617F)-driven erythrocytosis. In samples from patients with myeloproliferative neoplasm, the number of sCFU-E-like cells increases, and inhibition of IGR1R and IRS2 signaling blocks Epo-hypersensitive erythroid cell colony formation. In summary, we identified a new stress-specific erythroid progenitor cell population that links regenerative erythropoiesis to pathogenic erythrocytosis.

Amyotrophic lateral sclerosis-specific quality of life-short form (ALSSQOL-SF): A brief, reliable, and valid version of the ALSSQOL-R.

INTRODUCTION: The Amyotrophic Lateral Sclerosis (ALS)-Specific Quality of Life instrument and its revised version (ALSSQOL and ALSSQOL-R) have strong psychometric properties, and have demonstrated research and clinical utility. In this study we aimed to develop a short form (ALSSQOL-SF) suitable for limited clinic time and patient stamina. METHODS: The ALSSQOL-SF was created using Item Response Theory and confirmatory factor analysis on 389 patients. A cross-validation sample of 162 patients assessed convergent, divergent, and construct validity of the ALSSQOL-SF compared with psychosocial and physical functioning measures. RESULTS: The ALSSQOL-SF consisted of 20 items. Compared with the ALSSQOL-R, optimal precision was retained, and completion time was reduced from 15-25 minutes to 2-4 minutes. Psychometric properties for the ALSSQOL-SF and its subscales were strong. DISCUSSION: The ALSSQOL-SF is a disease-specific global QOL instrument that has a short administration time suitable for clinical use, and can provide clinically useful, valid information about persons with ALS. Muscle Nerve 58: 646-654, 2018.

Fixed dynamometry is more sensitive than vital capacity or ALS rating scale.

INTRODUCTION: Improved outcome measures are essential to efficiently screen the growing number of potential amyotrophic lateral sclerosis (ALS) therapies. METHODS: This longitudinal study of 100 (70 male) participants with ALS compared Accurate Test of Limb Isometric Strength (ATLIS), using a fixed, wireless load cell, with ALS Functional Rating Scale-Revised (ALSFRS-R) and vital capacity (VC). RESULTS: Participants enrolled at 5 U.S. sites. Data were analyzed from 66 participants with complete ATLIS, ALSFRS-R, and VC data over at least 3 visits. Change in ATLIS was less variable both within- and among-person than change in ALSFRS-R or VC. Additionally, participants who had normal ALSFRS-R arm and leg function averaged 12 to 32% below expected strength values measured by ATLIS. CONCLUSIONS: ATLIS was more sensitive to change than ALSFRS-R or VC and could decrease sample size requirements by approximately one-third. The ability of ATLIS to detect prefunctional change has potential value in early trials. Muscle Nerve 56: 710-715, 2017.

National Study of Muscle Cramps in ALS in the USA.

The objective of this study was to describe muscle cramps in an US sample of amyotrophic lateral sclerosis (ALS) patients. Utilizing an anonymous web based questionnaire we queried ALS patients regarding the severity, frequency, time-course, treatment of muscle cramps and their relationship to pain. The survey had 282 respondents with 92% reporting that they had cramps. For 20% of the sample, cramps were stated to be the presenting ALS symptom. Cramp severity was rated at a mean of 5.2/10 and the mean cramp frequency was 5.3 cramps per day. Cramp intensity and frequency did not correlate with duration or severity of ALS. Pain as measured with the Patient Reported Outcome Measurement Information System (PROMIS) pain scales was not statistically different from the US general population. Cramp severity and frequency significantly and positively correlated with the PROMIS pain scales. Patients with more severe cramps were more likely to use prescription medications for their cramps compared to patients with milder symptoms. Treatments directed at cramps were tried by 57%. In conclusion, cramps are a common symptom in ALS and it does not correlate with disease duration or severity. The severity of cramps is on average moderate and many patients try treatments.

The role of mental health and self-efficacy in the pain experience of patients with amyotrophic lateral sclerosis.

Complex interactions between pain, depression, and anxiety impact quality of life in patients with ALS. Psychological approaches to pain control may be useful. This study explored the role of self-efficacy in mitigating pain. Individuals registered with the Agency for Toxic Substances and Disease Registry National ALS Registry and who experienced pain were invited to participate in an online survey. Subjects completed the Brief Pain Inventory-Short Form, Hospital Anxiety and Depression Scale, and Chronic Pain Self-Efficacy Scale. Correlations between variables were determined. Multiple linear regression models assessed relationships between depression, anxiety and self-efficacy predictions, and pain severity, interference, and relief. Results recorded that there were 197 participants (58% males, mean age 59 ± 10 years). Cases or borderline cases of depression or anxiety were common. Mean levels of pain were moderate. Higher pain self-efficacy scores predicted lower pain severity, lower pain interference, and higher pain relief with treatment. As depression scores increased, pain interference with daily life was higher. In conclusion, anxiety and depression are common in patients with ALS and pain. Self-efficacy appears to mitigate pain. A multifactorial approach to pain management should be considered in these patients, addressing mental health and self-efficacy to augment pharmacologic pain treatments.

Patient-reported problematic symptoms in an ALS treatment trial.

This study was undertaken to determine which symptoms are perceived to be most problematic for patients with ALS and how their severity changes over time. A retrospective study was performed of data from a randomized, double-blind, placebo-controlled trial of ceftriaxone in ALS. Participants completed the ALS Specific Quality of Life Instrument (ALSSQoL) at baseline and at intervals up to 96 weeks. Ten ALSSQoL items ask participants to rate how problematic symptoms are (the subjective feeling of burden of these symptoms), ranging from 0 (no problem) to 10 (tremendous problem). Six are non-bulbar (pain, fatigue, breathing, strength and ability to move, sleep, and bowel and bladder) and four are bulbar (eating, speaking, excessive saliva, and mucus). Results revealed that there were 82 subjects (56% males, mean age 53 ± 10.3 years) with ALSSQoL data for weeks 0 and 96. All 10 symptoms became more problematic over time. For non-bulbar symptoms, strength/ability to move and fatigue were the most problematic. Speaking was the most problematic bulbar symptom. In conclusion, although all the symptoms in the ALSSQoL were acknowledged as problematic, some had greater impact than others. All became more problematic over time. This should help prioritize research into symptom management, and assist individual clinicians in their approach to patient care.

A Qualitative Study of Multidisciplinary ALS Clinic Use in the United States.

OBJECTIVES: The multidisciplinary clinic (MDC) has become the standard of care for individuals with amyotrophic lateral sclerosis (ALS) in the United States, yet many patients choose not to receive care at MDCs. We undertook a qualitative study of individuals with ALS to explore patients' perceptions of this form of service delivery. METHODS: Participants completed an online survey that posed open-ended questions about their attitudes and behaviors surrounding MCDs. Qualitative analysis was performed whereby response data was evaluated and grouped into themes. RESULTS: The unique aspect of MDCs most commonly cited by patients was integrated care. Other reasons for attending MDC included those common to specialist centers, such as expertise, access to clinical trials, and participation in research. Perceived disadvantages unique to the MDC model were long and tiring visits. In common with many specialist centers, long travel times were cited as a disadvantage of MDCs. CONCLUSIONS: This information provides a foundation for improving ALS care. For those able to travel, the MDC model has much to offer, but patients' time should be respected. For those patients who cannot travel, alternative models of care should be devised to provide integrated care, clinical expertise, and access to research.

Compliance with recommendations made in a multidisciplinary ALS clinic.

Multidisciplinary ALS clinics provide recommendations at each visit, but these do little good unless recalled and followed. This study was conducted to determine recall of, and compliance with, these recommendations, and to study factors affecting compliance. Patients were contacted by telephone six weeks after their ALS clinic visit and asked about recommendations made by the multidisciplinary team. Themes for recall and compliance were generated by three coders using qualitative analysis, and validated using triangulation and consensual validation. Pearson correlation coefficients were calculated for the relationship of function and quality of life to recommendation categories. Results demonstrated that most recommendations centered around physical needs, whereas few were provided for Caregiver Support and Mental Health. Fewer than 40% of all recommendations were recalled, with the highest category being Physical Function. Compliance was highest for this category as well (mean 4.27/5). Monitoring of patients between clinic visits appeared to enhance compliance. In conclusion, for ALS clinic teams seeking to maximize the impact of recommendations, discussions to facilitate understanding, instruction in problem-solving skills, and closer follow-up between clinic visits should facilitate better recall and compliance, and thus improve care. The potential benefits of greater emphasis on mental health and caregiver well-being should be explored.

Pain in amyotrophic lateral sclerosis: Patient and physician perspectives and practices.

Our objective was to better understand the experience and impact of pain on ALS patients in the U.S., and to survey ALS physicians on their pain assessment and management practices. Individuals with ALS were invited to complete an online survey of pain in ALS. ALS specialist physicians were sent an e-mail survey about their experiences in evaluating and managing patients' pain. Nearly 75% of patients with ALS reported significant pain, and most thought that ALS was the source of at least some of this pain. Pain intensity scores (mean 3.9/10) and pain interference scores (mean 4.3/10) were moderate on average, but nearly 80% of participants were using pain medication, including 22% using opioids. Nearly 25% of patients thought they needed stronger pain medication than they were receiving. Physicians generally assess and manage pain in ALS patients, but few use standardized assessment tools. Nearly two-thirds felt that there is a need for better pain management practices and more than one-third felt better training was needed. In conclusion, pain in patients with ALS is not always well controlled. Improvement in care may be facilitated by a more standardized approach to evaluation, and by additional education and training of ALS health care professionals.

Macroecology of Australian Tall Eucalypt Forests: Baseline Data from a Continental-Scale Permanent Plot Network.

Tracking the response of forest ecosystems to climate change demands large (≥1 ha) monitoring plots that are repeatedly measured over long time frames and arranged across macro-ecological gradients. Continental scale networks of permanent forest plots have identified links between climate and carbon fluxes by monitoring trends in tree growth, mortality and recruitment. The relationship between tree growth and climate in Australia has been recently articulated through analysis of data from smaller forest plots, but conclusions were limited by (a) absence of data on recruitment and mortality, (b) exclusion of non-eucalypt species, and (c) lack of knowledge of stand age or disturbance histories. To remedy these gaps we established the Ausplots Forest Monitoring Network: a continental scale network of 48 1 ha permanent plots in highly productive tall eucalypt forests in the mature growth stage. These plots are distributed across cool temperate, Mediterranean, subtropical and tropical climates (mean annual precipitation 850 to 1900 mm per year; mean annual temperature 6 to 21°C). Aboveground carbon stocks (AGC) in these forests are dominated by eucalypts (90% of AGC) whilst non-eucalypts in the understorey dominated species diversity and tree abundance (84% of species; 60% of stems). Aboveground carbon stocks were negatively related to mean annual temperature, with forests at the warm end of the temperature range storing approximately half the amount of carbon as forests at the cool end of the temperature range. This may reflect thermal constraints on tree growth detected through other plot networks and physiological studies. Through common protocols and careful sampling design, the Ausplots Forest Monitoring Network will facilitate the integration of tall eucalypt forests into established global forest monitoring initiatives. In the context of projections of rapidly warming and drying climates in Australia, this plot network will enable detection of links between climate and growth, mortality and carbon dynamics of eucalypt forests.

Multidisciplinary ALS clinics in the USA: A comparison of those who attend and those who do not.

Optimization of quality of life (QoL) is perceived by many as the primary goal for patients with amyotrophic lateral sclerosis (ALS), often via multidisciplinary clinics (MDCs). The aim of this study was to examine the differences in QoL, physical function, and social problem-solving skills for individuals with ALS attending MDCs compared to non-attenders. An online survey was completed by 295 people with ALS in the United States. Results showed there were no differences between the groups in global QoL, measures of physical function, or social problem-solving skills. Attenders and non-attenders of MDCs reported similar use of treatments for their ALS, although attenders received more health care services from nurses, therapists, social workers, dieticians, and in-home care providers. In conclusion, oher instruments may be needed to assess the benefits of MDCs. Qualitative studies of attenders and non-attenders of MDCs may reveal important differences that could guide care.

Serum ferritin is elevated in amyotrophic lateral sclerosis patients.

Our objective was to measure serum ferritin levels, which reflect iron metabolism, in ALS patients versus healthy and disease controls, and determine whether serum ferritin levels correlate with survival. We retrospectively analyzed data from 138 ALS patients, 152 healthy controls, and 82 disease controls. Gender, age, site of onset, and dates of symptom onset and death were recorded. Survival was defined as the time from symptom onset to death. Serum ferritin levels were measured using immunoassay. ANOVA and Pearson's correlation were used to compare ferritin levels between groups and test the association between ferritin levels and age and survival. Ferritin levels were categorized into high and low groups, and Kaplan-Meier analysis performed. Results showed that gender proportions differed between ALS patients versus healthy and disease controls, and gender affected serum ferritin levels. Ferritin comparisons were stratified for gender. In both males and females, ferritin levels were higher in ALS patients versus healthy and disease controls. However, ferritin levels were unrelated to survival in either gender, by tests of association or survival analysis. In conclusion, ALS patients have altered iron metabolism that is not simply due to the presence of neurological disease. Serum ferritin levels alone are not sufficient to predict survival.

Acceptance of brain-computer interfaces in amyotrophic lateral sclerosis.

Brain-computer interfaces (BCI) have the potential to permit patients with amyotrophic lateral sclerosis (ALS) to communicate even when locked in. Although as many as half of patients with ALS develop cognitive or behavioral dysfunction, the impact of these factors on acceptance of and ability to use a BCI has not been studied. We surveyed patients with ALS and their caregivers about BCIs used as assistive communication tools. The survey focused on the features of a BCI system, the desired end-use functions, and requirements. Functional, cognitive, and behavioral data were collected from patients and analyzed for their influence over decisions about BCI device use. Results showed that behavioral impairment was associated with decreased receptivity to the use of BCI technology. In addition, the operation of a BCI system during a pilot study altered patients' opinions of the utility of the system, generally in line with their perceived performance at controlling the device. In conclusion, these two findings have implications for the engineering design and clinical care phases of assistive device deployment.

Biomarker-based predictive models for prognosis in amyotrophic lateral sclerosis.

IMPORTANCE: Although median survival in amyotrophic lateral sclerosis (ALS) is 2 to 4 years, survival ranges from months to decades, creating prognostic uncertainty. Strategies to predict prognosis would benefit clinical management and outcomes assessments of clinical trials. OBJECTIVE: To identify biomarkers in plasma and cerebrospinal fluid (CSF) of patients with ALS that can predict prognosis. DESIGN, PARTICIPANTS, AND SETTING: We conducted a retrospective study of plasma (n = 29) and CSF (n = 33) biomarkers identified in samples collected between March 16, 2005, and August 22, 2007, from patients with ALS at an academic tertiary care center. Participants included patients who were undergoing diagnostic evaluation in the neurology outpatient clinic and were eventually identified as having definite, probable, laboratory-supported probable, or possible ALS as defined by revised El-Escorial criteria. All were white and none had a family history of ALS. Clinical information extended from initial presentation to death. Genotyping for hemochromatosis (HFE) gene status was performed. Multiplex and immunoassay analysis of plasma and CSF was used to measure levels of 35 biomarkers. Statistical modeling was used to identify biomarker panels that could predict total disease duration. MAIN OUTCOMES AND MEASURES: Total disease duration, defined as the time from symptom onset to death, was the main outcome. The hypothesis being tested was formulated after data collection. RESULTS: Multivariable models for total disease duration using biomarkers from plasma, CSF, and plasma and CSF combined incorporated 7, 6, and 6 biomarkers to achieve goodness-of-fit R2 values of 0.769, 0.617, and 0.962, respectively. After classification into prognostic categories, actual and predicted values achieved moderate to good agreement, with Cohen κ values of 0.526, 0.515, and 0.930 for plasma, CSF, and plasma and CSF combined models, respectively. Inflammatory biomarkers, including select interleukins, growth factors such as granulocyte colony-stimulating factor, and l-ferritin, had predictive value. CONCLUSIONS AND RELEVANCE: This study provides proof-of-concept for a novel multivariable modeling strategy to predict ALS prognosis. These results support unbiased biomarker discovery efforts in larger patient cohorts with detailed longitudinal follow-up.

H63D HFE polymorphisms are associated with increased disease duration and decreased muscle superoxide dismutase-1 expression in amyotrophic lateral sclerosis patients.

INTRODUCTION: H63D HFE polymorphisms increase the risk of neurodegenerative disorders and, specifically, may increase amyotrophic lateral sclerosis (ALS) risk. Investigating the physiological alterations induced by H63D polymorphisms in ALS patients may elucidate mechanisms by which this genotype alters disease. METHODS: Clinical measures and muscle biopsies were available from patients previously diagnosed with ALS who underwent HFE genotyping. Clinical outcomes and SOD1 protein expression were analyzed using standard statistical analyses. RESULTS: ALS patients harboring H63D HFE (n = 16) had 28.1 months longer average disease duration and 39.3% lower muscle SOD1 protein than ALS patients with wild-type HFE (n = 22). CONCLUSIONS: Combined with previous reports suggesting the H63D polymorphism is associated with ALS, these results support a model wherein the H63D polymorphism is involved in ALS by means of pathways involving SOD1 but may limit cellular damage in individuals who develop disease. The association between HFE genotype and disease duration has important implications for clinical care and treatment trials.

Non-invasive ventilation and gastrostomy may not impact overall quality of life in patients with ALS.

Non-invasive positive pressure ventilation (NIPPV) may improve health-related quality of life (HRQoL) in patients with ALS. The effect of percutaneous endoscopic gastrostomy (PEG) on HRQoL is not known. Instruments measuring QoL more broadly have not been used to assess effects of these interventions. This study was undertaken to do so via the ALS-Specific Quality of Life Instrument-revised (ALSSQOL-R). A retrospective review was carried out of ALS patients who had undergone one QoL assessment prior to NIPPV or PEG initiation and two assessments following one of these interventions. Random coefficients models were developed. Twenty-two patients met criteria for inclusion: six NIPPV, 11 PEG, and five NIPPV + PEG. The ALSSQoL-R did not change significantly following NIPPV or PEG or both. Function declined in all three groups over the same time-period. In conclusion, overall QoL in ALS does not appear to change after NIPPV or PEG. This may reflect the impact of non-health-related factors or may be due to a response shift. QoL instruments that include domains outside of health status may not be sensitive to changes from single interventions. Larger, prospective studies are needed.

Psychological health in patients with ALS is maintained as physical function declines.

Although quality of life (QoL) in patients with ALS has been shown to be independent of physical function and to be maintained over time, the status of psychological health over the disease course has not been studied using an ALS-specific instrument. It is also uncertain how three common interventions - antidepressants, percutaneous endoscopic gastrostomy (PEG), and non-invasive ventilatory support (NIPPV) - influence psychological health. We performed a retrospective review of the Negative Emotion subscale (NES) score, a measure of psychological health within the ALS-Specific QoL Instrument. Analysis of 72 patients over three months, and of a subset of 48 over six months, showed stability of psychological health despite a decline in the ALS Functional Rating Scale-Revised to 88.4% of baseline at three months and 82.6% at six months. NES did not change after antidepressants, PEG, or NIPPV, although there was a suggestion of improvement with antidepressants in a subgroup. In conclusion, as with overall QoL, psychological health of ALS patients as measured with an ALS-specific instrument does not decline as physical function is lost. Supports found in a multidisciplinary ALS clinic may influence expectations, facilitate response shift, and stabilize psychological health while masking the independent effects of specific interventions.

Plasma biomarkers associated with ALS and their relationship to iron homeostasis.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with complicated pathogenesis with variable presentation and disease progression. There is a critical need for a panel of biomarkers to provide clinicians and researchers with additional information. In this study, multiplex immunoassays were used to screen a number of cytokines, growth factors, and iron-related proteins. ALS patients had significantly higher plasma levels of L-ferritin and lower concentrations of transferrin when compared to healthy controls and together classified a test group of subjects with 82% accuracy. Duration of ALS symptoms correlated positively with levels of monocyte chemoattractant protein 1 (MCP-1) and negatively with levels of granulocyte-macrophage colony stimulating factor (GM-CSF). The biomarker profile suggests iron homeostasis is disrupted in ALS patients, and changes in ferritin and transferrin (Tf) appear to be indicators of ongoing inflammatory processes. The data demonstrate a plasma biomarker profile in ALS patients that may differ from published reports of cerebrospinal fluid biomarkers.