Helen E. Stephens

A CSF biomarker panel for identification of patients with amyotrophic lateral sclerosis

Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with complicated pathogenesis that poses challenges with respect to diagnosis and monitoring of disease progression. Objectives: To identify a biomarker panel that elucidates ALS disease pathogenesis, distinguishes patients with ALS from neurologic disease controls, and correlates with ALS disease characteristics, and to determine the effect of HFE gene variants, a potential risk factor for sporadic ALS, on the biomarker profile. Methods: We obtained CSF samples by lumbar puncture from 41 patients with ALS and 33 neurologic disease controls. All patients were genotyped for HFE polymorphisms. We performed a multiplex cytokine and growth factor analysis and immunoassays for iron-related analytes. Classification statistics were generated using a support vector machine algorithm. Results: The groups of patients with ALS and neurologic disease controls were each associated with distinct profiles of biomarkers. Fourteen biomarkers differed between patients with ALS and the control group. The five proteins with the lowest p values differentiated patients with ALS from controls with 89.2% accuracy, 87.5% sensitivity, and 91.2% specificity. Expression of IL-8 was higher in those patients with lower levels of physical function. Expression of β2-microglobulin was higher in subjects carrying an H63D HFE allele, while expression of several markers was higher in subjects carrying a C282Y HFE allele. Conclusions: A CSF inflammatory profile associated with amyotrophic lateral sclerosis (ALS) pathogenesis may distinguish patients with ALS from neurologic disease controls, and may serve as a biomarker panel to aid in the diagnosis of ALS pending further validation. Some of these biomarkers differ by HFE genotype.

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. Muscle Nerve, 2010

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.

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

Abstract 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.

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

Abstract 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.

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

Abstract 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.

Patient-reported problematic symptoms in an ALS treatment trial.

Abstract 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

Abstract 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.

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

Abstract 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.

Abstract 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 Pearsons 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.