Elevated serum creatine kinase in the early stage of sporadic amyotrophic lateral sclerosis

Creatine Kinase and Respiratory Decline in Amyotrophic Lateral Sclerosis

Respiratory dysfunction is an important hallmark of amyotrophic lateral sclerosis (ALS). Elevation of creatine kinase (CK) has been reported in 23-75% of ALS patients, but the underlying mechanisms remain unknown. This work aims to enlighten the role of CK as a prognostic factor of respiratory dysfunction in ALS. A retrospective analysis of demographic and clinical variables, CK, functional decline per month (ΔFS), forced vital capacity (%FVC), and mean amplitude of the phrenic nerve compound motor action potential (pCMAP) in 319 ALS patients was conducted. These measurements were evaluated at study entry, and patients were followed from the moment of first observation until death or last follow-up visit. High CK values were defined as above the 90th percentile (CK ≥ P90) adjusted to sex. We analyzed survival and time to non-invasive ventilation (NIV) as proxies for respiratory impairment. Linear regression analysis revealed that high CK was associated with male sex (p < 0.001), spinal onset (p = 0.018), and FVC ≥ 80% (p = 0.038). CK was 23.4% higher in spinal-onset ALS patients (p < 0.001). High CK levels were not linked with an increased risk of death (p = 0.334) in Cox multivariate regression analysis. CK ≥ P90 (HR = 1.001, p = 0.038), shorter disease duration (HR = 0.937, p < 0.001), lower pCMAP (HR = 0.082, p < 0.001), and higher ΔFS (HR = 1.968, p < 0.001) were risk factors for respiratory failure. The association between high CK levels and poorer respiratory outcomes could derive from cellular metabolic stress or a specific phenotype associated with faster respiratory decline. Our study suggests that CK measurement at diagnosis should be more extensively investigated as a possible marker of poor respiratory outcome in future studies, including a larger population of patients.

Effects of tofersen treatment in patients with SOD1-ALS in a "real-world" setting - a 12-month multicenter cohort study from the German early access program

Background

In April 2023, the antisense oligonucleotide tofersen was approved by the U.S. Food and Drug Administration (FDA) for treatment of SOD1-amyotrophic lateral sclerosis (ALS), after a decrease of neurofilament light chain (NfL) levels had been demonstrated.

Methods

Between 03/2022 and 04/2023, 24 patients with SOD1-ALS from ten German ALS reference centers were followed-up until the cut-off date for ALS functional rating scale revised (ALSFRS-R), progression rate (loss of ALSFRS-R/month), NfL, phosphorylated neurofilament heavy chain (pNfH) in cerebrospinal fluid (CSF), and adverse events.

Findings

During the observation period, median ALSFRS-R decreased from 38.0 (IQR 32.0-42.0) to 35.0 (IQR 29.0-42.0), corresponding to a median progression rate of 0.11 (IQR -0.09 to 0.32) points of ALSFRS-R lost per month. Median serum NfL declined from 78.0 pg/ml (IQR 37.0-147.0 pg/ml; n = 23) to 36.0 pg/ml (IQR 22.0-65.0 pg/ml; n = 23; p = 0.02), median pNfH in CSF from 2226 pg/ml (IQR 1061-6138 pg/ml; n = 18) to 1151 pg/ml (IQR 521-2360 pg/ml; n = 18; p = 0.02). In the CSF, we detected a pleocytosis in 73% of patients (11 of 15) and an intrathecal immunoglobulin synthesis (IgG, IgM, or IgA) in 9 out of 10 patients. Two drug-related serious adverse events were reported.

Interpretation

Consistent with the VALOR study and its Open Label Extension (OLE), our results confirm a reduction of NfL serum levels, and moreover show a reduction of pNfH in CSF. The therapy was safe, as no persistent symptoms were observed. Pleocytosis and Ig synthesis in CSF with clinical symptoms related to myeloradiculitis in two patients, indicate the potential of an autoimmune reaction.

Funding

No funding was received towards this study.

Cerebrospinal fluid and blood exosomes as biomarkers for amyotrophic lateral sclerosis; a systematic review

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal motor neuron disease. Due to the limited knowledge about potential biomarkers that help in early diagnosis and monitoring disease progression, today's diagnoses are based on ruling out other diseases, neurography, and electromyography examination, which takes a time-consuming procedure.

METHODS

PubMed, ScienceDirect, and Web of Science were explored to extract articles published from January 2015 to June 2023. In the searching strategy following keywords were included; amyotrophic lateral sclerosis, biomarkers, cerebrospinal fluid, serum, and plama.

RESULTS

A total number of 6 studies describing fluid-based exosomal biomarkers were included in this study. Aggregated proteins including SOD1, TDP-43, pTDP-43, and FUS could be detected in the microvesicles (MVs). Moreover, TDP-43 and NFL extracted from plasma exosomes could be used as prognostic biomarkers. Also, downregulated miR-27a-3p detected through exoEasy Maxi and exoQuick Kit in the plasma could be measured as a diagnostic biomarker. Eventually, the upregulated level of CORO1A could be used to monitor disease progression.

CONCLUSION

Based on the results, each biomarker alone is insufficient to evaluate ALS. CNS-derived exosomes contain multiple ALS-related biomarkers (SOD1, TDP-43, pTDP-43, FUS, and miRNAs) that are detectable in cerebrospinal fluid and blood is a proper alternation. Exosome detecting kits listed as exoEasy, ExoQuick, Exo-spin, ME kit, ExoQuick Plus, and Exo-Flow, are helpful to reach this purpose.

The value of routine blood work-up in clinical stratification and prognosis of patients with amyotrophic lateral sclerosis

BACKGROUND

There is an unmet need in amyotrophic lateral sclerosis (ALS) to provide specific biomarkers for the disease. Due to their easy availability, we aimed to investigate whether routine blood parameters provide useful clues for phenotypic classification and disease prognosis.

METHODS

We analyzed a large inpatient cohort of 836 ALS patients who underwent deep phenotyping with evaluation of the clinical and neurophysiological burden of upper (UMN) and lower (LMN) motor neuron signs. Disability and progression rate were measured through the revised ALS Functional Rating Scale (ALSFRS-R) and its changes during time. Cox regression analysis was performed to assess survival associations.

RESULTS

Creatinine significantly correlated with LMN damage (r = 0.38), active (r = 0.18) and chronic (r = 0.24) denervation and baseline ALSFRS-R (r = 0.33). Creatine kinase (CK), alanine (ALT) and aspartate (AST) transaminases correlated with active (r = 0.35, r = 0.27, r = 0.24) and chronic (r = 0.37, r = 0.20, r = 0.19) denervation, while albumin and C-reactive protein significantly correlated with LMN score (r = 0.20 and r = 0.17). Disease progression rate showed correlations with chloride (r = -0.19) and potassium levels (r = -0.16). After adjustment for known prognostic factors, total protein [HR 0.70 (95% CI 0.57-0.86)], creatinine [HR 0.86 (95% CI 0.81-0.92)], chloride [HR 0.95 (95% CI 0.92-0.99)], lactate dehydrogenase [HR 0.99 (95% CI 0.99-0.99)], and AST [HR 1.02 (95% CI 1.01-1.02)] were independently associated with survival.

CONCLUSIONS

Creatinine is a reliable biomarker for ALS, associated with clinical features, disability and survival. Markers of nutrition/inflammation may offer additional prognostic information and partially correlate with clinical features. AST and chloride could further assist in predicting progression rate and survival.

Primary care blood tests show lipid profile changes in pre-symptomatic amyotrophic lateral sclerosis

Multiple sources of evidence suggest that changes in metabolism may precede the onset of motor symptoms in amyotrophic lateral sclerosis. This study aimed to seek evidence for alterations in the levels of blood indices collected routinely in the primary care setting prior to the onset of motor symptoms in amyotrophic lateral sclerosis. Premorbid data, measured as part of routine health screening, for total cholesterol, high-density and low-density lipoprotein cholesterol, triglyceride, glycated haemoglobin A1c and creatinine were collected retrospectively from (i) a cohort of amyotrophic lateral sclerosis patients attending a specialist clinic (n = 143) and (ii) from primary care-linked data within UK Biobank. Data were fitted using linear mixed effects models with linear b-splines to identify inflection points, controlling for age and sex. In specialist amyotrophic lateral sclerosis clinic cases, models indicated decreasing levels of total and low-density lipoprotein cholesterol prior to an inflection point in the years before symptom onset (total cholesterol 3.25 years, low-density lipoprotein cholesterol 1.25 years), after which they stabilized or rose. A similar pattern was observed in amyotrophic lateral sclerosis cases within UK Biobank, occurring several years prior to diagnosis (total cholesterol 7 years, low-density lipoprotein cholesterol 7.25 years), differing significantly from matched controls. High-density lipoprotein cholesterol followed a similar pattern but was less robust to sensitivity analyses. Levels of triglyceride remained stable throughout. Glycated haemoglobin temporal profiles were not consistent between the clinic and biobank cohorts. Creatinine level trajectories prior to amyotrophic lateral sclerosis did not differ significantly from controls but decreased significantly in the symptomatic period after an inflection point of 0.25 years after symptom onset (clinic cohort) or 0.5 years before diagnosis (UK Biobank). These data provide further evidence for a pre-symptomatic period of dynamic metabolic change in amyotrophic lateral sclerosis, consistently associated with alterations in blood cholesterols. Such changes may ultimately contribute to biomarkers applicable to population screening and for pathways guiding the targeting of preventative therapy.

Metabolomics identifies shared lipid pathways in independent amyotrophic lateral sclerosis cohorts

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease lacking effective treatments. This is due, in part, to a complex and incompletely understood pathophysiology. To shed light, we conducted untargeted metabolomics on plasma from two independent cross-sectional ALS cohorts versus control participants to identify recurrent dysregulated metabolic pathways. Untargeted metabolomics was performed on plasma from two ALS cohorts (cohort 1, n = 125; cohort 2, n = 225) and healthy controls (cohort 1, n = 71; cohort 2, n = 104). Individual differential metabolites in ALS cases versus controls were assessed by Wilcoxon, adjusted logistic regression and partial least squares-discriminant analysis, while group lasso explored sub-pathway level differences. Adjustment parameters included age, sex and body mass index. Metabolomics pathway enrichment analysis was performed on metabolites selected using the above methods. Additionally, we conducted a sex sensitivity analysis due to sex imbalance in the cohort 2 control arm. Finally, a data-driven approach, differential network enrichment analysis (DNEA), was performed on a combined dataset to further identify important ALS metabolic pathways. Cohort 2 ALS participants were slightly older than the controls (64.0 versus 62.0 years, P = 0.009). Cohort 2 controls were over-represented in females (68%, P < 0.001). The most concordant cohort 1 and 2 pathways centred heavily on lipid sub-pathways, including complex and signalling lipid species and metabolic intermediates. There were differences in sub-pathways that were enriched in ALS females versus males, including in lipid sub-pathways. Finally, DNEA of the merged metabolite dataset of both ALS and control cohorts identified nine significant subnetworks; three centred on lipids and two encompassed a range of sub-pathways. In our analysis, we saw consistent and important shared metabolic sub-pathways in both ALS cohorts, particularly in lipids, further supporting their importance as ALS pathomechanisms and therapeutics targets.

Creatine kinase and prognosis in amyotrophic lateral sclerosis: a literature review and multi-centre cohort analysis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a prognostically heterogeneous neurodegenerative disease. Blood creatine kinase (CK) level has been inconsistently reported as a prognostic biomarker and raised levels in some ALS patients have been presumed to reflect muscle wasting, which is also variable.

METHODS

MEDLINE was systematically searched for papers related to CK in ALS and the relevant studies were reviewed. Using data from 222 ALS patients in a multi-centre, prospective, longitudinal cohort, survival analyses using Kaplan-Meier and Cox proportional hazards models were undertaken in relation to CK and other prognostic factors.

RESULTS

Twenty-five studies investigating CK in ALS were identified, of which 10 specifically studied the link between CK and survival. Five studies observed no association, four found that higher CK levels were associated with longer survival and one, the opposite. In our cohort (n = 222), 39% of patients had a CK level above the laboratory reference range. Levels were higher in males compared to females (p < 0.001), in patients with limb versus bulbar onset of symptoms (p < 0.001) and in patients with higher lower motor neuron burden (p < 0.001). There was no significant trend in longitudinal CK values. Although a higher standardised log (CK) at first visit was associated with longer survival in univariate analysis (hazard ratio 0.75, p = 0.003), there was no significant association after adjusting for other prognostic covariates.

CONCLUSION

While raised CK levels in ALS do reflect lower motor neuron denervation to a large extent, they are not independently associated with survival when measured in the symptomatic phase of the disease.

Analysis of routine blood parameters in patients with amyotrophic lateral sclerosis and evaluation of a possible correlation with disease progression—a multicenter study

Objective

Amyotrophic lateral sclerosis (ALS) pathogenesis is still unclear, its course is considerably variable, and prognosis is hard to determine. Despite much research, there is still a lack of easily accessible markers predicting prognosis. We investigated routine blood parameters in ALS patients regarding correlations with disease severity, progression rate, and survival. Additionally, we analyzed disease and patients' characteristics relating to baseline blood parameter levels.

Methods

We analyzed creatine kinase (CK), albumin (ALB), creatinine (CREA), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), and triglycerides (TG) levels around time of diagnosis in 1,084 ALS patients. We carried out linear regression analyses including disease and patients' characteristics with each blood parameter to detect correlations with them. Linear regression models were performed for ALSFRS-R at study entry, its retrospectively defined rate of decay and prospectively collected progression rate. Different survival analysis methods were used to examine associations between blood parameters and survival.

Results

We found higher CK (p-value 0.001), ALB (p-value <0.001), CREA (p-value <0.001), and HDL levels (p-value 0.044) at time of diagnosis being associated with better functional status according to ALSFRS-R scores at study entry. Additionally, higher CREA levels were associated with lower risk of death (p-value 0.003).

Conclusions

Our results indicate potential of CK, ALB, CREA, and HDL as disease severity or progression markers, and may also provide clues to ALS pathogenesis. However, these values are highly dependent on other variables, and further careful, longitudinal analyses will be necessary to prove the relevance of our findings.

Clinical implication of denervation in sporadic inclusion body myositis

INTRODUCTION

Sporadic inclusion body myositis (sIBM) is often accompanied by signs suggestive of denervation on electromyography (EMG), which mimics neurogenic disorders. Hence, the current study aimed to assess reinnervation after denervation in sIBM and its clinical impllcation.

METHODS

We retrospectively examined consecutive muscle biopsy specimens collected from 109 sIBM patients who were referred to our institution for diagnostic muscle biopsy from 2001 to 2018. Reinnervation after denervation in sIBM patients was assessed via muscle biopsy and EMG. The levels of acetylcholine receptor subunit γ (Chrng) and muscle-specific kinase (MuSK) mRNA, which are markers of denervation, were examined using real-time polymerase chain reaction. Response to treatment was defined as an increase of grade 1 or higher in two or more muscle groups as assessed using the Medical Research Council scale.

RESULTS

In total, 93 (85.3%) of 109 sIBM patients had reinnervation after denervation on histological examination and/or EMG. The mean disease duration before biopsy was significantly longer in patients with reinnervation after denervation than in those without (p < 0.00001). Patients with denervation had significantly higher levels of Chrng and MuSK mRNA than those without. The proportion of patients who responded to immunosuppressive therapies was smaller in the patients with denervation than those without (p < 0.05). However, there was no significant difference regarding time from onset to using a walking aid between the two groups.

DISCUSSION

Reinnervation after denervation is associated with disease duration and short-term response to therapy in individuals with sIBM.

A phase II open label clinical study of the safety, tolerability and efficacy of ILB® for Amyotrophic Lateral Sclerosis

Introduction

Amyotrophic lateral sclerosis (ALS) is an invariably lethal progressive disease, causing degeneration of neurons and muscle. No current treatment halts or reverses disease advance. This single arm, open label, clinical trial in patients with ALS investigated the safety and tolerability of a novel modified low molecular weight dextran sulphate (LMW-DS, named ILB^®) previously proven safe for use in healthy volunteers and shown to exert potent neurotrophic effects in pre-clinical studies. Secondary endpoints relate to efficacy and exploratory biomarkers.

Methods

Thirteen patients with ALS were treated with 5 weekly subcutaneous injections of ILB^®. Safety and efficacy outcome measures were recorded weekly during treatment and at regular intervals for a further 70 days. Functional and laboratory biomarkers were assessed before, during and after treatment.

Results

No deaths, serious adverse events or participant withdrawals occurred during or after ILB^® treatment and no significant drug-related changes in blood safety markers were evident, demonstrating safety and tolerability of the drug in this cohort of patients with ALS. The PK of ILB^® in patients with ALS was similar to that seen in healthy controls. The ILB^® injection elicited a transient elevation of plasma Hepatocyte Growth Factor, a neurotrophic and myogenic growth factor. Following the ILB^® injections patients reported increased vitality, decreased spasticity and increased mobility. The ALSFRS-R rating improved from 36.31 ± 6.66 to 38.77 ± 6.44 and the Norris rating also improved from 70.61 ± 13.91 to 77.85 ± 14.24 by Day 36. The improvement of functions was associated with a decrease in muscle atrophy biomarkers. These therapeutic benefits decreased 3–4 weeks after the last dosage.

Conclusions

This pilot clinical study demonstrates safety and tolerability of ILB^® in patients with ALS. The exploratory biomarker and functional measures must be cautiously interpreted but suggest clinical benefit and have a bearing on the mechanism of action of ILB^®. The results support the drug’s potential as the first disease modifying treatment for patients with ALS.

Trial registration

EudraCT 2017-005065-47.

Combined Treatment with Bojungikgi-Tang and Riluzole Regulates Muscle Metabolism and Dysfunction in the hSOD1G93A Mouse Model

The progressive neurodegenerative disease, amyotrophic lateral sclerosis (ALS), is characterized by muscle weakness and atrophy owing to selective motoneuron degeneration. The anti-glutamatergic drug, riluzole (RZ), is the standard-of-care treatment for ALS. Bojungikgi-tang (BJIGT), a traditional herbal formula, improves motor function and prolongs the survival of mice with ALS. As ALS is a multicomplex disease, effective therapies must target multiple mechanisms. Here, we evaluated the efficacy of a BJIGT/RZ combination (5-week treatment) in 2-month-old hSOD1^G93A mice with ALS. We performed quantitative polymerase chain reaction, Western blotting, immunohistochemistry, and enzyme activity assays. BJIGT/RZ significantly attenuated inflammation, autophagy, and metabolic and mitochondrial dysfunctions in the gastrocnemius (GC) compared with the control. It reduced the mRNA and protein levels of muscle denervation-related proteins and creatine kinase levels. The total creatine level was significantly higher in the BJIGT/RZ-treated GC. Moreover, after BJIGT/RZ treatment, the number of Nissl-stained motoneurons and choline acetyl transferase-positive neurons in the spinal cord significantly increased via the regulation of proinflammatory cytokines. Collectively, the BJIGT/RZ treatment was superior to single-drug treatments in alleviating multiple ALS-related pathological mechanisms in the ALS mouse model. Overall, BJIGT can serve as a dietary supplement and be combined with RZ to achieve superior therapeutic effects against ALS.

Swim training affects Akt signaling and ameliorates loss of skeletal muscle mass in a mouse model of amyotrophic lateral sclerosis

We tested the hypothesis that swim training reverses the impairment of Akt/FOXO3a signaling, ameliorating muscle atrophy in ALS mice. Transgenic male mice B6SJL-Tg (SOD1^G93A) 1Gur/J were used as the ALS model (n = 35), with wild-type B6SJL (WT) mice as controls (n = 7). ALS mice were analyzed before ALS onset, at ALS onset, and at terminal ALS. Levels of insulin/Akt signaling pathway proteins were determined, and the body and tibialis anterior muscle mass and plasma creatine kinase. Significantly increased levels of FOXO3a in ALS groups (from about 13 to 21-fold) compared to WT mice were observed. MuRF1 levels in the ONSET untrained group (12.0 ± 1.7 AU) were significantly higher than in WT mice (1.12 ± 0.2 AU) and in the BEFORE ALS group (3.7 ± 0.9 AU). This was associated with body mass and skeletal muscle mass reduction. Swim training significantly ameliorated the reduction of skeletal muscle mass in both TERMINAL groups (p < 0.001) and partially reversed changes in the levels of Akt signaling pathway proteins. These findings shed light on the swimming-induced attenuation of skeletal muscle atrophy in ALS with possible practical implications for anti-cachexia approaches.

Ratio of urinary N-terminal titin fragment to urinary creatinine is a novel biomarker for amyotrophic lateral sclerosis

OBJECTIVE

We aimed to investigate the validity of urinary N-terminal titin fragment as a biomarker for amyotrophic lateral sclerosis (ALS).

METHODS

We consecutively enrolled patients with ALS (n=70) and healthy controls (HC) (n=43). We assessed the urinary titin N-terminal fragment, urinary neurotrophin receptor p75 extracellular domain, serum neurofilament light chain (NfL), motor functional measurements and prognosis. We used urinary creatinine (Cr) levels to normalise the urinary levels of titin fragment.

RESULTS

Compared with HC, patients with ALS had significantly increased urinary levels of titin N-terminal fragment normalised with Cr (titin/Cr) (ALS, 27.2 pmol/mg/dL; HC, 5.8 pmol/mg/dL; p<0.001), which were correlated with the scores of the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (r=-0.422, p<0.001). A Cox proportional hazards model demonstrated that the high urinary level of titin/Cr was a survival predictor in patients with ALS. Multivariate analysis of prognostic factors showed that the urinary titin/Cr and serum NfL were independent factors for poor prognosis.

CONCLUSIONS

Our findings indicate that urinary N-terminal titin fragment is a non-invasive measure of muscle damage in ALS, which could be applied in disease monitoring and prediction of disease progression, in combination with serum NfL.

Serum creatine kinase and creatinine in adult spinal muscular atrophy under nusinersen treatment

OBJECTIVE

To determine whether serum creatine kinase activity (CK) and serum creatinine concentration (Crn) are prognostic and predictive biomarkers for disease severity, disease progression, and nusinersen treatment effects in adult patients with 5q-associated spinal muscular atrophy (SMA).

METHODS

Within this retrospective, multicenter observational study in 206 adult patients with SMA, we determined clinical subtypes (SMA types, ambulatory ability) and repeatedly measured CK and Crn and examined disease severity scores (Hammersmith Functional Motor Scale Expanded, Revised Upper Limb Module, and revised Amyotrophic Lateral Sclerosis Functional Rating Scale). Patients were followed under nusinersen treatment for 18 months.

RESULTS

CK and Crn differed between clinical subtypes and correlated strongly with disease severity scores (e.g., for Hammersmith Functional Motor Scale Expanded: (CK) ρ = 0.786/ (Crn) ρ = 0.558). During the 18 months of nusinersen treatment, CK decreased (∆CK = -17.56%, p < 0.0001), whereas Crn slightly increased (∆Crn = +4.75%, p < 0.05).

INTERPRETATION

Serum creatine kinase activity and serum creatinine concentration reflect disease severity of spinal muscular atrophy and are promising biomarkers to assess patients with spinal muscular atrophy during disease course and to predict treatment response. The decrease of creatine kinase activity, combined with the tendency of creatinine concentration to increase during nusinersen treatment, suggests reduced muscle mass wasting with improved muscle energy metabolism.

Decreased serum creatinine levels predict short survival in amyotrophic lateral sclerosis

Objective

To explore the associations between serum creatinine and creatine kinase (CK) levels with survival in male and female ALS patients.

Methods

A prospective cohort study was carried out including 346 ALS patients with repeated serum creatinine and CK measurements. Kaplan Meier analysis and multivariable Cox regression were used to perform survival analysis.

Results

There were 218 male and 128 female patients, and the males had significantly higher baseline serum creatinine and CK levels than females. After multivariable Cox regression analysis, lower baseline serum creatinine levels were associated with a short survival in both male (≤61 μmol/L, HR: 1.629; 95%CI: 1.168–2.273) and female ALS patients (≤52 μmol/L, HR: 1.677; 95%CI: 1.042–2.699), whereas, the serum CK levels were not correlated with survival. Besides, creatinine levels were positively associated with ALSFRS‐R scores, and inversely with the decline rate of ALSFRS‐R per month. During follow‐up, serum creatinine levels tended to be decreased along with the disease progression, and the higher decline rate of creatinine per month (>1.5) showed significantly shorter survival, compared to the lower group (≤1.5) (30.0 months vs. 65.0 months, Chi square = 28.25, P < 0.0001).

Interpretation

Serum creatinine could be a reliable and easily accessible prognostic chemical marker for ALS, and decreased baseline creatinine levels could predict a poor prognosis and a short survival in both male and female ALS patients.

Aberrations of biochemical indicators in amyotrophic lateral sclerosis: a systematic review and meta-analysis

Accumulating evidence has suggested that the pathological changes in amyotrophic lateral sclerosis (ALS) are not only confined to the central nervous system but also occur in the peripheral circulating system. Here, we performed a meta-analysis based on the PubMed, EMBASE, EBSCO, and CNKI databases, to find out biochemical indicators associated with energy metabolism, iron homeostasis, and muscle injury that are altered in ALS patients and their correlations with ALS phenotypes. Forty-six studies covering 17 biochemical indicators, representing 5454 ALS patients and 7986 control subjects, were included in this meta-analysis. Four indicators, including fasting blood glucose level (weighted mean difference [WMD] = 0.13, 95% CI [0.06–0.21], p = 0.001), serum ferritin level (WMD = 63.42, 95% CI [48.12–78.73], p < 0.001), transferrin saturation coefficient level (WMD = 2.79, 95% CI [1.52–4.05], p < 0.001), and creatine kinase level (WMD = 80.29, 95% CI [32.90–127.67], p < 0.001), were significantly higher in the ALS patients, whereas the total iron-binding capacity (WMD = − 2.42, 95% CI [− 3.93, − 0.90], p = 0.002) was significantly lower in ALS patients than in the control subjects. In contrast, the other 12 candidates did not show significant differences between ALS patients and controls. Moreover, pooled hazard ratios (HR) showed significantly reduced survival (HR = 1.38, 95% CI [1.02–1.88], p = 0.039) of ALS patients with elevated serum ferritin levels. These findings suggest that abnormalities in energy metabolism and disruption of iron homeostasis are involved in the pathogenesis of ALS. In addition, the serum ferritin level is negatively associated with the overall survival of ALS patients.

Untargeted metabolomics yields insight into ALS disease mechanisms

OBJECTIVE

To identify dysregulated metabolic pathways in amyotrophic lateral sclerosis (ALS) versus control participants through untargeted metabolomics.

METHODS

Untargeted metabolomics was performed on plasma from ALS participants (n=125) around 6.8 months after diagnosis and healthy controls (n=71). Individual differential metabolites in ALS cases versus controls were assessed by Wilcoxon rank-sum tests, adjusted logistic regression and partial least squares-discriminant analysis (PLS-DA), while group lasso explored sub-pathway-level differences. Adjustment parameters included sex, age and body mass index (BMI). Metabolomics pathway enrichment analysis was performed on metabolites selected by the above methods. Finally, machine learning classification algorithms applied to group lasso-selected metabolites were evaluated for classifying case status.

RESULTS

There were no group differences in sex, age and BMI. Significant metabolites selected were 303 by Wilcoxon, 300 by logistic regression, 295 by PLS-DA and 259 by group lasso, corresponding to 11, 13, 12 and 22 enriched sub-pathways, respectively. 'Benzoate metabolism', 'ceramides', 'creatine metabolism', 'fatty acid metabolism (acyl carnitine, polyunsaturated)' and 'hexosylceramides' sub-pathways were enriched by all methods, and 'sphingomyelins' by all but Wilcoxon, indicating these pathways significantly associate with ALS. Finally, machine learning prediction of ALS cases using group lasso-selected metabolites achieved the best performance by regularised logistic regression with elastic net regularisation, with an area under the curve of 0.98 and specificity of 83%.

CONCLUSION

In our analysis, ALS led to significant metabolic pathway alterations, which had correlations to known ALS pathomechanisms in the basic and clinical literature, and may represent important targets for future ALS therapeutics.

Serum creatinine levels in patients with amyotrophic lateral sclerosis: a systematic review and meta-analysis

BACKGROUND

Serum creatinine (Cr) is a biosynthetic product of creatine phosphate metabolism in muscles and is closely related to total muscle mass, but it is not easily affected by diet. Several studies have tried to explore the role of serum Cr levels in amyotrophic lateral sclerosis (ALS), but the results were inconsistent. Therefore, our study aims to explore the differences of serum Cr levels between ALS patients and controls and whether serum Cr at baseline is an independent predictor of survival. Methods: We searched all the related studies that probed into the association between Serum Cr levels and ALS based on PubMed, EMBASE and Cochrane library from October 1952 to February 2019. The quality of the included studies was evaluated by using Newcastle-Ottawa Scale (NOS), and all the statistical analysis of this meta-analysis was performed by Stata version 12.0. Results: Eight studies with a total of 11377 ALS patients and 937 controls were included. Among them, five studies indicated that ALS patients had lower serum Cr levels (SMD = -0.78, 95%CI [-0.97, -0.60]) compared to controls, and three studies showed that higher serum Cr levels in ALS patients were related to lower overall mortality (HR 0.89, 95%CI [0.80, 0.99]). Conclusion: The levels of serum Cr in ALS patients are significantly lower than those in controls, and they are inversely related to overall mortality in ALS patients. Therefore, the serum Cr, an easily accessible serological factor, may serve as a prognostic biomarker.