C-reactive protein levels in patients with amyotrophic lateral sclerosis: A systematic review

Effect of sodium phenylbutyrate and taurursodiol on plasma concentrations of neuroinflammatory biomarkers in amyotrophic lateral sclerosis: results from the CENTAUR trial

BACKGROUND

An oral sodium phenylbutyrate and taurursodiol combination (PB and TURSO) significantly reduced functional decline in people living with amyotrophic lateral sclerosis (ALS) in the CENTAUR trial. Biomarkers linking clinical therapeutic effect with biological changes are of high interest in ALS. We performed analyses of neuroinflammatory biomarkers associated with ALS in the literature, including YKL-40 (also known as chitinase-3-like protein 1), chitinase 1 (CHIT1) and C reactive protein (CRP), in plasma samples collected in CENTAUR.

METHODS

Log10-transformed plasma biomarker measurements were analysed using a linear mixed-effects model. Correlation between paired biomarker concentrations and ALS Functional Rating Scale-Revised (ALSFRS-R) total scores was assessed via Pearson correlation coefficients.

RESULTS

By week 24, geometric least squares mean YKL-40 plasma concentration decreased by approximately 20% (p=0.008) and CRP by 30% (p=0.048) in the PB and TURSO versus placebo group. YKL-40 (r of -0.21; p<0.0001) and CRP (r of -0.19; p=0.0002) concentration correlated with ALSFRS-R total score. CHIT1 levels were not significantly different between groups.

CONCLUSIONS

YKL-40 and CRP plasma levels were significantly reduced in participants with ALS receiving PB and TURSO in CENTAUR and correlated with disease progression. These findings suggest YKL-40 and CRP could be treatment-sensitive biomarkers in ALS, pending further confirmatory studies.

TRIAL REGISTRATION NUMBER

https://clinicaltrials.gov/study/NCT03127514.

Unraveling the Heterogeneity of ALS-A Call to Redefine Patient Stratification for Better Outcomes in Clinical Trials

Despite tremendous efforts in basic research and a growing number of clinical trials aiming to find effective treatments, amyotrophic lateral sclerosis (ALS) remains an incurable disease. One possible reason for the lack of effective causative treatment options is that ALS may not be a single disease entity but rather may represent a clinical syndrome, with diverse genetic and molecular causes, histopathological alterations, and subsequent clinical presentations contributing to its complexity and variability among individuals. Defining a way to subcluster ALS patients is becoming a central endeavor in the field. Identifying specific clusters and applying them in clinical trials could enable the development of more effective treatments. This review aims to summarize the available data on heterogeneity in ALS with regard to various aspects, e.g., clinical, genetic, and molecular.

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.

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.

Neutrophils Are Associated with Higher Risk of Incident Amyotrophic Lateral Sclerosis in a BMI- and Age-Dependent Manner

OBJECTIVE

Peripheral immune markers have been associated with the progression and prognosis of amyotrophic lateral sclerosis (ALS). However, whether dysregulation of peripheral immunity is a risk factor for ALS or a consequence of motor neuron degeneration has not yet been clarified. We aimed to identify longitudinal associations between prediagnostic peripheral immunity and the risk of incident ALS.

METHODS

A total of 345,000 individuals from the UK Biobank between 2006 and 2010 were included at the baseline. The counts of peripheral immune markers (neutrophils, lymphocytes, monocytes, platelets, and CRP) and its derived metrics (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], lymphocyte-to-monocyte ratio [LMR], and systemic immune-inflammation index [SII]) were analyzed in relation to the following incident ALS by Cox proportional hazard models. Subgroup and interaction analyses were performed to explore the covariates of these relationships further.

RESULTS

After adjusting for all covariates, the multivariate analysis showed that high neutrophil counts and their derived metrics (NLR and SII) were associated with an increased risk of ALS incidence (per SD increment hazard ratio [HR] = 1.15, 95% confidence interval [CI] = 1.02-1.29 for neutrophils; HR = 1.15, 95% CI = 1.03-1.28 for NLR; and HR = 1.17, 95% CI = 1.05-1.30 for SII). Subgroup and interaction analyses revealed that body mass index (BMI) and age had specific effects on this association. In participants with BMI ≥ 25 or age < 65 years, higher neutrophil counts, and their metrics increased the risk of incident ALS; however, in participants with BMI < 25 or age ≥ 65 years, neutrophils had no effect on incident ALS.

INTERPRETATION

Our study provides evidence that increased neutrophil levels and neutrophil-derived metrics (NLR and SII) are associated with an increased risk of developing ALS. ANN NEUROL 2023;94:942-954.

Urinary biomarkers for amyotrophic lateral sclerosis: candidates, opportunities and considerations

Amyotrophic lateral sclerosis is a relentless neurodegenerative disease that is mostly fatal within 3-5 years and is diagnosed on evidence of progressive upper and lower motor neuron degeneration. Around 15% of those with amyotrophic lateral sclerosis also have frontotemporal degeneration, and gene mutations account for ∼10%. Amyotrophic lateral sclerosis is a variable heterogeneous disease, and it is becoming increasingly clear that numerous different disease processes culminate in the final degeneration of motor neurons. There is a profound need to clearly articulate and measure pathological process that occurs. Such information is needed to tailor treatments to individuals with amyotrophic lateral sclerosis according to an individual's pathological fingerprint. For new candidate therapies, there is also a need for methods to select patients according to expected treatment outcomes and measure the success, or not, of treatments. Biomarkers are essential tools to fulfil these needs, and urine is a rich source for candidate biofluid biomarkers. This review will describe promising candidate urinary biomarkers of amyotrophic lateral sclerosis and other possible urinary candidates in future areas of investigation as well as the limitations of urinary biomarkers.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Regulation of the Innate Immune System as a Therapeutic Approach to Supporting Respiratory Function in ALS

Amyotrophic lateral sclerosis (ALS) is a clinical diagnosis used to define a neurodegenerative process that involves progressive loss of voluntary muscle function and leads to death within 2–5 years after diagnosis, in most cases because of respiratory function failure. Respiratory vital capacity (VC) measurements are reproducible and strong predictors of survival. To understand the role of the innate immune response in progressive VC loss we evaluated ALS clinical trial and biomarker results from a 6-month phase 2 study of NP001, a regulator of innate immune function. All ALS baseline values were similar between treated and controls except for those > 65 years old who were excluded from analysis. Treated patients with plasma CRP ≥ 1.13 mg/L (high CRP) showed a 64% slower rate of VC decline compared with placebo and those with plasma CRP < 1.13 mg/L (low CRP) who showed no response. High CRP patients showed no age associated loss of VC whereas low CRP patients showed an age dependent loss of VC function. Plasma levels of serum amyloid A (SAA) were similarly elevated in high CRP patients consistent with ongoing innate immune activation. Plasma TGFB1 in high CRP treated patients was 95% higher than placebo at 6-months, confirming the activation and release of this anti-inflammatory factor by the innate immune alpha 2 macroglobulin (A2M) system. This report is the first to link a biomarker confirmed regulation of the innate immune system with a therapeutic approach for controlling VC loss in ALS patients.

Inflammatory checkpoints in amyotrophic lateral sclerosis: From biomarkers to therapeutic targets

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive motor neuron damage. Due to the complexity of the ALS, so far the etiology and underlying pathogenesis of sporadic ALS are not completely understood. Recently, many studies have emphasized the role of inflammatory networks, which are comprised of various inflammatory molecules and proteins in the pathogenesis of ALS. Inflammatory molecules and proteins may be used as independent predictors of patient survival and might be used in patient stratification and in evaluating the therapeutic response in clinical trials. This review article describes the latest advances in various inflammatory markers in ALS and its animal models. In particular, this review discusses the role of inflammatory molecule markers in the pathogenesis of the disease and their relationship with clinical parameters. We also highlight the advantages and disadvantages of applying inflammatory markers in clinical manifestations, animal studies, and drug clinical trials. Further, we summarize the potential application of some inflammatory biomarkers as new therapeutic targets and therapeutic strategies, which would perhaps expand the therapeutic interventions for ALS.

miRNA extracted from extracellular vesicles is a robust biomarker of amyotrophic lateral sclerosis

BACKGROUND AND OBJECTIVES

We examined miRNA biomarkers for ALS extracted from extracellular vesicles in blood samples using a large and diverse patient and control population. Different blood collection and storage protocols by different investigators could impact repeatability of miRNA analysis. We tested the hypotheses that miRNA extracted from extracellular vesicles using immunoaffinity purification techniques are robust and repeatable across investigators, laboratories and in a broad ALS population.

METHODS

De-identified patient blood plasma samples obtained from the U.S. National ALS Biorepository were compared with plasma from non-ALS controls. Extracellular vesicles were extracted and isolated using L1CAM immunoaffinity purification. Total RNA was extracted, and miRNA quantified using qPCR following careful quality control measures. Gene fold expressions of eight miRNAs were compared using a Mann-Whitney two-tailed test.

RESULTS

One hundred blinded, blood plasma samples were analyzed. Thirty-five men and 15 women with ALS were compared with controls consisting of 30 men and 20 women. None of the ALS patient cohort reported family members with ALS suggesting sporadic ALS. Five of the eight biomarkers previously published were found to significantly discriminate ALS patient samples from control samples.

DISCUSSION

The methods used in this study provide a repeatable measure of miRNA biomarkers that statistically differentiate ALS patient samples from control samples. The broad inclusion criteria for both the ALS patient cohort and controls along with the collection of blood samples by different investigators suggest that these methods are robust and represent good candidates for further research and development aimed at clinical application.

Biomarkers and molecular mechanisms of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease in adults involving non-demyelinating motor disorders. About 90% of ALS cases are sporadic, while 10-12% of cases are due to some genetic reasons. Mutations in superoxide dismutase 1 (SOD1), TAR, c9orf72 (chromosome 9 open reading frame 72) and VAPB genes are commonly found in ALS patients. Therefore, the mechanism of ALS development involves oxidative stress, endoplasmic reticulum stress, glutamate excitotoxicity and aggregation of proteins, neuro-inflammation and defective RNA function. Cholesterol and LDL/HDL levels are also associated with ALS development. As a result, sterols could be a suitable biomarker for this ailment. The main mechanisms of ALS development are reticulum stress, neuroinflammation and RNA metabolism. The multi-nature development of ALS makes it more challenging to pinpoint a treatment.

Label-free fibre optic Raman spectroscopy with bounded simplex-structured matrix factorization for the serial study of serum in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease in urgent need of disease biomarkers for the assessment of promising therapeutic candidates in clinical trials. Raman spectroscopy is an attractive technique for identifying disease related molecular changes due to its simplicity. Here, we describe a fibre optic fluid cell for undertaking spontaneous Raman spectroscopy studies of human biofluids that is suitable for use away from a standard laboratory setting. Using this system, we examined serum obtained from patients with ALS at their first presentation to our centre (n = 66) and 4 months later (n = 27). We analysed Raman spectra using bounded simplex-structured matrix factorization (BSSMF), a generalisation of non-negative matrix factorisation which uses the distribution of the original data to limit the factorisation modes (spectral patterns). Biomarkers associated with ALS disease such as measures of symptom severity, respiratory function and inflammatory/immune pathways (C3/C-reactive protein) correlated with baseline Raman modes. Between visit spectral changes were highly significant (p = 0.0002) and were related to protein structure. Comparison of Raman data with established ALS biomarkers as a trial outcome measure demonstrated a reduction in required sample size with BSSMF Raman. Our portable, simple to use fibre optic system allied to BSSMF shows promise in the quantification of disease-related changes in ALS over short timescales.

Diagnoses Based on C-Reactive Protein Point-of-Care Tests

C-reactive protein (CRP) is an important part of the immune system's reaction to various pathological impulses such as bacterial infections, systemic inflammation, and internal organ failures. An increased CRP level serves to diagnose the mentioned pathological states. Both standard laboratory methods and simple point-of-care devices such as lateral flow tests and immunoturbidimetric assays serve for the instrumental diagnoses based on CRP. The current method for CRP has many flaws and limitations in its use. Biosensor and bioassay analytical devices are presently researched by many teams to provide more sensitive and better-suited tools for point-of-care tests of CRP in biological samples when compared to the standard methods. This review article is focused on mapping the diagnostical relevance of CRP, the applicability of the current analytical methods, and the recent innovations in the measurement of CRP level.