The Application Of The Technology Of Surface Enhanced Raman Spectroscopy In Amyotrophic Lateral Sclerosis

Background: Amyotrophic lateral sclerosis(ALS)is the most common adult-onset motor neuron disease,the prognosis of ALS is poor,which ultimately leads to death due to respiratory failure usually 3–5 years after the appearance of first symptoms.The clinical manifestations of the disease are very heterogeneity and progresses varies widely,lifetime ranges from 6 months to decades.Raman spectroscopy can provide molecular vibration/rotation spectroscopy information,surface-enhanced Raman spectroscopy analysis technique is gaining a wider use in Life Sciences due to its advantages of non-destructive,no sample preparation,rich information etc.To explore prognostic factors related to short survival times in sporadic amyotrophic lateral sclerosis(ALS)patients based on clinical features and plasma metabolic signatures using SERS.Methods: Patients were recruited serially from the Department of Neurology,First Affiliated Hospital of Fujian Medical University from December 2014 to June 2018,and their results of laboratory examinations were recorded at diagnosis.Univariate and multivariate logistic regression models were employed to explore the association between potential factors(Age of onset,gender,diagnostic level,ALSFRS-R score,FVC,riluzole,serum CK,ALB,TC,TG,HDL,LDL,Apo-A1,Cr,UA)and the progression of ALS.With the silver nanoparticles(NPs)as enhancement substrate,SERS was used to examine the blood plasma of ALS patients(138 cases).Statistical analyses of whole SERS spectra and band intensities between the short-duration and long-duration groups were evaluated using the Wilcoxon rank sum test,principal components analysis(PCA),and decision trees(DT).Results: One hundred thirty-eight sporadic ALS cases were included in the statistics:62 for the short-duration group(?3 years)and 76 for the long-duration group(>3years),based on the time between symptom onset and tracheotomy or death.1.Comparisons between the short-duration and the long-duration group according to gender,site of onset,diagnosis level,use of riluzole and levels of TC,TG,HDL,LDL,Apo-A1,ALB,CK,and Cr showed no significant differences.Conversely,age of onset,BMI,FVC,ALSFRS-R score,diagnostic delay and level of blood UA were significantly different between groups(P < 0.05).Multivariate analysis showed that an older age of onset(>60 years;odds ratio [OR] = 3.98,95% CI:1.09–14.53),lower BMI(<18.5;OR = 6.80,95% CI: 1.36–33.92),and lower ALSFRS-R score(<35;OR = 6.03,95% CI: 1.42–25.63)were associated with higher odds of tracheotomy or death.The increased diagnostic delay(>10 months;OR = 0.16,95%CI 0.05-0.50)and the higher blood UA level(OR = 0.19,95%CI 0.05-0.73).was inversely associated with the odds of tracheostomy or death.2.After statistical analysis,SERS spectra showed significant differences with high sensitivity and specificity.SERS measurements also showed a broad dysregulation of amino acid,nucleic acid,glucose,and oxidant-antioxidant homeostasis.Typical pathways that were determined to be associated with disease progression were pyrimidine metabolism and purine metabolism(nucleic acid);glutathione metabolism(antioxidant);phenylalanine metabolism and phenylalanine,tyrosine and tryptophan biosynthesis(amino acid);galactose metabolism(glucose);together with porphyrin and chlorophyll metabolismConclusions: Age of onset,BMI,FVC,ALSFRS-R score,diagnostic delay and UA were associated with the survival time of ALS and are therefore potential therapeutic targets for sporadic ALS.Dysregulation of glucose,amino acid,and antioxidant metabolism contributed to disease progression.SERS could serve as a potential tool to rapidly and accurately distinguish the duration of ALS patients,which may become a clinical classification and stratification method for ALS.