Biomarkers of Guillain-Barré Syndrome: Some Recent Progress, More Still to Be Explored

Increased Cerebrospinal Fluid Adenosine 5'-Triphosphate Levels in Patients with Guillain-Barré Syndrome and Chronic Inflammatory Demyelinating Polyneuropathy

Background

Extracellular adenosine 5'-triphosphate (ATP) acts as a signaling molecule in the peripheral nerves, regulating myelination after nerve injury. The present study examined whether the cerebrospinal fluid (CSF) ATP levels in patients with Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) are related to disease severity.

Methods

CSF ATP levels in 13 patients with GBS and 18 patients with CIDP were compared with those in a control group of 16 patients with other neurological diseases (ONDs). In patients with CIDP, CSF ATP levels were compared before and after treatment. The correlations between CSF ATP levels and other factors, including clinical data and CSF protein levels, were also evaluated.

Results

Median CSF ATP levels were significantly higher in patients with GBS and CIDP than in those with ONDs. When patients with CIDP were classified into two groups depending on their responsiveness to immunotherapy, median CSF ATP levels were significantly higher in good responders than in ONDs. CSF ATP levels tended to decrease after treatment in patients with CIDP. In patients with CIDP, there is a negative correlation between CSF ATP and CSF protein levels.

Conclusions

CSF ATP levels were increased in patients with GBS and CIDP. In particular, CSF ATP levels tended to decrease following treatment in patients with CIDP. CSF ATP levels may be useful biomarkers for the diagnosis or monitoring of therapeutic effects in patients with GBS and CIDP.

Current Biomarker Strategies in Autoimmune Neuromuscular Diseases

Inflammatory neuromuscular disorders encompass a diverse group of immune-mediated diseases with varying clinical manifestations and treatment responses. The identification of specific biomarkers has the potential to provide valuable insights into disease pathogenesis, aid in accurate diagnosis, predict disease course, and monitor treatment efficacy. However, the rarity and heterogeneity of these disorders pose significant challenges in the identification and implementation of reliable biomarkers. Here, we aim to provide a comprehensive review of biomarkers currently established in Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), myasthenia gravis (MG), and idiopathic inflammatory myopathy (IIM). It highlights the existing biomarkers in these disorders, including diagnostic, prognostic, predictive and monitoring biomarkers, while emphasizing the unmet need for additional specific biomarkers. The limitations and challenges associated with the current biomarkers are discussed, and the potential implications for disease management and personalized treatment strategies are explored. Collectively, biomarkers have the potential to improve the management of inflammatory neuromuscular disorders. However, novel strategies and further research are needed to establish clinically meaningful biomarkers.

Guillain-Barré Syndrome in Adults in a Decade: The Largest, Single-Center, Cross-Sectional Study From the Kingdom of Saudi Arabia

BACKGROUND

Guillain-Barré Syndrome (GBS) is the most common cause of acute, usually post-infectious, peripheral neuropathy resulting in a symmetrical, ascending paralysis. We evaluated the clinical and neurophysiological features, treatment, and outcomes of patients with GBS in our center.

METHODS

A retrospective chart review on patients with GBS admitted to King Abdulaziz Medical City, Riyadh, Saudi Arabia, from January 2011 to December 2020. Data were analyzed using JMP statistical software version 15 pro.

RESULTS

A total of 86 patients who met the criteria were included, 55 (64%) were males, with a mean age of 49.5+/-17.5 years. Antecedent infection was reported in 53 (61.6%), 51 (62.2%) presented within one week of symptoms onset. Ascending weakness was seen in 55 (70.5%), while 70 (81.4%) had areflexia. Acute motor axonal neuropathy (AMAN) was the commonest electrophysiological type of GBS in 41 (51.9%) patients. Albuminocytologic dissociation was seen in 48 (57%) who had lumbar puncture. Nearly half, 41 (47.7%) were admitted to the intensive care unit (ICU). Seventy (81.3%) were treated with intravenous immunoglobulin. There was no significant difference in the clinical presentation, management, ICU requirement, and discharge disposition between males and females. Females were more likely to have a higher disability at discharge (p=0.01). Patients younger than 60 years were more likely to require ICU admission (p=<0.01).

CONCLUSION

Our patients with GBS were slightly older than previously reported from the region. AMAN was the commonest type of GBS. Younger patients were more likely to need ICU admission, whereas females were more likely to have a more severe disability.

Sural Sparing Pattern and Sensory Ratio as Electrodiagnostic and Prognostic Markers in Pediatric Guillain-Barré Syndrome

BACKGROUND

We aimed to evaluate the presence of sural sparing pattern (SSP) and sensory ratio in pediatric Guillain-Barré syndrome (GBS), their distribution to subtypes, and their relationship with demographic and clinical features with a focus on the disability and muscle strength.

METHODS

This single-center retrospective study was conducted on pediatric GBS patients of both sexes with 2 years follow-up and two nerve conduction studies in which SSP and sensory ratio were calculated. Three subgroups of SSP were formed by separate calculation of median (SSP-m) and ulnar (SSP-u) and both median and ulnar sensory nerve action potentials (SNAPs; SSP-total). Muscle strength and disability were evaluated with the Medical Research Council (MRC) sum score and Hughes functional grading scale (HFGS), respectively.

RESULTS

SSP total was identified in 70.6% (n: 24) of the patients, while sensory ratio >1 was observed in 20 (66.7%) patients. Patients with SSP-m, SSP-u, SSP-total, or sensory ratio >1 had higher HFGS scores, while patients with SSP-m, SSP-u, or SSP-total had lower MRC sum scores. SSP parameters were significantly associated with muscle strength and disability scores in acute motor axonal neuropathy patients.

CONCLUSION

Both SSP and sensory ratio can be used for diagnostic and prognostic purposes. Disability and muscle strength are associated with SSP and sensory ratio in pediatric GBS.

Elevated monocyte to high-density lipoprotein cholesterol ratio correlates with clinical severity in acute inflammatory demyelinating polyradiculoneuropathy patients

While monocyte to high-density lipoprotein cholesterol ratio (MHR) has been reported to be associated with nervous system lesions, the role of MHR has not been determined in patients with Guillain-Barré Syndrome (GBS). The purpose of our study was to explore the role of MHR in patients with GBS. A total of 52 GBS patients were involved in the study retrospectively, including patients with acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor axonal neuropathy (AMAN), and acute motor sensory axonal neuropathy (AMSAN). We used Hughes Functional Grading Scale (HFGS) score to evaluate functional status in GBS patients. Among patients with different subtypes of GBS, MHR was significantly elevated in those with demyelination compared to patients without demyelination (p < 0.001); AIDP patients had an increased MHR compared with AMAN or AMSAN patients (p = 0.001; p = 0.013). There was a positive correlation between MHR and HFGS score (r = 0.463, p = 0.006) in AIDP patients, but not in AMAN or AMSAN. Multiple linear regression analysis revealed that MHR was independently associated with HFGS score (beta = 0.405, p = 0.013) in AIDP patients. Our study suggests that MHR as an inflammatory marker is elevated in patients with AIDP compared to AMAN or AMSAN patients, while MHR has a positive correlation with clinical severity in AIDP patients, suggesting that MHR may provide an additional information to reflect the pathophysiology of AIDP.

Role of altered IL-33/ST2 immune axis in the immunobiology of Guillain-Barré syndrome

BACKGROUND

IL-33/ST2 immune axis plays crucial roles in infection and immunity. A dysregulated IL-33/ST2 axis can induce autoimmune reaction and inflammatory responses. Guillain-Barré Syndrome (GBS) is an acute peripheral neuropathy, mostly caused by post-infection autoimmunity. The role of IL-33/ST2 axis is not known in GBS. This study aimed to explore the role of IL-33/ST2 axis in GBS.

METHODS

Three single nucleotide polymorphisms (SNPs) of Il33 gene (rs16924159; rs7044343; rs1342336) and three SNPs of Il1rl1 gene (rs10192157, rs1041973, rs10206753), coding for ST2 were genotyped in 179 GBS patients and 186 healthy controls by TaqMan Allelic Discrimination Assay. Plasma levels of IL-33 and sST2 were measured in a subset of GBS (n=80) and healthy controls (n=80) by ELISA.

RESULTS

The frequencies of CC genotype of rs10192157 (p=0.043) and TT genotype of rs10206753 (p=0.036) SNPs of Il1rl1 gene differed significantly between GBS patients and healthy subjects. Gene-gene interaction between Il33 and Il1rl1 genes also conferred significant risk to GBS. In addition, the plasma sST2 levels were significantly elevated in GBS patients compared to healthy subjects (24,934.31 ± 1.81 pg/ml vs. 12,518.97 ± 1.51 pg/ml, p<0.001). Plasma sST2 levels showed a significant correlation with the disability scores at the peak of neurological deficit in GBS patients.

CONCLUSIONS

IL-33/ST2 axis is suggested to influence the immunopathogenesis of GBS. Genetic variants of Il1rl1 gene might serve as a risk determinant of GBS and plasma sST2 levels might emerge as a biomarker of severity of GBS, if replicated further by other studies.

Potential biomarkers identified by tandem mass tags based quantitative proteomics for diagnosis and classification of Guillain-Barré syndrome

BACKGROUND AND PURPOSE

Guillain-Barré syndrome (GBS) is an acute inflammatory autoimmune and demyelinating disease of the peripheral nervous system. Currently, valid biomarkers are unavailable for the diagnosis of GBS.

METHODS

A comparative proteomics analysis was performed on the cerebrospinal fluid (CSF) from 10 patients with GBS and 10 patients with noninflammatory neurological disease (NND) using the tandem mass tags technique. The differentially expressed proteins were analyzed by bioinformatics, and then the candidate proteins were validated by the enzyme-linked immunosorbent assay method in another cohort containing 160 samples (paired CSF and plasma of 40 patients with GBS, CSF of 40 NND patients and plasma of 40 healthy individuals).

RESULTS

In all, 298 proteins were successfully identified in the CSF samples, of which 97 differentially expressed proteins were identified in the GBS and NND groups. Three key molecules were identified as candidate molecules for further validation. The CSF levels of TGOLN2 and NCAM1 decreased in GBS patients compared with NND patients, whereas the CSF levels of APOC3 increased. The enzyme-linked immunosorbent assay results were consistent with our proteomics analysis. Interestingly, in the validation cohort, serum APOC3 levels in the GBS group were consistent with those in the CSF samples and significantly higher than those in the healthy control group.

CONCLUSIONS

Our preliminary data suggest that the CSF protein expression profile of patients with GBS is different from that of patients with NND. Moreover, alterations of TGOLN2, NCAM1and APOC3 may be used as novel biomarkers for identifying patients with GBS.

Case Report: Plasma Biomarkers Reflect Immune Mechanisms of Guillain-Barré Syndrome

This case series reported a group of patients with Guillain–Barré syndrome (GBS) and their plasma cytokine changes before and after immunotherapy. We aimed to understand GBS's pathogenesis and pathophysiology through observing the interval differences of the representative cytokines, which were the thymus and activation regulated chemokine (TARC) for T-cell chemotaxis, CD40 ligand (CD40L) for cosimulation of B and T cells, activated complement component C5/C5a, and brain-derived neurotrophic factor (BDNF) for survival and regenerative responses to nerve injuries. The fluorescence magnetic bead-based multiplexing immunoassay simultaneously quantified the five cytokines in a single sample. From June 2018 to December 2019, we enrolled five GBS patients who had completed before–after blood cytokine measurements. One patient was diagnosed with paraneoplastic GBS and excluded from the following cytokine analysis. The BDNF level decreased consistently in all the patients and made it a potential biomarker for the acute stage of GBS. Interval changes of the other four cytokines were relatively inconsistent and possibly related to interindividual differences in the immune response to GBS triggers, types of GBS variants, and classes of antiganglioside antibodies. In summary, utilizing the multiplexing immunoassay helps in understanding the complex immune mechanisms of GBS and the variation of immune responses in GBS subtypes; this method is feasible for identifying potential biomarkers of GBS.

Relationship between cerebrospinal fluid protein level and electrophysiologic abnormalities in the acute inflammatory demyelinating polyradiculoneuropathy variant of Guillain-Barré syndrome

Objective: Guillain-Barré syndrome (GBS) is an autoimmune disease characterized by weakness in limbs or cranial nerve innervated muscles. Acute inflammatory demyelinating polyradiculoneuropathy (AIDP) is the most common variant. Electrophysiologic abnormalities and elevated cerebrospinal fluid (CSF) protein are frequently present in AIDP, but the relationship between these two parameters is not well known. We aimed to fill this gap by studying this relationship.

Methods: This was a prospective cross-sectional study conducted for two years in the Department of Neurology, Dr. Ruth K. M. Pfau Civil Hospital, Karachi, Pakistan. All 90 adult patients with the AIDP variant of GBS were selected. Nerve conduction studies were performed to determine the degree of demyelination through the four electrophysiologic demyelination criteria. The CSF sample was sent to lab immediately after lumbar puncture. SPSS version 20.0 was used. The CSF protein level was measured with mean ±SD. Demyelination criteria were measured in frequency and percentages. Chi-square test was applied to a number of demyelination criteria and T-test/ANOVA was applied on mean CSF protein level.

Results: We found a mean CSF protein of 37.41 mg/dl (±3.69) with one demyelination criterion, 81.87 mg/dl (±17.39) with two demyelination criteria, 119.75 mg/dl (±31.42) with three demyelination criteria, and 134.00 mg/dl (±42.87) with four demyelination criteria (P-value <0.001).

Conclusion: This study demonstrates a significant relationship between CSF protein levels and degree of demyelination in the AIDP variant of GBS. This is an under-researched area in GBS and this study adds favorably to limited data in this regard.

Assessment of Expression of SOCS Genes in Acquired Immune-Mediated Polyneuropathies

Acquired immune-mediated polyneuropathies are classified to some subtypes among them are acute and chronic inflammatory demyelinating polyradiculoneuropathies (AIDP and CIDP). These two conditions share some common signs and underlying mechanisms. Based on the roles of Suppressor of cytokine signaling (SOCS) genes in the modulation of immune system reactions, these genes might be involved in the pathogenesis of these conditions. We evaluated expression of SOCS1-3 and SOCS5 genes in the leukocytes of 32 cases of CIDP, 19 cases of AIDP and 40 age- and sex-matched controls using real time PCR method. The Bayesian regression model was used to estimate differences in mean values of genes expressions between cases and control group. Expression levels of SOCS1 and SOCS2 were significantly lower in male patients compared with controls. This sex-specific pattern was also observed for SOCS3 down-regulation. Based on the area under curve values in Receiver Operating Characteristics (ROC) curve, diagnostic powers of SOCS1, SOCS2, SOCS3 and SOCS5 genes in the mentioned disorder were 0.61, 0.73, 0.68 and 0.58, respectively. Expression of none of genes was correlated with age of enrolled cases. The current study shows evidences for participation of SOCS genes in the pathophysiology of acquired immune-mediated polyneuropathies.

Genetic basis of Guillain-Barre syndrome

Guillain-Barré syndrome (GBS) is an autoimmune disease in which the peripheral nerves are affected. GBS has different subtypes, such as acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). Infections, e.g. Campylobacter jejuni, influenza, etc., can lead to GBS. Both environmental and genetic factors play a major role in the occurrence of GBS. Several studies have investigated the genetic basis of GBS. Human leukocyte antigens (HLA) genes, Cluster of Differentiation (CD) 1A, FAS, Fc gamma receptors (FcGR), Intercellular adhesion molecule-1 (ICAM1), different interleukins, Nucleotide oligomerization domain (NOD), Toll-like receptor 4 (TLR4), Tumor necrosis factor-α (TNF-α) are among the genes reported to be involved in susceptibility to the disease. Dysregulation and dysfunction of the mentioned gene products, even though their role in the pathogenesis of GBS is controversial, play a role in inflammatory pathways, regulation of immune cells and system, antigen presentation, axonal degeneration, apoptosis, and cross-reaction. This review aims to summarize associated genes with GBS to contribute to better understanding of GBS pathogenesis and discover the gene pathways that play role in GBS occurrence.

The value of sensory nerve conduction studies in the diagnosis of Guillain-Barré syndrome

Electrophysiology plays a determinant role in Guillain-Barré syndrome (GBS) diagnosis, classification, and prognostication. However, traditional electrodiagnostic (EDX) criteria for GBS rely on motor nerve conduction studies (NCS) and are suboptimal early in the course of the disease or in the setting of GBS variants. Sensory nerve conduction studies, including the sural-sparing pattern and the sensory ratio are not yet included in EDX criteria despite their well-established role in GBS diagnosis. The aim of this review is to discuss the diagnostic value of sensory NCS in GBS, their role in establishing the diagnosis and predicting the outcome according to the various subtypes of the disease.

CSF sphingomyelin: a new biomarker of demyelination in the diagnosis and management of CIDP and GBS

OBJECTIVE

To validate sphingomyelin (SM) dosage in the cerebrospinal fluid (CSF) of patients affected by chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and Guillain-Barré syndrome (GBS) as a reliably assessable biomarker.

METHODS

We prospectively enrolled 184 patients from six Italian referral centres, in whom CSF SM levels were quantified by a fluorescence-based assay optimised and patented in our laboratory.

RESULTS

We confirmed increased levels of SM in the CSF of patients affected by typical CIDP (n=35), atypical CIDP (n=18) and acute inflammatory demyelinating polyradiculoneuropathy, AIDP (n=12) compared with patients affected by non-demyelinating neurological diseases, used as controls (n=85) (p<0.0001, p=0.0065 and p<0.0001, respectively). In patients with CIDP classified for disease stage, SM was higher in active CIDP compared with both controls and stable CIDP (p<0.0001), applying for a selective tool to treatment tailoring or withdrawal. SM was also increased in AIDP compared with axonal GBS, discerning the demyelinating from axonal variant of the disease. SM did not correlate with CSF protein levels, stratifying patients independently from commonly used CSF indexes, and displaying high specificity to avoid potential misdiagnosis. Finally, SM correlated with the main clinical scores and some neurophysiological parameters in patients with CIDP and AIDP.

CONCLUSIONS

CSF SM is a diagnostic and staging wet biomarker for acquired demyelinating neuropathies and may effectively improve the management of patients affected by GBS and CIDP.

Elevated cerebrospinal fluid levels of beta-2-microglobulin in patients with Guillain-Barré syndrome and their correlations with clinical features

BACKGROUNDS

Beta-2-microglobulin (β2-MG) levels vary in many infectious and autoimmune diseases. We investigated plasma and cerebrospinal fluid (CSF) β2-MG levels in patients with Guillain-Barré syndrome (GBS) and their correlations with clinical parameters.

METHODS

CSF samples from 50 patients with GBS including 19 acute inflammatory demyelinating polyneuropathy (AIDP), 6 acute motor axonal neuropathy (AMAN), 10 acute motor-sensory axonal neuropathy (AMSAN), 7 Miller-Fisher syndrome (MFS), and 8 unclassified patients were collected. Moreover, 23 CSF samples from patients with non-inflammatory neurological disorders (NIND) as controls were collected. Plasma samples from 42 enrolled patients and 29 healthy individuals were also collected. The β2-MG levels were measured by immunoturbidimetry on automatic biochemical analyser. Besides, clinical data were extracted from electronic patient documentation system.

RESULTS

CSF levels of β2-MG, lactate dehydrogenase (LDH), and lactate were significantly increased in patients with GBS (p = 0.004, p = 0.041, p = 0.040, respectively), particularly in patients with AIDP (p < 0.001, p = 0.001, p = 0.015, respectively), whereas no statistically significant difference was found in plasma levels of β2-MG. Furthermore, CSF levels of β2-MG were positively correlated with Hughes functional score (r = 0.493, p = 0.032), LDH (r = 0.796, p < 0.001), and lactate (r = 0.481, p = 0.037) but not with protein (r = - 0.090, p = 0.713) in AIDP patients.

CONCLUSIONS

CSF β2-MG levels may help identify AIDP and indicate clinical severity. CSF LDH and lactate levels correlate with CSF β2-MG levels; interaction among these biomarkers would need further investigation.

Cerebrospinal Fluid of Preeclamptic and Normotensive Pregnant Women Compared to Nonpregnant Women Analyzed with Mass Spectrometry

Preeclampsia is a pregnancy-specific multiorgan disorder in which impaired placental functioning and excessive oxidative stress play an important role. We previously showed distinct differences between cerebrospinal fluid proteins in patients with preeclampsia and normotensive pregnant women. An additional group of nonpregnant women was included to study the presence of pregnancy-related proteins in normotensive and preeclamptic pregnancies and whether pregnancy-related proteins were associated with preeclampsia. Cerebrospinal fluid samples were tryptically digested and subsequently measured with a nano-LC-tribrid Orbitrap mass spectrometry system. Proteins were identified by shotgun proteomic analysis based on a data-dependent acquisition method. Proteins identified in preeclampsia, normotensive pregnant controls, and nonpregnant groups were compared to the Progenesis method according to the criteria as previously described and with a secondary analysis using a Scaffold method including Benjamini-Hochberg correction for multiple testing. For preeclampsia, the Progenesis and the Scaffold method together identified 15 (eight proteins for both analyses with one overlap) proteins that were significantly different compared to normotensive control pregnancies. Three of these 15 proteins, which were elevated in cerebrospinal fluid of preeclamptic women, were described to be pregnancy proteins with a calcium-binding function. Using two analysis methods (Progenesis and Scaffold), four out of 15 differential proteins were associated with pregnancy, as described in the literature. Three out of the four pregnancy-related proteins were elevated in preeclampsia. Furthermore, the contribution of elevated (n = 4/15) and downregulated (n = 2/15) calcium-binding proteins in preeclampsia is remarkably high (40%) and needs to be elucidated further.

Inferring immune-associated signatures based on a co-expression network in Guillain-Barré syndrome

Objectives

Guillain‐Barré syndrome (GBS) is a type of acute autoimmune disease, which occurs in peripheral nerves and their roots. There is extensive evidence that suggests many immune‐associated genes have essential roles in GBS. However, the associations between immune genes and GBS have not been sufficiently examined as most previous studies have only focused on individual genes rather than their entire interaction networks.

Materials and methods

In this study, multiple levels of data including immune‐associated genes, GBS‐associated genes, protein‐protein interaction (PPI) networks and gene expression profiles were integrated, and an immune or GBS‐directed neighbour co‐expressed network (IOGDNC network) and a GBS‐directed neighbour co‐expressed network (GDNC network) were constructed.

Results

Our analysis shows the immune‐associated genes are strongly related to GBS‐associated genes whether at the interaction level or gene expression level. Five immune‐associated modules were also identified which could distinguish between GBS and normal samples. In addition, functional analysis indicated that immune‐associated genes are essential in GBS.

Conclusions

Overall, these results highlight a strong relationship between immune‐associated genes and GBS existed and provide a potential role for immune‐associated genes as novel diagnostic and therapeutic biomarkers for GBS.

Peripheral Demyelinating Diseases: From Biology to Translational Medicine

Demyelinating diseases represent a spectrum of disorders that impose significant burden on global economy and society. Generally, the prognosis of these diseases is poor and there is no available cure. In recent decades, research has shed some light on the biology and physiology of Schwann cells and its neuroprotective effects in the peripheral nervous system (PNS). Insults to the PNS by various infectious agents, genetic predisposition and immune-related mechanisms jeopardize Schwann cell functions and cause demyelination. To date, there are no effective and reliable biomarkers for PNS-related diseases. Here, we aim to review the following: pathogenesis of various types of peripheral demyelinating diseases such as Guillain-Barre syndrome, Chronic Inflammatory Demyelinating Polyradiculoneuropathy, Anti-Myelin Associated Glycoprotein Neuropathy, POEMS syndrome, and Charcot-Marie-Tooth disease; emerging novel biomarkers for peripheral demyelinating diseases, and Schwann cell associated markers for demyelination.

Integrative metabolomics reveals unique metabolic traits in Guillain-Barré Syndrome and its variants

Guillain-Barré syndrome (GBS) is an acute fatal progressive disease caused by autoimmune mechanism mainly affecting peripheral nervous system. Although the syndrome is clinically sub-classified into several variants, specific biomarker and exact pathomechanism of each subtypes are not well elucidated yet. In current study, integrative metabolomic and lipidomic profiles were acquisitioned from cerebrospinal fluid samples of 86 GBS from three variants and 20 disease controls. And the data were systematically compared to our previous result on inflammatory demyelination disorders of central nervous system (IDDs) and healthy controls. Primary metabolite profiles revealed unique metabolic traits in which 9 and 7 compounds were specifically changed in GBS and IDD, respectively. Next, the biomarker panel with 10 primary metabolites showed a fairly good discrimination power among 3 GBS subtypes, healthy controls, and disease controls (AUCs ranged 0.849-0.999). The robustness of the biomarker panel was vigorously validated by multi-step statistical evaluation. Subsequent lipidomics revealed GBS variant-specific alteration where the significant elevations of lyso-phosphatidylcholines and sphingomyelins were unique to AIDP (acute inflammatory demyelinating polyneuropathy) and AMAN (acute motor axonal neuropathy), respectively. And metabolome-wide multivariate correlation analysis identified potential clinical association between GBS disability scale (Hughes score) and CSF lipids (monoacylglycerols, and sphingomyelins). Finally, Bayesian network analysis of covarianced structures of primary metabolites and lipids proposed metabolic hub and potential biochemical linkage associated with the pathology.

Association of CD1 and FcγR gene polymorphisms with Guillain-Barré syndrome susceptibility: a meta-analysis

CD1 and immunoglobulin G Fc receptor (FcγR) genes have been proposed to be involved in the pathogenesis of Guillain-Barré syndrome (GBS). However, results of different studies are conflicting. This meta-analysis aimed to systematically examine the association between CD1 and FcγR gene polymorphisms and GBS. A comprehensive literature search through PubMed, EmBase, ScienceDirect, and Cochrane Library was performed to identify all eligible studies. The strength of association was assessed by pooled odds ratios (ORs) and corresponding 95% confidence intervals (95% CI) in allelic, dominant, recessive, homozygous and heterozygous genetic models. Four case-control studies about polymorphisms of exon 2 in CD1A and CD1E genes and GBS risk and five studies (six cohorts) about FcγR gene polymorphisms and GBS risk were included in this meta-analysis. The association between exon 2 of CD1E gene polymorphism and GBS was marginally significant in Caucasians in allelic model (OR = 1.193, 95% CI = 1.001-1.423, P = 0.049). FcγRIIA gene polymorphism was significantly associated with GBS risk in Caucasians under allelic model (OR = 1.553, 95% CI = 1.018-2.368, P = 0.041) and dominant model (OR = 1.320, 95% CI = 1.027-1.697, P = 0.030). However, no significant association was found between polymorphisms in exon 2 of CD1A, FcγRIIIA and FcγRIIIB genes and GBS susceptibility. This meta-analysis suggested that FcγRIIA gene polymorphism may contribute to GBS risk in Caucasians and revealed a certain trend toward significance in the association of exon 2 of CD1E gene with GBS in Caucasians. Further studies with larger sample size are required to validate these results.

Effect of serum inflammatory markers on the prognosis of adult and pediatric patients with Guillain-Barré syndrome

OBJECTIVE

The aim of this study was to evaluate blood neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), C-reactive protein (CRP), and albumin levels for their prognostic value in adult Guillain-Barré syndrome (GBS-A) and pediatric Guillain-Barré syndrome (GBS-P) patients.

PATIENTS AND METHODS

We retrospectively analyzed the medical records of 68 Guillain-Barré syndrome (GBS) patients (36 adults, 32 children) who were treated as inpatients at Harran University Faculty of Medicine, Neurology and Pediatric Neurology Departments. The pretreatment NLR, PLR, CRP, and albumin levels and Hughes scores at hospital admission, discharge, and third-month control were documented.

RESULTS

In GBS-A patients, the mean CRP and NLR levels at admission/discharge and third-month control were significantly higher, and the mean albumin level was significantly lower in the Hughes disability scale (HDS)≥3 group. In GBS-P group, the mean NLR level at third month was significantly higher in the HDS≥3 group. GBS-A patients had higher mean NLR, PLR, and CRP levels and lower mean albumin values than GBS-P patients. Both GBS-A and GBS-P patients had higher mean NLR, PLR, and CRP levels and lower mean albumin values than healthy controls. Only the albumin level of the GBS-A group was found to be a significant predictor of prognosis at discharge from hospital.

CONCLUSION

NLR, CRP, and albumin levels in the GBS-A group and NLR levels in the GBS-P group may be helpful in predicting the prognosis of the disease. The albumin level of GBS-A patients is an independent risk factor for prognosis at discharge from hospital.

Sphingomyelin as a myelin biomarker in CSF of acquired demyelinating neuropathies

Fast, accurate and reliable methods to quantify the amount of myelin still lack, both in humans and experimental models. The overall objective of the present study was to demonstrate that sphingomyelin (SM) in the cerebrospinal fluid (CSF) of patients affected by demyelinating neuropathies is a myelin biomarker. We found that SM levels mirror both peripheral myelination during development and small myelin rearrangements in experimental models. As in acquired demyelinating peripheral neuropathies myelin breakdown occurs, SM amount in the CSF of these patients might detect the myelin loss. Indeed, quantification of SM in 262 neurological patients showed a significant increase in patients with peripheral demyelination (p = 3.81 * 10 − 8) compared to subjects affected by non-demyelinating disorders. Interestingly, SM alone was able to distinguish demyelinating from axonal neuropathies and differs from the principal CSF indexes, confirming the novelty of this potential CSF index. In conclusion, SM is a specific and sensitive biomarker to monitor myelin pathology in the CSF of peripheral neuropathies. Most importantly, SM assay is simple, fast, inexpensive, and promising to be used in clinical practice and drug development.

Increased serum concentrations of transforming growth factor-β1 (TGF-β1) in patients with Guillain-Barré syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) is an acquired demyelinating peripheral neuropathy. It has shown that macrophage activation contribute to the pathogenesis of GBS. Therefore macrophage-mediated factors could be the potential markers for disease diagnosis and status of GBS.

METHODS

We measured serum concentrations of 4 macrophage-mediated factors, including interleukin-6 (IL-6), transforming growth factor-β1 (TGF-β1), vascular cell adhesion protein 1 (VCAM-1) and vascular endothelial growth factor (VEGF), in 23 chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), 28 GBS, 11 Miller-Fisher syndrome (MFS), 40 multiple sclerosis (MS), and 12 Alzheimer's disease (AD) patients, as well as 15 healthy controls.

RESULTS

Serum TGF-β1 concentration of GBS patients (35.94±2.55ng/ml) was significantly higher compared with CIDP (25.46±1.40ng/ml, P<0.001), MFS (25.32±2.31ng/ml, P=0.010), MS (21.35±0.90ng/ml, P<0.001) and AD patients (22.92±1.82ng/ml, P<0.001), as well as healthy controls (23.12±1.67ng/ml, P<0.001). A positive correlation between serum TGF-β1 concentrations and Hughes' functional grading scales was observed in GBS patients. Serum concentrations of IL-6, VCAM-1 and VEGF were similar between the studied groups.

CONCLUSION

The high serum concentrations of TGF-β1 and the correlation between serum TGF-β1 concentration and disease severity highlight the potential of TGF-β1 as a biomarker of GBS.

Successful surgical treatment of scoliosis secondary to Guillain-Barré syndrome: Case report

Guillain-Barré syndrome (GBS) is an acute autoimmune inflammatory demyelinating polyneuropathy that mostly affects the peripheral nervous system. Little is reported about spinal deformity associated with GBS. This study aims to present a case of scoliosis occurring in the setting of GBS.Case report and literature review.The patient was a 14-year-old male with scoliosis. His spinal plain radiographs showed that the Cobb angle of thoracic scoliosis was 114°. History review revealed that he developed profound lower extremity pain, weakness, and numbness after catching a cold 5 years ago. These symptoms progressed to unsteady gait and inability to stand up from squatting position. The diagnosis of GBS was confirmed based on these symptoms. He underwent a posterior correction at Thoracic 5-Lumbar 5 (T5-L12) levels using the (LEGACY, USA) spinal system. The Cobb angle was corrected from 114° to 45° (correction rate 60.5%). His follow-up was symptomatic, well balanced in the coronal planes, with solid fusion 12 months after the operation.Neuromuscular scoliosis could develop secondary to GBS. When evaluating patients with acute inflammatory polyneuropathy, clinical examination of the spine is essential to identify patients with rare neuromuscular scoliosis.

Looks can be deceiving: three cases of neurological diseases mimicking Guillain-Barrè syndrome

Guillain-Barrè syndrome (GBS) is an acute, paralyzing, inflammatory peripheral nerve disease, featured by monophasic disease course, symmetrical limb weakness and areflexia. Several pathologies can mimic the clinical presentation of GBS, making hard the differential diagnosis for patients complaining of acute flaccid paralysis. In this paper we describe three cases of different neurological diseases presenting with acute motor symptoms mimicking GBS, reviewing the relevant literature on misdiagnosis of GBS.