Cerebrospinal fluid protein in Guillain-Barré syndrome: Need for age-dependent interpretation

Immune Checkpoint Inhibitor-Induced Guillain Barre Syndrome: A Single-Institution Case Report and Narrative Review

Guillain-Barré syndrome (GBS) resulting from the use of immune checkpoint inhibitors (ICIs) is relatively uncommon but has been reported. Herein, we discuss a case of a 67-year-old patient who received neoadjuvant ICI for treatment of non-small cell lung cancer and then presented with lower extremity weakness and areflexia, progressing to respiratory muscle and upper extremity weakness. Given the increasing use of ICI in cancer management, awareness of neurological autoimmune side effects is essential. ICI-mediated GBS can be severe and fatal if not diagnosed promptly. We discuss a case of ICI-induced GBS and review literature on current management approaches.

A 'Decrescendo' in a Woman With Ascending Paralysis: A Diagnostic Challenge

Guillain-Barre Syndrome (GBS) is an autoimmune condition that causes muscular weakness and can be potentially life-threatening if not identified early. GBS is diagnosed definitively by cerebrospinal fluid (CSF) analysis and electromyographic (EMG) studies. Identifying illnesses that may have triggered GBS is crucial, as they could affect the course of the disease. Our patient was a 27-year-old woman who developed lower extremity weakness a few days after being treated for a dental abscess. Laboratory and imaging studies ruled out central nervous system (CNS) lesions, myelopathies, and metabolic causes. Diagnosis was difficult due to inconclusive initial investigations, refusal of lumbar puncture, and delayed availability of EMG studies. Additionally, there were no identifiable triggers to support GBS as a diagnosis. During the hospital course, the patient developed tachycardia with new electrocardiogram (EKG) changes. A transthoracic echocardiogram (TTE) showed suspicious vegetation, and a transesophageal echocardiogram (TEE) confirmed severe mitral regurgitation. The new valvular lesions and autonomic dysfunction with worsening lower extremity weakness increased our suspicion of GBS. Intravenous immunoglobulin (IVIG) was administered empirically, but she developed bulbar symptoms, prompting admission to the intensive care unit (ICU). A lumbar puncture performed at this time was negative for albumino-cytological dissociation and CNS infections.  Signs of sepsis with valvular lesions raised concerns for infective endocarditis (IE). Due to recent treatment with antibiotics for dental abscess, a negative blood culture was a confounding factor in Duke's criteria, delaying the diagnosis of IE. Infectious disease experts suggested empirical treatment for suspected blood culture-negative infective endocarditis (BCNE) and valvular abscess. She was transferred to a cardiothoracic care facility for valvular surgery evaluation. EMG studies identified the patient's condition as the acute motor sensory axonal neuropathy (AMSAN) variant of GBS. The patient's antibodies tested positive for Campylobacter jejuni (C. Jejuni) immunoglobulin G (IgG). Since this indicates a past infection, it is uncertain whether C. Jejuni triggered the patient's GBS. However, new valvular vegetation and acute-onset lower extremity weakness make us hypothesize that BCNE may have triggered GBS.

Cervical Myelopathy with Concomitant Guillain-Barré Syndrome: A Case Report

CASE

We present a case of a 67-year-old female patient with concomitant cervical spondylotic myelopathy (CSM) and Guillain-Barré syndrome (GBS). Surgical intervention, including cervical decompression and arthrodesis, was performed to address cervical myelopathy symptoms. Despite initial improvement, the patient's motor function deteriorated, leading to the diagnosis of GBS. The patient's hospital course was protracted with a complicated recovery.

CONCLUSION

This case emphasizes the clinical details of coexisting CSM and GBS, highlighting the importance of diagnosing and considering demyelinating diseases when determining the optimal timeline for surgical intervention. These findings inform decision-making for clinicians encountering similar patient presentations.

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.

Cerebrospinal fluid and blood profiles of transfer RNA fragments show age, sex, and Parkinson's disease-related changes

Transfer RNA fragments (tRFs) have recently been shown to be an important family of small regulatory RNAs with diverse functions. Recent reports have revealed modified tRF blood levels in a number of nervous system conditions including epilepsy, ischemic stroke, and neurodegenerative diseases, but little is known about tRF levels in the cerebrospinal fluid (CSF). To address this issue, we studied age, sex, and Parkinson's disease (PD) effects on the distributions of tRFs in the CSF and blood data of healthy controls and PD patients from the NIH and the Parkinson's Progression Markers Initiative (PPMI) small RNA-seq datasets. We discovered that long tRFs are expressed in higher levels in the CSF than in the blood. Furthermore, the CSF showed a pronounced age-associated decline in the level of tRFs cleaved from the 3'-end and anti-codon loop of the parental tRNA (3'-tRFs, i-tRFs), and more pronounced profile differences than the blood profiles between the sexes. In comparison, we observed moderate age-related elevation of blood 3'-tRF levels. In addition, distinct sets of tRFs in the CSF and in the blood segregated PD patients from controls. Finally, we found enrichment of tRFs predicted to target cholinergic mRNAs (Cholino-tRFs) among mitochondrial-originated tRFs, raising the possibility that the neurodegeneration-related mitochondrial impairment in PD patients may lead to deregulation of their cholinergic tone. Our findings demonstrate that the CSF and blood tRF profiles are distinct and that the CSF tRF profiles are modified in a sex-, age-, and disease-related manner, suggesting that they reflect the inter-individual cerebral differences and calling for incorporating this important subset of small RNA regulators into future studies.

Population-Based Evaluation of Total Protein in Cerebrospinal Fluid

OBJECTIVES

To present a normal range of cerebrospinal fluid (CSF) protein levels in a community-based population and to evaluate factors that contribute to CSF protein level variability.

PATIENTS AND METHODS

Samples of CSF protein were obtained from participants aged 32 to 95 years who underwent lumbar puncture (LP) between November 1, 2007, and October 1, 2017, as part of the Mayo Clinic Study of Aging, a longitudinal, population-based study of residents of Olmsted County, Minnesota.

RESULTS

A total of 633 participants (58.1% male; 99.1% White; mean ± SD age, 70.9±11.6 years) underwent LP with recorded CSF protein level. Mean ± SD CSF protein level was 52.2±18.4 mg/dL (to convert to mg/L, multiply by 10), with a 95% reference interval of 24.0 to 93.4 mg/dL (range, 14.0-148.0 mg/dL). Spinal stenosis and arterial hypertension were associated with higher CSF protein levels on univariable analysis (P<.001). Increasing age, male sex, and diabetes were all independently associated with higher CSF protein levels on multivariable analysis (P<.001). In the 66 participants with repeated LPs within 2.5 years, the coefficient of repeatability was 26.1 mg/dL. Eleven participants (16.7%) had a CSF protein level difference of 20 mg/dL or more between serial LPs, and 4 (6.1%) had a difference of 25 mg/dL or more. There was a trend toward greater CSF protein level variability in patients with spinal stenosis (P=.054).

CONCLUSION

This large population-based study showed that CSF protein level can vary significantly among individuals. Elevated CSF protein level was independently associated with older age, male sex, and diabetes and is higher than listed in many laboratories. These findings emphasize the necessity of evidence-based reevaluation and standardization of CSF protein metrics.

Looks Like Neurosyphilis, Feels Like Guillain-Barre: At the Confluence of Infection and Immunology

We present a 51-year-old male, with a past medical history of type 2 insulin-dependent diabetes mellitus (T2IDDM) without neuropathy, coronavirus disease 2019 (COVID-19) in April 2020 without residual symptoms, Raynaud's, and recent occupational outdoor exposure to insects as a construction manager who came to the emergency room complaining of a three-week history of bilateral progressive numbness and weakness beginning in his lower extremities and ascending toward his pelvis. Notably, he received the second dose of his Moderna COVID-19 vaccine one week prior to symptom onset and four weeks prior to admission. He also reported a recent appearance of a maculopapular rash on his upper extremities and flanks. Physical exam was remarkable for bilateral distal motor weakness in the upper and lower extremities with associated paresthesia and decreased reflexes in the lower extremities. The patient had slight ataxia and difficulty with heel walk and toe walk. Notably, the cranial nerve exam was normal, and the patient was afebrile. Intravenous immune globulin (IVIG) was started empirically for the treatment of Guillain-Barre syndrome (GBS), and doxycycline 100mg intravenous twice a day and ceftriaxone 2g intravenous daily were started for possible tick-borne disease. Subsequently, rapid plasma reagin (RPR) returned reactive at 1:64, and cerebral spinal fluid (CSF) venereal disease research laboratory (VDRL) test was reactive at 1:2 with markedly elevated protein and pleocytosis. Human immunodeficiency virus (HIV) testing was negative. Lyme disease testing was negative. Nerve conduction studies (NCS) and electromyography (EMG) showed a sensorimotor polyneuropathy with mixed demyelinating and axonal features. IVIG was continued for a total of five days, and antibiotics were changed to penicillin G (PCN G) for a total of 14 days for definitive treatment of early neurosyphilis (NS). While both clinical and laboratory findings confirm a positive diagnosis of NS, the patient’s CSF composition showed very elevated total protein levels and pleocytosis. Additionally, his early peripheral neuropathy and EMG findings are not characteristics of a single disease and, instead, suggested a mixed pathology. We postulate that this patient had confirmed secondary syphilis with early NS associated with, and possibly correlated with, a simultaneous episode of acute inflammatory demyelinating polyneuropathy (AIDP) and/or a vaccine-related phenomenon.

Contemporary challenges in the diagnosis and management of chronic inflammatory demyelinating polyneuropathy

INTRODUCTION

Despite extensive research, multiple inter-related diagnostic and management challenges remain for chronic inflammatory demyelinating polyneuropathy (CIDP).

AREAS COVERED

A literature review was performed on diagnosis and treatment in CIDP. The clinical features and disease course were evaluated. Investigative techniques, including electrophysiology, cerebrospinal fluid examination, neuropathology, imaging and neuroimmunology, were considered in relation to technical aspects, sensitivity, specificity, availability and cost. Available evidenced-based treatments and those with possible efficacy despite lack of evidence, were considered, as well as current methods for evaluation of treatment effects.

EXPERT OPINION

CIDP remains a clinical diagnosis, supported first and foremost by electrophysiology. Other investigative techniques have limited impact. Most patients with CIDP respond to available first-line treatments and immunosuppression may be efficacious in those who do not. Consideration of the natural history and of the high reported remission rate, of under-recognised associated disabling features, of treatment administration modalities and assessment methods, require enhanced attention.

The Correlation Among the Immunoglobulin G Synthesis Rate, IgG Index and Albumin Quotient in Guillain-Barré Syndrome and Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Retrospective Case–Control Study

Background: The immunoglobulin G synthesis rate (IgG SR) and immunoglobulin G (IgG) index are indicators of abnormal intrathecal humoural immune responses, and the albumin quotient (QALB) is an indicator used to evaluate the completeness of the blood-cerebrospinal fluid barrier (BCB). No systematic reports regarding differences in Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are available. We assessed differences in the IgG SR, IgG index and QALB between GBS and CIDP patients in a Chinese cohort.

Methods: A total of 234 patients were retrospectively enrolled in this study, and 167 clinically confirmed GBS and CIDP patients were selected. Meanwhile, 67 non-GBS and non-CIDP patients requiring cerebrospinal fluid (CSF) examination were enrolled as the control group. The IgG SR, IgG index and QALB were calculated using formulas. The relevant clinical data were subjected to statistical analysis.

Results: Among the GBS and CIDP study groups and the control group, the QALB had the highest positive rate (80.00%) in the CIDP group (P < 0.01). The QALB stratification analysis showed that the ranges of 10 < QALB ≤ 30 were dominant in the GBS and CIDP groups, and the positive rate of CIDP was higher than that of GBS. Furthermore, a QALB ≤ 7 was dominant in the control group, and a QALB > 30 was dominant in the CIDP group. In receiver operating characteristic (ROC) curve analysis with the CIDP group as the trial group and the GBS group as the control group, the differences in the QALB were statistically significant (P < 0.01). To achieve a high specificity of 98~99%, the diagnostic cut-off value for the QALB was above 57.37 (sensitivity: 9.33%) or below 0.60 (sensitivity: 4.35%). Multivariate logistic regression analysis showed that the CIDP patients had a QALB higher than 57.37, and compared with that in the GBS patients, the difference in the QALB was statistically significant (P < 0.01).

Conclusion: QALB elevation was associated with CIDP, while QALB values above 57.37 or below 0.60 had high specificity in differentiating between GBS and CIDP. In CIDP, the BCB is generally moderately to severely damaged; in GBS, the BCB is generally moderately damaged.

Cerebrospinal Fluid Protein Concentration in Healthy Older Japanese Volunteers

The concentration of cerebrospinal fluid total protein (CSF-TP) is important for the diagnosis of neurological emergencies. Recently, some Western studies have shown that the current upper reference limit of CSF-TP is quite low for older patients. However, little is reported about the concentration of CSF-TP in the older Asian population. In this study, we retrospectively analyzed the CSF-TP concentrations in healthy older Japanese volunteers. CSF samples in 69 healthy Japanese volunteers (age range: 55–73 years) were collected by lumbar puncture, and the data of CSF were retrospectively analyzed. The mean (standard deviation) CSF-TP was 41.7 (12.3) mg/dL. The older group (≥65 years old) had higher CSF-TP concentration than the younger group (55–64 years old). The 2.5th percentile and 97.5th percentile of CSF-TP were estimated as 22.5 and 73.2 mg/dL, respectively, which were higher than the current reference range in Japan (10–40 mg/dL). Conclusions: The reference interval of CSF-TP in the older population should be reconsidered for the precise diagnosis of neurological emergencies.

Neue Grenzwerte für das Gesamtprotein im Liquor verbessern die Diagnose von chronisch inflammatorisch demyelinisierender Polyneuropathie

Chronisch inflammatorisch demyelinisierende Polyneuropathie (CIDP) ist klinisch durch motorische und sensible Defizite und elektrophysiologische Zeichen der Demyelinisierung peripherer Nerven charakterisiert. Da es keinen reliablen diagnostischen Biomarker gibt, hat der Kliniker häufig das Problem, die klinischen und supportiven Daten (Liquor, Bildgebung und Biopsie) korrekt einzuordnen. Leider kommt es häufig zu Fehldiagnosen. Das Gesamtprotein im Liquor wird von Alter und Begleiterkrankungen beeinflusst. Bisher ist 45 mg/dl der obere Grenzwert für Gesunde, jedoch stammen die Referenzwerte aus dem Jahr 1938. Aktuell werden in der Literatur Werte von 50 mg/dl bei Gesunden bis 50 Jahre und 60 mg/dl bei Gesunden ab 50 Jahren diskutiert. Breiner et al. wollen die diagnostische Spezifität und Sensibilität erhöhen.