Association between clinical characteristics, acute steroid treatment and oligoclonal bands result in multiple sclerosis: A retrospective study.

BACKGROUND: Detection of oligoclonal bands (OCBs) in the cerebrospinal fluid (CSF) is important for diagnosis of multiple sclerosis (MS). Previous studies reported that treatment with intravenous methylprednisolone (IVMP) before lumber puncture (LP) could suppress OCBs production. The aim of this study was to assess whether IVMP initiation prior to CSF collection affects OCBs results in patients with an acute demyelinating event. Additionally, we examined which clinical characteristics are associated with the presence of OCBs in the CSF. METHODS: We retrospectively evaluated patients admitted to the neurology department at rabin medical center (RMC) between 2010 and 2022 who underwent LP with OCBs analysis as part of their demyelinating attack workup. Patients were divided into OCB-positive and OCB-negative groups and demographical and clinical characteristics (including timing and duration of acute steroid treatment and history of prior demyelinating attacks) were analyzed for association with OCBs results. RESULTS: A total of 342 patients were included with a median age of 35 years (IQR, 27-46). Two hundred thirty-eight (69.6 %) were OCB-positive. Initiation of IVMP before LP was not associated with negative OCBs (11.8 % Vs. 13.5 %, P = 0.721), nor was it correlated with OCBs positivity (OR=0.86, P = 0.66). CSF cell count was higher in OCB-positive patients (5 Vs. 3, P = 0.001), and a history of prior demyelinating attacks was associated with- (33.6 % Vs. 20.2 %, P = 0.014) and predictive of OCBs positivity (OR=2, P = 0.013). CONCLUSIONS: Timing of steroids was not associated with OCB positivity. However, pleocytosis and a prior attack were associated with OCB positivity in this cohort. Our results suggest that steroid treatment is unlikely to affect OCBs results. Ideally, larger prospective studies would be needed to confirm our observations.

Concordance rate between oligoclonal bands and the Kappa index in patients with suspected multiple sclerosis (MS).

BACKGROUND: Oligoclonal bands (OCBs) and Kappa free light chains (FLCs) in the cerebrospinal fluid (CSF) are sensitive markers of intrathecal immunoglobulin (Ig)G synthesis in patients with multiple sclerosis. OBJECTIVE: To evaluate the concordance rate between OCBCs and the Kappa index (KI) in patients with suspected multiple sclerosis (MS). METHODS: Patients with suspected MS were referred to a specialized CSF laboratory as part of their diagnostic investigation. Paired CSF and serum samples were collected and submitted to detection of OCBs and determination of the KI. Positive and negative results were determined with both methods, and the percentage of agreement between them was established. RESULTS: In total, 171 serum and CSF samples from 171 patients were included in the analysis. The mean age of the patients was of 40 ± 14.2 years; 18.9% of them were male, and 81.1% were female. The OCBs and KI presented concordant results in 161 (94.2%) samples: in 74 (43.3%), both were positive, and in 87 (50.9%), both were negative. In 10 cases, the results were discrepant: KI positive/OCB negative in 8 and OCB positive/KI negative in 2 cases. CONCLUSION: The KI and OCBs presented high concordance level. Currently, the detection of OCBs in the CSF is the standard method for MS diagnosis, but it is time-consuming, and its visual interpretation can be difficult. The results suggest that the KI is a good alternative for the detection of intrathecal immunoproduction in cases of suspected MS.

ANTECEDENTES: Bandas oligoclonais (BOCs) e cadeias leves de imunoglobulina (free light chains, FLCs, em inglês) Kappa no líquido cefalorraquidiano (LCR) são marcadores sensíveis da síntese intratecal de imunoglobulina (Ig)G em pacientes com esclerose múltipla (EM). OBJETIVO: Avaliar a taxa de concordância entre BOCs e o índice Kappa (IK) em pacientes com suspeita de EM. MéTODOS: Pacientes com suspeita de EM foram encaminhados a um laboratório especializado em LCR como parte de sua investigação diagnóstica. Amostras pareadas de LCR e soro foram coletadas e investigadas quanto à presença de BOCs e submetidas à determinação do IK. Resultados positivos e negativos foram determinados com ambos os métodos, e estabeleceu-se o percentual de concordância entre eles. RESULTADOS: Ao todo, 171 amostras de soro e LCR de 171 pacientes foram incluídas na análise. A média de idade dos pacientes foi de 40 ± 14,2 anos; 18,9% deles eram do sexo masculino, e 81,1%, do sexo feminino. Resultados concordantes entre as BOCs e o IK foram observados em 161 (94,2%) amostras: em 74 (43,3%), ambos foram positivos, e em 87 (50,9%), ambos foram negativos. Em 10 casos, os resultados foram discrepantes: IK positivo/BOC negativo em 8, e BOC positivo/IK negativo em 2. CONCLUSãO: Observou-se alto nível de concordância entre o IK e as BOCs. A detecção de BOCs no LCR é atualmente o método padrão para o diagnóstico de EM, mas é demorado, e sua interpretação visual pode ser difícil. Os resultados sugerem que o IK pode ser uma alternativa para a detecção de imunoprodução intratecal em casos de suspeita de EM.

Infrequent patterns in cerebrospinal fluid isofocusing test: Clinical significance and contribution of IgG index and Reiber diagram to their interpretation.

Cerebrospinal fluid (CSF) isoelectrofocusing (IEF) is considered as the gold standard for detecting an intrathecal synthesis of IgG, which is a hallmark of multiple sclerosis (MS). This corresponds to the presence of CSF-restricted IgG oligoclonal bands (OCB) (typically type 2 pattern). Moreover, this technique can also detect a systemic immune reaction with passive transfer of IgG (type 3 and 4 patterns) for which the clinical relevance is less understood. The aim of our study was to determine the frequency and disease associations of IEF type 3 and 4 patterns and to investigate the potential usefulness of including quantitative data (IgG index and Reiber Diagram) in interpreting such IEF profiles. Among 544 patients who underwent CSF IEF (Hydragel CSF isofocusing kit, Sebia®, France) in our Laboratory during a six-year-period, those who presented type 3 or 4 patterns were selected. Clinical data and results of other immunological tests were analyzed for 27 patients followed in the Neurological Department. Frequencies of type 3 and type 4 patterns were relatively low (2.3 % and 3.4 % respectively). Among patients with type 3 pattern included in our study (n = 10), 5 were diagnosed with MS. For the 5 other patients, the diagnosis was a clinically isolated syndrome (CIS) (2 cases), a probable auto-immune encephalitis (2 cases) and a possible genetic neurodegenerative disease (1 case). MS patients had an IgG index >0.7 and fell into area 4 of Reiber diagram while non-MS patients had an IgG index <0.7 and fell into area 1, except the last case. Regarding type 4 pattern (n = 17), the diagnoses were as follows: MS (3), CIS (4), Neuromyelitis optica spectrum disorders with positive anti-AQP4 antibodies (3) and anti-NMDAR autoimmune encephalitis (1). The remaining cases had central nervous system impairment related to vascular, metabolic or tumoral etiologies (3) or peripheral nervous system impairment (3). In this group (type 4 pattern), IgG index was <0.7 in 15/17 cases. Interpretation using Reiber diagram showed an abnormal blood-brain barrier for 8/17 patients. Type 3 and 4 IEF patterns are infrequently observed in routine neurology practice. It is important for the diagnostic laboratory professional as well as for the neurologist to understand their clinical relevance. Our findings highlight the contribution of quantitative evaluation of CSF (IgG index, Reiber diagram) for the interpretation of such situations. Despite the small size of our study population, our results emphasize the importance of reporting the exact type of IEF pattern and not only the positivity or not of OCB.

The role of oligoclonal band count and IgG index in treatment response and disease activity in multiple sclerosis.

BACKGROUND/AIM: Multiple sclerosis (MS) is an inflammatory demyelinating central nervous system (CNS) disease. Among the paraclinical tests, brain and spinal Magnetic Resonance Imaging (MRI) is primarily involved in the diagnosis process, and cerebrospinal fluid (CSF) analysis is fundamental in diagnosing MS and the differential diagnosis. A positive relationship was demonstrated between oligoclonal band (OCB) positivity, CSF band number and immunoglobulin G(IgG) index. The study aimed to evaluate whether the number of OCB can predict disease activity and determine a correlation with the IgG index. METHODS: Our study included 401 MS patients who had relapsing-remitting multiple sclerosis (RRMS), primary progressive multiple sclerosis (PPMS), secondary progressive multiple sclerosis (SPMS), clinic isolated syndrome (CIS), radiologic isolated syndrome (RIS), Neuromyelitis optica spectrum disorder (NMOSD) and Acute disseminated encephalomyelitis (ADEM) with OCB number groups of 2-4, 4-8, 8-12, and 12 and above. RESULTS: No significant correlation was observed between IgG index, pre-and post-treatment EDSS (Expanded Disability Status Scale Scores) and disease-modifying therapies (DMT). Drug response was better in the patient group with band number between 2 and 8 and post-treatment EDSS scores were lower (1.62±0.44). CONCLUSION: The study results suggested that band number may be as valuable as the IgG index and a predictive biomarker for disease activity.

The elusive nature of the oligoclonal bands in multiple sclerosis.

Intrathecal immunoglobulin G (IgG) and oligoclonal bands (OCBs) detected in both the brain and cerebrospinal fluid (CSF) are seminal features of multiple sclerosis (MS). The presence of OCBs correlates with elevated disease burden and severity and supports the diagnosis of MS. Despite numerous investigations into the potential viral and autoantigen targets, the precise antigenic specificity of OCBs has remained elusive. We have little knowledge of the nature regarding these oligoclonal IgG bands. Here, we present compelling evidence highlighting the key findings that both OCBs and intrathecal IgG antibodies are under genetic control and that OCBs originate from clonal B-cells in both the periphery and CNS. We propose that MS OCBs are IgG immune complexes composed of IgG1 and IgG3 antibodies and that the pathological role of OCB stems from the IgG effector functions of these complexes, leading to demyelination and axonal injuries. We present additional evidence regarding the nature of MS OCBs: (1) disease-modifying therapies have been shown to affect CSF OCB; (2) OCBs have also been detected in several neuroinfectious diseases; (3) Epstein-Barr virus (EBV) has been particularly linked with MS pathogenesis, and its association with OCB is an important area of study. Although OCBs are closely associated with MS, more meticulously planned research is necessary to clarify the precise role of OCB in MS, both in terms of disease pathogenesis and diagnosis.

Cerebrospinal fluid oligoclonal bands in Chinese patients with multiple sclerosis: the prevalence and its association with clinical features.

Background: Cerebrospinal fluid oligoclonal band (CSF-OCB) is an established biomarker in diagnosing multiple sclerosis (MS), however, there are no nationwide data on CSF-OCB prevalence and its diagnostic performance in Chinese MS patients, especially in the virtue of common standard operation procedure (SOP). Methods: With a consensus SOP and the same isoelectric focusing system, we conducted a nationwide multi-center study on OCB status in consecutively, and recruited 483 MS patients and 880 non-MS patients, including neuro-inflammatory diseases (NID, n = 595) and non-inflammatory neurological diseases (NIND, n=285). Using a standardized case report form (CRF) to collect the clinical, radiological, immunological, and CSF data, we explored the association of CSF-OCB positivity with patient characters and the diagnostic performance of CSF-OCB in Chinese MS patients. Prospective source data collection, and retrospective data acquisition and statistical data analysis were used. Findings: 369 (76.4%) MS patients were OCB-positive, while 109 NID patients (18.3%) and 6 NIND patients (2.1%) were OCB-positive, respectively. Time from symptom onset to diagnosis was significantly shorter in OCB-positive than that in OCB-negative MS patients (13.2 vs 23.7 months, P=0.020). The prevalence of CSF-OCB in Chinese MS patients was significantly higher in high-latitude regions (41°-50°N)(P=0.016), and at high altitudes (>1000m)(P=0.025). The diagnostic performance of CSF-OCB differentiating MS from non-MS patients yielded a sensitivity of 76%, a specificity of 87%. Interpretation: The nationwide prevalence of CSF-OCB was 76.4% in Chinese MS patients, and demonstrated a good diagnostic performance in differentiating MS from other CNS diseases. The CSF-OCB prevalence showed a correlation with high latitude and altitude in Chinese MS patients.

Insight into Early Diagnosis of Multiple Sclerosis by Targeting Prognostic Biomarkers.

Multiple sclerosis (MS) is a central nervous system (CNS) immune-mediated disease that mainly strikes young adults and leaves them disabled. MS is an autoimmune illness that causes the immune system to attack the brain and spinal cord. The myelin sheaths, which insulate the nerve fibers, are harmed by our own immune cells, and this interferes with brain signal transmission. Numbness, tingling, mood swings, memory problems, exhaustion, agony, vision problems, and/or paralysis are just a few of the symptoms. Despite technological advancements and significant research efforts in recent years, diagnosing MS can still be difficult. Each patient's MS is distinct due to a heterogeneous and complex pathophysiology with diverse types of disease courses. There is a pressing need to identify markers that will allow for more rapid and accurate diagnosis and prognosis assessments to choose the best course of treatment for each MS patient. The cerebrospinal fluid (CSF) is an excellent source of particular indicators associated with MS pathology. CSF contains molecules that represent pathological processes such as inflammation, cellular damage, and loss of blood-brain barrier integrity. Oligoclonal bands, neurofilaments, MS-specific miRNA, lncRNA, IgG-index, and anti-aquaporin 4 antibodies are all clinically utilised indicators for CSF in MS diagnosis. In recent years, a slew of new possible biomarkers have been presented. In this review, we look at what we know about CSF molecular markers and how they can aid in the diagnosis and differentiation of different MS forms and treatment options, and monitoring and predicting disease progression, therapy response, and consequences during such opportunistic infections.

Kappa free light chains index in multiple sclerosis very long-term prognosis.

Introduction: The role of the kappa-free light chain (kFLC) in the diagnosis of multiple sclerosis (MS) and, to a lesser extent, its role as a medium-term prognostic marker have been extensively studied. This study aimed to explore its potential as a long-term prognostic marker for MS. Methods: We performed an exploratory retrospective observational study by selecting patients systemically followed up in our MS unit with available cerebrospinal fluid and serum samples at the time of initial evaluation. Two groups were defined: benign MS (bMS), defined as patients with Expanded Disability Status Scale (EDSS) ≤ 3 at 10 years of follow-up, and aggressive MS (aMS), defined as patients with EDSS ≥ 6 at 15 years of follow-up. Clinical variables were collected, and the immunoglobulin G (IgG) index, kFLC index, and oligoclonal bands (OCB) were determined for all patients and compared between the groups. Results: Twenty bMS and 15 aMS patients were included in this study. Sixty percent (21/35) were female, and the mean age at the time of the first symptom was 31.5 ± 9.45 years, with no statistical differences between groups. Median follow-up time was 19.8 years (Interquartile range, IQR 15.9-24.6). The median EDSS scores at the last follow-up were 1.5 and 7.5 in the bMS and the aMS group, respectively. No statistically significant differences were found in the kFLC index between the two groups (136.6 vs. 140.27, p=0.59). The IgG index was positive in 62.9% of patients (55% bMS vs. 73.3% aMS, p>0.05), and OCB was positive in 88.6% (90% bMS vs. 86.7% aMS, p>0.05). A significant positive correlation was found between IgG and kFLC indices (rs = 0.85, p<0.001). Conclusion: Given the absence of differences between the two groups with opposite disease courses, it is unlikely that the kFLC index is a reliable and powerful marker of long-term prognosis in MS.

African American patients with Multiple Sclerosis (MS) have higher proportions of CD19+ and CD20+ B-cell lineage cells in their cerebrospinal fluid than White MS patients.

OBJECTIVES: To compare proportions of B-cell lineage CD19+ and CD20+ cells in CSF of African-American (AA) and White (W) patients with MS. BACKGROUND: AA MS patients are more likely to have oligoclonal bands in CSF, higher IgG index in CSF, and higher circulating plasmablasts in blood than W MS patients. It is unknown whether the proportion of B-cells in CSF differs between AA and W patients in MS. METHODS: Demographics, disease-related information, treatment history were retrospectively collected on patients with MS who self-identified as AA or W and underwent flow cytometry of CSF during diagnostic work-up. Proportion of B-lymphocytes, T-lymphocytes, NK cells, monocytes, and plasma cells were analyzed with flow cytometry. RESULTS: 20 AA and 56 W MS patients fulfilled our inclusion criteria. The groups had similar demographics, CSF cell counts, protein and glucose CSF concentrations, and oligoclonal band number. IgG index was higher in AA compared to W (1.08 vs. 0.85, p = 0.031). AA had higher proportions of CD19+ (5.46 % AA vs. 2.26 % W, p = 0.006) and CD20+ (4.64 % AA vs. 1.91 % W, p = 0.004) cells but did not significantly differ in proportion of CD4+, CD8+, CD38+ bright B-cells, NK cells and monocytes. CONCLUSIONS: B-cells are overrepresented in the CSF of African American patients with MS relative to Whites.

The role of intrathecal free light chains kappa for the detection of autoimmune encephalitis in subacute onset neuropsychiatric syndromes.

Intrathecal synthesis of free light chains kappa (FLCK) is increasingly recognized as a marker of inflammatory CNS pathologies. Here, we tested the performance of FLCK in differentiating autoimmune encephalitis (AIE) from non-inflammatory etiologies in subacute onset neuropsychiatric syndromes. Patients undergoing diagnostic work-up for suspected autoimmune encephalitis at our department between 2015 and 2020 were retrospectively assessed for definitive diagnosis, available CSF and blood samples, as well as complete clinical records. Intrathecal FLCK was measured along with established CSF markers of CNS inflammation. The study cohort consisted of 19 patients with antibody-mediated AIE (AIE+), 18 patients with suspected AIE but without detectable autoantibodies (AIE-), 10 patients with infectious (viral) encephalitis (INE), and 15 patients with degenerative encephalopathies (DGE). 25 age- and sex-matched patients with non-inflammatory neurological diseases (NIND) were used as a control group. All AIE+ patients exhibited intrathecal synthesis of FLCK compared to only 39% of AIE- patients and 81% of patients in the INE group. No intrathecal synthesis of FLCK was found in DGE and NIND patients. While intrathecal FLCK was equally specific for an inflammatory etiology as oligoclonal bands (OCB) in the cerebrospinal fluid (CSF), the sensitivity of intrathecal FLCK for any inflammatory intrathecal process was higher than that of OCB (83% vs. 38%). Intrathecal FLCK synthesis was found to discriminate AIE+ from non-inflammatory encephalopathies and AIE- when the CSF cell count was normal [receiver operating characteristic (ROC) analysis area under the curve (AUC): 0.867, p = 0.002], while it failed to differentiate between AIE+ and INE in the presence of CSF pleocytosis (AUC: 0.561, p = 0.607). In conclusion, in the absence of CSF pleocytosis, intrathecal FLCK discriminated AIE+ from competing diagnoses in our cohort of subacute onset neuropsychiatric syndromes. In addition to established markers of CSF inflammation, intrathecal FLCK might support clinical decision-making and contribute to selecting patients for (repeated) antibody testing.

A multicenter study of radiologically isolated syndrome in children and adolescents: Can we predict the course?

OBJECTIVES: To evaluate clinical characteristics, imaging features and etiological profile of Radiologically Isolated Syndrome (RIS) along with clinical and radiological follow-up. METHODS: Demographic, clinical and radiological data of patients younger than 18 years fulfilling the criteria for RIS were retrospectively analyzed. RIS was defined by the detection of lesions meeting the revised 2010 McDonald Criteria for dissemination in space on magnetic resonance imaging (MRI) in the absence of any symptoms of demyelinating disease or an alternative cause for the MRI findings. RESULTS: There were total 69 patients (38 girls, 31 boys). The median age at index MRI was 15.7 years, and median follow-up time was 28 months. The most common reason for neuroimaging was headache (60.9%). A first clinical event occurred with median 11 months in 14/69 (20%) of cases. Those with oligoclonal bands (OCB) in cerebrospinal fluid (CSF) and follow-up longer than 3 years were more likely to experience a clinical event (p<0.05): 25% of those with OCB manifested clinical symptoms within the first year and 33.3% within the first two years compared to 6.3% and 9.4%, respectively in those without OCB. Radiological evolution was not associated with any variables: age, sex, reason for neuroimaging, serum 25-hydroxyvitamin D level, elevated IgG index, OCB positivity, total number and localization of lesions, presence of gadolinium enhancement, achievement of 2005 criteria for DIS and duration of follow-up. CONCLUSION: Children and adolescents with RIS and CSF OCB should be followed-up for at least 3 years in order to detect any clinical symptoms suggestive of a demyelinating event. Because disease-modifying treatments are not approved in RIS and no consensus report justifies their use especially in pediatric RIS, close follow-up of OCB-positive patients is needed for early recognition of any clinical event and timely initiation of specific treatment.

Biochemical biomarkers for multiple sclerosis.

INTRODUCTION: Multiple sclerosis (MS) is the most frequent demyelinating disease of the central nervous system. Although there is currently no definite cure for MS, new therapies have recently been developed based on a continuous search for new biomarkers. DEVELOPMENT: MS diagnosis relies on the integration of clinical, imaging and laboratory findings as there is still no singlepathognomonicclinical feature or diagnostic laboratory biomarker. The most commonly laboratory test used is the presence of immunoglobulin G oligoclonal bands (OCB) in cerebrospinal fluid of MS patients. This test is now included in the 2017 McDonald criteria as a biomarker of dissemination in time. Nevertheless, there are other biomarkers currently in use such as kappa free light chain, which has shown higher sensitivity and specificity for MS diagnosis than OCB. In addition, other potential laboratory tests involved in neuronal damage, demyelination and/or inflammation could be used for detecting MS. CONCLUSIONS: CSF and serum biomarkers have been reviewed for their use in MS diagnosis and prognosis to stablish an accurate and prompt MS diagnosis, crucial to implement an adequate treatment and to optimize clinical outcomes over time.

Free light chains as a reliable biomarker of intrathecal synthesis in the diagnosis of CNS inflammatory diseases.

OBJECTIVE: To address the diagnostic performances of cerebrospinal fluid (CSF) free light chains (FLC) measurements compared to oligoclonal bands (OCB) to support multiple sclerosis (MS) diagnosis. RESULTS: kFLC index showed the highest diagnostic accuracy to detect MS patients with the highest AUC compared to OCB, IgG index, IF kFLC R, kFLC H, λFLC index and IF λFLC. CONCLUSIONS: FLC indices are biomarkers of intrathecal Immunoglobulin synthesis and central nervous system (CNS) inflammation. kFLC index can discriminate between MS and other CNS inflammatory disorders, while λFLC index is less informative for MS but can play a role to support the diagnosis of other inflammatory CNS disorders.

Determination of sensitivities and specificities of cerebrospinal fluid free light chains to diagnose multiple sclerosis- a multicentric case-control study.

BACKGROUND: CSF free light chains help diagnose multiple sclerosis, but no data is available on the Asian population. Our objective was to study the diagnostic utility of CSF free light chains for diagnosing multiple sclerosis in Indian patients. METHODS: Prospective multicentric case-control study. Cases included those who were tested for oligoclonal bands and fulfilled the modified McDonald criteria 2017 for multiple sclerosis and clinically isolated syndromes. Those tested for oligoclonal bands (OCB) but with other diagnoses- inflammatory and non-inflammatory were included as controls. Clinical details were collected from electronic medical records. CSF and serum kappa and lambda free light chains were measured, apart from oligoclonal bands, immunoglobulin, and albumin in paired serum and CSF samples. RESULTS: There were 70 patients (31 cases and 39 controls). The mean age was 43.41(SD 16.073) years, and 43(61.4%) were females. CSF kappa showed highest specificity 97.4%, at a cut off 2.06 mg/L (sensitivity 71%) and highest sensitivity 90.3%, at a cut off 0.47 mg/L (specificity 79.5%). Best balance of sensitivity and specificity for CSF kappa was seen at a cut-off of ≥ 0.63 mg/L {sensitivity 87·1 (CI - 70.17-96.37), and specificity 87·18 (CI -72.57-95.70)}. The ratio of Kappa/lambda showed highest specificity of 100%(similar to OCB) with a sensitivity of 71% at a cut off of 1.72. The ratio of sum of kappa and lambda light chains, and Qalb (∑CSF FLC/Qalb), showed the highest specificity (94.87%)among the blood brain barrier corrected ratios. CONCLUSION: This study showed that the diagnostic utility of CSF kappa was comparable to OCB to diagnose multiple sclerosis in sensitivity, but not specificity, so can be a screening test before testing for OCB in our population.

No evidence of oligoclonal bands, intrathecal immunoglobulin synthesis and B cell recruitment in acute ischemic stroke.

BACKGROUND: Within the past 10 years, immune mechanisms associated with acute ischemic stroke (AIS) have been brought into focus, but data on B cell activation and intrathecal Ig production is still scarce. In this study, we determined the prevalence of an elevated IgG index, positive oligoclonal bands (OCBs) and chemokine C-X-C motif ligand 13 (CXCL13) levels in the cerebrospinal fluid (CSF) as markers of intrathecal IgG synthesis and B cell activation in patients with AIS. METHODS: In a retrospective study we analyzed the cerebrospinal fluid (CSF) from 212 patients with AIS from December 2013 to May 2018 assessing intrathecal Ig synthesis, OCBs and CXCL13 concentrations. RESULTS: Overall, 5.7% (12/212) of AIS patients showed an intrathecal IgG synthesis, 0.5% (1/212) with isolated elevated IgG index, 5.2% (7/136) isolated positive OCBs and 2.9% (4/136) both elevated IgG index and positive OCBs. CXCL13 levels were elevated in 3.6% (3/83) of the patients. Approximately one third of these patients had simultaneously chronic inflammatory CNS disease (multiple sclerosis, neuromyelitis optica spectrum disorder, neurosarcoidosis). There was no significant association between CSF findings and stroke characteristics including vascular territory, localization, volume, etiology, acute treatment, or blood-brain barrier dysfunction. Intrathecal IgG synthesis was more common in patients with prior stroke. Longitudinal CSF analysis did not reveal any newly-occurring, but instead mostly persistent or even disappearing intrathecal IgG synthesis after AIS. CONCLUSIONS: We found no evidence of a relevant B cell recruitment and intrathecal IgG synthesis in patients with AIS. In fact, the occurrence of intrathecal IgG synthesis was associated with concurrent chronic inflammatory CNS disease or previous stroke. Consequently, in patients with first-ever AIS and intrathecal IgG synthesis, physicians should search for concomitant inflammatory CNS disease.

Performance of McDonald 2017 multiple sclerosis diagnostic criteria and evaluation of genetic ancestry in patients with a first demyelinating event in Argentina.

BACKGROUND: Information on performance of multiple sclerosis (MS) diagnostic criteria is scarce for populations from Latin America, Asia, or the Caribbean. OBJECTIVE: To assess performance of revised 2017 McDonald criteria as well as evaluate genetic ancestry in a group of MS patients from Argentina experiencing a debut demyelinating event. METHODS: Demographic and clinical characteristics, cerebrospinal fluid (CSF), and magnetic resonance imaging (MRI) findings and new T2 lesions were recorded at baseline and during relapses. Diagnostic accuracy in predicting conversion to clinically defined MS (CDMS) based on initial imaging applying revised 2017 criteria was evaluated and genetic ancestry-informative markers analyzed. RESULTS: Of 201 patients experiencing their first demyelinating event (median follow-up 60 months), CDMS was confirmed in 67. We found 2017 diagnostic criteria were more sensitive (84% vs 67%) and less specific (14% vs 33%) than 2010 criteria, especially in a group of patients revised separately, presenting positive oligoclonal bands (88% vs 8%). Genetic testing performed in 128 cases showed 72% of patients were of European ancestry and 27% presented genetic admixture. CONCLUSION: 2017 McDonald criteria showed higher sensitivity and lower specificity compared with 2010 criteria, shortening both time-to-diagnosis and time-to-treatment implementation.

Intrathecal versus Peripheral Inflammatory Protein Profile in MS Patients at Diagnosis: A Comprehensive Investigation on Serum and CSF.

Intrathecal inflammation plays a key role in the pathogenesis of multiple sclerosis (MS). To better elucidate its relationship with peripheral inflammation, we investigated the correlation between cerebrospinal fluid (CSF) and serum levels of 61 inflammatory proteins. Paired CSF and serum samples were collected from 143 treatment-naïve MS patients at diagnosis. A customized panel of 61 inflammatory molecules was analyzed by a multiplex immunoassay. Correlations between serum and CSF expression levels for each molecule were performed by Spearman's method. The expression of sixteen CSF proteins correlated with their serum expression (p-value < 0.001): only five molecules (CXCL9, sTNFR2, IFNα2, Pentraxin-3, and TSLP) showed a Rho value >0.40, suggesting moderate CSF/serum correlation. No correlation between inflammatory serum patterns and Qalb was observed. Correlation analysis of serum expression levels of these sixteen proteins with clinical and MRI parameters pinpointed a subset of five molecules (CXCL9, sTNFR2, IFNα2, IFNß, and TSLP) negatively correlating with spinal cord lesion volume. However, following FDR correction, only the correlation of CXCL9 remained significant. Our data support the hypothesis that the intrathecal inflammation in MS only partially associates with the peripheral one, except for the expression of some immunomodulators that might have a key role in the initial MS immune response.

Assessment of oligoclonal bands in cerebrospinal fluid and serum of dogs with meningoencephalitis of unknown origin.

BACKGROUND: Meningoencephalitis of unknown origin (MUO) is an inflammatory disease of the canine central nervous system (CNS) that shares several features with multiple sclerosis (MS) in humans. In approximately 95% of MS patients, ≥ two immunoglobulin G (IgG) oligoclonal bands (OCBs) are detectable exclusively in the cerebrospinal fluid (CSF). HYPOTHESIS/OBJECTIVES: To investigate OCBs in CSF and serum in dogs affected by MUO, intervertebral disc disease (IVDD), idiopathic epilepsy (IE), intracranial neoplasia (IN), steroid-responsive meningitis-arteritis (SRMA), and diseases outside the CNS. We hypothesize that the highest prevalence of CSF-specific OCBs (≥ two OCBs uniquely in the CSF) would be found in dogs affected by MUO. ANIMALS: Client-owned dogs (n = 121) presented to the neurology service due to neurological deficits. METHODS: Prospective study. Measurement of IgG concentration in CSF and serum via a canine IgG ELISA kit. OCB detection via isoelectric focusing (IEF) and immunoblot. RESULTS: Presence of CSF-specific OCBs was significantly higher in dogs with MUO (57%) compared to 22% in IN, 6% in IE, 15% in SRMA, 13% in IVDD, and 0% in the non-CNS group (p < .001). Dogs with MUO were 9.9 times more likely to show CSF-specific OCBs than all other diseases together (95% confidence interval, 3.7-26.4; p < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: MUO showed the highest prevalence of CSF-specific OCBs, indicating an inflammatory B cell response. Future studies are needed to evaluate the prevalence in the specific MUO subtypes and a possible similarity with human MS.

Cerebrospinal fluid kappa free light chains for the diagnosis of multiple sclerosis: A consensus statement.

Cerebrospinal fluid (CSF) analysis is of utmost importance for diagnosis and differential diagnosis of patients with suspected multiple sclerosis (MS). Evidence of intrathecal immunoglobulin G (IgG) synthesis proves the inflammatory nature of the disease, increases diagnostic certainty and substitutes for dissemination in time according to current diagnostic criteria. The gold standard to determine intrathecal IgG synthesis is the detection of CSF-restricted oligoclonal bands (OCBs). However, advances in laboratory methods brought up κ-free light chains (FLCs) as a new biomarker, which are produced in excess over intact immunoglobulins and accumulate in CSF in the case of central nervous system-derived inflammation. Overwhelming evidence showed a high diagnostic accuracy of intrathecal κ-FLC synthesis in MS with sensitivity and specificity of approximately 90% similar to OCB. κ-FLCs have advantages as its detection is fast, easy, cost-effective, reliable, rater-independent and returning quantitative results which might also improve the value of predicting MS disease activity. An international panel of experts in MS and CSF diagnostics developed a consensus of all participants. Six recommendations are given for establishing standard CSF evaluation in patients suspected of having MS. The panel recommended to include intrathecal κ-FLC synthesis in the next revision of MS diagnostic criteria as an additional tool to measure intrathecal immunoglobulin synthesis.

The Interpretation of Mirror Pattern Bands During Oligoclonal Immunoglobulin Isoelectric Focusing Electrophoresis: A Retrospective Study.

OBJECTIVE: Mirror patterns are incidental types that accompany the analysis of the oligoclonal band (OCB) in cerebrospinal fluid (CSF). However, their interpretation remains controversial. In this study, we analyzed all graphic results of mirror patterns from 86 patients to provide an optimal interpretation scheme for mirror patterns. METHODS: Matched CSF and serum specimens were obtained from patients with various neurological disorders that required OCB analysis. A total of 86 patients were screened and serum immunofixation electrophoresis (IFE) was performed in all 86. The interobserver agreement for interpreting mirror patterns by visual inspection was tested. The method agreement between the visual inspection and IFE was also evaluated. The CSF/serum albumin quotient (QALB) was calculated to determine the blood-brain barrier integrity of all patients. RESULTS: Of the 86 patients with mirror patterns, 19.8% (17/86) had typical mirror bands and most (80.2%) had atypical mirror bands. There was a good agreement between the 2 observers in interpreting typical mirror patterns. However, kappa statistics analysis showed poor agreement regarding the interpretation of atypical mirror bands by visual observation alone (kappa value, -0.026 to 0.314 between 2 observers). The disagreement was pronounced between the visual inspection and validation of IFE (kappa value, -0.0238 to 0.176 between the first observer and IFE; -0.322 to 0.118 between the second observer and IFE). The normal QALB rates in the type V groups were significantly higher than those in the type IV group and the positive QALB rates in the type IV were significantly higher than those in the type V. CONCLUSION: Visual inspection to interpret mirror pattern bands is unreliable. Considering the completely different clinical significance between type IV and type V and high risk of potential misinterpretations, it is necessary to perform IFE on all the atypical mirror types to discriminate atypical type IV from atypical type V.