Analysis of CSF D-Dimer to Identify Intrathecal Fibrin-Driven Autoimmunity in Patients With Multiple Sclerosis

Fibrinolysis associated proteins and lipopolysaccharide bioactivity in plasma and cerebrospinal fluid in multiple sclerosis

The coagulation cascade and fibrinolysis have links with neuroinflammation and increased activation of the coagulation system has been reported in MS patients. We quantified levels of D-dimer, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and the bioactivity of bacterial lipopolysaccharide (LPS) in cerebrospinal fluid (CSF) and plasma from newly diagnosed untreated MS patients and controls. These molecules showed multiple correlations with each other as well as with age, HLA-DRB1*15:01, body-mass-index and CSF IgG. Our results confirm previous findings of increased plasma PAI-1 and LPS in MS patients compared to controls indicating changes in platelet function and gut permeability in MS.

The Role of Peripheral Inflammatory Markers and Coagulation Factors in Patients with Central Nervous System (CNS) Immune Disease and Glioma

OBJECTIVE

Gliomas are associated with high rates of disability and mortality, and currently, there is a lack of specific and sensitive biomarkers for diagnosis. The ideal biomarkers should be detected early through noninvasive methods. Our research aims to develop a rapid, convenient, noninvasive diagnostic method for gliomas, as well as for grading and differentiation.

METHOD

We retrospectively collected data from patients who underwent surgery for glioma, trigeminal neuralgia/hemifacial spasmschwannoma, and those diagnosed with multiple sclerosis at our institution from January 2018 to December 2020. Inflammatory markers and coagulation factor levels were collected on admission, and neutrophil count (NLR), (WBC count minus neutrophil count) / lymphocyte count, platelet count / lymphocyte count, lymphocyte count / monocyte count, and albumin count [g/L] + total lymphocyte count × 5 were calculated for patients. Analyze the significance of biomarkers in the diagnosis and grading of gliomas, the diagnosis of MS, and the differential diagnosis of them.

RESULTS

We evaluated 155 healthy individuals, 64 trigeminal neuralgia/hemifacial spasm patients, 47 MS patients, 316 schwannoma patients, and 814 with glioma patients. Compared with healthy controls and MS group, the preoperative levels of NLR, (WBC count minus neutrophil count) / lymphocyte count, D-dimer, Fibrinogen, Antithrobin, and Factor VIII of glioma patients were significantly higher in glioma patients and positively correlated with the grade of glioma. Conversely, 0020 lymphocyte count / Monocyte count and albumin count [g/L] + total lymphocyte count × 5 were significantly lower and negatively correlated with glioma grading. ROC curves confirmed that for the diagnosis of glioma, NLR showed a maximum area under the curve value of 0.8616 (0.8322-0.8910), followed by D-dimer and Antithrombin, with area under the curve values of 0.8205 (0.7601-0.8809) and 0.8455 (0.8153-0.8758), respectively. NLR and d-dimer also showed great sensitivity in the diagnosis of MS and differential diagnosis with gliomas.

CONCLUSIONS

Our study demonstrated that multiple inflammatory markers and coagulation factors could be utilized as biomarkers for the glioma diagnosis, grading, and differential diagnosis of MS. Furthermore, the combination of these markers exhibited high sensitivity and specificity.

Evaluating the utility of serum NfL, GFAP, UCHL1 and tTAU as estimates of CSF levels and diagnostic instrument in neuroinflammation and multiple sclerosis

BACKGROUND

This study aimed to evaluate the utility of neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase L1 (UCHL1) and total tau (tTAU) serum concentrations as approximation for cerebrospinal fluid (CSF) concentrations of the respective biomarkers in the context of neuroinflammation and multiple sclerosis (MS).

METHODS

NfL, GFAP, UCHL1 and tTAU concentrations in serum and CSF were measured in 183 patients (122 with neuroinflammatory disease and 61 neurological or somatoform disease controls) using the single molecule array HD-1 analyzer (Quanterix, Boston, MA). Spearman's rank correlations were computed between serum and CSF concentrations. In a second step, the effects of age, BMI, gadolinium-enhancing lesions in MRI, integrity of the blood-brain barrier (BBB) and presence of acute relapse were accounted for by computing partial correlations. The analyses were repeated for a subsample consisting of MS phenotype patients only (n = 118). EDSS, MS disease activity and acute relapse were considered as additional covariates. Receiver operating characteristic (ROC) analysis was performed for each serum/CSF biomarker concentration to assess how well the particular biomarker concentration differentiates MS patients from somatoform disease controls. Correlations between serum and CSF levels as well as area under the curve (AUC) values were compared for the different biomarkers using z-test statistics.

RESULTS

Serum concentrations correlated positively with CSF levels for NfL (r = 0.705, p < 0.01) as well as for GFAP (r = 0.259, p < 0.01). Correlation coefficients were significantly higher for NfL than for GFAP (z = 5.492, p < 0.01). We found no significant serum-CSF correlations for UCHL1 or tTAU. After adjusting for covariates, the results remained unchanged. In the analysis focusing only on MS patients, the results were replicated. ROC analysis demonstrated similarly acceptable performance of serum and CSF NfL values in differentiating MS phenotype patients from somatoform disease controls. AUC values were significantly higher for serum and CSF NfL compared to other biomarkers.

CONCLUSION

NfL and GFAP but not UCHL1 or tTAU serum concentrations are associated with CSF levels of the respective biomarker. NfL exhibits more robust correlations between its serum and CSF concentrations as compared to GFAP independently from BBB integrity, clinical and radiological covariates. Both serum and CSF NfL values differentiate between MS and controls.

Matching proposed clinical and MRI criteria of aggressive multiple sclerosis to serum and cerebrospinal fluid markers of neuroaxonal and glial injury

BACKGROUND

Definitions of aggressive MS employ clinical and MR imaging criteria to identify highly active, rapidly progressing disease courses. However, the degree of overlap between clinical and radiological parameters and biochemical markers of CNS injury is not fully understood. Aim of this cross-sectional study was to match clinical and MR imaging hallmarks of aggressive MS to serum/CSF markers of neuroaxonal and astroglial injury (neurofilament light chain (sNfL, cNfL), and glial fibrillary acidic protein (sGFAP, cGFAP)).

METHODS

We recruited 77 patients with relapsing-remitting MS (RRMS) and 22 patients with clinically isolated syndrome. NfL and GFAP levels in serum and CSF were assessed using a single-molecule-array HD-1-analyzer. A general linear model with each biomarker as a dependent variable was computed. Clinical and imaging criteria of aggressive MS, as recently proposed by the ECTRIMS Consensus Group, were modeled as independent variables. Other demographic, clinical or laboratory parameters, were modeled as covariates. Analyses were repeated in a homogenous subgroup, consisting only of newly diagnosed, treatment-naïve RRMS patients presenting with an acute relapse.

RESULTS

After adjusting for covariates and multiplicity of testing, sNfL and cNfL concentrations were strongly associated with the presence of ≥2 gadolinium-enhancing lesions (psNfL = 0.00008; pcNfL = 0.004) as well as the presence of infratentorial lesions on MRI (psNfL = 0.0003; pcNfL < 0.004). No other clinical and imaging criteria of aggressive MS correlated significantly with NfL or GFAP in serum and CSF. In the more homogeneous subgroup, sNfL still was associated with the presence of ≥2 gadolinium-enhancing lesions (psNfL = 0.001), presence of more than 20 T2-lesions (psNfL = 0.049) as well as the presence of infratentorial lesions on MRI (psNfL = 0.034), while cNfL was associated with the presence of ≥2 gadolinium-enhancing lesions (psNfL = 0.011) and presence of more than 20 T2-lesions (psNfL = 0.029).

CONCLUSIONS

Among proposed risk factors for an aggressive disease course, MRI findings but not clinical characteristics correlated with sNfL and cNfL as a marker of neuroaxonal injury and should be given appropriate weight considering MS prognosis and therapy. No significant correlation was detected for GFAP alone.

Macrophage colony-stimulating factor and its role in the tumor microenvironment: novel therapeutic avenues and mechanistic insights

The tumor microenvironment is a complex ecosystem where various cellular and molecular interactions shape the course of cancer progression. Macrophage colony-stimulating factor (M-CSF) plays a pivotal role in this context. This study delves into the biological properties and functions of M-CSF in regulating tumor-associated macrophages (TAMs) and its role in modulating host immune responses. Through the specific binding to its receptor colony-stimulating factor 1 receptor (CSF-1R), M-CSF orchestrates a cascade of downstream signaling pathways to modulate macrophage activation, polarization, and proliferation. Furthermore, M-CSF extends its influence to other immune cell populations, including dendritic cells. Notably, the heightened expression of M-CSF within the tumor microenvironment is often associated with dismal patient prognoses. Therefore, a comprehensive investigation into the roles of M-CSF in tumor growth advances our comprehension of tumor development mechanisms and unveils promising novel strategies and approaches for cancer treatment.

Association of coagulation markers with the severity of white matter hyperintensities in cerebral small vessel disease

Background and purpose

This study aimed to explore the correlation and causal relationship between fibrinogen, D-dimer, and the severity of cerebral white matter hyperintensity (MMH).

Methods

A retrospective analysis of 120 patients with cerebral small vessel disease (CSVD) confirmed by head MRI attending the Third Affiliated Hospital of Beijing University of Traditional Chinese Medicine from August 2021 to February 2023 was performed. According to the Fazekas scale score, the patients were divided into 42 cases in the mild group, 44 cases in the moderate group, and 34 cases in the severe group. The levels of fibrinogen and D-dimer were compared among the three groups; the correlations between fibrinogen, D-dimer, and WMH severity were further analyzed; and independent risk factors for WMH severity were explored using the multivariate ordered logistic regression analysis. Furthermore, a two-sample Mendelian randomization (MR) analysis was performed to investigate the genetically predicted effect of fibrinogen and D-dimer on WMH.

Results

As the severity of WMH increased, the levels of D-dimer and fibrinogen also gradually increased, and the results showed a positive correlational association, with significant differences within the groups (all p < 0.05); the multivariate ordered logistic regression model showed that after adjusting for the relevant covariates, D-dimer (OR = 5.998, 95% CI 2.213-16.252, p < 0.001) and fibrinogen (OR = 9.074, 95% CI 4.054-20.311, p < 0.001) remained independent risk factors for the severity of WMH. In the MR study, the random-effect inverse variance weighted (IVW) model showed that increased levels of genetically predicted D-dimer (OR, 1.01; 95% confidence interval 0.95-1.06; p = 0.81) and fibrinogen (OR, 1.91; 95% confidence interval 0.97-3.78; p = 0.06) were not associated with increased risk of WMH. The authors did not obtain strong evidence of a direct causal relationship between D-dimer, fibrinogen, and WMH.

Conclusion

In this retrospective-based study, the authors found possible associations between D-dimer, fibrinogen, and WMH, but there was no obvious causal evidence. Further efforts are still needed to investigate the pathophysiology between D-dimer, fibrinogen, and WMH.

Blood-brain barrier dysfunction in multiple sclerosis: causes, consequences, and potential effects of therapies

Established by brain endothelial cells, the blood-brain barrier (BBB) regulates the trafficking of molecules, restricts immune cell entry into the CNS, and has an active role in neurovascular coupling (the regulation of cerebral blood flow to support neuronal activity). In the early stages of multiple sclerosis, around the time of symptom onset, inflammatory BBB damage is accompanied by pathogenic immune cell infiltration into the CNS. In the later stages of multiple sclerosis, dysregulation of neurovascular coupling is associated with grey matter atrophy. Genetic and environmental factors associated with multiple sclerosis, including dietary habits, the gut microbiome, and vitamin D concentrations, might contribute directly and indirectly to brain endothelial cell dysfunction. Damage to brain endothelial cells leads to an influx of deleterious molecules into the CNS, accelerating leakage across the BBB. Potential future therapeutic approaches might help to prevent BBB damage (eg, monoclonal antibodies targeting cell adhesion molecules and fibrinogen) and help to repair BBB dysfunction (eg, mesenchymal stromal cells) in people with multiple sclerosis.

Immunohistochemical evaluation of fibrin/fibrinogen, d-dimers, and intravascular thrombosis in brains of dogs with meningoencephalitis of unknown origin

Granulomatous meningoencephalitis (GME) and necrotizing encephalitides (NE) are the most common immune-mediated inflammatory diseases of the central nervous system in dogs. Activation of the fibrinolytic system in multiple sclerosis, a similar immune-mediated disease affecting the central nervous system in humans, seems to be related to disease progression. The aim of this study was to identify fibrin/fibrinogen and D-dimer deposition, as well as presence of intravascular thrombosis (IVT) in brains of dogs with a diagnosis of GME or NE. Immunohistochemical studies using antibodies against fibrin/fibrinogen and D-dimers were performed. Statistical analyses were performed to determine whether there were differences in the presence and location of fibrin/fibrinogen, D-dimers deposits, and IVT between GME and NE. Samples from sixty-four dogs were included in the study: 32 with a diagnosis of GME and 32 with a diagnosis of NE. Fibrin/fibrinogen depositions were detected in all samples and d-dimers were detected in 43/64 samples. IVT was present in 29/64 samples, with a significantly higher score in samples from dogs with NE than in samples from dogs with GME (P = 0.001). These data support hemostatic system activation in both diseases, especially NE. This finding might be related to the origin of the necrotic lesions seen in NE, which could represent chronic ischemic lesions. Further studies are needed to investigate the association between vascular lesions and the histopathological differences between GME and NE and the hemostatic system as a potential therapeutic target.

Effect of Estimated Blood Volume and Body Mass Index on GFAP and NfL Levels in the Serum and CSF of Patients With Multiple Sclerosis

BACKGROUND AND OBJECTIVES

To increase the validity of biomarker measures in multiple sclerosis (MS), factors affecting their concentration need to be identified. Here, we test whether the volume of distribution approximated by the patients' estimated blood volume (BV) and body mass index (BMI) affect the serum concentrations of glial fibrillary acidic protein (GFAP). As a control, we also determine the relationship between BV/BMI and GFAP concentrations in CSF. To confirm earlier findings, we test the same hypotheses for neurofilament light chain (NfL).

METHODS

NfL and GFAP concentrations were measured in serum and CSF (sNFL/sGFAP and cNFL/cGFAP) in 157 patients (n = 106 with MS phenotype and n = 51 with other neurologic/somatoform diseases). Using multivariate linear regressions, BV was tested in the MS cohort as a predictor for each of the biomarkers while controlling for age, sex, MS phenotype, Expanded Disability Status Scale score, gadolinium-enhancing lesions, and acute relapse. In addition, overweight/obese patients (BMI ≥25 kg/m2) were compared with patients with BMI <25 kg/m2 using the general linear model. The analyses were repeated including the neurologic/somatoform controls.

RESULTS

In the MS cohort, BV predicted sGFAP (ß = -0.301, p = 0.014). Overweight/obese patients with MS had lower sGFAP concentrations compared with patients with MS and BMI <25 kg/m2 (F = 4.732, p = 0.032). Repeating the analysis after adding patients with other neurologic/somatoform diseases did not change these findings (ß = -0.276, p = 0.009; F = 7.631, p = 0.006). Although sNfL was inversely correlated with BV (r = -0.275, p = 0.006) and body weight (r = -0.258, p = 0.010), those results did not remain significant after adjusting for covariates. BV and BMI were not associated with cGFAP or cNfL concentrations.

DISCUSSION

These findings support the notion that the volume of distribution of sGFAP approximated by BV and BMI is a relevant variable and should therefore be controlled for when measuring sGFAP in MS, while this might not be necessary when measuring cGFAP concentrations.

Elevated plasma D-dimer levels in patients with anti-N-methyl-D-aspartate receptor encephalitis

PURPOSE

We aimed to explore the difference in coagulation function between healthy individuals and patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis and its relationship with disease severity.

METHODS

We retrospectively compared coagulation function in 161 patients with first-attack anti-NMDAR encephalitis and 178 healthy individuals. The association between D-dimer levels and disease severity was analyzed using binary logistic regression. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of D-dimer levels for the severity of anti-NMDAR encephalitis.

RESULTS

Compared to control individuals, patients with anti-NMDAR encephalitis had higher D-dimer levels (median 0.14 vs. 0.05 mg/L, p < 0.001), blood white blood cell (WBC) count (median 8.54 vs. 5.95 × 109/L, p < 0.001), and neutrophil count (median 6.14 vs. 3.1 × 109/L, p < 0.001). D-dimers (median 0.22 vs. 0.10 mg/L, p < 0.001), blood WBC count (median 9.70 vs. 7.70 × 109/L, p < 0.001), neutrophil count (median 7.50 vs. 4.80 × 109/L, p < 0.001), and C-reactive protein (median 2.61 vs. 1.50 mg/l, p = 0.017) were higher; however, eosinophils (median 0.02 vs. 0.06 × 109/L, p < 0.001), and blood calcium (median 2.26 vs. 2.31 mmol/L, p = 0.003) were lower in patients with severe forms of anti-NMDAR encephalitis than in those with mild to moderate forms, and were associated with initial modified Rankin Scale scores. Multivariate analysis showed that D-dimer levels were significantly associated with severity [odds ratio =2.631, 95% confidence interval (CI) = 1.018-6.802, p = 0.046]. The ROC curve was used to analyze the predictive value of D-dimer levels for disease severity. The area under the curve was 0.716 (95% CI = 0.64-0.80, p < 0.001), and the best cut-off value was D-dimer = 0.147 mg/L (sensitivity 0.651; specificity, 0.705).

CONCLUSION

Serum D-dimer and neutrophil levels were independent predictors of disease severity in patients with first-attack anti-NMDAR encephalitis.

Measurement of D-dimer in cerebrospinal fluid using a luminescent oxygen channeling immunoassay

Background

Measurement of D-dimer in cerebrospinal fluid (CSF) allows insight into coagulation system activation in the central nervous system and can be utilized to monitor intracranial hemorrhage as well as acute phase processes beyond hemostasis in inflammatory and neoplastic diseases. So far, the measurability of D-dimer in low and very low concentrations in CSF was limited in conventional immunoassays. Novel high-sensitivity chemiluminescent immunoassays such as the luminescent oxygen channeling immunoassay (LOCI^®) are getting increasingly available but have not been validated in CSF. The aim of this study was to investigate the accuracy and linearity of the LOCI^® in assessing D-dimer in CSF.

Methods

INNOVANCE LOCI hs D-dimer reagent cartridge was used for the measurement of D-dimer in CSF of patients with different neurological diseases. For the evaluation of linearity, dilution series were performed in a pooled CSF sample with the determination of intra-assay precision (CV, coefficient of variation) in 3 individual samples with 20 replicates. Furthermore, D-dimer concentrations measured by LOCI^® were compared with the respective results of a routinely available clinical latex-enhanced immunoassay (HemosiIL D-Dimer HS 500).

Results

Linear regression analysis of the LOCI^® method revealed a r² of 1.00 (p < 0.001) with a regression coefficient B of 1.012 ± 0.003 (CI: 1.005–1.019, p < 0.001) and an intercept of −1.475 ± 1.309 (CI: −4.493 to 1.543); the median intra-assay CV was 0.69% (range: 0.68–0.75). In total, 185 CSF samples were measured by LOCI^® technology, showing a mean concentration of 204.84 ± 2,214.93 ng/ml. D-dimer concentration between LOCI and latex-enhanced immunoassay differed by a factor of 10.6 ± 13.6 on average with a maximum deviation by a factor of 61.3; the maximum deviation was found at low concentrations.

Conclusion

D-dimer in CSF of patients with neurological disease can be reliably measured by the LOCI^® method with high linearity and accuracy at low concentrations.