Circulating levels of tight junction proteins in multiple sclerosis: Association with inflammation and disease activity before and after disease modifying therapy.

BACKGROUND: Tight junction proteins contribute to maintenance of epithelial and endothelial barriers such as the intestinal barrier and the blood brain barrier (BBB). Increased permeability of these barriers has been linked to disease activity in MS and there is currently a lack of easily accessible biomarkers predicting disease activity in MS. AIM: To investigate whether levels of circulating tight junction proteins occludin and zonula occludens-1 (ZO-1) are associated with biomarkers of inflammation and disease activity; and to determine whether they could serve as clinical biomarkers. METHODS: We prospectively included 72 newly diagnosed patients with relapsing remitting MS or clinically isolated syndrome with no prior disease modifying therapy (DMT) use and 50 healthy controls (HCs). Patients were followed with blood samples, 3 tesla MRI, and clinical evaluation for 12 months. Occludin, ZO-1, calprotectin and soluble urokinase-type plasminogen activator receptor (suPAR) were measured by ELISA; serum neurofilament light (NfL) and IL-6 by single-molecule array (SIMOA). The mRNA expression of IFNG, IL1R1, IL10, IL1B, ARG1 and TNF was measured by quantitative real time polymerase chain reaction (qPCR) in whole blood. RESULTS: Plasma occludin levels were higher in MS patients compared with HCs. After 12 months on DMT, occludin levels were reduced by approximately 25% irrespective of 1st or 2nd line DMT (p<0.001). Furthermore, NfL and calprotectin levels were significantly reduced by 31% and 29%, respectively. Occludin and ZO-1 did not correlate with biomarkers of inflammation and did not predict disease activity at baseline or after 12 months. CONCLUSIONS: Higher levels of occludin suggest an increased permeability of the BBB and/or the intestinal barrier in MS patients. The reduction of occludin after 12 months on DMTs might reflect repair of these barriers upon treatment. However, plasma levels of ZO-1 and occludin could not predict clinical or MRI disease activity as determined by regression and ROC-curve analysis. Our results do not indicate a clear clinically relevant role for circulating tight junction proteins as biomarkers of disease activity in MS and further investigations in larger cohorts are needed to clarify this issue.

Biomarkers of inflammation and epithelial barrier function in multiple sclerosis.

BACKGROUND: There is a lack of reliable biomarkers predicting disability and disease activity in multiple sclerosis (MS). Recent evidence suggests an involvement of intestinal and pulmonary epithelial barrier function related to immune activation and the pathophysiology of MS. Blood biomarkers of epithelial barrier function have, however, not been widely studied in MS. OBJECTIVE: To examine biomarkers of inflammation and epithelial barrier function in relapsing remitting MS (RRMS) patients compared with healthy controls (HCs), and to assess associations between biomarkers and disease activity. METHODS: A panel of 30 biomarkers were measured in serum or plasma from 49 newly diagnosed, untreated RRMS patients and 58 HCs with electrochemiluminescence or ELISA. Neurofilament light chain (NfL) was measured with single-molecule array. Validation was performed in a second independent cohort of 68 newly diagnosed, treatment naive RRMS patients and 50 HCs. Patients were divided into groups of active and inactive disease based on NfL levels and the presence of gadolinium enhancing magnetic resonance imaging lesions. RESULTS: Patients with active MS showed significantly higher serum levels of calprotectin and soluble urokinase plasminogen activator receptor compared with inactive MS in the exploratory cohort. Validation confirmed higher levels of calprotectin in active compared with inactive MS, and HCs. Biomarkers of intestinal and pulmonary epithelial barrier function did not differ significantly between groups. CONCLUSIONS: The measured biomarkers of epithelial barrier function do not seem to play a major role in the pathophysiology of MS, but serum calprotectin could represent a clinically useful biomarker of innate immune activation and disease activity.

Cerebrospinal fluid levels of chitinase 3-like 1 and neurofilament light chain predict multiple sclerosis development and disability after optic neuritis.

BACKGROUND: Cerebrospinal fluid (CSF) biomarkers have been suggested to predict multiple sclerosis (MS) after clinically isolated syndromes, but studies investigating long-term prognosis are needed. OBJECTIVE: To assess the predictive ability of CSF biomarkers with regard to MS development and long-term disability after optic neuritis (ON). METHODS: Eighty-six patients with ON as a first demyelinating event were included retrospectively. Magnetic resonance imaging (MRI), CSF leukocytes, immunoglobulin G index and oligoclonal bands were registered. CSF levels of chitinase-3-like-1, osteopontin, neurofilament light-chain, myelin basic protein, CCL2, CXCL10, CXCL13 and matrix metalloproteinase-9 were measured by enzyme-linked immunosorbent assay. Patients were followed up after 13.6 (range 9.6-19.4) years and 81.4% were examined, including Expanded Disability Status Scale and MS functional composite evaluation. 18.6% were interviewed by phone. Cox regression, multiple regression and Spearman correlation analyses were used. RESULTS: Forty-six (53.5%) developed clinically definite MS (CDMS) during follow-up. In a multivariate model MRI (p=0.0001), chitinase 3-like 1 (p=0.0033) and age (p=0.0194) combined predicted CDMS best. Neurofilament light-chain predicted long-term disability by the multiple sclerosis severity scale (p=0.0111) and nine-hole-peg-test (p=0.0202). Chitinase-3-like-1 predicted long-term cognitive impairment by the paced auditory serial addition test (p=0.0150). CONCLUSION: Neurofilament light-chain and chitinase-3-like-1 were significant predictors of long-term physical and cognitive disability. Furthermore, chitinase-3-like-1 predicted CDMS development. Thus, these molecules hold promise as clinically valuable biomarkers after ON as a first demyelinating event.

Progression and CSF Inflammation after Eradication of Oligoclonal Bands in an MS Patient Treated with Allogeneic Hematopoietic Cell Transplantation for Follicular Lymphoma.

BACKGROUND: Allogeneic hematopoietic cell transplantation (allo-HCT) has been proposed as treatment for multiple sclerosis (MS) and other autoimmune diseases. AIMS: To describe the effects of allo-HCT on the course of MS in a 49-year-old woman with longstanding progressive MS who was treated with allo-HCT for follicular lymphoma. METHODS: Non-myeloablative conditioning allo-HCT, examination for IgG oligoclonal bands and measurement of CXCL13 and matrix metalloproteinase-9 (MMP-9) concentration in the cerebrospinal fluid (CSF). RESULTS: Despite the disappearance of oligoclonal bands in CSF, disease progression and CSF inflammation was observed. CONCLUSIONS: We hypothesize that CXCL13 and MMP-9 detected in CSF may reflect ongoing, pathogenic immune activation even after the eradication of intrathecal IgG synthesis. This suggests that progressive MS may depend more on innate than on adaptive immune activation.

Neutralizing antibodies hamper IFNbeta bioactivity and treatment effect on MRI in patients with MS.

We measured neutralizing antibodies (NABs) and the in vivo biologic response to interferon-beta on neopterin and beta(2)-microglobulin blood levels. All NAB-negative patients had an in vivo biologic response (full or partial), whereas all high-level positive patients had no response. High-level NAB patients had more MRI activity than NAB-negative patients (p = 0.031). Patients with a full response had less MRI activity than patients without biologic response (p = 0.032).

CD8+ T cell activation correlates with disease activity in clinically isolated syndromes and is regulated by interferon-beta treatment.

An increased percentage of blood CD8+ T cells from patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS) was found to express CD26 and CD69. The percentage of CD26 or CD69 positive CD8+ T cells was higher in patients with MRI evidence of disease dissemination in space or with active MRI lesions than in the remaining patients. Treatment of MS with interferon (IFN)-beta resulted in a decrease in the percentage of CD26 and CD71 positive CD8+ T cells and an increase in the percentage of CD8+ T cells that expressed interleukin (IL)-10 and IL-13. CD8+ T cell activation in MS may be linked to disease activity already at disease onset, and is regulated by treatment with IFN-beta.

CD4 T cell activation and disease activity at onset of multiple sclerosis.

We studied CD4 T cell activation in patients with clinically isolated syndromes (CIS) suggesting an initial attack of multiple sclerosis. The percentage of blood CD26+ CD4 T cells was increased in these patients, and correlated with magnetic resonance imaging disease activity and clinical disease severity. In contrast, the percentage of CD25+ CD4 T cells in cerebrospinal fluid correlated negatively with the cerebrospinal fluid concentration of myelin basic protein and the presence of IgG oligoclonal bands. These results suggest that distinct systemic and intrathecal T cell activation states correlate with disease activity and risk of subsequently developing MS in CIS patients.

Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis.

The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed a reduced blood oxygenation level dependent (BOLD) signal increase and a greater asymmetry in the visual cortex, compared with controls. The volume of visual cortical activation was significantly correlated to the result of the contrast sensitivity test. The BOLD signal increase correlated significantly to both the results of the contrast sensitivity test and to the Snellen visual acuity. Our results indicate that fMRI is a useful method for the study of ON, even in cases where the visual acuity is severely impaired. The reduction in activated volume could be explained as a reduced neuronal input; however, the greater asymmetry might point to a cortical reorganization as a consequence of neuronal damage. Future fMRI studies in ON will add to the understanding of the neural adaptive behaviour following ON.

Diagnostic challenges in combined multiple sclerosis and centronuclear myopathy.

The first case of combined centronuclear myopathy and multiple sclerosis is reported. The difficulties of diagnosing multiple sclerosis in patients with muscular disorders associated with the central nervous system involvement are discussed.