Expression pattern of matrix metalloproteinases-2 and -9 and their tissue inhibitors in patients with chronic inflammatory demyelinating polyneuropathy

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.

Parameters Associated with the Required Drug Dose of Intravenous Immunoglobulin in Stable Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Background: Intravenous immunoglobulin (IVIg) is efficient and one of very few treatment options for patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). However, finding the optimal dose of IVIg for individual CIDP patients remains challenging. The dose of IVIg needs to be adjusted individually. Considering the high healthcare costs of IVIg therapy, the overtreatment of some patients seen in placebo studies and the shortage of IVIg we recently experienced, as well as identifying factors associated with the required dose of IVIg in maintenance treatment, is extremely important. Thus, in this retrospective study, we analyze characteristics of patients with stable CIDP, which are associated with the required drug dose. Methods: 32 patients with stable CIDP treated with IVIg between July 2021 and July 2022 were identified from our database and included in this retrospective study. Patients’ characteristics were registered, and parameters were identified that were associated with the IVIg dose. Results: Age, cerebrospinal fluid protein elevation, disease duration, delay between symptom onset/diagnosis, Inflammatory Neuropathy Cause and Treatment (INCAT) score, and Medical Research Council Sum Score (MRC SS) were significantly associated with the required drug dose. In addition, an association of age, sex, elevated CSF protein, time interval between symptom onset and diagnosis, and the MRC SS with the required IVIg dose could be demonstrated in the multivariable regression analysis. Conclusions: Our model, which is based on routine parameters that are simple to address in the clinical practice, can be useful in adjusting the IVIg dose in patients with stable CIDP.

Metalloproteinases and Tissue Inhibitors in Generalized Myasthenia Gravis. A Preliminary Study

INTRODUCTION

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have recently been proposed as promising biomarkers in different immune-mediated disorders. We evaluated the plasma levels of MMP-9 and MMP-2 and their tissue inhibitors TIMP-1 and TIMP-2 in a patients' cohort with generalized myasthenia gravis (MG).

METHODS

Plasma concentrations of MMP-9, MMP-2, TIMP-1 and TIMP-2 were evaluated in 14 patients with generalized MG and 13 age- and sex-matched healthy controls. The severity of disease was assessed by the modified Osserman classification.

RESULTS

Compared to the healthy subjects, MG patients had increased plasma concentrations of MMP-9, but reduced plasma levels of MMP-2 and TIMP-1. MG patients also showed a positive correlation between MMP-2 concentrations and disease severity. An increase in MMP-9 levels and MMP-9/TIMP-1 ratio and a decrease in MMP-2 levels and MMP-2/TIMP-2 ratio were detected in patients with generalized MG. Higher levels of MMP-2 correlated with greater disease severity.

DISCUSSION

Our preliminary findings suggest that MMPs and TIMPs could play a role in the pathogenesis of MG and might be associated with the risk of clinical deterioration.

Adherence and Reactogenicity to Vaccines against SARS-COV-2 in 285 Patients with Neuropathy: A Multicentric Study

Background: The safety of the new vaccines against SARS-CoV-2 have already been shown, although data on patients with polyneuropathy are still lacking. The aim of this study is to evaluate the adherence to SARS-CoV-2 vaccination, as well as the reactogenicity to those vaccines in patients affected by neuropathy. Methods: A multicentric and web-based cross-sectional survey was conducted among patients affected by neuropathy from part of South Italy. Results: Out of 285 responders, n = 268 were included in the final analysis and n = 258 of them (96.3%) were fully vaccinated. Adherence to vaccination was higher in patients with hereditary neuropathies compared to others, while it was lower in patients with anti-MAG neuropathy (all p < 0.05). The overall prevalence of adverse events (AEs) was 61.2% and its occurrence was not associated with neuropathy type. Being female and of younger age were factors associated with higher risk of AEs, while having an inflammatory neuropathy and steroids assumption were associated with a lower risk (all p < 0.05). Younger age, having had an AE, and COVID-19 before vaccination were factors associated with symptoms worsening after vaccination (all p < 0.05). (4) Conclusions: Patients with neuropathy showed a high level of adherence to COVID-19 vaccination. Safety of vaccines in patients with neuropathies was comparable to the general population and it was more favorable in those with inflammatory neuropathy.

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.

MMP-9 as a Biomarker for Predicting Hemorrhagic Strokes in Moyamoya Disease

Objective: This study was conducted in order to investigate the association of matrix metalloproteinase (MMP)-9 levels with phenotypes of moyamoya disease (MMD).

Methods: This study included plasma samples from 84 MMD patients. The clinical variables of these patients were reviewed from the medical record. The serum concentration of tight junction, adherens junction proteins, and MMPs (MMP-2 and MMP-9) was determined using the ELISA method. Patients with hemorrhagic-onset MMD were compared with those with ischemic-onset MMD.

Results: Compared with pediatric patients, the expression of MMP-9 was significantly higher, while the MMP-2 and vascular endothelial-cadherin were lower in adult patients. In adult subgroup analysis, hemorrhagic MMD patients exhibited significantly higher serum concentrations of MMP-9 compared with ischemic MMD patients. The ROC curve identified that a baseline serum MMP-9 level >1,011 ng/ml may be associated with spontaneous hemorrhage in adult MMD patients with 70.37% sensitivity and 71.88% specificity [area under curve (AUC), 0.73; 95% CI 0.597–0.864; P = 0.003]. A late Suzuki stage (>4) (OR 4.565, 95% CI 1.028–20.280, P = 0.046) and serum concentrations of MMP-9 >1,011 ng/ml (OR 7.218, 95% CI 1.826–28.533, P = 0.005) are risk predictors of hemorrhages in MMD patients. Hemorrhagic-type MMD patients had higher serum levels of MMP-9 and BBB permeability compared with ischemic-type MMD patients. Adult MMD patients had higher serum levels of MMP-9 and BBB permeability compared with pediatric patients.

Conclusions: MMP-9 might serve as a biomarker for hemorrhage prediction in MMD. Serum MMP-9 level >1,011 ng/ml is an independent risk factor of MMD hemorrhagic strokes.