INCAT disability score: a critical analysis of its measurement properties

Efgartigimod in the treatment of Guillain-Barré syndrome

BACKGROUND

Guillain-Barré Syndrome (GBS) is caused by immunoglobulin G (IgG) autoantibodies. Efgartigimod, a human IgG antibody Fc fragment that acts as a natural ligand for the FcRn, can increase IgG degradation, which thus may be a promising therapeutic drug for GBS.

CASE PRESENTATION

The two patients presented with postinfectious and acute flaccid paralysis. On admission, they were bedridden. Nerve conduction studies indicated peripheral neuropathy. GBS was suspected and they are treated with two doses of efgartigimod (10 mg/kg) within 5 days. Their muscle strength improved gradually and 4 weeks after the initial dose, they could walk independently. Following the first dose, Patient 1 complaint of muscle soreness, which subsided the next morning. Patient 2 was intubated due to respiratory failure the day after the initial dose, and did not report other adverse effects.

DISCUSSION

In GBS patients, two doses of efgartigimod (10 mg/kg) were effective in rapidly improving muscle strength, with a satisfactory safety profile. The findings suggest a potential role for efgartigimod in modifying the disease process in GBS patients.

CONCLUSION

Efgartigimod seems effective and safe in the treatment of GBS. This study indicates the potential role of efgartigimod as a novel treatment option for GBS. Well-designed clinical trials should be conducted.

Case report: Chronic inflammatory demyelinating polyneuropathy superimposed on Charcot-Marie-tooth type 1A disease after SARS-CoV-2 vaccination and COVID-19 infection

Background

There is growing evidence that severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or COVID-19 infection is associated with the development of immune mediated neuropathies like chronic inflammatory demyelinating polyneuropathy (CIDP), but the impact of SARS-CoV-2 vaccination and COVID-19 infection on genetic disorders such as Charcot-MarieTooth (CMT) remains unclear.

Case presentation

A 42-year-old male with occulted CMT neuropathy type lA (CMT1A) who developed limb numbness and weakness after the second SARS-CoV-2-vaccination was confirmed by identifying characteristic repeats in the p11.2 region of chromosome 17. Due to the progressive deterioration of muscle strength over 8 weeks, limb atrophy, moderately elevated protein counts in the cerebrospinal fluid, and significant improvement with intravenous human immunoglobulin, which were characteristic of acquired inflammatory neuropathies, he was eventually diagnosed with CIDP superimposed on CMT1A. However, after a three-month plateau, the patient contracted COVID-19, which led to repeated and worsening symptoms of limb weakness and atrophy, thus was diagnosed with a recurrence of CIDP and treated with Intravenous immunoglobulin and methylprednisolone 500 mg/d for 5 consecutive days, followed by oral prednisone and mycophenolate mofetil tablets. On 2 month follow-up, he exhibited remarkable clinical improvement and could walk independently with rocking gait. After 1 year of follow-up, the patient's condition was stable without further change.

Conclusion

Our case indicates that CMT1A can deteriorate after SARS-CoV-2 vaccination. Thus, SARS-CoV-2 vaccination should be considered a potential predisposing factor for CMT1A worsening. The possible superposition of CMTIA and CIDP in the context of SARS-CoV-2 infection or immunity suggests that any clinical exacerbation in patients with CMT1A should be carefully evaluated to rule out treatable superposition inflammation. In addition, electrophysiological and imaging examination of the proximal nerves, such as the axillary nerve, is helpful for the diagnosis of CIDP.

Therapeutic Outcomes and Electrophysiological Biomarkers in Anti-Myelin-Associated Glycoprotein Neuropathy: A Multicenter Cohort Study in South Korea

BACKGROUND AND PURPOSE

Unlike other immune-mediated neuropathies, anti-myelin-associated glycoprotein (MAG) neuropathy is often refractory to immunotherapy. It is necessary to compare the relative efficacies of various immunotherapies and develop objective biomarkers in order to optimize its clinical management.

METHODS

This study recruited 91 patients with high anti-MAG antibody titers from 7 tertiary hospitals in South Korea. We analyzed the baseline characteristics, therapeutic outcomes, and nerve conduction study (NCS) findings of 68 patients and excluded 23 false positive cases.

RESULTS

The rate of positive responses to treatment was highest using zanubrutinib (50%) and rituximab (36.4%), followed by corticosteroids (16.7%), immunosuppressants (9.5%), intravenous immunoglobulin (5%), and plasma exchange (0%). Disability and weakness were significantly associated with multiple NCS parameters at the time of diagnosis, especially distal compound muscle action potential (CMAP) amplitudes. Moreover, the longitudinal trajectory of the average CMAP amplitudes paralleled the clinical courses, with a 16.2 percentile decrease as an optimal cutoff for predicting a clinical exacerbation (area under the receiver operating characteristic curve=0.792).

CONCLUSIONS

Our study supports the use of NCS as an objective marker for estimating disease burden and tracking clinical changes in patients with anti-MAG neuropathy. We have described the beneficial effects of rituximab and a new drug, zanubrutinib, compared with conventional immunotherapies.

Effectiveness and safety of rituximab in autoimmune nodopathy: a single-center cohort study

Autoimmune nodopathy is a peripheral neuropathy characterized by acquired motor and sensory deficit with autoantibodies against the node of Ranvier or paranodal region in the peripheral nervous system. The clinical and pathological characteristics of the disease are distinct from that of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and the standard treatment for CIDP is partially effective. Rituximab is a chimeric monoclonal antibody which binds and depletes B cells in peripheral blood. This prospective observational study included 19 patients with autoimmune nodopathy. Participants received intravenous rituximab treatment 100 mg the first day and 500 mg the next day and given every 6 months. The Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, Inflammatory Rasch-Built Overall Disability Scale (I-RODS), Medical Research Council (MRC) sum score, and Neuropathy Impairment Score (NIS) were collected at entry and before the rituximab infusion every 6 months. At the last visit, 94.7% (18/19) of the patients showed clinical improvement on either the INCAT, I-RODS, MRC, or NIS scale. After the first infusion, 9 patients (47.7%) showed improvement on the INCAT score, and 11 patients (57.9%) on cI-RODS. In patients who received more than one rituximab infusion, the improvement of INCAT score and cI-RODS at the last assessment was higher than that after the first infusion. We also observed tapered or withdrawn concomitant oral medications in these patients.

Cytokine Gene Polymorphisms in Patients with Chronic Inflammatory Demyelinating Polyneuropathy

Innate and adaptive immune responses exert their role in CIDP pathogenesis through cytokine production. Single-nucleotide polymorphisms (SNPs) may alter cytokine gene expression, with a potential influence on the pathogenesis of autoimmune diseases. However, cytokine gene SNPs have not been assessed in CIDP patients yet. We assessed functional SNPs in the genes encoding IL-10 (rs1800896, rs1800871, rs1800872 and rs3024505), IL-6 (rs1800795), TNF (rs1800629 and rs361525), IL-12B (rs3212227), IFN-γ (rs2430561), GM-CSF (rs25882) and IL-17F (rs11465553) in a cohort of 88 CIDP patients and 486 healthy controls (HCs) via qPCR. We found an association of SNP in the IL10 promotor and CIDP occurrence. Major homozygotes (AA) were more frequent in the HCs compared to CIDP patients (p = 0.049), but the GA genotype prevailed among the patients (p = 0.032). A lower frequency of the C allele was observed for rs1800871 and rs1800872 in CIDP patients compared to the HCs (p = 0.048). A higher proportion of A carriers at position -1082 (rs1800896) (presumed to be a low IL-10 producer) was noted in patients with milder disability (low INCAT). All mild-INCAT patients were C carriers for rs1800871 and rs1800872 in IL10 (p = 0.038). Furthermore, the IL6 rs1800795 GG genotype was more frequent in patients (p = 0.049) and the CG heterozygote in the HCs (p = 0.013). Among the CIDP patients, being a G carrier for this SNP was associated with a higher frequency of type 2 diabetes (T2D) compared to being a non-carrier (p = 0.032). Our data indicate a possible association of the IL10 and IL6 SNPs with CIDP, but also with disease severity and T2D occurrence. Given the paucity of CIDP patients, multicentric studies are necessary to draw definite conclusions on these associations.

Fatigue, depression, and product tolerability during long-term treatment with intravenous immunoglobulin (Gamunex® 10%) in patients with chronic inflammatory demyelinating polyneuropathy

INTRODUCTION/AIMS

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is characterized by progressive weakness and sensory loss, often affecting patient's ability to walk and perform activities of daily living independently. Furthermore, patients often report fatigue and depression which can affect their quality of life. These symptoms were assessed in CIDP patients receiving long-term intravenous immunoglobulin (IVIG) treatment.

METHODS

GAMEDIS was a multi-center, prospective, non-interventional study in adult CIDP patients treated with IVIG (10%) and followed for two years. Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, Hughes Disability Scale (HDS), Fatigue Severity Scale (FSS), Beck Depression Inventory II (BDI), Short Form-36 health survey (SF-36) and Work Productivity and Activity Impairment Score Attributable to General Health (WPAI-GH) were assessed at baseline and quarterly. Dosing and treatment intervals, changes in outcome parameters, and adverse events (AEs) were analyzed.

RESULTS

148 evaluable patients were followed for a mean of 83.3 weeks. The mean maintenance IVIG dose was 0.9 g/kg/cycle (mean cycle interval 38 days). Disability and fatigue remained stable throughout the study. Mean INCAT score: 2.4 ± 1.8 at baseline and 2.5 ± 1.9 at study end. HDS: 74.3% healthy/minor symptoms at baseline and 71.6% at study end. Mean FSS: 4.2 ± 1.6 at baseline and 4.1 ± 1.7 at study end. All patients reported minimal/no depression at baseline and throughout. SF-36 and WPAI-GH scores remained stable. Fifteen patients (9.5%) experienced potentially treatment-related AEs. There were no AEs in 99.3% of infusions.

DISCUSSION

Long-term treatment of CIDP patients with IVIG 10% in real-world conditions maintained clinical stability on fatigue and depression over 96 weeks. This treatment was well-tolerated and safe.

Focused Neuromuscular Ultrasound Approach for the Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy

PURPOSE

Previous ultrasonographic studies of individuals with chronic inflammatory demyelinating polyneuropathy (CIDP) have shown nerve enlargement at several sites. This prospective study compares only the bilateral median and ulnar nerves of individuals with CIDP with reference values to determine the clinical usefulness of this focused approach as a diagnostic tool.

METHODS

The cross-sectional area, echogenicity, and vascularity of the bilateral median and ulnar nerves of 25 subjects with CIDP were measured using ultrasound. Nineteen had typical CIDP based on the European Federation of Neurological Societies and the Peripheral Nerve Society guidelines, whereas six had atypical CIDP and were diagnosed based on clinical impression.

RESULTS

Focal nerve enlargement was found in at least one segment in all subjects. Subjects with typical CIDP had larger cross-sectional areas compared with subjects with atypical CIDP.

CONCLUSION

A focused ultrasound study, involving only the median and ulnar nerves, is sensitive for the detection of nerve enlargement in CIDP. Measuring the cross-sectional area of the median and ulnar nerves is clinically feasible and may help establish the diagnosis of CIDP.

Beneficial effects and safety of traditional Chinese medicine for chronic inflammatory demyelinating polyradiculoneuropathy: A case report and literature review

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated neuropathy. First-line treatments for CIDP include corticosteroids, intravenous immunoglobulin, and plasma exchange. However, the application is always limited by high costs, effectiveness, and adverse events. This study investigated a new potentially effective and safe therapeutic treatment to alleviate CIDP symptoms and improve the quality of life. In the present case, a 47-year-old rural woman presented with weakness and numbness of progressive extremities. She was diagnosed with CIDP based on abnormal cerebrospinal fluid and electromyography. The patient was treated with intravenous dexamethasone for 1 week and with Huangqi-Guizhi-Wuwu and Bu-Yang-Huan-Wu decoctions for 90 days. Surprisingly, after the treatment, the weakness and numbness were eliminated, and the quality of life improved. The varying INCAT, MRC, and BI scores also reflected the treatment effects. After 8 months of discharge, the symptoms did not relapse during the follow-up. We also searched “traditional Chinese medicine (TCM)” and “CIDP” in PubMed, EMBASE, the Web of Science, the Cochrane Library, the Chinese National Knowledge Infrastructure Databases, Wanfang Data, and the Chongqing Chinese Science and Technology Periodical Database. Finally, only ten studies were included in the literature review. Three studies were randomized controlled trials, and seven were case reports or case series. There were 419 CIDP patients, but all study sites were in China. Nine TCM formulas involving 44 herbs were reported, with Huang Qi (Astragalus membranaceus) being the most important herb. In conclusion, the case and literature demonstrated that TCM treatment might be a more effective, low-cost, and safe option for treating CIDP. Although these preliminary findings are promising, a larger sample size and higher-quality randomized clinical trials are urgently required to confirm our findings.

miR-31-5p as a Potential Circulating Biomarker and Tracer of Clinical Improvement for Chronic Inflammatory Demyelinating Polyneuropathy

Background

MicroRNAs are endogenous, small noncoding RNA molecules that play a pivotal role in the regulation of gene expression. MicroRNAs are involved in many biological processes such as proliferation, cell differentiation, neovascularization, and apoptosis. Studies on microRNA expression may contribute to a better understanding of the pathomechanism of chronic inflammatory demyelinating polyneuropathy (CIDP) and consequently enable the development of new therapeutic measures using antisense miRNAs (antagomirs). In this study, we evaluated the level of miR-31-5p in the serum of patients with CIDP and its correlation with the miR-31-5p level and clinical presentation and electrophysiological and biochemical parameters.

Methods

The study group consisted of 48 patients, mean age 61.60 ± 11.76, who fulfilled the diagnostic criteria of a typical variant of CIDP. The expression of miR-31-5p in patient serum probes was investigated by droplet digital PCR. The results were correlated with neurophysiological findings and the patient's clinical and biochemical parameters.

Results

The mean copy number of miRNA-31 in 100 μl serum was 1288.64 ± 2001.02 in the CIDP group of patients, while in the control group, it was 3743.09 ± 4026.90. There was a significant positive correlation (0.426) between IgIV treatment duration and miR-31-5p expression. Patients without IgIV treatment showed significantly lower levels of miR-31 compared to the treated group (259.44 ± 304.02 vs. 1559.48 ± 2168.45; p = 0.002). The group of patients with body weight > 80 kg showed statistically significantly lower levels of miRNA-31-5p than the patients with lower body weight (934.37 ± 1739.66 vs. 1784.62 ± 2271.62, respectively; p = 0.014). Similarly, the patients with elevated cerebrospinal fluid (CSF) protein levels had significantly higher miRNA-31-5p expression than those with normal protein levels (1393.93 ± 1932.27 vs. 987.38 ± 2364.10, respectively; p = 0.044).

Conclusion

The results may support the hypothesis that miR-31-5p is strongly involved in the autoimmune process in CIDP. The positive correlation between higher miR-31-5p levels and duration of IVIg treatment may be an additional factor explaining the efficacy of prolonged IVIg therapy in CIDP.

Disease activity in chronic inflammatory demyelinating polyneuropathy: A comparative study of clinical and skin biopsy markers

INTRODUCTION/AIMS

Epidermal nerve fiber involvement in chronic inflammatory demyelinating neuropathy (CIDP) has been reported in a limited number of patients. We quantified small-fiber involvement in a mixed cohort of patients with typical CIDP and CIDP variants to evaluate relationships with clinical outcome measures at different disease stages.

METHODS

Intraepidermal nerve fiber densities (IENFDs) were evaluated by skin punch biopsies of 23 patients with CIDP and 13 healthy controls at the forearm, thigh, and distal leg. Skin sections were optimally interpreted in all three regions in 16 CIDP patients and 10 age- and sex-matched healthy controls. Statistical analysis was performed in these subjects.

RESULTS

The IENFDs in forearm, thigh, and distal leg were similar among seven typical CIDP and nine CIDP variants. IENFDs in those regions were significantly reduced in CIDP compared with healthy controls, with a moderate negative correlation with scores on the International Neuropathy Cause and Treatment (INCAT) Upper Limb Functional Disability Scale. The reduction in IENFD compared with controls was more remarkable in the distal leg. In clinically unstable CIDP patients, the IENFDs of distal leg and forearm were significantly reduced compared with stable CIDP patients and controls. Stable CIDP patients had significantly reduced IENFDs in distal leg and forearm compared with controls.

DISCUSSION

In this exploratory study, we confirm that small fibers are also affected in CIDP. Larger studies are needed to explore longitudinal changes of IENFD in CIDP and its relation to disease stage.

Analysis of Relapse by Inflammatory Rasch-built Overall Disability Scale Status in the PATH Study of Subcutaneous Immunoglobulin in Chronic Inflammatory Demyelinating Polyneuropathy

Clinical trials in chronic inflammatory demyelinating polyneuropathy (CIDP) often assess efficacy using the ordinal Inflammatory Neuropathy Cause and Treatment (INCAT) disability score. Here, data from the PATH study was reanalyzed using change in Inflammatory Rasch‐built Overall Disability Scale (I‐RODS) to define CIDP relapse instead of INCAT. The PATH study comprised an intravenous immunoglobulin (IVIG) dependency period and an IVIG (IgPro10 [Privigen]) restabilization period; subjects were then randomized to weekly maintenance subcutaneous immunoglobulin (SCIG; IgPro20 [Hizentra]) 0.2 g/kg or 0.4 g/kg or placebo for 24 weeks. CIDP relapse was defined as ≥1‐point deterioration in adjusted INCAT, with a primary endpoint of relapse or withdrawal rates. This retrospective exploratory analysis redefined relapse using I‐RODS via three different cut‐off methods: an individual variability method, fixed cut‐off of ≥8‐point deterioration on I‐RODS centile score or ≥4‐point deterioration on I‐RODS raw score. Relapse or withdrawal rates were 47% for placebo, 34% for 0.2 g/kg IgPro20 and 19% for 0.4 g/kg IgPro20 using the raw score; 40%, 28% and 15%, respectively using the centile score, and 49%, 40% and 27%, respectively using the individual variability method. IgPro20 was shown to be efficacious as a maintenance therapy for CIDP when relapse was defined using I‐RODS. A stable response pattern was shown for I‐RODS across various applied cut‐offs, which could be applied in future clinical trials.

Daratumumab for treatment-refractory antibody-mediated diseases in neurology

BACKGROUND

A fraction of patients with antibody-mediated autoimmune diseases remain unresponsive to first/second-line and sometimes even to escalation immunotherapies. Since these patients are still affected by poor outcome and increased mortality, we investigated the safety and efficacy of the plasma cell depleting anti-CD38 antibody daratumumab in life-threatening, antibody-mediated autoimmune diseases.

METHODS

In this retrospective, single-center case series, seven patients with autoantibody-driven neurological autoimmune diseases (autoimmune encephalitis n=5, neurofascin-antibody associated chronic inflammatory demyelinating polyneuropathy associated with sporadic late onset nemaline myopathy n=1, seronegative myasthenia gravis n=1) unresponsive to a median of 4 (range 4-9) immunotherapies were treated with 4-20 cycles of 16mg/kg daratumumab.

RESULTS

Daratumumab allowed a substantial clinical improvement in all patients, as measured by modified Rankin Scale (before treatment: mRS=5 n=7; after treatment: median mRS=4 [range 0-5]), Clinical Assessment Scale in Autoimmune Encephalitis (from median 21 to 3 points, n=5), Inflammatory Neuropathy Cause and Treatment Disability Score (from 7 to 0 points, n=1) and Quantitative Myasthenia gravis Score (from 16 to 8 points, n=1). Daratumumab induced a substantial reduction of disease-specific autoreactive antibodies, total IgG (serum 66%, n=7; CSF 58%, n=5) and vaccine-induced titers for rubella (50%) and tetanus toxoid (74%). Treatment-related toxicities grade 3 or higher occurred in 5 patients, including one death.

CONCLUSION

Our findings suggest that daratumumab provided a clinically relevant depletion of autoreactive long-lived plasma cells, identifying plasma cell-targeted therapies as promising escalation therapy for highly active, otherwise treatment-refractory autoantibody-mediated neurological diseases.

The value of MUNIX as an objective electrophysiological biomarker of disease progression in CIDP

INTRODUCTION/AIMS

Objective outcome measures to monitor treatment response and guide treatment are lacking in chronic inflammatory demyelinating polyneuropathy (CIDP). We aimed to evaluate the motor unit number index (MUNIX) as an outcome measurement in patients with CIDP and investigate the correlation of MUNIX with functional and standard electrodiagnostic tests in a single follow-up study.

METHODS

We evaluated MUNIX of the abductor pollicis brevis (APB), abductor digiti minimi (ADM), and tibialis anterior (TA) muslces bilaterally. Muscle force was assessed by Medical Research Council sumscores (MRCSS). Functional measures used were the Overall Neuropathy Limitation Score (ONLS) and the Rasch-built Overall Disability Scale (R-ODS) at baseline and after six months of treatment. Standard electrophysiology was evaluated by the Nerve Conduction Study Score (NCSS).

RESULTS

Twenty patients were included at baseline, and 16 completed the follow-up study. Significant correlations were found between the MUNIX sumscore and both MRCSS and NCSS at baseline, between both the pinch strength and grip and upper limb MUNIX at baseline and follow-up, and between MUNIX of TA and both lower limb MRCSS with lower limb ONLS at baseline and follow-up. Significant correlations also were found between MUNIX sumscore change and MRCSS change, R-ODS change, and ONLS change.

DISCUSSION

MUNIX changes correlated with strength and electrophysiological improvements in CIDP patients. This suggests that MUNIX may represent a useful objective biomarker for patient follow-up.

Atypical presentation of Charcot-Marie-Tooth disease type 1C with a new mutation: a case report

Background

Charcot-Marie-Tooth 1C (CMT1C) is a rare form of dominantly inherited CMT1 neuropathy caused by a mutated gene encoding lipopolysaccharide-induced tumour necrosis alpha factor (LITAF).

Case presentation

We report a 56-year-old patient with an atypical clinical phenotype of CMT1C, which started as progressive weakness of a single upper limb resembling acquired inflammatory neuropathy. Nerve conduction studies (NCS) and temporarily limited and partial effects of immunotherapy supported the diagnosis of inflammatory neuropathy. Significant progression of polyneuropathy, despite intensive long-lasting immunotherapy, together with repeatedly negative auxiliary investigations (CSF, MRI and antibodies) and genetic testing results finally led to the diagnosis of CMT1C neuropathy.

Conclusions

CMT1C should be added to the list of inherited neuropathies that need to be considered in suspected cases of inflammatory demyelinating neuropathy.

The influence of the COVID-19 pandemic on patients with chronic inflammatory demyelinating polyradiculoneuropathy

OBJECTIVES

At a time of global health crisis, fear, anxiety, and stress levels increase. The effects of protracted social isolation, and media related misinformation's about the coronavirus disease 2019 (COVID-19) resulting in increased fear/stress related to the insufficiently known illness. The aim was to assess the influence of the COVID-19 health crisis on patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

A cross-sectional study on 29 adult CIDP patients was performed. The Medical Research Council scale was used to evaluate muscle strength. The degree of functional disability was measured using the Inflammatory Neuropathy Cause and Treatment disability scale. The overall quality of life (QoL) was self-estimated on a 0-100 numeric rating scale. We also used a specifically designed 22-question-survey about COVID-19.

RESULTS

Regarding the COVID-19 pandemic, 62% of CIDP patients were concerned. The daily activities of 55% of patients were negatively influenced by the pandemic. During the COVID-19 outbreak, 21% of patients reported their CIDP got worse. In 39% of CIDP patients, the influence of the pandemic on CIDP therapy was reported (reducing the dose or time interval or even discontinuation). The mean value of the self-estimated QoL was 64 ± 19. Independent predictors of worse QoL were age of patients (beta = -0.35, p < 0.05) and fear of the COVID-19 (beta = -0.34, p < 0.05).

CONCLUSION

The COVID-19 pandemic has a significant impact on CIDP patients. Besides the direct influence of the virus and fear of the virus, restrictive measures can indirectly harm the patients with CIDP.

Prospective analysis of disability and quality of life in patients with chronic inflammatory demyelinating polyradiculoneuropathy

PURPOSE

Even treated chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) continues to pose a significant burden in patients' everyday functioning and may continuously affect their quality of life (QoL). The aims of our prospective study were to analyze health-related QoL in CIDP patients during a 1-year follow-up period in real-life settings and to compare QoL changes with changes in disability and with patient impression of change.

METHODS

The study comprised 59 patients diagnosed with CIDP. SF-36 questionnaire was applied in order to evaluate patients' QoL. Inflammatory neuropathy cause and treatment (INCAT) disability scale was used to assess patients' functionality. The second question from the SF-36 questionnaire was used as an estimation of the patient impression of change (PIC) after 1 year.

RESULTS

SF-36 scores did not change over time in the group as a whole. According to INCAT disability scores, worsening was registered in 24 (40%) patients and improvement in 8 (14%). Fifteen (25%) patients reported worsening and the same number reported improvement, according to PIC. Concordant results on INCAT and PIC were registered in 49% of patients. Pooled SF-36 scores moderately correlated with pooled INCAT disability scores (rho = - 0.27 to - 0.59, p < 0.01). One-year changes of SF-36 scores did not differ when compared to different INCAT outcomes (worsening, stable, improvement). On the other hand, significant changes of SF-36 scores in different outcome groups according to PIC (worsening, stable, improvement) were noted (p < 0.01).

CONCLUSION

INCAT, PIC, and SF-36 are complementary outcome measures that provide neurologists with useful items of information. We propose complementary use of these scales in CIDP patients in everyday clinical practice in order to detect worsening of the disease and/or of related symptoms on time.

Longer-term effects of intravenous immunoglobulin treatment in chronic inflammatory demyelinating polyneuropathy: Who benefits?

Intravenous immunoglobulins (IVIg) represent an established cornerstone for the immunotherapy of chronic inflammatory demyelinating polyneuropathy (CIDP). Efficacy of IVIg for CIDP was proven in a large phase III trial. Yet, data on longer-term efficacy and effects in distinct subgroups are scarce. Our trial investigates the long-term efficacy of IVIg treatment in CIDP patients. In this observational real-world study, we retrospectively analyzed 49 CIDP patients receiving continuous IVIg treatment with a mean initial dosage of 87 g (1 g/kg body weight) every 4 weeks over a mean time of 45 months between 2010 and 2018. INCAT-Scores before the start of treatment and at the end of the observation period were compared. Over the observation period, IVIg treatment led to a median improvement of one INCAT score point. Subgroup analyses revealed a more pronounced improvement of INCAT scores in female CIDP patients, individuals with relapsing disease courses, patients with more pronounced motor impairment (higher initial INCAT scores) and in the cohort without need for concomitant other immunotherapies. These data argue for sustained beneficial effects of longer-term immunotherapy with IVIg in CIDP, particularly in females and relapsing disease forms with higher disease activity.

Quality of life in patients with polyneuropathy associated with different types of monoclonal gammopathy of undetermined significance

Polyneuropathy associated with monoclonal gammopathy of undetermined significance (MGUS-PNP) has a chronic and slowly progressive course but can lead to significant disability and reduced quality of life (QoL). The aim of this study was to analyze QoL in MGUS-PNP patients and to determine its predictors. Our study included 51 patients diagnosed with MGUS-PNP (23.5% with IgM, 66.7% IgG or IgA, 7.8% undetermined paraprotein, 2.0% light chains). QoL was assessed using the SF-36 questionnaire. The Medical Research Council Sum Score (MRC-SS), INCAT disability and sensory scores, ataxia score, Krupp's Fatigue Severity Scale and Beck's Depression Inventory were also used. Total SF-36 score was 50.0 ± 21.4 and no difference was observed between IgM and IgG/IgA MGUS-PNP. Physical composite score was worse than mental (44.4 ± 21.4 vs. 54.5 ± 20.9). Following factors showed correlation with SF-36 total score in univariate analysis: INCAT disability score, MRC-SS, INCAT sensory score, level of ataxia, fatigue and depression (p < 0.01). Significant predictors of worse SF-36 total score in our MGUS-PNP patients were depression (β = - 0.46, p < 0.01), fatigue (β = - 0.32, p < 0.01) and INCAT disability score (β = - 0.27, p < 0.01). QoL in MGUS-PNP is equally affected in patients with different types of paraprotein. MGUS-PNP patients with more severe functional disability, fatigue and depression need special attention of clinicians since they could be at higher risk to have worse QoL. This should be taken into account when treating subjects with MGUS-PNP.

Outcome measures for chronic inflammatory demyelinating polyneuropathy in research: relevance and applicability to clinical practice

Outcome measures are recommended in the management of chronic inflammatory demyelinating polyneuropathy (CIDP). Various scales have been proposed in recent years, some now commonly utilized in daily clinical practice. The available evidence base relies itself on randomized controlled trial data obtained over the past 30 years, with several studies using different primary and secondary outcomes. We here review the different outcome measures used in CIDP research in relation to those currently recommended for clinical management. We consider the evidence base for CIDP treatment from the primary and secondary outcomes used in these studies and attempt to assess how this may relate to current clinical practice of routine evaluation of treatment effects and long-term monitoring.

Contactin-1 autoimmunity: Serologic, neurologic, and pathologic correlates

OBJECTIVE

To determine serologic characteristics, frequency, phenotype, paraneoplastic associations, and electrodiagnostic and histopathologic features accompanying contactin-1 autoimmunity.

METHODS

Archived sera known to produce synaptic tissue-based immunofluorescence patterns were reevaluated, and contactin-1 specificity was confirmed by recombinant protein assays. Screening of 233 chronic/relapsing demyelinating neuropathies for additional cases was performed.

RESULTS

We identified 10 contactin-1 IgG seropositive cases. Frequency of contactin-1 immunoglobulin (Ig) G among tested Mayo Clinic chronic/relapsing demyelinating neuropathies was 2%. Sensory predominant presentations (n = 9, 90%), neuropathic pain (n = 6, 60%), and subacute progression (n = 5, 50%) were commonly encountered among contactin-1 neuropathies. Two patients had chronic immune sensory polyradiculopathy-like phenotype at presentation. Electrodiagnostic studies were consistent with demyelination (slowed conduction velocities and/or prolonged distal latencies) without conduction block. Markedly elevated CSF protein (median 222 mg/dL, range 69-960 mg/dL), thickening/gadolinium enhancement of nerve roots (4/5), and subperineural edema on nerve biopsy (4/4) were other characteristic features. Three cases were diagnosed with paraneoplastic demyelinating neuropathies (thymoma, n = 1; breast cancer, n = 1; plasmacytoma, n = 1). Four of the 9 patients treated with IV immunoglobulin demonstrated initial clinical improvement, but the favorable response was sustained in only 1 case (median follow-up, 60 months). Sustained clinical stabilization or improvement was observed among 3 of the 6 cases in whom second-line therapies (rituximab, cyclophosphamide, and azathioprine) were used.

CONCLUSION

Contactin-1 IgG has a distinct sensory predominant presentation commonly associated with neuropathic pain, with demyelinating changes on electrophysiologic studies. A paraneoplastic cause should be considered. Testing of contactin-1 IgG among cases with similar presentations may guide immunotherapy selection, especially second-line immunotherapy consideration.

Clinical characteristics of fibroblast growth factor receptor 3 antibody-related polyneuropathy: a retrospective study

BACKGROUND AND PURPOSE

Autoantibodies are increasingly being used as a diagnostic biomarker of chronic inflammatory neuropathies. However, their role and associated clinical syndrome are not well defined.

METHODS

This retrospective chart review evaluated the clinical presentation, diagnostic workup and therapeutic responses in fibroblast growth factor receptor 3 (FGFR3) antibody-associated neuropathy.

RESULTS

A total of 27 patients [14 men, aged 29-87 (65 ± 14) years] with positive FGFR3 antibody were included. Distal lower-extremity paresthesia (66%), unsteady gait (26%) and foot drop (11%) were common presenting symptoms. Symptom onset was acute in four (15%) cases. Distal lower-extremity weakness (mild in eight and severe in three patients) was the most frequent motor finding. Decreased distal sensation to pinprick (59%) and loss of vibration sensation (37%) were observed. Titer of FGFR3 ranged between 3100 and 30 000 (normal < 3000) with a mean of 10 688 ± 7284. Apart from the occasional association of other neuropathy-related autoantibodies, comprehensive neuropathy workup was otherwise unrevealing. Six patients had other autoimmune disease and seven patients had a history of cancer. Electromyography reflected sensorimotor neuropathy with mixed axonal and demyelinating features in 11 cases. Pure sensory neuropathy was noted in three patients. Demyelination was found in five of six nerve biopsies. Intravenous immunoglobulin response was observed in 8/10 treated patients.

CONCLUSIONS

The FGFR3 antibody appears not to be restricted to sensory neuropathy only. Its role in the pathogenicity of chronic inflammatory neuropathies is not yet well established and, although there may be a role for immunotherapy, larger studies are warranted.

Varied phenotypes and management of immune checkpoint inhibitor-associated neuropathies

OBJECTIVE

To describe the spectrum, clinical course, and management of neuropathies associated with immune checkpoint inhibitors (ICIs).

METHODS

Patients with ICI-related neuropathy (irNeuropathy) were identified and their clinical characteristics compared to neuropathy attributed to cytotoxic agents.

RESULTS

We identified 19 patients with irNeuropathies. ICIs included anti-programmed death-1 (PD1), 9; anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), 2; and combination of anti-CTLA4 and anti-PD1, 8. Median number of ICI doses prior to neuropathy onset was 4. Rate of neuropathies following ICI therapy was 0.7%. Underlying malignancies included melanoma (n = 15), lung adenocarcinoma (n = 3), and cholangiocarcinoma (n = 1). Neuropathy phenotypes were cranial neuropathies with or without meningitis (n = 7), nonlength-dependent polyradiculoneuropathies with and without cranial nerve involvement (n = 6), small-fiber/autonomic neuropathy (n = 2), ANCA-associated mononeuritis multiplex (n = 1), sensory neuronopathy (n = 1), length-dependent sensorimotor axonal polyneuropathy (n = 1), and neuralgic amyotrophy (n = 1). Immune-related adverse events involving other organ systems were common (58%). Corticosteroid use for management of neuropathy was associated with improvement in median modified Rankin Scale score (1 vs 0, p = 0.001) and Inflammatory Neuropathy Cause and Treatment Disability score (2 vs 0.5, p = 0.012) (Class IV). Significantly higher proportion of irNeuropathies had acute or subacute and nonlength-dependent presentations (p < 0.001) and rate of hospitalization for irNeuropathy was also higher (p = 0.002) compared to toxic neuropathy from chemotherapy.

CONCLUSION

Neuropathy is a rare complication of ICIs that often responds to immunosuppression. Recognition of its wide phenotypic spectrum and distinct clinical characteristics and prompt management with corticosteroids may lead to favorable outcomes.

Transthyretin stabilization activity of the catechol-O-methyltransferase inhibitor tolcapone (SOM0226) in hereditary ATTR amyloidosis patients and asymptomatic carriers: proof-of-concept study. Amyloid 2019;26:74-84. [PMID: 31119947 DOI: 10.1080/13506129.2019.1597702]

Objective: To assess the transthyretin (TTR) stabilization activity of tolcapone (SOM0226) in patients with hereditary ATTR amyloidosis, asymptomatic carriers and healthy volunteers. Methods: A phase IIa proof-of-concept trial included two phases separated by a 6-week washout period. Phase A: single 200 mg dose of tolcapone; phase B: three 100 mg doses taken at 4 h intervals. The primary efficacy variable was TTR stabilization. Results: Seventeen subjects were included (wild type, n = 6; mutation TTR Val30Met, n = 11). TTR stabilization was observed in all participants. Two hours after dosing, 82% of participants in phase A and 93% of those in phase B reached a TTR stabilization value of at least 20%. In phase A, there was an increase of 52% in TTR stabilization vs baseline values 2 h after dosing, which decreased to 22.9% at 8 h. In phase B, there was a significant increase of 38.8% in TTR stabilization 2 h after the first 100 mg dose. This difference was maintained after 10 h and decreased after 24 h. No serious adverse events were observed. Conclusions: The ability of tolcapone for stabilizing TTR supports further development and repositioning of the drug for the treatment of ATTR amyloidosis. EudraCT trial number: 2014-001586-27 ClinicalTrials.gov Identifier: NCT02191826.

One-year follow-up study of neuropathic pain in chronic inflammatory demyelinating polyradiculoneuropathy

We sought to gather information about frequency and features of neuropathic pain (NeP) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients and to investigate course of NeP during 1-year follow-up. Study included 105 patients diagnosed with CIDP. Patients with diabetes (N = 26) were excluded. NeP was diagnosed by the official guidelines and painDETECT questionnaire (PD-Q). Medical Research Council Sum Score (MRC-SS), INCAT disability and sensory scores, and Beck Depression Inventory were also measured. PD-Q showed presence of NeP in 16 (20%) of 79 CIDP patients and their mean pain was moderate (5.1 ± 3.0 of 10). Diagnostic delay in CIDP patients with NeP was prolonged compared to CIDP patients without NeP (21 ± 28 vs 9 ± 12 months, P < .05). Slowly progressive course of the disease was more frequent in patients with NeP (81% vs 52%, P < .05). Patients with NeP had worse INCAT sensory score (P < .01), INCAT disability score (P < .05), MRC-SS, as well as worse disease outcome at time of testing (P < .05). Depression was more common in patients with NeP (69% vs 17%, P < .01). During 1-year follow-up, majority of our CIDP patients had good control of NeP with gabapentinoids or amitriptyline. NeP was common in our cohort of non-diabetic CIDP patients. It was associated with worse functional disability, worse sensory deficit, and depression. Special attention should be paid to CIDP patients with NeP because they request additional symptomatic therapy that appeared efficacious in our cohort.

Neuromuscular disease-specific questionnaire to assess quality of life in patients with chronic inflammatory demyelinating polyradiculoneuropathy

To date, generic questionnaires have been used to investigate quality of life (QoL) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients. Although these measures are very useful, they are not usually precise enough to measure all specific characteristics of the disease. Our aim was to investigate QoL using the neuromuscular disease-specific questionnaire (individualized neuromuscular quality of life, INQoL) in a large cohort of patients with CIDP. Our study comprised 106 patients diagnosed with CIDP. INQoL questionnaire, Medical Research Council (MRC) sum score, Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, Visual Analogue Pain Scale, Beck Depression Inventory, and Krupp's Fatigue Severity Scale were used in our study. Physical domains of INQoL were more affected than mental, and the overall score was 57 ± 25. Significant predictors of higher INQoL score in our patients with CIDP were severe fatigue (β = 0.35, p < 0.01), higher INCAT disability score at time of testing (β = 0.29, p < 0.01), and being unemployed/retired (β = 0.22, p < 0.05). QoL was reduced in our cohort of CIDP patients, which was more pronounced in physical segments. Patients with fatigue, more severe disability, and unemployed/retired need special attention of neurologists because they could be at greater risk to have worse QoL.

Two years' long-term follow up in chronic inflammatory demyelinating polyradiculoneuropathy: efficacy of intravenous immunoglobulin treatment

BACKGROUND

Administration of intravenous immunoglobulins (IVIgs) is established for long-term treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Prevention of secondary axonal loss going along with permanent clinical disability and muscular atrophy is a major aim in CIDP therapy. To assess long-term clinical efficacy of IVIg treatment despite heterogenous disease course and variable complaints reported by the patients, long-term electrophysiological monitoring was performed for systematic evaluation of therapeutic efficacy of IVIg.

METHODS

A total of 21 patients with CIDP treated with IVIg 1 g/kg bodyweight every 3-6 weeks were examined electrophysiologically every 12 months over a period of 2 years.

RESULTS

Assessment of clinical symptoms, using the Inflammatory Neuropathy Cause and Treatment (INCAT) and Hughes functional grading score (F-score) revealed improvement of motor and sensory symptoms over a period of 2 years. As electrophysiological results remained stable, IVIg treatment seems to be suitable to prevent axonal loss in CIDP.

CONCLUSIONS

This study confirms efficacy of IVIg as firstline therapy in CIDP. Doses and frequency of IVIg application should be adapted based on clinical evaluation and analysis of long-term electrophysiological findings.

Treatment of patients with multifocal motor neuropathy with immunoglobulins in clinical practice: the SIGNS registry

OBJECTIVES

The management of patients with multifocal motor neuropathy (MMN) under everyday clinical conditions has been insufficiently studied. We therefore collected comprehensive observational data on patients with MMN who received intravenous (IV) or subcutaneous (SC) immunoglobulins (IGs) as maintenance therapy.

METHODS

This was a prospective, noninterventional study (registry) in neurological centres (hospitals and offices) throughout Germany.

RESULTS

As of 1 December 2015, 80 patients with MMN were included (mean age 55.4 ± 9.8 years, 67% males, mean disease duration 10.7 ± 10.2 years). The affected limb regions were predominantly distal muscle groups of the upper extremities. On the inflammatory neuropathy cause and treatment (INCAT) scale, 94% of the patients had some disability in the arms and 61% in the legs. At inclusion, 98.8% received IVIG and 1.3% SCIG. Substantial variation was observed between IVIG treatment intervals (every 0.7 to 17.3 weeks) and dosage (0.2-2.1 g/kg body weight received during a single administration; mean monthly dosage, 0.9 g/kg body weight). However, the mean monthly dosage was steady over time. At 1-year follow up, improvement was seen in muscle strength, INCAT and quality of life (QoL) scores (SF-36 questionnaire).

CONCLUSIONS

The management of patients with MMN in everyday clinical practice demonstrates a wide range of absolute dosages and treatment intervals of IG, supporting the recommended practice of determining treatment dose on an individual patient basis. The improvements in muscle strength and reduction in disability, accompanied by increased QoL, strengthen the case for use of IG as a maintenance treatment for MMN.

Long-term immunoglobulin therapy for chronic inflammatory demyelinating polyradiculoneuropathy

Immunoglobulins are an effective but expensive treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Although the goal is to improve function, use of functional scales to monitor therapy is not widespread. Limited recent evidence suggests that doses lower than those used traditionally may be as effective. There are no proven correlations of effective dose with weight, disease severity, or duration. The clinical course of CIDP is heterogeneous and includes monophasic forms and complete remissions. Careful monitoring of immunoglobulin use is necessary to avoid overtreatment. Definitive evidence for immunoglobulin superiority over steroids is lacking. Although latest trial evidence favors immunoglobulins over steroids, the latter may result in higher remission rates and longer remission periods. This article addresses the appropriateness of first-line, high-dose immunoglobulin treatment for CIDP and reviews important clinical questions regarding the need for long-term therapy protocols, adequate monitoring, treatment withdrawal, and consideration of corticosteroids as an alternative to immunoglobulin therapy.