Serum levels of tumor necrosis factor-alpha in chronic inflammatory demyelinating polyneuropathy

Cytokines and chemokines in patients with chronic inflammatory demyelinating polyradiculoneuropathy and multifocal motor neuropathy: A systematic review

Advances in the understanding of cytokines have revolutionized mechanistic treatments for chronic inflammatory and autoimmune diseases, as exemplified by rheumatoid arthritis. We conducted a systematic literature review on the role of cytokines and chemokines in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). Ovid Medline, EMBASE and Web of Science were searched until August 31, 2022 for human studies investigating cytokines levels in CIDP or MMN. Fifty-five articles on 1061 CIDP patients and 86 MMN patients were included, with a median of 18 patients per study (range 3-71). Studies differed in the inclusion criteria, type of assay, manufacturer, control subjects, and tested biological material. Only a minority of studies reported data on disease activity. Interleukin (IL)-6, IL-17, CXCL10, and tumor necrosis factor alpha (TNF-α), were elevated in CIDP compared to controls in most of the studies. IL-6 and TNF-α levels are also correlated with disability. In MMN patients, IL-1Ra was elevated in the majority of the reports. While acknowledging the challenges in comparing studies and the various limitations of the studies, including small patient numbers, particularly in MMN, our review suggests that IL-6, IL-17, CXCL10, and TNF-α might play a role in CIDP pathogenesis. Larger studies are needed in MMN.

Disease activity in chronic inflammatory demyelinating polyneuropathy: association between circulating B-cell subsets, cytokine levels, and clinical outcomes

Chronic inflammatory demyelinating polyneuropathy (CIDP), a common and treatable autoimmune neuropathy, is frequently misdiagnosed. The aim of this study is to evaluate the relationship between immunological markers and clinical outcome measures in a mixed cohort of patients with typical CIDP and CIDP variants at different disease stages. Twenty-three typical, 16 multifocal and five distal CIDP patients were included. Twenty-five sex and age-matched healthy controls and 12 patients with Charcot-Marie-Tooth type 1A (CMT1A) disease served as controls. Peripheral B-cell populations were analyzed by flow cytometry. IL6, IL10, TNFA mRNA and mir-21, mir-146a, and mir-155-5p expression levels were evaluated by real-time polymerase chain reaction in peripheral blood mononuclear cells (PBMC) and/or skin biopsy specimens. Results were then assessed for a possible association with clinical disability scores and intraepidermal nerve fiber densities (IENFD) in the distal leg. We detected a significant reduction in naive B cells (P ≤ 0.001), plasma cells (P ≤ 0.001) and regulatory B cells (P < 0.05), and an elevation in switched memory B cells (P ≤ 0.001) in CIDP compared to healthy controls. CMT1A and CIDP patients had comparable B-cell subset distribution. CIDP cases had significantly higher TNFA and IL10 gene expression levels in PBMC compared to healthy controls (P < 0.05 and P ≤ 0.01, respectively). IENFDs in the distal leg showed a moderate negative correlation with switched memory B-cell ratios (r = -0.51, P < 0.05) and a moderate positive correlation with plasma cell ratios (r = 0.46, P < 0.05). INCAT sum scores showed a moderate positive correlation with IL6 gene expression levels in PBMC (r = 0.54, P < 0.05). Altered B-cell homeostasis and IL10 and TNFA gene expression levels imply chronic antigen exposure and overactivity in the humoral immune system, and seem to be a common pathological pathway in both typical CIDP and CIDP variants.

Proximity extension assay-based discovery of biomarkers for disease activity in chronic inflammatory demyelinating polyneuropathy

BACKGROUND

Objective disease activity biomarkers are lacking in chronic inflammatory demyelinating polyneuropathy (CIDP), impacting treatment decisions in clinical care and outcomes in clinical trials. Using a proximity extension assay, we aimed to identify candidate serum protein biomarkers for disease activity in CIDP.

METHOD

We collected clinical data and serum of 106 patients with CIDP. Patients starting induction treatment (n=53) and patients on maintenance treatment starting treatment withdrawal (n=40) were assessed at baseline and at 6 months (or at relapse). Patients in remission (n=13) were assessed once. Clinical disease activity was defined based on improvement or deterioration by the minimal clinically important difference on the inflammatory Rasch-built Overall Disability Scale in combination with either grip strength or the Medical Research Council sum score. Using a proximity extension assay (Olink Explore platform), 1472 protein levels were analysed in serum. Candidate proteins were selected based on fold change>0.5 or <-0.5 and p<0.05 between clinically active and inactive disease. Longitudinal changes of candidate proteins between baseline and follow-up were analysed.

RESULTS

We identified 48 candidate proteins that differed between clinically active and inactive disease on cross-sectional comparison. Five of these proteins (SUGT1, IRAK4, DCTN1, 5'-nucleotidase cytosolic IIIA (NT5C3A), glutaredoxin (GLRX)) also showed longitudinal changes consistent with disease activity changes. IRAK4 was also identified in a sensitivity analysis, using another definition for disease activity.

CONCLUSION

Our results indicate that IRAK4 and possibly SUGT1, DCTN1, NT5C3A and GLRX are candidate biomarkers for monitoring clinical disease activity in CIDP.

Immune-Mediated Neuropathies: Pathophysiology and Management

Dysfunction of the immune system can result in damage of the peripheral nervous system. The immunological mechanisms, which include macrophage infiltration, inflammation and proliferation of Schwann cells, result in variable degrees of demyelination and axonal degeneration. Aetiology is diverse and, in some cases, may be precipitated by infection. Various animal models have contributed and helped to elucidate the pathophysiological mechanisms in acute and chronic inflammatory polyradiculoneuropathies (Guillain-Barre Syndrome and chronic inflammatory demyelinating polyradiculoneuropathy, respectively). The presence of specific anti-glycoconjugate antibodies indicates an underlying process of molecular mimicry and sometimes assists in the classification of these disorders, which often merely supports the clinical diagnosis. Now, the electrophysiological presence of conduction blocks is another important factor in characterizing another subgroup of treatable motor neuropathies (multifocal motor neuropathy with conduction block), which is distinct from Lewis-Sumner syndrome (multifocal acquired demyelinating sensory and motor neuropathy) in its response to treatment modalities as well as electrophysiological features. Furthermore, paraneoplastic neuropathies are also immune-mediated and are the result of an immune reaction to tumour cells that express onconeural antigens and mimic molecules expressed on the surface of neurons. The detection of specific paraneoplastic antibodies often assists the clinician in the investigation of an underlying, sometimes specific, malignancy. This review aims to discuss the immunological and pathophysiological mechanisms that are thought to be crucial in the aetiology of dysimmune neuropathies as well as their individual electrophysiological characteristics, their laboratory features and existing treatment options. Here, we aim to present a balance of discussion from these diverse angles that may be helpful in categorizing disease and establishing prognosis.

Pathogenic TNF-α drives peripheral nerve inflammation in an Aire-deficient model of autoimmunity

Immune cells infiltrate the peripheral nervous system (PNS) after injury and with autoimmunity, but their net effect is divergent. After injury, immune cells are reparative, while in inflammatory neuropathies (e.g., Guillain Barré Syndrome and chronic inflammatory demyelinating polyneuropathy), immune cells are proinflammatory and promote autoimmune demyelination. An understanding of immune cell phenotypes that distinguish these conditions may, therefore, reveal new therapeutic targets for switching immune cells from an inflammatory role to a reparative state. In an autoimmune regulator (Aire)-deficient mouse model of inflammatory neuropathy, we used single-cell RNA sequencing of sciatic nerves to discover a transcriptionally heterogeneous cellular landscape, including multiple myeloid, innate lymphoid, and lymphoid cell types. Analysis of cell-cell ligand-receptor interactions uncovered a macrophage-mediated tumor necrosis factor-α (TNF-α) signaling axis that is induced by interferon-γ and required for initiation of autoimmune demyelination. Developmental trajectory visualization suggested that TNF-α signaling is associated with metabolic reprogramming of macrophages and polarization of macrophages from a reparative state in injury to a pathogenic, inflammatory state in autoimmunity. Autocrine TNF-α signaling induced macrophage expression of multiple genes (Clec4e, Marcksl1, Cxcl1, and Cxcl10) important in immune cell activation and recruitment. Genetic and antibody-based blockade of TNF-α/TNF-α signaling ameliorated clinical neuropathy, peripheral nerve infiltration, and demyelination, which provides preclinical evidence that the TNF-α axis may be effectively targeted to resolve inflammatory neuropathies.

Potential therapeutic strategies in chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an autoimmune neuropathy involving peripheral nerve and nerve roots. The pathological hallmark of CIDP is macrophage-induced demyelination. Antibodies against nerve fibers, complement decomposition, abnormalities in plasma and cerebrospinal fluid cytokine profile, and changes of peripheral blood cell proportion were also reported in CIDP patients. These findings in immunopathology provide support for the introduction of potential therapeutic options for the treatment of CIDP. In this review, we systematically listed the potential therapeutic strategies targeting different components of the immune system by comparing the treatment of other autoimmune inflammatory diseases of the nervous system. Several ongoing clinical trials will assess the efficacy and safety of potential CIDP treatments.

The immune response and aging in chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) consists of various autoimmune subtypes in which the peripheral nervous system (PNS) is attacked. CIDP can follow a relapsing-remitting or progressive course where the resultant demyelination caused by immune cells (e.g., T cells, macrophages) and antibodies can lead to disability in patients. Importantly, the age of CIDP patients has a role in their symptomology and specific variants have been associated with differing ages of onset. Furthermore, older patients have a decreased frequency of functional recovery after CIDP insult. This may be related to perturbations in immune cell populations that could exacerbate the disease with increasing age. In the present review, the immune profile of typical CIDP will be discussed followed by inferences into the potential role of relevant aging immune cell populations. Atypical variants will also be briefly reviewed followed by an examination of the available studies on the immunology underlying them.

Comprehensive approaches for diagnosis, monitoring and treatment of chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common chronic inflammatory neuropathy. CIDP is diagnosed according to the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria, which combine clinical features with the electrophysiological evidence of demyelination. However, firstly, diagnosis is challenging, as some patients e.g. with severe early axonal damage do not fulfil the criteria. Secondly, objective and reliable tools to monitor the disease course are lacking. Thirdly, about 25% of CIDP patients do not respond to evidence-based first-line therapy. Recognition of these patients is difficult and treatment beyond first-line therapy is based on observational studies and case series only. Individualized immunomodulatory treatment does not exist due to the lack of understanding of essential aspects of the underlying pathophysiology.

Novel diagnostic imaging techniques and molecular approaches can help to solve these problems but do not find enough implementation. This review gives a comprehensive overview of novel diagnostic techniques and monitoring approaches for CIDP and how these can lead to individualized treatment and better understanding of pathophysiology.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Its Variants

PURPOSE OF REVIEW

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and its variants comprise a group of immune-mediated neuropathies with distinctive clinical presentations and electrodiagnostic features. Prompt recognition of these treatable disorders is mandatory as delays result in significant disability and morbidity. This article highlights the clinical presentation, pathophysiology, diagnostic evaluation, and treatment approach of these polyneuropathies.

RECENT FINDINGS

The spectrum of CIDP is expanding with the recent characterization of neuropathies associated with nodal and paranodal antibodies. These neuropathies are distinguished by their unique presentations and are often refractory to IV immunoglobulin (IVIg) therapy. Subcutaneous immunoglobulins have recently been approved as a treatment option for CIDP and join corticosteroids, IVIg, and plasma exchange as first-line treatment.

SUMMARY

CIDP is characterized by progressive symmetric proximal and distal weakness, large fiber sensory loss, and areflexia, with clinical nadir reached more than 8 weeks after symptom onset. Autoimmune demyelinating neuropathies fall on a continuum, with differences in the type of nerve fibers affected and pattern of deficits. Distinguishing between typical CIDP and its variants allows for selection of the most appropriate treatment.

Therapeutic Plasma Exchange in Guillain-Barre Syndrome and chronic inflammatory demyelinating polyradiculoneuropathy

Therapeutic plasma exchange (TPE) has been used as a treatment modality in many autoimmune disorders, including neurological conditions, such as Guillain-Barre syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The American Society for Apheresis (ASFA) publishes its guidelines on the use of therapeutic apheresis every 3 years based on published evidence to assist physicians with both the medical and technical aspects of apheresis consults. The ASFA Guidelines included the use of TPE in both GBS and CIDP as an acceptable first-line therapy, either alone and/or in conjunction with other therapeutic modalities. In this article, we briefly reviewed GBS and CIDP, discussed the role of apheresis in these conditions as well as various technical aspects of the TPE procedure, such as apheresis calculation, number of volume exchange, replacement fluid, and management of potential complications.

Increased IP-10 production by blood-nerve barrier in multifocal acquired demyelinating sensory and motor neuropathy and multifocal motor neuropathy

OBJECTIVE

Dysfunction of the blood-nerve barrier (BNB) plays important roles in chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). The aim of the present study was to identify the candidate cytokines/chemokines that cause the breakdown of the BNB using sera from patients with CIDP and MMN.

METHODS

We determined the levels of 27 cytokines and chemokines in human peripheral nerve microvascular endothelial cells (PnMECs) after exposure to sera obtained from patients with CIDP variants (typical CIDP and multifocal acquired demyelinating sensory and motor neuropathy [MADSAM]), MMN and amyotrophic lateral sclerosis (ALS), and healthy controls (HC), using a multiplexed fluorescent bead-based immunoassay system.

RESULTS

The induced protein (IP)10 level in the cells in both the MADSAM and MMN groups was markedly increased in comparison with the typical CIDP, ALS and HC groups. The other cytokines, including granulocyte colony-stimulating factor,vascular endothelial growth factor (VEGF) and interleukin-7, were also significantly upregulated in the MADSAM group. The increase of IP-10 produced by PnMECs was correlated with the presence of conduction block in both the MADSAM and MMN groups.

CONCLUSION

The autocrine secretion of IP-10 induced by patient sera in PnMECs was markedly upregulated in both the MADSAM and MMN groups. The overproduction of IP-10 by PnMECs leads to the focal breakdown of the BNB and may help to mediate the transfer of pathogenic T cells across the BNB, thereby resulting in the appearance of conduction block in electrophysiological studies of patients with MADSAM and MMN.

Immune-mediated neuropathies

Since the discovery of an acute monophasic paralysis, later coined Guillain-Barré syndrome, almost 100 years ago, and the discovery of chronic, steroid-responsive polyneuropathy 50 years ago, the spectrum of immune-mediated polyneuropathies has broadened, with various subtypes continuing to be identified, including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). In general, these disorders are speculated to be caused by autoimmunity to proteins located at the node of Ranvier or components of myelin of peripheral nerves, although disease-associated autoantibodies have not been identified for all disorders. Owing to the numerous subtypes of the immune-mediated neuropathies, making the right diagnosis in daily clinical practice is complicated. Moreover, treating these disorders, particularly their chronic variants, such as CIDP and MMN, poses a challenge. In general, management of these disorders includes immunotherapies, such as corticosteroids, intravenous immunoglobulin or plasma exchange. Improvements in clinical criteria and the emergence of more disease-specific immunotherapies should broaden the therapeutic options for these disabling diseases.

Pyrexia-associated Relapse in Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy is a relapsing-remitting or chronic progressive demyelinating polyradiculoneuropathy. We report the case of a patient with chronic inflammatory demyelinating polyradiculoneuropathy who experienced relapses on four occasions after experiencing pyrexia and flu-like symptoms. Our patient showed characteristic features, such as relapse after pyrexia and flu-like symptoms, remission after pyretolysis without treatment, and the absence of remarkable improvement in a nerve conduction study in the remission phase. The serum level of tumor necrosis factor-α was elevated in the relapse phase and reduced in the remission phase; thus, the induction of cytokine release by viral infection might have caused the relapses.

Immune dysregulation in patients with carpal tunnel syndrome

Peripheral immunity plays a key role in maintaining homeostasis and conferring crucial neuroprotective effects on the injured nervous system, while at the same time may contribute to increased vulnerability to neuropathic pain. Little is known about the reciprocal relationship between entrapment neuropathy and peripheral immunity. This study investigated immune profile in patients with carpal tunnel syndrome (CTS), the most prevalent entrapment neuropathy. All patients exhibited neurophysiological abnormalities in the median nerve, with the majority reporting neuropathic pain symptoms. We found a significant increase in serum CCL5, CXCL8, CXCL10 and VEGF, and in CD4+ central and effector memory T cells in CTS patients, as compared to healthy controls. CCL5 and VEGF were identified as having the highest power to discriminate between patients and controls. Interestingly, and contrary to the prevailing view of CCL5 as a pro-nociceptive factor, the level of circulating CCL5 was inversely correlated with neuropathic pain intensity and median nerve motor latency. In contrast, the level of central memory T cells was positively associated with abnormal neurophysiological findings. These results suggest that entrapment neuropathy is associated with adaptive changes in the homeostasis of memory T cells and an increase in systemic inflammatory modulating cytokines/chemokines, which potentially regulate neuropathic symptoms.

Transcriptome Analysis of Peripheral Blood in Chronic Inflammatory Demyelinating Polyradiculoneuropathy Patients Identifies TNFR1 and TLR Pathways in the IVIg Response

We have studied the response to intravenous immunoglobulins (IVIg) by a transcriptomic approach in 11 chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients (CIDP duration = 6 [0.83-6.5] years). RNA was extracted from cells in whole blood collected before and 3 weeks after IVIg treatment, and hybridized on Illumina chips. After RNA quality controls, gene expression was analyzed using statistical tests fitted for microarrays (R software, limma package), and a pathway analysis was performed using DAVID software. We identified 52 genes with expression that varied significantly after IVIg (fold change [FC] > 1.2, P < 0.001, false discovery rate [FDR] <0.05). Among these 52 genes, 7 were related to immunity, 3 were related to the tumor necrosis factor (TNF)-α receptor 1 (TNFR1) pathway (inhibitor of caspase-activated DNase (ICAD): FC = 1.8, P = 1.7E-7, FDR = 0.004; p21 protein-activated kinase 2 [PAK2]: FC = 1.66, P = 2.6E-5, FDR = 0.03; TNF-α-induced protein 8-like protein 1 [TNFAIP8L1]: P = 1.00E-05, FDR = 0.026), and 2 were related to Toll-like receptors (TLRs), especially TLRs 7 and 9, and were implicated in autoimmunity. These genes were UNC93B1 (FC = 1.6, P = 2E-5, FDR = 0.03), which transports TLRs 7 and 9 to the endolysosomes, and RNF216 (FC = 1.5, P = 1E-05, FDR = 0.03), which promotes TLR 9 degradation. Pathway analysis showed that the TNFR1 pathway was significantly lessened by IVIg (enrichment score = 24, Fischer exact test = 0.003). TNF-α gene expression was higher in responder patients than in nonresponders; however, it decreased after IVIg in responders (P = 0.04), but remained stable in nonresponders. Our data suggest the actions of IVIg on the TNFR1 pathway and an original mechanism involving innate immunity through TLRs in CIDP pathophysiology and the response to IVIg. We conclude that responder patients have stronger inflammatory activity that is lessened by IVIg.

Treatment of chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is one of the acquired demyelinating neuropathies and is considered to be immune mediated. Diagnosis is typically based on clinical history, neurologic examination, electrophysiologic studies, CSF studies, and pathologic examination. Early diagnosis and treatment is important to prevent irreversible axonal loss and optimize improvement in function. The first-line agents for treatment are intravenous immunoglobulin (IVIg), corticosteroids, and plasmapheresis, which have all been demonstrated to be effective in controlled studies. Studies have not shown a significant difference between these three treatments, and the initial choice of therapy is often based on availability, cost, ease of administration, and side effect profile. If patients do not respond to one of these agents, they may respond to one of the others and sometimes in combination. If the first-line agents are not effective, chemotherapeutic or immunosuppressive agents may be considered. There are limited controlled studies of these modalities, and they are often used in conjunction with a first-line treatment. The majority of patients require long-term therapy to maintain a response and to prevent relapse.

Current and future immunotherapy targets in autoimmune neurology

Randomized controlled treatment trials of autoimmune neurologic disorders are generally lacking and data pertaining to treatment are mostly derived from expert opinion, large case series, and anecdotal reports. The treatment of autoimmune neurologic disorders comprises oncologic therapy (where appropriate) and immunotherapy. In this chapter, we first describe the standard acute and chronic immunotherapies and provide a practical overview of their use in the clinic (mechanisms of action, dosing, monitoring, and side effects). Novel approaches to treatment of autoimmune neurologic disorders, through new drug discovery or repurposing, are dependent on improved mechanistic understanding of immunopathology. Such approaches, with emphasis on monoclonal antibodies, are discussed using the paradigm of three autoimmune neurologic disorders whose immunopathogenesis is better understood, specifically myasthenia gravis, neuromyelitis optica, and chronic inflammatory demyelinating polyradiculoneuropathy. It is important to realize that the treatment strategy and management plan must be individualized for each patient. In general these are influenced by the following: clinical severity, antibody type, presence or absence of cancer, and prior treatment response, if known.

Different electrophysiological profiles and treatment response in 'typical' and 'atypical' chronic inflammatory demyelinating polyneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyneuropathy (CIDP) is currently classified into 'typical' CIDP and 'atypical' subtypes such as multifocal acquired demyelinating sensory and motor neuropathy (MADSAM).

OBJECTIVES

To assess the frequency of CIDP subtypes, and to elucidate clinical and electrophysiological features, and treatment response in each subtype.

METHODS

We reviewed data from 100 consecutive patients fulfilling criteria for CIDP proposed by the European Federation of Neurological Societies and the Peripheral Nerve Society. The Kaplan-Meier curve was used to estimate long-term outcome.

RESULTS

Patients were classified as having typical CIDP (60%), MADSAM (34%), demyelinating acquired distal symmetric neuropathy (8%) or pure sensory CIDP (1%). Compared with patients with MADSAM, patients with typical CIDP showed more rapid progression and severe disability, and demyelination predominant in the distal nerve segments. MADSAM was characterised by multifocal demyelination in the nerve trunks. Abnormal median-normal sural sensory responses were more frequently found for typical CIDP (53% vs 13%). Patients with typical CIDP invariably responded to corticosteroids, immunoglobulin or plasmapheresis, whereas patients with MADSAM were more refractory to these treatments. The Kaplan-Meier analyses showed that 64% of patients with typical CIDP and 41% of patients with MADSAM had a clinical remission 5 years later (p=0.02).

CONCLUSIONS

Among the CIDP spectrum, typical CIDP and MADSAM are the major subtypes, and their pathophysiology appears to be distinct. In typical CIDP, the distal nerve terminals and possibly the nerve roots, where the blood-nerve barrier is anatomically deficient, are preferentially affected, raising the possibility of antibody-mediated demyelination, whereas cellular immunity with breakdown of the barrier may be important in MADSAM neuropathy.

Chronic inflammatory demyelinating polyradiculoneuropathy: from pathology to phenotype

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an inflammatory neuropathy, classically characterised by a slowly progressive onset and symmetrical, sensorimotor involvement. However, there are many phenotypic variants, suggesting that CIDP may not be a discrete disease entity but rather a spectrum of related conditions. While the abiding theory of CIDP pathogenesis is that cell-mediated and humoral mechanisms act together in an aberrant immune response to cause damage to peripheral nerves, the relative contributions of T cell and autoantibody responses remain largely undefined. In animal models of spontaneous inflammatory neuropathy, T cell responses to defined myelin antigens are responsible. In other human inflammatory neuropathies, there is evidence of antibody responses to Schwann cell, compact myelin or nodal antigens. In this review, the roles of the cellular and humoral immune systems in the pathogenesis of CIDP will be discussed. In time, it is anticipated that delineation of clinical phenotypes and the underlying disease mechanisms might help guide diagnostic and individualised treatment strategies for CIDP.

Differential gene expression of cytokines and neurotrophic factors in nerve and skin of patients with peripheral neuropathies

Pathophysiologically relevant alterations in cytokine and neurotrophic factor levels have been reported in neuropathy subtypes. We characterized gene expression profiles of pro- and anti-inflammatory cytokines and neurotrophic factors in nerve and skin samples of patients with neuropathies of different etiologies. We prospectively studied 133 patients with neuropathies and compared data between subtypes and with healthy controls. All patients underwent sural nerve and/or skin punch biopsy at the lateral thigh and lower leg; controls received skin punch biopsies. Gene expression of pro- and anti-inflammatory cytokines (IL-1β, IL-2, IL-6, TNF, IL-10), neurotrophic factors (BDNF, NGF, NT3, TrkA), and erythropoietin with the erythropoietin receptor (Epo, EpoR) was analyzed. Sural nerve gene expression of the investigated cytokines and neurotrophic factors did not differ between neuropathies of different etiologies; however, IL-6 (p < 0.01) and IL-10 (p < 0.05) expression was higher in painful compared to painless neuropathies. Skin IL-6 and IL-10 gene expression was increased in patients compared to controls (p < 0.05), and IL-10 expression was higher in lower leg skin of patients with non-inflammatory neuropathies compared to inflammatory neuropathies (p < 0.05). Proximal and distal skin neurotrophic factor and Epo gene expression of patients with neuropathies was reduced compared to controls (NGF, NT3, Epo; p < 0.05). Neuropathies are associated with an increase in cytokine expression and a decrease in neurotrophic factor expression including nerve and skin.

Divergent effects of T cell costimulation and inflammatory cytokine production on autoimmune peripheral neuropathy provoked by Aire deficiency

Chronic inflammatory demyelinating polyneuropathy results from autoimmune destruction of the peripheral nervous system and is a component of the multiorgan autoimmunity syndrome that results from Aire gene mutations in humans. In parallel, peripheral nervous system autoimmunity resembling chronic inflammatory demyelinating polyneuropathy develops spontaneously in NOD mice with a partial loss of Aire function (NOD.Aire(GW/+) mice) and is a T cell-mediated disease. In this study, we analyze how key aspects of T cell activation and function modulate disease development in Aire-deficient mice. We show that genetic ablation of the Th1 cytokine IFN-γ completely prevents clinical and electrophysiological evidence of neuropathy in NOD.Aire(GW/+) mice. IFN-γ deficiency is associated with absence of immune infiltration and decreased expression of the T cell chemoattractant IP-10 in sciatic nerves. Thus, IFN-γ is absolutely required for the development of autoimmune peripheral neuropathy in NOD.Aire(GW/+) mice. Because IFN-γ secretion is enhanced by B7-CD28 costimulation of T cells, we sought to determine the effects of these costimulatory molecules on neuropathy development. Surprisingly, B7-2 deficiency accelerated neuropathy development in NOD.Aire(GW/+) mice, and Ab blockade of both B7-1 and B7-2 resulted in fulminant, early-onset neuropathy. Thus, in contrast to IFN-γ, B7-2 alone and B7-1/B7-2 in combination function to ameliorate neuropathy development in NOD.Aire(GW/+) mice. Together, these findings reveal distinct and opposing effects of the T cell costimulatory pathway and IFN-γ production on the pathogenesis of autoimmune peripheral neuropathy.

A review of the use of biological agents for chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a group of idiopathic, acquired, immune-mediated inflammatory demyelinating diseases of the peripheral nervous system. A majority of patients with CIDP respond to "first-line" treatment with IVIG, plasmapheresis and/or corticosteroids. There exists insufficient evidence to ascertain the benefit of treatment with "conventional" immunosuppressive drugs. The inconsistent efficacy, long-term financial burden and health risks of non-specific immune altering therapy have drawn recurrent attention to the possible usefulness of a variety of biological agents that target key aspects in the CIDP immunopathogenic pathways. This review aims to give an updated account of the scientific rationale and potential use of biological therapeutics in patients with CIDP. No specific treatment recommendations are given. The discovery, development and application of biological markers by modern molecular diagnostic techniques may help identify drug-naïve or treatment-resistant CIDP patients most likely to respond to targeted immunotherapy.

Chronic inflammatory demyelinative polyneuropathy

Chronic inflammatory demyelinative polyneuropathy (CIDP) is an acquired polyneuropathy presumably of immunological origin. It is characterized by a progressive or a relapsing course with predominant motor deficit. The diagnosis rests on the association of non-length-dependent predominantly motor deficit following a progressive or a relapsing course associated with increased CSF protein content. The demonstration of asymmetrical demyelinating features on nerve conduction studies is needed for diagnosis. The outcome depends on the amplitude of axon loss associated with demyelination. CIDP must be differentiated from acquired demyelinative neuropathies associated with monoclonal gammopathies. CIDP responds well to treatment with corticosteroids, intravenous immunoglobulins, and plasma exchanges, at least initially.

Successful management with intravenous immunoglobulins in alemtuzumab-induced acute inflammatory demyelinating neuropathy: clinical report of three patients

Several neurological complications have been associated with the use of monoclonal antibodies (mAbs), and demyelinating disorders have been estimated to affect the 0.02-0.20% of treated patients. Alemtuzumab is a humanized chimeric mAbthat targets the CD52 antigen, it is currently approved for relapsed/refractory and high-risk untreated chronic lymphocytic leukemia (CLL). The major complication of alemtuzumab therapy is the increased risk of opportunistic infections secondary to the profound immunosuppression. Autoimmune diseases as Graves disease, immune thrombocytopenic purpura and Good pasture syndrome, have been reported to be associated to the treatment. In the present report, we present three CLL patients developing acute inflammatory demyelinating neuropathy during treatment with alemtuzumab. Despite the severity of the complication, all the patients showed an univocal good clinical response after treatment with intravenous immunoglobulin (IVIG). As alemtuzumab represents, nowadays, a key therapeutic option for CLL, clinicians should be aware of this rare and disabling toxicity.

[Neurological adverse events under anti-TNF alpha therapy]

INTRODUCTION

Anti-TNF alpha treatments are increasingly prescribed in various rheumatological or gastroenterological inflammatory diseases. Several adverse events, including neurological episodes have been reported in the literature. Relation to treatment is a major concern and guidelines for management of those patients are not available. The aim of our study is to collect and analyze neurological adverse events occurring during anti-TNF alpha therapy, and to propose guidelines for diagnosis of demyelinating-induced diseases.

METHODS

All patients treated with anti-TNF alpha drug, who were addressed in our department following a neurological event, were collected. We gathered clinical data including previous neurological history and immunosuppressive treatments. Paraclinical data included brain and spinal MRI, CSF study and outcome after anti-TNF therapy was collected.

RESULTS

Nine patients were included in this study. Sex ratio was eight and mean age was 49±9 years. One patient had previous history of subarachnoïdian hemorrage. All the patients previously received immunosuppressive drugs, including methotrexate (nine) and leflunomide (four). Three patients had a brain MRI before initiation of anti-TNF treatment, which was normal. Clinical episode was stroke-like in three cases, clinically isolated syndrome (CIS) in five cases, and peripheral neuropathy in one case. MRI showed lesions suggestive of demyelinating T2 hyperintensities in four cases, vascular infarcts in two cases, and non-specific T2 hyperintensities in three cases. Barkhof and Tintore criteria were fulfilled in one of the four CIS cases. CSF study was available for six patients. It was normal (four cases), showed oligoclonal bands (one case) and lymphocytic meningitis (one case). Anti-TNF alpha discontinuation was decided in five cases. Outcome was favorable for eight patients. One patient, whom MRI fulfilled Barkhof and Tintore criteria, and CSF showed oligoclonal bands, further developed relapsing remitting multiple sclerosis.

CONCLUSION

Our study is compatible with data found in the literature. Barkhof and Tintore criteria and CSF study are useful in clinical practice to diagnose a first demyelinating event. Standardized paraclinical neurological explorations should be proposed to physicians who are in charge of anti-TNF treated patients.

Plasma exchange and intravenous immunoglobulins: mechanism of action in immune-mediated neuropathies

Immune-mediated neuropathies are a heterogeneous group of peripheral nerve disorders, which are classified by time course, clinical pattern, affected nerves and pathological features. Plasma exchange (PE) and intravenous immunoglobulins (IVIg) are mainstays in the treatment of immune-mediated neuropathies. Of all treatments currently used, IVIg has probably the widest application range in immune-mediated neuropathies and efficacy has been well documented in several randomized controlled trials for Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP). Beneficial effects of IVIg have also been proven for multifocal motor neuropathy (MMN). Likewise, PE is an established treatment for GBS and CIDP, whereas it is considered to be ineffective in MMN. Different mechanisms of action are sought to be responsible for the immunemodulatory effect of PE and IVIg in autoimmune disorders. Some of those might be important for immune-mediated neuropathies, while others are probably negligible. The aim of this review is to summarize the recent advances in elucidating disease-specific mechanisms of actions of PE and IVIg in the treatment of immune-mediated neuropathies.

Neurological adverse events associated with anti-tumor necrosis factor α treatment

Anti-tumor necrosis factor alpha (TNF-alpha) drugs have been successfully used for the treatment of rheumatic autoimmune diseases including rheumatoid arthritis (RA), psoriatic arthritis, psoriasis, ankylosing spondylitis (AS), juvenile chronic arthritis, and Crohn's disease. However, they have been associated with different neurological disorders, including alterations of peripheral nerves, multiple sclerosis (MS), optic neuritis (ON) and acute transverse myelitis (ATM). This article reviews the most current aspect regarding neurological adverse events associated with anti-TNF-alpha drugs with emphasis on the possible explanations for this relation and the pathogenic mechanism of TNF-alpha in neurological disorders.

Chronic inflammatory demyelinating polyradiculoneuropathy: diagnostic and therapeutic challenges for a treatable condition

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic neuropathy of supposed immune origin. Understanding of its pathophysiology has recently improved, although its causes remain unclear. The classic presentation of CIDP includes sensory and motor symptoms in the distal and proximal segments of the four limbs with areflexia, evolving over more than 8 weeks. Raised protein concentrations in CSF and heterogeneous slowing of nerve conduction are typical of the condition. In addition to this usual phenotype, distribution of symptoms, disease course, and disability can be heterogeneous, leading to underdiagnosis of the disorder. Diagnosis is sometimes challenging and can require use of imaging and nerve biopsy. Steroids and intravenous immunoglobulin are effective, and plasma exchange can be helpful as rescue therapy. The usefulness of immunosuppressants needs to be established. The identification of specific diagnostic markers and new therapeutic strategies with conventional or targeted immunotherapy are needed to improve the outlook for patients with CIDP.

Chronic inflammatory demyelinating polyradiculoneuropathy: a role for haematopoietic stem cell transplantation?

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a clinical syndrome of a chronic progressive or relapsing and remitting, symmetrical, sensory and motor radiculoneuropathy. The immune reaction in CIDP is characterised by selective inflammation of peripheral nerves and is probably due to the interaction of cellular and humoral responses. Only three treatments for CIDP have demonstrated benefit in randomised studies, corticosteroids, plasma exchange and intravenous immunoglobulin. 25% of patients fail to respond or do not respond adequately to these treatments. Experimental data in animal models have shown that several autoimmune disorders, either congenital or acquired, can be transferred and/or treated by the transplantation of bone marrow stem cells. Haematopoietic stem cell transplantation (HSCT) has been performed with varying success in over 700 patients with autoimmune disorders throughout Europe. The experience in CIDP is very limited. This article will review current understanding of CIDP and experience of the use of HSCT in refractory CIDP.

Chronic inflammatory demyelinating polyradiculoneuropathy, in an 8-year-old girl, complicated by deafness and kidney fibrosis

Based on case history and clinical and electrophysiological examinations, the authors report on a case of an 8-year-old girl who was diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy. The disease was complicated by deafness and kidney fibrosis. During treatment with methylprednisolone and intravenous immunoglobulin, followed by mycophenolate mofetil, prompt improvement of neurological findings occurred. The improvement of hearing was poor. Because the pathogenesis of chronic inflammatory demyelinating polyradiculoneuropathy has still not been clear, and on the grounds of several cases of chronic inflammatory demyelinating polyradiculoneuropathy conjoined with the kidney disease described in literature (glomerulopathy, interstitial nephritis), every patient with chronic inflammatory demyelinating polyradiculoneuropathy needs to undergo the urinalyses.

Molecularly targeted therapies for dysimmune neuropathies

Conventional treatment options, including corticosteroids, intravenous immunoglobulin, or plasma exchange, often fail to treat dysimmune neuropathies, such as chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, and monoclonal gammopathy with its subtypes. Therefore, a significant percentage of patients require adjunctive immunosuppressive therapies. Considering that even immunosuppressive agents often are ineffective and/or associated with significant toxicities, the need for the development of safe and effective new treatment options is rising. Currently, several monoclonal antibodies (MAbs) have been tested in open-label small-sized studies or even in single cases so as to establish future directions in the therapy of diseases of the peripheral nervous system (PNS). Rituximab, an MAb targeting against the B cell surface membrane protein CD20, is the most widely used and promising MAb for the treatment of dysimmune neuropathies, especially for those in which immunoglobulin M (IgM) autoantibodies are pathogenetically involved. The efficacy of alemtuzumab, bevacizumab, and etanercept to treat various forms of dysimmune neuropathies is currently under investigation. This review looks critically at recent developments in molecularly targeted therapies for dysimmune neuropathies and also highlights areas of future research to pursue.

Status of immune mediators in painful neuropathies

Peripheral neuropathies of identical etiology can be painful or painless. The reason for this difference in clinical presentation is as yet unknown; however, immune mediators, particularly cytokines, may play a role. Cytokines are proteins that are produced by immune and nonimmune cells and are categorized as pro- and anti-inflammatory. The role of cytokines in the induction and maintenance of pain has been well established in animal models. Proinflammatory cytokines are mostly algesic, whereas anti-inflammatory cytokines have analgesic properties. Clinical research also gives evidence for the involvement of cytokines in painful and painless neuropathies. A proinflammatory cytokine profile seems to be associated with pain in peripheral neuropathies of different etiologies and in other painful disorders such as the complex regional pain syndrome. Specifically, an imbalance between pro- and anti-inflammatory cytokines may contribute to pain generation. A better understanding of the underlying pathophysiology may open new opportunities for the treatment of pain.

Administration of dehydroepiandrosterone ameliorates experimental autoimmune neuritis in Lewis rats

Dehydroepiandrosterone (DHEA) is an abundant adrenal steroid in serum of humans, and has been reported to have anti-inflammatory, anti-proliferative, and certain immune-regulating properties. Experimental autoimmune neuritis (EAN) is a Th1 cell-mediated animal model of Guillain-Barré syndrome (GBS) in humans. In the present study, DHEA was administered subcutaneously to Lewis rats immunized with bovine peripheral myelin (BPM) in Freund's complete adjuvant. Rats treated with DHEA displayed significant delay in onset, decreased inflammatory cell infiltration in the PNS. Benefit was associated with significant decreases in numbers of IFN-gamma and TNF-alpha expressing cells in the PNS, BPM-stimulated T cell proliferation and IFN-gamma, TNF-alpha-secretion in the spleen cells. Only 2 mg DHEA-treated EAN rats decreased peak clinical score. No significant difference of supernatant IL-10 was found among the treatment and control groups. These results suggest that DHEA can ameliorate the severity of EAN by suppressing the proliferation of autoreactive T cell and expression of pro-inflammatory cytokines.

Tumor necrosis factor-alpha antagonists and neuropathy

Tumor necrosis factor (TNF)-alpha plays an important role in many aspects of immune system development, immune-response regulation, and T-cell-mediated tissue injury. The evidence that TNF-alpha, released by autoreactive T cells and macrophages, may contribute to the pathogenesis of immune-mediated demyelinating neuropathies is reviewed. TNF-alpha antagonists (infliximab, etanercept, adalimumab) are indicated for the treatment of advanced inflammatory rheumatic and bowel disease, but these drugs can induce a range of autoimmune diseases that also attack the central and peripheral nervous systems. Case histories and series report on the association between anti-TNF-alpha treatment and various disorders of peripheral nerve such as Guillain-Barré syndrome, Miller Fisher syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy with conduction block, mononeuropathy multiplex, and axonal sensorimotor polyneuropathies. The proposed pathogeneses of TNF-alpha-associated neuropathies include both a T-cell and humoral immune attack against peripheral nerve myelin, vasculitis-induced nerve ischemia, and inhibition of signaling support for axons. Most neuropathies improve over a period of months by withdrawal of the TNF-alpha antagonist, with or without additional immune-modulating treatment. Preliminary observations suggest that TNF-alpha antagonists may be useful as an antigen-nonspecific treatment approach to immune-mediated neuropathies in patients with a poor response to, or intolerance of, standard therapies, but further studies are required.

Idiopathic chronic inflammatory demyelinating polyneuropathy: an epidemiological study in Italy

AIM

The clinical and epidemiological characteristics of chronic inflammatory demyelinating polyneuropathy (CIDP) in an Italian population were assessed.

SUBJECTS AND METHODS

All subjects with a diagnosis of demyelinating neuropathy after 1990 in Piemonte and Valle d'Aosta (4,334,225 inhabitants) were considered. The diagnosis of CIDP was based on the research criteria of the American Academy of Neurology. 165 of 294 patients met the diagnostic criteria.

RESULTS

The crude prevalence rate was 3.58/100,000 population (95% CI 3.02 to 4.20). At the prevalence day, 76 (49.0%) cases had definite, 67 (43.2%) probable and 12 (7.7%) possible CIDP; disability was mild in 105 (67.7%) cases, moderate in 32 (20.6%) and severe in 18 (11.6%). The course was remitting-relapsing in 40 cases (25.8%), chronic progressive in 96 (61.9%) and monophasic in 19 (12.3%). Considering the 95 patients whose disorder presented in the period 1995-2001, the mean annual crude incidence rate was 0.36/100,000 population (95% CI 0.29 to 0.44), with a male to female ratio of 2.3:1. 14 cases were affected by diabetes mellitus. In multivariate analysis, factors related to severe disability at the prevalence day were: age >60 years; failure of immunomodulating therapies at the time of diagnosis; worse disability at nadir; and chronic course.

CONCLUSION

Incidence and prevalence rates of CIDP in Italy were higher than those observed in most previous studies. At the prevalence day, more than 80% of cases had a mild or moderate disability, indicating either a good response to immunomodulating therapy or a tendency of CIDP to have a mild course in most cases.

Problems encountered during anti-tumour necrosis factor therapy

Worldwide, over 400,000 patients have been treated with tumour necrosis factor (TNF)-alpha antagonists for indications that include rheumatoid arthritis, juvenile rheumatoid arthritis, inflammatory bowel disease, psoriatic arthritis and ankylosing spondylitis. Since their approval, concerns regarding safety have been raised. There is a risk of re-activation of granulomatous diseases, especially tuberculosis, and measures should be taken for detection and treatment of latent tuberculosis infections. Preliminary data suggest that anti-TNF therapy may be safe in chronic hepatitis C. However, TNF-alpha antagonists have resulted in re-activation of chronic hepatitis B if not given concurrently with antiviral therapy. Solid tumours do not appear to be increased with anti-TNF therapy. Variable rates of increased lymphoma risk have been described with anti-TNF therapy compared with the general population, although no increased risk was found compared with a rheumatoid arthritis population. Large phase II and III trials with TNF-alpha antagonists in advanced heart failure have shown trends towards a worse prognosis, and should therefore be avoided in this population. Both etanercept and infliximab are associated with the formation of autoantibodies, and these autoantibodies are rarely associated with any specific clinical syndrome. Rare cases of aplastic anaemia, pancytopenia, vasculitis and demyelination have been described with anti-TNF therapy. This chapter will discuss the safety profile and adverse events of the three commercially available TNF-alpha antagonists: etanercept, infliximab and adalimumab. The data presented in this review have been collected from published data, individual case reports or series, package inserts, the Food and Drug Administration postmarketing adverse events surveillance system, and abstracts from the American College of Rheumatology and European Congress of Rheumatology meetings for 2005.

Chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinative polyneuropathy (CIDP) is an acquired neuropathy, presumably of immunological origin. Its clinical presentation and course are extremely variable. CIDP is one of the few peripheral neuropathies amenable to treatment. Typical cases associate progressive or relapsing-remitting motor and sensory deficit with increased CSF protein content and electrophysiological features of demyelination. In other instances the neuropathy is predominantly or exclusively motor or sensory, CSF normal and electrophysiological studies fail to show evidence of demyelination. In such cases conventional diagnostic criteria are not filled yet the patient may respond to immunomodulatory treatments. In this paper we review the diagnostic pitfalls and clinical variants of CIDP to illustrate the problems that may arise. The different therapeutic options are reviewed. Axon loss associated with demyelination is the most important factor of disability and resistance to treatment.

Pathogenesis of chronic inflammatory demyelinating polyradiculoneuropathy

The acute lesions of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) consist of endoneurial foci of chemokine and chemokine receptor expression and T cell and macrophage activation. The myelin protein antigens, P2, P0, and PMP22, each induce experimental autoimmune neuritis in rodent models and might be autoantigens in CIDP. The strongest evidence incriminates P0, to which antibodies have been found in 20% of cases. Failure of regulatory T-cell mechanism is thought to underlie persistent or recurrent disease, differentiating CIDP from the acute inflammatory demyelinating polyradiculoneuropathy form of Guillain-Barré syndrome. Corticosteroids, intravenous immunoglobulin and plasma exchange each provide short term benefit but the possible long-term benefits of immunosuppressive drugs have yet to be confirmed in randomised, controlled trials.

Circulating levels of cytokines and their modulation by intravenous immunoglobulin in multifocal motor neuropathy

We found comparable levels of tumor necrosis factor (TNF)-alpha, interferon-gamma, interleukin (IL)-2, IL-4, IL-10, and IL-12 in the sera of 22 patients with multifocal motor neuropathy (MMN), 12 with amyotrophic lateral sclerosis (ALS), 12 multiple sclerosis, seven chronic inflammatory demyelinating polyneuropathy, five myasthenia gravis, and 13 healthy controls (NS). TNF-alpha levels, however, were higher in 15 (68%) MMN patients than in any NS. In all but one MMN patient tested, TNF-alpha levels repeatedly, albeit slightly, increased after each intravenous immunoglobulin infusion in parallel with clinical improvement and decreased 3-4 weeks after therapy, while in both ALS patients tested, they decreased or remained unchanged. The possible pathogenetic relevance of serum TNF-alpha modification in MMN remains to be clarified.

Tumor necrosis factor-alpha gene transfer induces cachexia and inhibits muscle regeneration

Chronic disease states are associated with elevated levels of inflammatory cytokines that have been demonstrated to lead to severe muscle wasting. A mechanistic understanding of muscle wasting is hampered by limited in vivo cytokine models which can be applied to emerging mouse mutants as they are generated. We developed a simple and novel approach to induce adult mouse skeletal muscle wasting based on direct gene transfer of an expression vector encoding the secreted form of the murine tumor necrosis factor-alpha (mTNFalpha). This procedure results in the production of elevated levels of circulating mTNFalpha followed by body weight loss, upregulation of Atrogin1, and muscle atrophy, including muscles distant from the site of gene transfer. We also found that mTNFalpha gene transfer resulted in a significant inhibition of regeneration following muscle injury. We conclude that in addition to being a potent inducer of cachexia, TNFalpha is a potent inhibitor of myogenesis in vivo.

Long term prognosis of chronic inflammatory demyelinating polyneuropathy: a five year follow up of 38 cases

BACKGROUND

Little is known about long term prognosis and course after immune treatments in chronic inflammatory demyelinating polyneuropathy (CIDP).

OBJECTIVE

To study long term outcomes and prognostic factors in patients with CIDP.

METHODS

Clinical and electrophysiological findings, responses to immune modulating treatments, and outcomes five years after the start of treatment were reviewed in 38 CIDP patients.

RESULTS

Patients were treated with corticosteroids (89%), immunoglobulin infusion (45%), or plasmapheresis (34%), and 58% received combined therapy. Five years after treatment was begun, 10 (26%) of the patients had complete remission (lasting >2 years with normal nerve conduction studies), and 23 (61%) had partial remission (able to walk) with (26%) or without (34%) immune treatments. The remaining five patients (13%) still had severe disability (unable to walk) or treatment dependent relapses. Patients with complete remission more often had subacute onset, symmetrical symptoms, good response to initial corticosteroid treatment, and nerve conduction abnormalities predominant in the distal nerve terminals. In contrast, insidious onset, asymmetrical symptoms, and electrophysiological evidence of demyelination in the intermediate nerve segments were associated with refractoriness to treatment or treatment dependent relapse.

CONCLUSIONS

The long term prognosis of CIDP patients was generally favourable, but 39% of patients still required immune treatments and 13% had severe disabilities. Mode of onset, distribution of symptoms, and electrophysiological characteristics may be prognostic factors for predicting a favourable outcome.