Alemtuzumab-induced immune-mediated thrombotic thrombocytopenic purpura: A newly described drug-related autoimmune disease.

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare and life-threatening disease that may result from drug exposure. We report a case of iTTP occurring in a 39-year-old patient, 45 months following introduction of the anti-CD52 lymphoid cell depleting monoclonal antibody alemtuzumab, to treat a relapsing-remitting multiple sclerosis. Treatment consisted in plasma exchange, corticosteroids and caplacizumab, allowing clinical remission 3 months after the diagnosis, attested by the absence of thrombocytopenia and recovery of ADAMTS-13 activity. As other autoimmune disorders, iTTP may occur following alemtuzumab. This diagnosis should be suspected in patients with features of thrombotic microangiopathy following this treatment.

Transthyretin amyloid polyneuropathy in France: A cross-sectional study with 413 patients and real-world tafamidis meglumine use (2009-2019).

OBJECTIVE: We aimed to describe characteristics of patients with ATTR variant polyneuropathy (ATTRv-PN) and ATTRv-mixed and assess the real-world use and safety profile of tafamidis meglumine 20mg. METHODS: Thirty-eight French hospitals were invited. Patient files were reviewed to identify clinical manifestations, diagnostic methods, and treatment compliance. RESULTS: Four hundred and thirteen patients (296 ATTRv-PN, 117 ATTRv-mixed) were analyzed. Patients were predominantly male (68.0%) with a mean age of 57.2±17.2 years. Interval between first symptom(s) and diagnosis was 3.4±4.3 years. First symptoms included sensory complaints (85.9%), dysautonomia (38.5%), motor deficits (26.4%), carpal tunnel syndrome (31.5%), shortness of breath (13.3%), and unexplained weight loss (16.0%). Mini-invasive accessory salivary gland or punch skin and nerve biopsies were most common, with a performance of 78.8-100%. TTR genetic sequencing, performed in all patients, revealed 31 TTR variants. Tafamidis meglumine was initiated in 156/214 (72.9%) ATTRv-PN patients at an early disease stage. Median treatment duration was 6.00 years in ATTRv-PN and 3.42 years in ATTRv-mixed patients. Tafamidis was well tolerated, with 20 adverse events likely related to study drug among the 336 patients. CONCLUSION: In France, ATTRv patients are usually identified early thanks to the national network and the help of diagnosis combining genetic testing and mini-invasive biopsies.

Treating hereditary transthyretin amyloidosis: Present & future challenges.

Hereditary transthyretin amyloidosis (ATTRv) is a rare, lethal, autosomal dominant adult-onset genetic gain-of function (GOF) disorder provoked by mutations in the TTR gene. Until recently, therapeutic options were limited and consisted mainly in liver transplantation and TTR-stabilizers. In the last few years, ATTRv has been at the center of major therapeutic breakthroughs, including development of effective small interfering RNA (siRNA) and antisense oligonucleotide (ASO) treatments targeting liver TTR mRNA. Both siRNA (patisiran) and ASO (inotersen) treatments are now commercially available and have dramatically improved ATTRv neurological outcome. Ongoing clinical trials currently evaluate another siRNA, vutrisiran and a novel ASO formulation, eplontersen. A CRISPR-Cas9-based TTR gene editing treatment is also currently evaluated, with encouraging preliminary results. These recent therapeutic developments demonstrate the shifting paradigm of ATTRv, a previously untreatable and lethal disorder and provide a proof-of-concept for developing siRNA, ASO and CRISPR-Cas9 treatments for other GOF genetic disorders.

Strategy for genetic analysis in hereditary neuropathy.

Inherited neuropathies are a heterogeneous group of slowly progressive disorders affecting either motor, sensory, and/or autonomic nerves. Peripheral neuropathy may be the major component of a disease such as Charcot-Marie-Tooth disease or a feature of a more complex multisystemic disease involving the central nervous system and other organs. The goal of this review is to provide the clinical clues orientating the genetic diagnosis in a patient with inherited peripheral neuropathy. This review focuses on primary inherited neuropathies, amyloidosis, inherited metabolic diseases, while detailing clinical, neurophysiological and potential treatment of these diseases.

Comparison of Lewis-Sumner syndrome with chronic inflammatory demyelinating polyradiculoneuropathy patients in a tertiary care centre.

BACKGROUND AND PURPOSE: Whether the Lewis-Sumner syndrome (L-SS) is a distinct entity from other types of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP-ot) remains controversial. METHOD: The clinical/electrophysiological characteristics and long-term outcomes of 45 L-SS and 35 CIDP-ot patients were retrospectively compared. RESULTS: The CIDP-ot group was composed of 11 patients with a typical CIDP, 17 with a pure sensory form, four with a distal form and three with a pure motor form. In the L-SS group, asymmetric (P < 0.001) and monomelic involvement (P = 0.04) of the upper limbs (P < 0.001) was significantly more frequent; paucisymptomatic forms (Overall Neuropathy Limitations Scale ≤ 1) were less frequent (P < 0.001); electroneuromyography showed that conduction block in intermediate nerve segments was the main demyelinating feature, with frequent F-wave abnormalities on nerves without conduction block (44%). Long-term prognosis was globally poorer in the L-SS group with more frequent aggravation during treatment (P = 0.02), less frequent treatment withdrawal (P = 0.03) and longer time to achieve successful withdrawal (39 vs. 15 months). CONCLUSIONS: Our study suggests that L-SS patients have a less favourable therapeutic response rate and long-term outcomes. Rapid differentiation of L-SS from other forms of CIDP is important in order to anticipate a more complicated disease course management, with from one side the inefficacy or even harmfulness of corticosteroids and from the other side a difficult weaning procedure. A prospective study is necessary to confirm these results.

Diagnostic usefulness of plexus magnetic resonance imaging in chronic inflammatory demyelinating polyradiculopathy without electrodiagnostic criteria of demyelination.

BACKGROUND AND PURPOSE: The usefulness of plexus magnetic resonance imaging (MRI) in the diagnosis of chronic inflammatory demyelinating polyradiculopathy (CIDP) without definite European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) electrodiagnostic criteria is currently unclear. METHODS: Data from consecutive patients with clinical manifestations suggesting CIDP, with or without (CIDP-D and CIDP-ND, respectively) definite EFNS/PNS electrodiagnostic criteria, and referred for plexus MRI in our imaging centre were retrospectively analysed. An expert committee of neurologists compared the level of suspicion of CIDP in CIDP-ND patients to the blinded/unblinded MRI findings. Plexus MRI was reviewed by a neuroradiologist blinded to the final diagnosis. RESULTS: In all, 38 patients were assessed with suspected CIDP-ND [7/38 (18%) probable; 13/38 (34%) possible; 18/38 (47%), no EFNS/PNS electrodiagnostic criteria], plus 10 with CIDP-D. Thirty-six of the 38 (95%) fulfilled clinical criteria of CIDP variants, including pure sensory neuropathy in 22/36 (61%). Plexus MRI showed abnormalities in 22/38 (58%) patients including increased nerve signal intensity on T2-weighted images in 22/22 (100%), nerve enlargement in 20/22 (91%) and contrast enhancement in 8/22 (36%). Plexus MRI enabled the expert committee's final diagnosis to be adjusted in 7/38 (18%) patients, and in conjunction with nerve conduction studies was a supportive criterion to classify 7/24 (29%) patients as definite CIDP. MRI abnormalities were more asymmetrical (P = 0.03) and less diffuse (P = 0.1) in CIDP-ND than in CIDP-D. CONCLUSIONS: Our observations suggest that plexus MRI makes a valuable contribution to the diagnosis of CIDP-ND patients. Further studies are needed to investigate inter-rater reliability of clinical and imaging criteria of CIDP in these patients, and the impact on outcomes.

Upper limb onset of hereditary transthyretin amyloidosis is common in non-endemic areas.

BACKGROUND AND PURPOSE: The aim is to describe an uncommon phenotype of hereditary ATTR neuropathy with upper limb onset. METHODS: The French TTR Familial Amyloid Polyneuropathy database was used for a retrospective evaluation of 32 consecutive patients with upper limb onset of the neuropathy (study group) and they were compared to 31 Portuguese early-onset patients and 99 late-onset patients without upper limb onset. RESULTS: Initial upper limb symptoms were mostly sensory. Lower limb symptoms began 2.3 ± 3 years after upper limb symptoms. Twenty-four (75%) patients were initially misdiagnosed, with 15 different diagnoses. More patients in the study group had a Neuropathy Impairment Score upper limb/lower limb ratio > 1 compared to the late-onset patient group. The study group had significantly more pronounced axonal loss in the median and ulnar motor nerves and the ulnar sensory and sural nerves. On radial nerve biopsies (n = 11), epineurial vessels were abnormal in six cases, including amyloid deposits in vessel walls (3/11), with vessel occlusion in two cases. CONCLUSION: Upper limb onset of hereditary ATTR neuropathy is not rare in non-endemic areas. It is important to propose early TTR sequencing of patients with idiopathic upper limb neuropathies, as specific management and treatment are required.

Familial amyloid polyneuropathy: When does it stop to be asymptomatic and need a treatment?

Transthyretin familial amyloid polyneuropathy (FAP) is a rare disease with autosomal transmission due to point mutation of the transthyretin (TTR) gene. It is the most disabling hereditary neuropathy affecting sensory, motor and autonomic nerves, and is irreversible and fatal within 7 to 12 years of onset in the absence of therapy. Diagnosis is usually delayed for 1-5 years because the onset is usually insidious, and a positive family history is lacking in 50% of late-onset cases. Penetrance is variable, and depends of the age of the carrier and age of onset in family members. Two treatments are available: liver transplantation, to suppress the main source of systemic production of mutant TTR; and TTR tetramer stabilizer drugs, to avoid the release of highly amyloidogenic monomers and oligomers. These therapies are able to stop or slow the progression of the disease in its early stages. Genetic counseling is crucial to detect carriers at risk of developing the disease. The European network for TTR-FAP recommends careful baseline assessment by questionnaire, clinical examination and neurophysiological tests, and periodic consultations to detect the onset of disease in time to start anti-amyloid therapy after biopsy findings of amyloid deposition. A therapeutic educational program is important for improving patients' awareness. Patients are considered symptomatic and ill when they themselves perceive symptoms or changes, including changes from baseline measurements on neurophysiological tests, followed by findings of amyloid deposition on biopsy. The most sensitive biopsies are from the labial salivary gland and skin.

French protocol for the diagnosis and management of hematopoietic stem cell transplantation in autoimmune diseases.

Hematopoietic stem cell transplantation (HSCT) for severe ADs was developed over the past 25years and is now validated by national and international medical societies for severe early systemic sclerosis (SSc) and relapsing-remitting multiple sclerosis (MS) and available as part of routine care in accredited center. HSCT is also recommended, with varying levels of evidence, as an alternative treatment for several ADs, when refractory to conventional therapy, including specific cases of connective tissue diseases or vasculitis, inflammatory neurological diseases, and more rarely severe refractory Crohn's disease. The aim of this document was to provide guidelines for the current indications, procedures and follow-up of HSCT in ADs. Patient safety considerations are central to guidance on patient selection and conditioning, always validated at the national MATHEC multidisciplinary team meeting (MDTM) based on recent (less than 3months) thorough patient evaluation. HSCT procedural aspects and follow-up are then carried out within appropriately experienced and Joint Accreditation Committee of International Society for Cellular Therapy and SFGM-TC accredited centres in close collaboration with the ADs specialist. These French recommendations were performed according to HAS/FAI2R standard operating procedures and coordinated by the Île-de-France MATHEC Reference Centre for Rare Systemic Autoimmune Diseases (CRMR MATHEC) within the Filière FAI2R and in association with the Filière MaRIH. The task force consisted of 3 patients and 64 clinical experts from various specialties and French centres. These data-derived and consensus-derived recommendations will help clinicians to propose HSCT for their severe ADs patients in an evidence-based way. These recommendations also give directions for future clinical research in this area. These recommendations will be updated according to newly emerging data. Of note, other cell therapies that have not yet been approved for clinical practice or are the subject of ongoing clinical research will not be addressed in this document.

[Peripheral neuropathies during systemic diseases: Part I (connective tissue diseases and granulomatosis)]. / Neuropathies périphériques au cours des maladies de système : partie I (connectivites et granulomatoses).

Systemic diseases (connective disease, granulomatosis) may be associated with peripheral neuropathies. The diagnosis can be complex when the neuropathy is the presenting manifestation of the disease, requiring close collaboration between neurologists and internists. Conversely, when the systemic disease is already known, the main question remaining is its imputability in the neuropathy. Regardless of the situation, the positive diagnosis of neuropathy is based on a systematic and rigorous electro-clinical investigation, specifying the topography, the evolution and the mechanism of the nerve damage. Certain imaging examinations, such as nerve and/or plexus MRI, or other more invasive examinations (skin biopsy, neuromuscular biopsy) enable to specify the topography and the mechanism of the injury. The imputability of the neuropathy in the course of a known systemic disease is based mainly on its electro-clinical pattern, on which the alternatives diagnoses depend. In the case of an inaugural neuropathy, a set of arguments orients the diagnosis, including the underlying terrain (young subject), possible associated systemic manifestations (inflammatory arthralgias, polyadenopathy), results of first-line laboratory tests (lymphopenia, hyper-gammaglobulinemia, hypocomplementemia), autoantibodies (antinuclear, anti-native DNA, anti-SSA/B) and sometimes invasive examinations (neuromuscular biopsy).

[Peripheral neuropathies during systemic diseases: Part II (vasculitis)]. / Neuropathies périphériques au cours des maladies de système : partie II (vascularites).

Primary systemic vasculitides, mainly of the small and medium-sized vessels, are frequently associated with peripheral neuropathies. When the disease is already known, the appearance of a neuropathy should suggest a specific injury, especially when associated with other systemic manifestations. Conversely, when neuropathy is inaugural, close collaboration between neurologists and internists is necessary to reach a diagnosis. A standardized electro-clinical investigation specifying the topography, the evolution and the mechanism of the nerve damage enables the positive diagnosis of the neuropathy. Several elements orient the etiological diagnosis and allow to eliminate the main differential diagnosis: non systemic vasculitic neuropathy. The existence of associated systemic manifestations (glomerular or vascular nephropathy, interstitial lung disease, intra-alveolar hemorrhage, ENT involvement…), biological markers (ANCA, cryoglobulinemia, rheumatoid factor), and invasive examinations allowing histological analysis (neuromuscular biopsy) are all useful tools for.

[Autologous hematopoietic stem cell transplantation for chronic inflammatory demyelinating polyneuropathy]. / Carrefour des spécialités : autogreffe de cellules souches hématopoïétiques périphériques pour la prise en charge thérapeutique des polyradiculonévrites inflammatoires démyélinisantes chroniques.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a dysimmune neuropathy with sensory and/or motor symptoms due to destruction of the myelin sheat secondary to an auto-immune attack. A quarter to a third of patients do not respond to immunomodulatory first line recommended therapies. No second line treatment has shown its effectiveness with a sufficient level of evidence. Autologous hematopoietic stem cell transplantation (AHSCT) is a promising therapy for autoimmune disease, especially for CIDP in recent works. We present in this article an update on the diagnosis of CIDP, its conventional treatments as well as the results of AHSCT in this indication, which was the subject of French recommendations under the aegis of the SFGMTC and neuromuscular disease french faculty (FILNEMUS) as a third line therapy after failure of two first-line and one second-line treatments.

Neuropathies périphériques associées aux syndromes lymphoprolifératifs : spectre clinique et démarche diagnostique.

Lymphoproliferative syndromes (multiple myeloma, Waldenström's disease, chronic lymphocytic leukemia, lymphomas) may be associated with peripheral neuropathies. The mechanism can be dysimmune, associated or not with monoclonal gammopathies; paraneoplastic; infiltrative; or more commonly, iatrogenic or due to vitamin deficiency. The diagnosis can be complex, especially when the neuropathy is the presenting manifestation, requiring a close cooperation between internists and neurologists. The positive diagnosis of the neuropathy is based on a systematic electro-clinical investigation, which specifies the topography and the mechanism of the nerve damage, sometimes reinforced by imaging examinations, in particular, nerve and/or plexus MRI. The imputability of the neuropathy to a lymphoproliferative syndrome is based on a set of arguments including the clinical context (B signs, tumour syndrome), first-line laboratory tests (hemogram, protein electrophoresis, viral serologies, complement), auto-antibodies discussed according to the neuropathy (anti-MAG, anti-gangliosides) and sometimes more invasive examinations (bone marrow or neuro-muscular biopsies).

[Cervical spinal sarcoidosis mimicking compressive cervical myelopathy: Poor prognosis after surgery]. / Sarcoïdose médullaire mimant une myélopathie cervico-arthrosique : mauvais pronostic après chirurgie.

INTRODUCTION: Cervical spinal sarcoidosis can mimic compressive cervical myelopathy leading to potentially harmful surgical procedures before the diagnosis can be made. METHODS: Retrospective description of 3 patients and review of the literature. RESULTS: Twenty-seven patients (16 men/11 women), median age 58 years [range 29-74] were described. Neurosurgical procedures consisted of laminectomy (n=10), laminoplasty (n=15) and anterior discectomy (n=2). Immediately after surgery, 17 patients (63%) worsened or remained disabled. Among the 10 patients who improved, 9 worsened secondarily. The analysis of preoperative MRI showed T2 hypersignal lesions and contrast enhancement in all patients. Neurological symptoms were inaugural in 25/27 patients, and systemic involvement of the sarcoidosis was found after surgery in 15/27 patients. After surgery, all patients received corticosteroids, along with immunosuppressive therapy in 8 cases/27. After a follow-up of 24 [16-72] months; 13 patients were stabilized or worsened, 7 were partially improved. Three died of other cause. Only 5 recovered without sequelae. CONCLUSION: In patients with compressive cervical myelopathy, leptomeningeal contrast enhancement, a T2-weighted hypersignal exceeding the compression level on MRI, and the presence of extraneurological symptoms should point to inflammatory disease. These rare manifestations may be the first symptoms of sarcoidosis and should be recognized to avoid harmful surgical procedures and to provide appropriate medical treatment.