Overcoming therapeutic challenges: Successful management of a supposedly triple seronegative, refractory generalized myasthenia gravis patient with efgartigimod.

BACKGROUND AND PURPOSE: This study was undertaken to highlight neonatal Fc receptor inhibition (efgartigimod) as a valuable therapeutic option for patients with refractory seronegative myasthenia gravis (MG) and to emphasize the concept that seronegative MG is greatly constrained by the limitations of currently available diagnostic methods and therapeutic measures. METHODS: We describe the first refractory, generalized MG (gMG) patient successfully treated with efgartigimod after testing negative on standard autoantibody detection tests. RESULTS: Our patient presented with severe fluctuating bulbar and generalized weakness, resulting in multiple myasthenic crises requiring intubation. After a 28-year medical history of multiple failed lines of treatment, our patient was started on efgartigimod. Over five treatment cycles, a definite improvement in her clinical condition was observed (Myasthenia Gravis Foundation of America class: IIIb to IIb; MG-Activities of Daily Living score: 11 to 0; MG-Quality of Life 15 score: 30 to 0; Quantitative MG score: 28 to 6). Standard autoantibody detection tests failed to detect known pathogenic autoantibodies, but cell-based assay (CBA) identified autoantibodies against clustered adult acetylcholine receptor (AChR). CONCLUSIONS: In light of recent approvals of efgartigimod by the European Medicines Agency and US Food and Drug Administration exclusively for AChR-positive gMG forms, our case highlights evidence suggesting that such an approach might be shortsighted and could limit therapeutic options for patients with refractory seronegative gMG. Additionally, introducing more sensitive analytical techniques, exemplified by CBA, may help bridge the gap between seronegative and seropositive patients. This represents an urgent unmet need for gMG patients, as the antibody profile dramatically influences the therapeutic approach.

Extreme phenotypic heterogeneity in non-expansion spinocerebellar ataxias.

Although the best-known spinocerebellar ataxias (SCAs) are triplet repeat diseases, many SCAs are not caused by repeat expansions. The rarity of individual non-expansion SCAs, however, has made it difficult to discern genotype-phenotype correlations. We therefore screened individuals who had been found to bear variants in a non-expansion SCA-associated gene through genetic testing, and after we eliminated genetic groups that had fewer than 30 subjects, there were 756 subjects bearing single-nucleotide variants or deletions in one of seven genes: CACNA1A (239 subjects), PRKCG (175), AFG3L2 (101), ITPR1 (91), STUB1 (77), SPTBN2 (39), or KCNC3 (34). We compared age at onset, disease features, and progression by gene and variant. There were no features that reliably distinguished one of these SCAs from another, and several genes-CACNA1A, ITPR1, SPTBN2, and KCNC3-were associated with both adult-onset and infantile-onset forms of disease, which also differed in presentation. Nevertheless, progression was overall very slow, and STUB1-associated disease was the fastest. Several variants in CACNA1A showed particularly wide ranges in age at onset: one variant produced anything from infantile developmental delay to ataxia onset at 64 years of age within the same family. For CACNA1A, ITPR1, and SPTBN2, the type of variant and charge change on the protein greatly affected the phenotype, defying pathogenicity prediction algorithms. Even with next-generation sequencing, accurate diagnosis requires dialogue between the clinician and the geneticist.

Out-of-Frame Mutations in ACTN2 Last Exon Cause a Dominant Distal Myopathy With Facial Weakness.

BACKGROUND AND OBJECTIVES: To clinically, genetically, and histopathologically characterize patients presenting with an unusual combination of distal myopathy and facial weakness, without involvement of upper limb or shoulder girdle muscles. METHODS: Two families with a novel form of actininopathy were identified. Patients had been followed up over 10 years. Their molecular genetic diagnosis was not clear after extensive investigations, including analysis of candidate genes and FSHD1-related D4Z4 repeats. RESULTS: Patients shared a similar clinical phenotype and a common pattern of muscle involvement. They presented with a very slowly progressive myopathy involving anterior lower leg and facial muscles. Muscle MRI finding showed complete fat replacement of anterolateral compartment muscles of the lower legs with variable involvement of soleus and gastrocnemius but sparing thigh muscles. Muscle biopsy showed internalized nuclei, myofibrillar disorganization, and rimmed vacuoles. High-throughput sequencing identified in each proband a heterozygous single nucleotide deletion (c.2558del and c.2567del) in the last exon of the ACTN2 gene. The deletions are predicted to lead to a novel but unstructured slightly extended C-terminal amino acid sequence. DISCUSSION: Our findings indicate an unusual form of actininopathy with specific molecular and clinical features. Actininopathy should be considered in the differential diagnosis of distal myopathy combined with facial weakness.

ZFYVE26/SPASTIZIN and SPG11/SPATACSIN mutations in hereditary spastic paraplegia types AR-SPG15 and AR-SPG11 have different effects on autophagy and endocytosis.

ZFYVE26/Spastizin and SPG11/Spatacsin encode 2 large proteins that are mutated in hereditary autosomal-recessive spastic paraplegia/paraparesis (HSP) type 15 (AR-SPG15) and type 11 (AR-SPG11), respectively. We previously have reported that AR-SPG15-related ZFYVE26 mutations lead to autophagy defects with accumulation of immature autophagosomes. ZFYVE26 and SPG11 were found to be part of a complex including the AP5 (adaptor related protein complex 5) and to have a critical role in autophagic lysosomal reformation with identification of autophagic and lysosomal defects in cells with both AR-SPG15- and AR-SPG11-related mutations. In spite of these similarities between the 2 proteins, here we report that ZFYVE26 and SPG11 are differently involved in autophagy and endocytosis. We found that both ZFYVE26 and SPG11 interact with RAB5A and RAB11, 2 proteins regulating endosome trafficking and maturation, but only ZFYVE26 mutations affected RAB protein interactions and activation. ZFYVE26 mutations lead to defects in the fusion between autophagosomes and endosomes, while SPG11 mutations do not affect this step and lead to a milder autophagy defect. We thus demonstrate that ZFYVE26 and SPG11 affect the same cellular physiological processes, albeit at different levels: both proteins have a role in autophagic lysosome reformation, but only ZFYVE26 acts at the intersection between endocytosis and autophagy, thus representing a key player in these 2 processes. Indeed expression of the constitutively active form of RAB5A in cells with AR-SPG15-related mutations partially rescues the autophagy defect. Finally the model we propose demonstrates that autophagy and the endolysosomal pathway are central processes in the pathogenesis of these complicated forms of hereditary spastic paraparesis. Abbreviations: ALR, autophagic lysosome reformation; AP5, adaptor related protein complex 5; AR, autosomal-recessive; HSP, hereditary spastic paraplegia/paraparesis; ATG14, autophagy related 14; BafA, bafilomycin A1; BECN1, beclin 1; EBSS, Earle balanced salt solution; EEA1, early endosome antigen 1; EGF, epidermal growth factor; EGFR, epidermal growth factor receptor; GDP, guanosine diphosphate; GFP, green fluorescent protein; GTP, guanosine triphosphate; HSP, hereditary spastic paraplegias; LBPA, lysobisphosphatidic acid; MAP1LC3B/LC3B, microtubule associated protein 1 light chain 3 beta; MVBs, multivesicular bodies; PIK3C3, phosphatidylinositol 3-kinase, catalytic subunit type 3; PIK3R4, phosphoinositide-3-kinase regulatory subunit 4; PtdIns3P, phosphatidylinositol-3-phosphate; RFP, red fluorescent protein; RUBCN, RUN and cysteine rich domain containing beclin 1 interacting protein; shRNA, short hairpin RNA; SQSTM1/p62, sequestosome 1; TCC: thin corpus callosum; TF, transferrin; UVRAG, UV radiation resistance associated.

Intra-arterial transplantation of HLA-matched donor mesoangioblasts in Duchenne muscular dystrophy.

Intra-arterial transplantation of mesoangioblasts proved safe and partially efficacious in preclinical models of muscular dystrophy. We now report the first-in-human, exploratory, non-randomized open-label phase I-IIa clinical trial of intra-arterial HLA-matched donor cell transplantation in 5 Duchenne patients. We administered escalating doses of donor-derived mesoangioblasts in limb arteries under immunosuppressive therapy (tacrolimus). Four consecutive infusions were performed at 2-month intervals, preceded and followed by clinical, laboratory, and muscular MRI analyses. Two months after the last infusion, a muscle biopsy was performed. Safety was the primary endpoint. The study was relatively safe: One patient developed a thalamic stroke with no clinical consequences and whose correlation with mesoangioblast infusion remained unclear. MRI documented the progression of the disease in 4/5 patients. Functional measures were transiently stabilized in 2/3 ambulant patients, but no functional improvements were observed. Low level of donor DNA was detected in muscle biopsies of 4/5 patients and donor-derived dystrophin in 1. Intra-arterial transplantation of donor mesoangioblasts in human proved to be feasible and relatively safe. Future implementation of the protocol, together with a younger age of patients, will be needed to approach efficacy.

Pentraxin-3 and VEGF in POEMS syndrome: a 2-year longitudinal study.

Circulating Pentraxin 3 (PTX3) and vascular endothelial growth factor (VEGF) levels were measured longitudinally (mean follow-up 2 years) by ELISA in 6 patients with polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes (POEMS) syndrome and 16 controls. Expression of PTX3 was also assessed (immunohistochemistry) on sural nerve biopsies from POEMS and vasculitic neuropathy patients. No correlation was found between PTX3 and VEGF levels in POEMS or controls. Sural nerve biopsies from vasculitic neuropathy patients, but not those from POEMS syndrome, showed strong PTX3 staining. PTX3, expression of vessel inflammation/remodeling, and VEGF, crucial pro-angiogenic cytokine, appear to be independently regulated in POEMS syndrome.

POEMS syndrome: the matter-of-fact approach.

PURPOSE OF REVIEW: The aim is to provide an up-to-date overview of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome with special regard to the available therapy options. RECENT FINDINGS: In the past 20 years this rare plasmaproliferative disorder has been extensively characterized from a clinical point of view with complete description of the typical features as well as of other organ involvement not considered in the acronym as nephropathy or pachimeningitis. In this syndrome, the serum levels of vascular endothelial growth factor (VEGF) are abnormally elevated and now this is considered one of the major criteria for making the diagnosis. VEGF has also a prognostic value, as it decreases in response to therapy and definitely has a pathogenetic role in the multisystem involvement of POEMS. Recently great advance occurred in the treatment of POEMS syndrome with new immunomodulatory drugs such as lenalidomide, autologous peripheral blood stem cell transplantation or bevacizumab, an anti-VEGF monoclonal antibody. SUMMARY: Although many aspects of POEMS syndrome remain unclear, a valid biomarker of disease, VEGF, is available for diagnosis as well as a wide range of therapeutic options.

A fatal case of Churg-Strauss syndrome presenting with acute polyneuropathy mimicking Guillain-Barré syndrome.

A 64-year-old woman, with asthma and sinusal polyposis in her history, suddenly developed a painful polyneuropathy with diplopia. Nerve conduction studies, performed at the very onset of the neuropathy, could not definitely rule out a Guillain-Barré syndrome (GBS) and high-dose i.v. immunoglobulins were administered. Clinical and laboratory findings subsequently supported the diagnosis of Churg-Strauss syndrome; corticosteroid therapy was started and clinical stabilisation of neuropathy was apparently achieved. No indicators of unfavourable outcome were present at that time. Nevertheless, 30 days after the onset the patient acutely worsened with severe polyneuropathy relapse and fatal systemic diffusion to heart, kidney and mesenteric district, which a single cyclophosphamide pulse failed to control. This case highlights the possibility that a GBS-like onset of Churg-Strauss syndrome neuropathy should be regarded as a part of multiorgan, severe or even life-threatening vasculitic involvement, requiring the most aggressive treatments, regardless of the presence of recognised factors of poor outcome.

Motor nerve biopsy: clinical usefulness and histopathological criteria.

Early differential diagnosis of motor neuropathies (MN) and lower motor neuron diseases (LMND) is important, as prognosis and therapeutic approaches are different. We evaluated the diagnostic contribution of the biopsy of the motor branch of the obturator nerve and gracilis muscle in 21 consecutive patients in which, after proper clinical and neurophysiological studies, the differential diagnosis was still open. At baseline, motor biopsy was performed; diagnostic confirmation was obtained by 2-year clinical follow-up. Our results support the usefulness of this diagnostic procedure for selected cases of MN and LMND.

Vascular endothelial growth factor helps differentiate neuropathies in rare plasma cell dyscrasias.

POEMS syndrome and amyloidosis are rare plasma cell diseases that share common features, including polyneuropathy. The aim of this study was to investigate serum vascular endothelial growth factor (sVEGF) in patients with amyloidosis and to evaluate changes in response to treatment. Twenty-five patients [17 primary light-chain amyloidosis (AL-A), 7 transthyretin amyloidosis (TTR-A), 1 senile wild-type TTR-A] were studied. sVEGF was analyzed by ELISA. Sera from 8 myeloma and 7 POEMS patients were also evaluated. The median sVEGF level was 420 pg/ml in AL-A and 179 pg/ml in TTR-A patients; this was significantly lower than in POEMS syndrome (median 2580 pg/ml, P = 0.0002 and 0.001, respectively). sVEGF of AL-A patients showed no changes in response to treatment. sVEGF was not increased in amyloid patients regardless of neuropathy, and did not mirror the course of the disease. sVEGF should be tested in patients with overlapping and atypical clinical features.

Analyzing histopathological features of rare charcot-marie-tooth neuropathies to unravel their pathogenesis.

BACKGROUND: Charcot-Marie-Tooth (CMT) neuropathies are very heterogeneous disorders from both a clinical and genetic point of view. The CMT genes identified so far encode different proteins that are variably involved in regulating Schwann cells and/or axonal functions. However, the function of most of these proteins still remains to be elucidated. OBJECTIVE: To characterize a large cohort of patients with demyelinating, axonal, and intermediate forms of CMT neuropathy. DESIGN: A cohort of 131 unrelated patients were screened for mutations in 12 genes responsible for CMT neuropathies. Demyelinating, axonal, and intermediate forms of CMT neuropathy were initially distinguished as usual on the basis of electrophysiological criteria and clinical evaluation. A sural nerve biopsy was also performed for selected cases. Accordingly, patients underwent first-level analysis of the genes most frequently mutated in each clinical form of CMT neuropathy. RESULTS: Although our cohort had a particularly high percentage of cases of rare axonal and intermediate CMT neuropathies, we found mutations in 40% of patients. Among identified changes, 7 represented new mutations occurring in the MPZ, GJB1, EGR2, MFN2, NEFL, and HSBP1/HSP27 genes. Histopathological analysis performed in selected cases revealed morphological features, which correlated with the molecular diagnosis and provided evidence of the underlying pathogenetic mechanism. CONCLUSION: Clinical and pathological analysis of patients with CMT neuropathies contributes to our understanding of the molecular mechanisms of CMT neuropathies.

Absence of angiogenic genes modification in Italian ALS patients.

To investigate the role of vascular endothelial growth factor (VEGF) and angiogenin (ANG) as genetic determinants in the susceptibility to sporadic ALS in Italian patients. VEGF genotype and haplotype analysis revealed no association between any variants and the risk of ALS. Regarding ANG gene, no mutation was detected and the rs11701 polymorphism, previously described as associated with ALS, was not differently distributed between patients and controls. Overall, our data argue against the hypothesis of both genes as risk factors for motoneuron neurodegeneration, at least in an Italian population.

Role of VEGF gene variability in longevity: a lesson from the Italian population.

Vascular endothelial growth factor (VEGF) gene polymorphisms have been associated with an increased risk of developing a wide variety of disorders from diabetes to neurodegenerative diseases suggesting functions not confined to its vascular effects originally described. Based on the VEGF protective roles undisclosed in pathological conditions, we evaluate whether VEGF variability might be a determinant also for longevity. Four polymorphisms (-2578C/A, -1190G/A, -1154G/A and -634G/C) within the VEGF gene promoter region in 490 unrelated Italian healthy subjects have been analysed. Significant changes of allele, genotype (-2578/AA versus -2578/CC: OR=2.08, p=0.007; -1190/AA versus -1190/GG: OR=2.01, p=0.011) and haplotype (AAGG: 10.4% versus 14.9%, p=0.03) frequency distributions were observed between young/elderly (25-84 years old) and long-lived (85-99 years old) subjects. These results suggest that VEGF gene variability can be inserted among the genetic factors influencing the lifespan.

VEGF gene variability and type 1 diabetes: evidence for a protective role.

Vascular endothelial growth factor (VEGF) is a multifunctional cytokine originally described as an angiogenic factor. A number of reports have recently demonstrated that VEGF increases pancreatic islet survival after islet transplantation by stimulating angiogenesis and improving islet revascularization. Whether VEGF can protect from the autoimmune destruction of insulin-producing beta-cells that characterizes the development of type 1 diabetes is presently unknown. To clarify this issue, we studied the association of three polymorphisms of the promoter region of VEGF with type 1 diabetes in the Italian and the Finnish populations. The polymorphisms considered [C(-2578)A, G(-1190)A, and G(-1154)A] are known to modulate in vitro and in vivo VEGF expression. We found that VEGF promoter genotypes are associated with type 1 diabetes in both populations, but with different combinations. In Italian individuals, the -2578AA and -1190AA genotypes are associated with type 1 diabetes and accelerate its onset, while in Finnish individuals, -1154GG and -1190GG protect from type 1 diabetes and delay its onset. In conclusion, because the expected functional consequence of both genotype combinations is a reduced VEGF expression in diabetic patients, we propose a protective role of VEGF in the development of type 1 diabetes.

Polyneuropathy in POEMS syndrome: role of angiogenic factors in the pathogenesis.

In order to clarify the role of angiogenic factors in polyneuropathy of POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes) syndrome, we measured the serum concentrations of vascular endothelial growth factor (VEGF) and erythropoietin (EPO) in 11 patients and correlated these with VEGF and EPO peripheral nerve expression and the degree of endoneurial vessel involvement. We found that POEMS syndrome was associated with high levels of serum VEGF and, conversely, low levels of serum EPO. Similarly, in POEMS nerves VEGF was highly expressed in blood vessels and some non-myelin-forming Schwann cells. In contrast, the expression of VEGF receptor 2 was down-regulated compared with that in normal nerves. Both EPO and EPO receptor were localized to the nerve vasculature and were expressed to similar extents in normal and POEMS nerves. The inverse correlation between VEGF and EPO serum levels was maintained during the clinical course; however, both levels returned to normal when there was a response to therapy. High serum VEGF, low serum EPO and high peripheral nerve VEGF were all associated with more severe endoneurial vessel involvement and nerve damage. Light microscopy showed an increased thickness of the basal lamina and a narrowing of the lumina of endoneurial vessels in POEMS samples, while proliferation of endothelial cells and opening of tight junctions were observed by electron microscopy. The present data support the role of angiogenic factors as diagnostic and prognostic markers of POEMS syndrome. They also suggest that VEGF and EPO are involved in the pathogenesis of polyneuropathy. In conclusion, establishing the role of angiogenic factors in polyneuropathy may lead to a better understanding of the effects of VEGF and EPO on microangiopathy and Schwann cell function.

Induction of neuropilins-1 and -2 and their ligands, Sema3A, Sema3F, and VEGF, during Wallerian degeneration in the peripheral nervous system.

The neuropilins, NP-1 and NP-2, are coreceptors for Sema3A and Sema3F, respectively, both of which are repulsive axonal guidance molecules. NP-1 and NP-2 are also coreceptors for vascular endothelial growth factor (VEGF). The neuropilins and their ligands are known to play prominent roles in axonal pathfinding, fasciculation, and blood vessel formation during peripheral nervous system (PNS) development. We confirmed a prior report (Exp. Neurol. 172 (2001) 398) that VEGF mRNA levels rise during Wallerian degeneration in the PNS and herein demonstrate that NP-1, NP-2, Sema3A, and Sema3F mRNA levels increase in peripheral nerves distal to a transection or crush injury. In a sciatic nerve crush model, in which axonal regeneration is robust, the highest levels of Sema3F mRNA below the injury site are in the epi- and perineurium. Our results suggest the possibility that the neuropilins and their semaphorin ligands serve to guide, rather than to impede, regenerating axons in the adult PNS.