A case of severe increase of liver enzymes in a ATTRv patient after one year of inotersen treatment

Background: Inotersen is an antisense oligonucleotide used to treat hereditary transthyretin amyloidosis (ATTRv). The most common drug-related adverse effects (AEs) include thrombocytopenia and glomerulonephritis. Hepatic damage is rare, but liver enzyme monitoring is mandatory. Case report: A 70-year-old man with ATTRv (Val30Met) treated with inotersen developed a severe increase of transaminases, with normal bilirubin and cholinesterase levels, that forced us to stop therapy. At the same time, other causes of acquired hepatitis were excluded, and the hypothesis of an inotersen-related hepatic toxicity was supported by the normalization of liver enzymes after 40 days from the drug interruption. Discussion: Our case showed that 1-year inotersen treatment can stabilize neurological impairment and even improve quality of life and suggests to carefully monitor liver enzymes in order to avoid an inotersen-related hepatic dysfunction

Microstructural Changes in Motor Functional Conversion Disorder: Multimodal Imaging Approach on a Case

Background: Functional motor conversion disorders are characterized by neurological symptoms unrelated to brain structural lesions. The present study was conducted on a woman presenting motor symptoms causing motor dysfunction, using advanced multimodal neuroimaging techniques, electrophysiological and neuropsychological assessment. Methods: The patient underwent fluorodeoxyglucose-positron emission tomography-computed tomography (FDG-PET-CT) and functional magnetic resonance imaging (fMRI) with both task and resting-state paradigms and was compared with 11 healthy matched controls. To test differences in structural parameters, Bayesian comparison was performed. To test differences in functional parameters, a first- and second-level analysis was performed in task fMRI, while a seed-to-seed analysis to evaluate the connections between brain regions and identify intersubject variations was performed in resting-state fMRI. Results: FDG-PET showed two patterns of brain metabolism, involving the cortical and subcortical structures. Regarding the diffusion data, microstructural parameters were altered for U-shape fibers for the hand and feet regions. Resting-state analysis showed hypoconnectivity between the parahippocampal and superior temporal gyrus. Neurophysiological assessment showed no alterations. Finally, an initial cognitive impairment was observed, paralleled by an anxiety and mild depressive state. Conclusions: While we confirmed no structural alterations sustaining this functional motor disorder, we report microstructural changes in sensory-motor integration for both the hand and feet regions that could functionally support clinical manifestations

Pregnancy experience in women with spinal muscular atrophy: a case series

: Many women with spinal muscular atrophy (SMA) types II, III, and IV reach fertile age, and some of them may consider pregnancy. However, limited data are available about the potential effects of pregnancy on the course of SMA and the outcomes of pregnancies in these patients. Furthermore, the use of several disease-modifying therapies for the treatment of all types of SMA is expected to increase the number of female SMA patients considering pregnancy in the coming years. The aim of this report is to provide clinicians with an overview of the patients in our cohort who have experienced pregnancies. We conducted a retrospective analysis on these women, through the administration of a questionnaire, which investigated how they experienced the different stages of the pregnancy. Ten patients (3 SMAII; 7 SMA III) participated in the survey; 40% had pregnancies for a total of nine, six of which were term-pregnancies. The mean age of first pregnancy was 32.5 ± 7.8 years for SMA II patients, and 30.5 ± 2.1 years for SMA III. All pregnancies ended in cesarean sections. Interestingly, the sitters had more frequent complications in pre-term labor and delivery, but the newborns were all healthy. This report shows that a successful pregnancy is possible in female patients with SMA. However, the ideal approach should involve a standardized multidisciplinary team capable of effectively addressing every possible scenario. For this reason, it is critically important that clinicians working with SMA patients gain more in-dept knowledge about this topic

Charcot-Marie-Tooth type 2CC misdiagnosed as Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Background and aims: Charcot-Marie-Tooth (CMT) is a heterogeneous group of genetic neuropathies and is typically characterized by distal muscle weakness, sensory loss, pes cavus and areflexia. Herein we describe a case of CMT2CC presenting with proximal muscle weakness and equivocal electrophysiological features, that was misdiagnosed as chronic inflammatory demyelinating polyneuropathy (CIDP). Case report: A 30-year-old woman complained of proximal muscle weakness with difficulty climbing stairs. Neurological examination showed weakness in lower limb (LL) muscles, that was marked proximally and mild distally, and absence of deep tendon reflexes in the ankles. Nerve conduction studies (NCS) showed sensory-motor neuropathy with non-uniform NC velocity and a partial conduction block (CBs) in peroneal nerve and tibial nerves. Thus, a diagnosis of CIDP was entertained and the patient underwent ineffective treatment with intravenous immunoglobulins. At electrophysiological revaluation CB in peroneal nerve was undetectable as also distal CMAP had decreased whereas the CBs persisted in tibial nerves. Hypothesizing a hereditary neuropathy, we examined the proband's son, who presented mild weakness of distal and proximal muscles at lower limbs. Neurophysiological investigation showed findings consistent with an intermediate-axonal electrophysiological pattern. A targeted-NGS including 136 CMT genes showed the heterozygous frameshift mutation (c.3057dupG; p.K1020fs*43) in the NEFH gene, coding for the neurofilament heavy chain and causing CMT2CC. Interpretation: Diagnosis of a genetic neuropathy may be challenging when clinical features are atypical and/or electrophysiological features are misleading. The most common misdiagnosis is CIDP. Our report suggests that also CMT2CC patients with proximal muscle weakness and equivocal electrophysiological features might be misdiagnosed as CIDP

Machine Learning for Early Diagnosis of ATTRv Amyloidosis in Non-Endemic Areas: A Multicenter Study from Italy

Background: Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv) is an adult-onset multisystemic disease, affecting the peripheral nerves, heart, gastrointestinal tract, eyes, and kidneys. Nowadays, several treatment options are available; thus, avoiding misdiagnosis is crucial to starting therapy in early disease stages. However, clinical diagnosis may be difficult, as the disease may present with unspecific symptoms and signs. We hypothesize that the diagnostic process may benefit from the use of machine learning (ML). Methods: 397 patients referring to neuromuscular clinics in 4 centers from the south of Italy with neuropathy and at least 1 more red flag, as well as undergoing genetic testing for ATTRv, were considered. Then, only probands were considered for analysis. Hence, a cohort of 184 patients, 93 with positive and 91 (age- and sex-matched) with negative genetics, was considered for the classification task. The XGBoost (XGB) algorithm was trained to classify positive and negative TTR mutation patients. The SHAP method was used as an explainable artificial intelligence algorithm to interpret the model findings. Results: diabetes, gender, unexplained weight loss, cardiomyopathy, bilateral carpal tunnel syndrome (CTS), ocular symptoms, autonomic symptoms, ataxia, renal dysfunction, lumbar canal stenosis, and history of autoimmunity were used for the model training. The XGB model showed an accuracy of 0.707 ± 0.101, a sensitivity of 0.712 ± 0.147, a specificity of 0.704 ± 0.150, and an AUC-ROC of 0.752 ± 0.107. Using the SHAP explanation, it was confirmed that unexplained weight loss, gastrointestinal symptoms, and cardiomyopathy showed a significant association with the genetic diagnosis of ATTRv, while bilateral CTS, diabetes, autoimmunity, and ocular and renal involvement were associated with a negative genetic test. Conclusions: Our data show that ML might potentially be a useful instrument to identify patients with neuropathy that should undergo genetic testing for ATTRv. Unexplained weight loss and cardiomyopathy are relevant red flags in ATTRv in the south of Italy. Further studies are needed to confirm these findings

Heterogenous electrophysiological features in early stage of hereditary transthyretin amyloidosis neuropathy

Introduction: Hereditary transthyretin-mediated amyloidosis (ATTRv, v for variant) is a progressive disease caused by mutations in the TTR gene, leading to sensory-motor, axonal and length-dependent neuropathy. However, some patients may show variable electrophysiological pattern. The aim of this study was to evaluate the electrophysiological features of TTR amyloid neuropathy at the time of the first nerve conduction study (NCS) to assess whether there were distinguishing features useful for early diagnosis. Methods: We retrospectively revised the first electrophysiological findings of ATTRv patients, and we categorized the neuropathy based on nerve conduction slowing, type of involved fibres and distribution pattern of PNS involvement. Cluster analysis was performed to evaluate the prevalence of neuropathy features between the early and late stage of disease, based on disease duration and disability burden assessed by NIS. Results: We recruited 33 patients (27 males) with mean age 63.9 ± 10.8 years, mean disease duration 2.8 ± 2.4 years and mean NIS 47.6 ± 41.8. Overall, the frequency analysis showed that the most common features of ATTRv neuropathy included the categories of axonal, sensory-motor and neuronopathic-like pattern. This electrophysiological pattern of PNS involvement was constant in patients in late stage of disease, whereas ATTRv patients in early stage of disease displayed variable electrophysiological pattern of PNS involvement. Discussion: Our findings demonstrated that ATTRv neuropathy may present at first NCS in a variable way, and it changes over the course of disease. Such heterogeneity makes the suspicion of ATTRv even more challenging at the time of first electrophysiological examination

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

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

Serum neurofilament light chain: a promising early diagnostic biomarker for hereditary transthyretin amyloidosis?

Background and purpose: Hereditary transthyretin amyloidosis (ATTRv) is a life-threatening disease caused by mutations in the gene encoding transthyretin (TTR). The recent therapeutic advances have underlined the importance of easily accessible, objective biomarkers of both disease onset and progression. Preliminary evidence suggests a potential role in this respect for neurofilament light chain (NfL). In this study, the aim was to determine serum NfL (sNfL) levels in a late-onset ATTRv population and evaluate whether it might represent a reliable biomarker of disease onset (i.e., 'conversion' from the asymptomatic status to symptomatic disease in TTR mutation carriers). Methods: In all, 111 individuals harbouring a pathogenic TTR variant (61 symptomatic ATTRv patients and 50 presymptomatic carriers) were consecutively enrolled. Fifty healthy volunteers were included as the control group. Ella™ apparatus was used to assess sNfL levels. Results: Serum NfL levels were increased in ATTRv patients compared to both presymptomatic carriers and healthy controls, whilst not differing between carriers and healthy controls. An sNfL cut-off of 37.10 pg/mL could discriminate between asymptomatic and symptomatic individuals with high diagnostic accuracy (area under the curve 0.958; p < 0.001), sensitivity (81.4%) and specificity (100%). Conclusions: Serum NfL seems to be a promising biomarker of peripheral nerve involvement in ATTRv amyloidosis and might become a reliable, objective measure to detect the transition from the presymptomatic stage to the onset of symptomatic disease. Further longitudinal studies are needed to confirm such a role and determine whether it could equally represent a biomarker of disease progression and response to therapy

Comparative Analysis of SiMoA and Ella Immunoassay Platforms for Measuring Serum Neurofilament Light Chain Levels in ATTRv With Polyneuropathy and Presymptomatic Carriers

Background: Neurofilament light chains (NfL) represent reliable serum biomarkers of neuroaxonal injury. Due to their low serum levels, precise detection methods are critical. This study aimed to scrutinize the comparability of two techniques: Single Molecule Array (SiMoA) and Ella automated immunoassay, analyzing serum NfL levels in ATTRv presymptomatic subjects and polyneuropathy patients. Methods: Blood samples were processed and analyzed using commercial Ella and SiMoA kits. Statistical analysis included the Wilcoxon signed-rank test, Spearman correlation, Bland-Altman, and Passing-Bablok regression. ANCOVA models were used to compare NfL levels between cohorts. Results: The study measured serum NfL levels in 55 symptomatic and 55 presymptomatic ATTRv subjects. Median NfL concentrations were significantly higher with Ella (median 27.5 pg/mL) than SiMoA (median 15.9 pg/mL). Both methods showed a strong positive correlation (r = 0.8, p < 0.001), but Ella overestimated NfL by 42%. Bland-Altman analysis revealed a mean bias of 15.4 pg/mL, with limits of agreement between -41.1 and 72.0 pg/mL. The slope of the Passing-Bablok regression line was 0.58, and the intercept was 3.48 pg/mL, suggesting that the Ella platform tends to overestimate NfL concentrations compared to the SiMoA platform, especially at higher concentrations. Both methods effectively distinguished presymptomatic from symptomatic patients (p < 0.001 for both). Conclusions: Our findings underscore that both platforms are effective in measuring serum NfL, with Ella consistently overestimating, especially at higher concentrations. The difference between the two platforms must be taken into account when deeming the concentrations as pathological or normal, as well as when conducting longitudinal studies

Elevated serum concentrations of GFAP in hereditary transthyretin amyloidosis since pre-symptomatic stages

Background: Hereditary transthyretin amyloidosis (ATTRv) is a rare disorder caused by pathogenic TTR gene variants. Glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) are potential biomarkers for astrocyte activation and neuroaxonal damage, respectively. This study investigates serum GFAP (sGFAP) and NfL (sNfL) levels in ATTRv patients, pre-symptomatic subjects, and healthy controls (HCs) to evaluate their utility as biomarkers of disease progression and CNS involvement. Methods: Our multicenter cross-sectional study included 111 ATTRv patients (56 symptomatic, 55 pre-symptomatic subjects) and 183 HCs. Serum levels of sGFAP and sNfL were measured using ultrasensitive immunoassays. The statistical comparisons were performed using ANCOVA models (age and sex adjusted), with correlations examined between serum biomarkers and disease severity (Neuropathy Impairment Score, NIS). Results: sGFAP levels were elevated in symptomatic (median: 238.35 pg/ml) and pre-symptomatic subjects (median: 105.50 pg/ml) vs. HCs (median: 75.5 pg/ml, p < 0.001). sNfL was elevated only in symptomatic patients (median: 43.68 pg/ml) compared to pre-symptomatic subjects (median: 9.36 pg/ml) and HCs (median: 7.54 pg/ml, p < 0.001). Both biomarkers correlated significantly with NIS, reflecting disease severity. Female HCs had higher sGFAP levels than males (median 88.6 pg/ml vs. 59.8 pg/ml; p 0.011). Conclusion: sGFAP and sNfL mark distinct ATTRv stages, with sGFAP indicating early preclinical changes and sNfL correlating with neurological progression. Sex differences in sGFAP levels among HCs suggest that sex should be considered as a covariate in biomarker analyses