Biomarkers of axonal damage to favor early diagnosis in variant transthyretin amyloidosis (A-ATTRv).

Early identification of ATTRv amyloidosis disease onset is still often delayed due to the lack of validated biomarkers of this disease. Light chain neurofilament (NfL) have shown promising results in early diagnosis in this disease, but data is still needed, including with alternative measuring methods. Our aim was to study the levels of NfL measured by ELISA. Furthermore, interstitial matrix metalloproteinase type 1 (MMP-1) serum levels were measured as a potential new biomarker in ATTRv. Serum NfL and MMP-1 were measured using ELISA assays in 90 participants (29 ATTR-V30M patients, 31 asymptomatic V30M-TTR variant carriers and 30 healthy controls). Median NfL levels among ATTRv amyloidosis patients were significantly higher (116 pg/mL vs 0 pg/mL in both comparison groups). The AUC comparing ATTRv amyloidosis patients and asymptomatic carriers was 0.90 and the NfL concentration of 93.55 pg/mL yielded a sensitivity of 79% and a specificity of 87%. NfL levels had a significant positive correlation with NIS values among patients. We found a negative significant correlation between eGFR and NfL levels. Finally, MMP1 levels were not different between groups. Evidence of NfL use for early diagnosis of ATTR-PN amyloidosis is growing. ELISA seems a reliable and available technique for it quantification. Decreased GFR could influence NfL plasma levels.

A narrative review and expert recommendations on the assessment of the clinical manifestations, follow-up, and management of post-OLT patients with ATTRv amyloidosis.

Orthotopic liver transplantation (OLT) was the first treatment able to modify the natural course of hereditary transthyretin (ATTRv) amyloidosis, which is a rare and fatal disorder caused by the accumulation of misfolded transthyretin (TTR) variants in different organs and tissues and which leads to a progressive and multisystem dysfunction. Because the liver is the main source of TTR, OLT dramatically reduces the production of the pathogenic TTR variant, which should prevent amyloid formation and halt disease progression. However, amyloidosis progression may occur after OLT due to wild-type TTR deposition, especially in the nerves and heart. In this review, we discuss the disease features influencing OLT outcomes and the clinical manifestations of ATTRv amyloidosis progression post-OLT to improve our understanding of disease worsening after OLT and optimize the follow-up and clinical management of these patients. By conducting a literature review on the PubMed database, we identified patient characteristics that have been associated with worse post-OLT outcomes, including late-onset V50M and non-V50M variants, age >40 years, long disease duration, advanced neuropathy and autonomic dysfunction, and malnutrition. Regarding post-OLT mortality, deaths occurring within the first year after OLT were mainly associated with fatal graft complications and infectious diseases, whereas cardiovascular-related deaths usually occurred later. Considering the diverse clinical manifestations of ATTRv amyloidosis progression post-OLT, including worsening neuropathy and/or cardiomyopathy, autonomic dysfunction, and oculoleptomeningeal involvement, we present advice on the most relevant tests for assessing disease progression post-OLT. Finally, we discuss the use of new therapies based on TTR stabilizers and TTR mRNA silencers for the treatment of ATTRv amyloidosis patients post-OLT.

Patisiran treatment in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy after liver transplantation.

Hereditary transthyretin-mediated (hATTR) amyloidosis, or ATTRv amyloidosis, is a progressive disease, for which liver transplantation (LT) has been a long-standing treatment. However, disease progression continues post-LT. This Phase 3b, open-label trial evaluated efficacy and safety of patisiran in patients with ATTRv amyloidosis with polyneuropathy progression post-LT. Primary endpoint was median transthyretin (TTR) reduction from baseline. Twenty-three patients received patisiran for 12 months alongside immunosuppression regimens. Patisiran elicited a rapid, sustained TTR reduction (median reduction [Months 6 and 12 average], 91.0%; 95% CI: 86.1%-92.3%); improved neuropathy, quality of life, and autonomic symptoms from baseline to Month 12 (mean change [SEM], Neuropathy Impairment Score, -3.7 [2.7]; Norfolk Quality of Life-Diabetic Neuropathy questionnaire, -6.5 [4.9]; least-squares mean [SEM], Composite Autonomic Symptom Score-31, -5.0 [2.6]); and stabilized disability (Rasch-built Overall Disability Scale) and nutritional status (modified body mass index). Adverse events were mild or moderate; five patients experienced ≥1 serious adverse event. Most patients had normal liver function tests. One patient experienced transplant rejection consistent with inadequate immunosuppression, remained on patisiran, and completed the study. In conclusion, patisiran reduced serum TTR, was well tolerated, and improved or stabilized key disease impairment measures in patients with ATTRv amyloidosis with polyneuropathy progression post-LT (www.clinicaltrials.gov NCT03862807).

A Descriptive Analysis of ATTR Amyloidosis in Spain from the Transthyretin Amyloidosis Outcomes Survey.

INTRODUCTION: Transthyretin amyloidosis (ATTR amyloidosis) is a clinically heterogeneous disease caused by mutations in the transthyretin (TTR) gene or aggregation of wild-type transthyretin (ATTRwt). In Spain, there are two large endemic foci of ATTR amyloidosis caused by the Val30Met variant, with additional cases across the country; however, these data may be incomplete, as there is no centralized patient registry. The Transthyretin Amyloidosis Outcomes Survey (THAOS) is an ongoing, global, longitudinal, observational survey of patients with ATTR amyloidosis, including both inherited and wild-type disease, and asymptomatic patients with TTR mutations. This analysis aimed to gain a deeper understanding of the clinical profile of patients with ATTR amyloidosis in Spain. METHODS: This was a descriptive analysis of the demographic and clinical characteristics of symptomatic patients enrolled at six sites geographically dispersed throughout Spain (data cutoff: January 6, 2020). Patient data at enrollment, including genotype, demographics, and clinical presentation for symptomatic patients, were recorded. Patients were grouped by predominant phenotype based on clinical measures at enrollment: predominantly cardiac, predominantly neurologic, or mixed (cardiac and neurologic). RESULTS: There were 379 patients (58.0% male; 63.3% symptomatic) enrolled in the six THAOS sites in Spain. Predominant genotypes were the Val30Met mutation (69.1%) or ATTRwt (15.6%). Predominant phenotype distribution was neurologic (50.4%), mixed (35.8%), and cardiac (13.8%) for all symptomatic patients (n = 240); neurologic (67.8%), mixed (21.2%), and cardiac (11.0%) for symptomatic Val30Met (n = 146); and mixed (64.9%), cardiac (22.8%), and neurologic (12.3%) for symptomatic ATTRwt (n = 57). Symptomatic patients reported a range of ATTR amyloidosis signs and symptoms at enrollment, with autonomic neuropathy and sensory neuropathy common in all phenotypes. CONCLUSIONS: These results from THAOS highlight the phenotypic heterogeneity associated with ATTR amyloidosis in Spain and the importance of comprehensive neurologic and cardiac evaluations in all patients with ATTR amyloidosis. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00628745.

Estimating the annual economic burden for the management of patients with transthyretin amyloid polyneuropathy in Spain.

Background: Transthyretin amyloid polyneuropathy (ATTR-PN) is a fatal disease associated with substantial burden of illness. Three therapies are approved by the European Medicines Agency for the management of this rare disease. The aim of this study was to compare the total annual treatment specific cost per-patient associated with ATTR-PN in Spain.Methods: An Excel-based patient burden and cost estimator tool was developed to itemize direct and indirect costs related to treatment with inotersen, patisiran, and tafamidis in the context of ATTR-PN. The product labels and feedback from five Spanish ATTR-PN experts were used to inform resource use and cost inputs.Results: Marked differences in costs were observed between the three therapies. The need for patisiran- and inotersen-treated patients to visit hospitals for pre-treatment, administration, and monitoring was associated with increased patient burden and costs compared to those treated with tafamidis. Drug acquisition costs per-patient per-year were 291,076€ (inotersen), 427,250€ (patisiran) and 129,737€ (tafamidis) and accounted for the majority of total costs. Overall, the total annual per-patient costs were lowest for patients treated with tafamidis (137,954€), followed by inotersen (308,358€), and patisiran (458,771€).Conclusions: Treating patients with tafamidis leads to substantially lower costs and patient burden than with inotersen or patisiran.

El volumen extracelular detecta la amiloidosis cardiaca y está correlacionado con el deterioro neurológico en la amiloidosis familiar relacionada con la transtiretina / Extracellular volume detects amyloidotic cardiomyopathy and correlates with neurological impairment in transthyretin-familial amyloidosis

INTRODUCCIÓN Y OBJETIVOS: La afección cardiaca determina el pronóstico y las opciones de tratamiento en la amiloidosis familiar relacionada con la transtiretina. Las técnicas de mapeo T1 de resonancia magnética cardiaca son útiles para determinar el volumen extracelular miocárdico. En este estudio se planteó la hipótesis de que el volumen extracelular miocárdico permite la identificación de la amiloidosis cardiaca y está correlacionado con el grado de deterioro neurológico en la amiloidosis familiar relacionada con la transtiretina. MÉTODOS: A un total de 31 pacientes con amiloidosis familiar relacionada con la transtiretina (19 varones; media de edad, 49 ± 12 años; 26 pacientes con la mutación Val30Met), se les realizaron estudios de mapeo T1 con resonancia magnética cardiaca y una evaluación neurológica con la Neuropathy Impairment Score of the Lower Limb, el cuestionario Norfolk Quality of Life y el índice de Karnofsky. RESULTADOS: Cinco pacientes tenían amiloidosis cardiaca (en todos los casos, confirmada mediante gammagrafía con 99mTc-DPD). El valor medio del volumen extracelular estaba aumentado en los pacientes con amiloidosis cardiaca (0,490 ± 0,131 frente a 0,289 ± 0,035; p = 0,026). El volumen extracelular mostró correlación con la edad (R = 0,467; p = 0,008), fracción aminoterminal del propéptido natriurético tipo B (Rs = 0,846; p < 0,001), el grosor máximo de la pared (R = 0,621; p < 0,001), el índice de masa ventricular izquierda (R = 0,685; p < 0,001), la fracción de eyección del ventrículo izquierdo (R = -0,378; p = 0,036), la puntuación de la Neuropathy Impairment Score of the Lower Limb (Rs = 0,604; p < 0,001), el cuestionario Norfolk Quality of Life (Rs = 0,529; p = 0,003) y el índice de Karnofsky (Rs = -0,517; p = 0,004). Se consideró que un valor de corte del volumen extracelular de 0,357 es diagnóstico de amiloidosis cardiaca con sensibilidad y especificidad del 100% (p < 0,001). El volumen extracelular y la fracción aminoterninal del propéptido natriurético tipo B son los únicos parámetros cardiacos que mostraron correlación significativa con las puntuaciones neurológicas. CONCLUSIONES: La cuantificación del volumen extracelular permite la identificación de la amiloidosis cardiaca y está correlacionada con el grado de deterioro neurológico en la amiloidosis familiar relacionada con la transtiretina. Esta técnica no invasiva puede ser un instrumento útil para el diagnóstico precoz de amiloidosis cardiaca y el seguimiento de la afección cardiaca y extracardiaca

INTRODUCTION AND OBJECTIVES: Cardiac involvement determines prognosis and treatment options in transthyretin-familial amyloidosis. Cardiac magnetic resonance T1 mapping techniques are useful to assess myocardial extracellular volume. This study hypothesized that myocardial extracellular volume allows identification of amyloidotic cardiomyopathy and correlates with the degree of neurological impairment in transthyretin-familial amyloidosis. METHODS: A total of 31 transthyretin-familial amyloidosis patients (19 mean age, 49 ± 12 years; 26 with the Val30Met mutation) underwent a T1 mapping cardiac magnetic resonance study and a neurological evaluation with Neuropathy Impairment Score of the Lower Limb score, Norfolk Quality of Life questionnaire, and Karnofsky index. RESULTS: Five patients had cardiac amyloidosis (all confirmed by 99mTc-DPD scintigraphy). Mean extracellular volume was increased in patients with cardiac amyloidosis (0.490 ± 0.131 vs 0.289 ± 0.035; P = .026). Extracellular volume correlated with age (R = 0.467; P = .008), N-terminal pro-B-type natriuretic peptide (RS = 0.846; P < .001), maximum wall thickness (R = 0.621; P < .001), left ventricular mass index (R = 0.685; P < .001), left ventricular ejection fraction (R = -0.378; P = .036), Neuropathy Impairment Score of the Lower Limb (RS = 0.604;P = .001), Norfolk Quality of Life questionnaire (RS = 0.529; P = .003) and Karnofsky index (RS= -0.517; P = .004). A cutoff value of extracellular volume of 0.357 was diagnostic of cardiac amyloidosis with 100% sensitivity and specificity (P < .001). Extracellular volume and N-terminal pro-B-type natriuretic peptide were the only cardiac parameters that significantly correlated with neurologic scores. CONCLUSIONS: Extracellular volume quantification allows identification of cardiac amyloidosis and correlates with the degree of neurological impairment in transthyretin-familial amyloidosis. This noninvasive technique could be a useful tool for early diagnosis of cardiac amyloidosis and to track cardiac and extracardiac amyloid disease

Extracellular Volume Detects Amyloidotic Cardiomyopathy and Correlates With Neurological Impairment in Transthyretin-familial Amyloidosis.

INTRODUCTION AND OBJECTIVES: Cardiac involvement determines prognosis and treatment options in transthyretin-familial amyloidosis. Cardiac magnetic resonance T1 mapping techniques are useful to assess myocardial extracellular volume. This study hypothesized that myocardial extracellular volume allows identification of amyloidotic cardiomyopathy and correlates with the degree of neurological impairment in transthyretin-familial amyloidosis. METHODS: A total of 31 transthyretin-familial amyloidosis patients (19 mean age, 49 ± 12 years; 26 with the Val30Met mutation) underwent a T1 mapping cardiac magnetic resonance study and a neurological evaluation with Neuropathy Impairment Score of the Lower Limb score, Norfolk Quality of Life questionnaire, and Karnofsky index. RESULTS: Five patients had cardiac amyloidosis (all confirmed by 99mTc-DPD scintigraphy). Mean extracellular volume was increased in patients with cardiac amyloidosis (0.490 ± 0.131 vs 0.289 ± 0.035; P = .026). Extracellular volume correlated with age (R = 0.467; P = .008), N-terminal pro-B-type natriuretic peptide (RS = 0.846; P < .001), maximum wall thickness (R = 0.621; P < .001), left ventricular mass index (R = 0.685; P < .001), left ventricular ejection fraction (R = -0.378; P = .036), Neuropathy Impairment Score of the Lower Limb (RS = 0.604; P = .001), Norfolk Quality of Life questionnaire (RS = 0.529; P = .003) and Karnofsky index (RS= -0.517; P = .004). A cutoff value of extracellular volume of 0.357 was diagnostic of cardiac amyloidosis with 100% sensitivity and specificity (P < .001). Extracellular volume and N-terminal pro-B-type natriuretic peptide were the only cardiac parameters that significantly correlated with neurologic scores. CONCLUSIONS: Extracellular volume quantification allows identification of cardiac amyloidosis and correlates with the degree of neurological impairment in transthyretin-familial amyloidosis. This noninvasive technique could be a useful tool for early diagnosis of cardiac amyloidosis and to track cardiac and extracardiac amyloid disease.

Recomendaciones para el diagnóstico y tratamiento de la polineuropatía amiloidótica familiar por transtiretina / Recommendations regarding diagnosis and treatment of transthyretin familial amyloid polyneuropathy

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Rituximab as an effective alternative therapy in refractory idiopathic inflammatory myopathies.

OBJECTIVES: To assess the efficacy and safety of B-lymphocyte depletion therapy (BCDT) utilising rituximab in refractory idiopathic inflammatory myositis. METHODS: We retrospectively evaluated 16 adult patients with active dermatomyositis (DM) or polymyositis (PM) who received 1 gram rituximab intravenous infusions two weeks apart after failing to respond to conventional therapy. The clinical and biochemical response were analysed by the Myositis Intention to Treat index (MITAX) and the serum creatine kinase (CK) levels at baseline and 6 and 12 months after treatment. The primary efficacy outcome was 20% improvement in the MITAX index and 30% reduction in CK. RESULTS: Eight patients responded to treatment and achieved both the MITAX and CK levels objectives within 6 months of rituximab therapy. Five out of these 8 responders remained clinically stable at 12 months and CK levels were still reduced or normalised. Of note, 4 patients who did not respond were re-assessed and had their diagnoses corrected. All patients showed adequate B cell depletion (BCD) with re-population occurring for a 15.4 months average (range 3-42 months). Those simultaneously treated with cyclophosphamide achieved more long-lasting depletion (average 18.6 months). CONCLUSIONS: The heterogeneous clinical and serological characteristics of patients diagnosed with IIM probably explain why some, but not all patients respond to rituximab. Myositis overlap and anti-synthetase syndromes seem to respond better than other patient subsets.