Transthyretin familial amyloid polyneuropathy (TTR-FAP) in Mallorca: a comparison between late- and early-onset disease.

The age of onset (AO) of hereditary ATTR amyloidosis (hATTR) is known to vary between populations, with differing characteristics reported according to AO in endemic/non-endemic foci. This was a retrospective study of patients with early AO (<50 years) and late AO (≥50 years) hATTR at our center in Mallorca. Data were collected on patient demographics, clinical disease manifestation, and physical symptoms. A total of 95 patients were analyzed, with mean follow-up of 9 years from diagnosis. The early AO group included 53 patients (33 male) and the late AO group included 42 patients (21 male). Neurologic involvement was the most common initial symptom, although it was significantly more frequent in the late AO vs. early AO group (p = 0.015). Autonomic involvement was observed in 26% of patients in the early AO group, but was rarely observed in the late AO group (5%). During follow up, cardiologic symptoms, renal involvement, and ophthalmologic symptoms were significantly more common in the late AO group (p < 0.05). This retrospective study demonstrates the variation in disease presentation and progression according to AO of hATTR at our Mallorcan center.

Clinical and Laboratory Features in Anti-NF155 Autoimmune Nodopathy.

BACKGROUND AND OBJECTIVES: To study the clinical and laboratory features of antineurofascin-155 (NF155)-positive autoimmune nodopathy (AN). METHODS: Patients with anti-NF155 antibodies detected on routine immunologic testing were included. Clinical characteristics, treatment response, and functional scales (modified Rankin Scale [mRS] and Inflammatory Rasch-built Overall Disability Scale [I-RODS]) were retrospectively collected at baseline and at the follow-up. Autoantibody and neurofilament light (NfL) chain levels were analyzed at baseline and at the follow-up. RESULTS: Forty NF155+ patients with AN were included. Mean age at onset was 42.4 years. Patients presented with a progressive (75%), sensory motor (87.5%), and symmetric distal-predominant weakness in upper (97.2%) and lower extremities (94.5%), with tremor and ataxia (75%). Patients received a median of 3 (2-4) different treatments in 46 months of median follow-up. Response to IV immunoglobulin (86.8%) or steroids (72.2%) was poor in most patients, whereas 77.3% responded to rituximab. HLA-DRB1*15 was detected in 91.3% of patients. IgG4 anti-NF155 antibodies were predominant in all patients; anti-NF155 titers correlated with mRS within the same patient (r = 0.41, p = 0.004). Serum NfL (sNfL) levels were higher in anti-NF155+ AN than in healthy controls (36.47 vs 7.56 pg/mL, p < 0.001) and correlated with anti-NF155 titers (r = 0.43, p = 0.001), with I-RODS at baseline (r = -0.88, p < 0.001) and with maximum I-RODS achieved (r = -0.58, p = 0.01). Anti-NF155 titers and sNfL levels decreased in all rituximab-treated patients. DISCUSSION: Anti-NF155 AN presents a distinct clinical profile and good response to rituximab. Autoantibody titers and sNfL are useful to monitor disease status in these patients. The use of untagged-NF155 plasmids minimizes the detection of false anti-NF155+ cases. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that anti-NF155 antibodies associate with a specific phenotype and response to rituximab.

Early diagnosis in patients with transthyretin familial amyloid polyneuropathy: A comparative study. / Diagnóstico precoz en pacientes con polineuropatía amiloidótica familiar asociada a transtirretina. Estudio comparativo.

INTRODUCTION AND OBJECTIVE: Transthyretin-associated familial amyloid polyneuropathy (TTR-FAP) is a disease caused by the deposit of abnormal transthyretin on tissues, mainly nerves. Small nerve fibers are altered earlier during the course of the disease; hence, detection of their involvement may have serious consequences on the natural history of disease. METHODS: A cross-sectional, observational study, was carried out on symptomatic patients, involving the conduct of several tests for small nerve fibers: Vibration, Touch Pressure (TP) and Heat Pain (HP). Results were compared with those obtained during a conventional neurological examination carried out on a group of healthy individuals. RESULTS: Fifteen symptomatic patients were recruited at an early stage of the disease (60% stage 1), along with 13 healthy individuals, with both patient groups having similar epidemiological characteristics in terms of gender, age, weight, height or BMI. A comparison carried out between the neuropsychological tests performed revealed statistically significant differences: Vibration (P<.05), TP (P<.05) and HP (P<.05, except volar forearm). CONCLUSIONS: The neurophysiological tests performed revealed significant differences between both groups, allowing for an earlier detection of neurological injuries compared to conventional neurological examinations.