Shohei Ikeda

Paranodal dissection in chronic inflammatory demyelinating polyneuropathy with anti-neurofascin-155 and anti-contactin-1 antibodies

Objective To investigate the morphological features of chronic inflammatory demyelinating polyneuropathy (CIDP) with autoantibodies directed against paranodal junctional molecules, particularly focusing on the fine structures of the paranodes. Methods We assessed sural nerve biopsy specimens obtained from 9 patients with CIDP with anti-neurofascin-155 antibodies and 1 patient with anti-contactin-1 antibodies. 13 patients with CIDP without these antibodies were also examined to compare pathological findings. Results Characteristic light and electron microscopy findings in transverse sections from patients with anti-neurofascin-155 and anti-contactin-1 antibodies indicated a slight reduction in myelinated fibre density, with scattered myelin ovoids, and the absence of macrophage-mediated demyelination or onion bulbs. Teased-fibre preparations revealed that segmental demyelination tended to be found in patients with relatively higher frequencies of axonal degeneration and was tandemly found at consecutive nodes of Ranvier in a single fibre. Assessment of longitudinal sections by electron microscopy revealed that detachment of terminal myelin loops from the axolemma was frequently found at the paranode in patients with anti-neurofascin-155 and anti-contactin-1 antibody-positive CIDP compared with patients with antibody-negative CIDP. Patients with anti-neurofascin-155 antibodies showed a positive correlation between the frequencies of axo–glial detachment at the paranode and axonal degeneration, as assessed by teased-fibre preparations (p<0.05). Conclusions Paranodal dissection without classical macrophage-mediated demyelination is the characteristic feature of patients with CIDP with autoantibodies to paranodal axo–glial junctional molecules.

Schwann cell and endothelial cell damage in transthyretin familial amyloid polyneuropathy.

Objective: To examine the morphology of Schwann cells and endoneurial microvessels with electron microscopy. Methods: Sural nerve biopsy specimens from 49 patients with familial amyloid polyneuropathy (FAP) with transthyretin Val30Met mutation were assessed. Patients included 11 early-onset cases from endemic foci and 38 late-onset cases from nonendemic areas. Results: Loss of nerve fibers with or without neighboring amyloid deposition was a common feature. The amount of amyloid deposition was greater relative to the extent of nerve fiber loss in early-onset cases than in late-onset cases. The atrophy of Schwann cells, particularly nonmyelinating Schwann cells, that were apposed to amyloid fibrils was more conspicuous in early-onset cases than in late-onset cases. The numbers of endothelial cell nuclei, endothelial cell profiles, and occluded microvessels were significantly increased in the patients with FAP compared with 37 patients with nutritional/alcoholic neuropathies (p < 0.05, 0.01, and 0.01, respectively). Findings suggestive of the disruption of blood-nerve barriers such as the loss of tight junctions and the fenestration of endothelial cells were also found more frequently in the patients with FAP (p < 0.001), regardless of the presence or absence of amyloid deposition. Conclusions: These findings suggest that direct insult of amyloid fibrils causes Schwann cell damage, resulting in the predominant loss of small-fiber axons characteristic of early-onset cases. In addition, vasculopathy may participate in the pathogenesis of neuropathy, particularly in late-onset cases.

Restoration of a Conduction Block after the Long-term Treatment of CIDP with Anti-neurofascin 155 Antibodies: Follow-up of a Case over 23 Years

We herein report a woman with chronic inflammatory demyelinating polyneuropathy (CIDP) in whom positivity for anti-neurofascin 155 antibodies was revealed 23 years after the onset of neuropathy. The patient initially reported numbness in the face at 50 years of age and subsequently manifested features compatible to typical CIDP. Steroid administration initiated at 54 years of age ameliorated her neuropathic symptoms. Although the nerve conduction indices at 59 years of age deteriorated, those at 68, 72, and 73 years of age showed a gradual recovery. The deterioration and subsequent restoration of compound muscle action potential amplitudes was the most dramatic, suggesting that a conduction block can be reversed earlier than other electrophysiological indices.

Alcoholic Myelopathy and Nutritional Deficiency

A patient with chronic alcoholism presented with myelopathy and low serum folate and cobalamin levels. A 42-year-old alcoholic man had gait disturbance for 4 months. A neurological examination revealed marked spasticity with increased deep tendon reflexes and extensor plantar responses of the lower limbs. His cobalamin level was decreased and his serum folate level was particularly low. His plasma ammonia level was not increased. Abstinence and folic acid and cobalamin supplementation stopped the progression of his neurological deficits. This case indicates that nutritional deficiency should be monitored closely in patients with chronic alcoholism who present with myelopathy.

Widespread Cardiac and Vasomotor Autonomic Dysfunction in Non-Val30Met Hereditary Transthyretin Amyloidosis

Objective The autonomic functions of hereditary transthyretin (ATTRm) amyloidosis, traditionally referred to as familial amyloid polyneuropathy, have primarily been investigated in patients with Val30Met mutations, and information regarding non-Val30Met patients is scarce. The aim of this study was to systematically investigate the cardiac and peripheral vasomotor autonomic functions in non-Val30Met patients. Methods The coefficient of variation of R-R intervals (CVR-R), responses to the Valsalva manoeuvre, head-up tilt test results, noradrenaline infusion test results, and the (123)I-metaiodobenzylguanidine (MIBG) uptake on myocardial scintigraphy were assessed in five patients. The predominant manifestations were neuropathy in three patients (Val94Gly, Val71Ala, and Pro24Ser), cardiomyopathy in one (Thr60Ala), and oculoleptomeningeal involvement in one (Tyr114Cys). Results Although one patient with predominant cardiomyopathy did not manifest orthostatic hypotension during the head-up tilt test, the CVR-R, responses to the Valsalva manoeuvre, and myocardial MIBG uptake indicated the presence of cardiac sympathetic and parasympathetic dysfunction in all patients. The total peripheral resistance at 60° tilt did not increase from the baseline values in any of the examined patients. An infusion of low-dose noradrenaline induced an increase in the systolic blood pressure, except in one patient with mild neuropathy. Conclusion Cardiac and peripheral vasomotor autonomic dysfunctions were prevalent in non-Val30Met patients, irrespective of their phenotype, suggesting a common pathology of autonomic involvement. However, the vasoconstrictor function was preserved, even in a patient with advanced neuropathy.

The morphology of amyloid fibrils and their impact on tissue damage in hereditary transthyretin amyloidosis: An ultrastructural study

INTRODUCTION We evaluated the morphology of amyloid fibrils in the peripheral nervous system using biopsy or autopsy specimens from hereditary transthyretin amyloidosis patients. The impact of amyloid fibril formation on neighboring tissues was also investigated. METHODS Sural nerve biopsy specimens from 34 patients were examined using electron microscopy. Twenty-eight patients had Val30Met mutations, and the remaining 6 patients had non-Val30Met mutations (i.e., Glu54Lys, Pro24Ser, Thr49Ala, Val71Ala, Val94Gly, and Ala97Gly). The patients with the Val30Met mutation included a case from Brazil (supposedly of Portuguese origin), 6 early-onset cases from endemic foci in Japan, and 21 late-onset cases from non-endemic areas in Japan. RESULTS Long amyloid fibers were abundant in the early-onset Val30Met cases from the Japanese endemic foci and Brazil, whereas the amyloid fibrils were generally short in the late-onset Val30Met and non-Val30Met cases. The amyloid fibrils seemed to mature from dotty structures among amorphous electron-dense extracellular materials and pull surrounding tissues during the maturation process. The distortion of Schwann cells close to amyloid fibril masses was conspicuous, particularly in cases with long amyloid fibrils. Atrophy was conspicuous in non-myelinating Schwann cells and bands of Büngner (i.e., Schwann cell subunits that previously contained myelinated axons), particularly those completely surrounded by amyloid fibrils. In contrast, the myelinated fibers tended to be only partially surrounded by amyloid fibrils and morphologically preserved due to their large size. Only a few demyelinated axons were found. CONCLUSION Pre-fibrillar amyloid precursors appear to play a pivotal role during the initial phase of amyloid fibril formation. The mechanical distortion and subsequent atrophy of Schwann cells resulting from the elongation of amyloid fibrils may be related to small-fiber predominant loss, which is a classical characteristic of amyloid neuropathy. Although rather rare, the destruction of myelin (i.e., demyelination) resulting from amyloid deposition may relate to nerve conduction abnormalities mimicking chronic inflammatory demyelinating polyneuropathy.

Systemic angiopathy and axonopathy in hereditary transthyretin amyloidosis with Ala97Gly (p. Ala117Gly) mutation: a post-mortem analysis

Hereditary (variant) transthyretin (ATTRv) amyloidosis also known as familial amyloid polyneuropathy is a disease wherein systemic deposition of amyloidogenic mutant transthyretin results in multi-organ failure. The Val30Met mutation has been considered to be the most common; however, recent progress in diagnostic techniques has shown an increased number of newly diagnosed patients with the non-Val30Met mutations [1]. Moreover, in some countries, patients with non-Val30Met mutations have been found to be more frequent than those with Val30Met mutation [1]. The phenotypes of non-Val30Met ATTRv amyloidosis are extensively diverse and mainly affect the peripheral nervous system, heart, or oculoleptomeninges [1–3]. However, pathological information regarding patients with non-Val30Met ATTRv amyloidosis remains scarce. Here, we systematically examined autopsy findings in a 74year-old male ATTRv amyloidosis patient with Ala97Gly the (p. Ala117Gly) mutation. At 56 years of age, progressive sensorimotor somatic neuropathy had begun, and preserved autonomic functions were reported as clinical manifestations at the time of diagnosis [2]. No signs of cardiac amyloidosis were observed in the initial phase of neuropathy; however, he was diagnosed with complete atrioventricular conduction block at 67 years of age and died of heart failure. An autopsy was performed after obtaining written informed consent approved by the Institutional Ethics Committees. The heart weighed 500 g, and non-uniform amyloid deposition was evident throughout the layer of myocardium (Supplementary Table 1 and Figure 1(A)). Regarding other visceral organs,

Pathological features of NOD B7-2 KO mice treated by high dose immunoglobulins

for Aquaporin 4 Antibody and PCR) were unremarkable. Our patient’s symptoms resolved following a single course of pulsed intravenous methylprednisolone. Dengue serology repeated one month after the clinical event confirmed recent infection. Conclusion: While both Dengue and the presence of anti-MOG antibodies have been separately reported to have associations with transverse myelitis and Acute Disseminated Encephalomyelitis (ADEM), this is the first time to our knowledge that the 2 entities have been observed to co-exist in the setting of transverse myelitis. Such an observation hints at the possible association between dengue fever and anti-MOG antibody associated morbidity, including ADEM and anti-MOG neuromyelitis optica, a disease of which our understanding is still evolving. Whether this association exists will need to be verified through further structured and more definitive studies.

Disruption of blood–nerve barriers in hereditary transthyretin (ATTR) amyloidosis

Recent progress in diagnostic techniques has revealed that hereditary transthyretin (ATTR) amyloidosis is widely prevalent in areas other than conventional endemic foci [1–3]. Peripheral neuropathy...

Vasculopathy in transthyretin Val30Met familial amyloid polyneuropathy

Background Transthyretin (TTR) Val30Met-associated familial amyloid polyneuropathy (FAP ATTR Val30Met) is the most common form of FAP and has become prevalent in areas other than conventional endemic foci. The clinicopathological features of FAP ATTR Val30Met are known to vary between endemic foci and non-endemic areas in Japan. Characteristic features of early-onset cases from Japanese endemic foci include the presence of sensory dissociation and marked autonomic dysfunction associated with a predominant loss of small-diameter myelinated and unmyelinated nerve fibers. These characteristics are uncommon in late-onset cases from non-endemic areas.