Amyloid-Forming Corpora Amylacea and Spheroid-Type Amyloid Deposition: Comprehensive Analysis Using Immunohistochemistry, Proteomics, and a Literature Review.

This study aimed to elucidate the similarities and differences between amyloid-forming corpora amylacea (CA) in the prostate and lung, examine the nature of CAs in cystic tumors of the atrioventricular node (CTAVN), and clarify the distinctions between amyloid-forming CA and spheroid-type amyloid deposition. We conducted proteomics analyses using liquid chromatography-tandem mass spectrometry with laser microdissection and immunohistochemistry to validate the characteristics of CAs in the lung and prostate. Our findings revealed that the CAs in these organs primarily consisted of common proteins (ß2-microglobulin and lysozyme) and locally produced proteins. Moreover, we observed a discrepancy between the histopathological and proteomic analysis results in CTAVN-associated CAs. In addition, while the histopathological appearance of the amyloid-forming CAs and spheroid-type amyloid deposits were nearly identical, the latter deposition lacked ß2-microglobulin and lysozyme and exhibited evident destruction of the surrounding tissue. A literature review further supported these findings. These results suggest that amyloid-forming CAs in the lung and prostate are formed through a shared mechanism, serving as waste containers (wasteosomes) and/or storage for excess proteins (functional amyloids). In contrast, we hypothesize that while amyloid-forming CA and spheroid-type amyloid deposits are formed, in part, through common mechanisms, the latter are pathological.

Development of diagnostic antibodies against immunoglobulin heavy chain variable region for heavy chain amyloidosis (AH amyloidosis).

It is difficult to diagnose immunoglobulin heavy chain amyloidosis (AH amyloidosis) without proteomic analysis due to no useful diagnostic antibodies. The aim of this study was to develop diagnostic antibodies available to immunohistochemistry and immunoblotting. Two rabbit anti-heavy chain variable region antibodies were generated and evaluated in immunohistochemical studies performed on 11 AH amyloidosis patients and 64 patients with other systemic amyloidoses. Additionally, immunoblotting was performed using extracted amyloid protein from one patient and serum samples from two patients with AH amyloidosis. Immunohistochemical analysis generated a positive outcome in 10 of 11 AH amyloidosis patients (sensitivity 90.9%). While positive staining was also observed in 9 of 64 non-AH amyloidosis patients (specificity 85.9%), substitution of the blocking agent reversed the positive reactivity in 5 of 9 patients. Amyloid protein band was clearly detected via immunoblotting analysis, and protein bands with similar molecular weights of amyloid protein were observed in serum samples from patients with AH amyloidosis. The two antibodies may represent a powerful diagnostic tool for AH amyloidosis. In addition, our data revealed the existence of amyloidogenic variable region fragments in the serum of patients, suggesting their potential as diagnostic markers for AH amyloidosis.

Distribution of amyloidosis subtypes based on tissue biopsy site - Consecutive analysis of 729 patients at a single amyloidosis center in Japan.

This study was performed to elucidate the distribution of amyloidosis subtypes based on tissue biopsy site. Samples obtained from 729 consecutive patients with amyloidosis were analyzed by immunohistochemical staining (IHC) and supplemental mass spectrometry (MS). The correlations between the type of organs from which samples were obtained and amyloidosis subtypes were investigated retrospectively. Among the patients, 95.1% were diagnosed by IHC and 4.9% were diagnosed by MS. The distribution of amyloidosis subtypes was as follows: AL, 59.1%; ATTR, 32.9%; AA, 4.0%; AH, 1.4%; Aß2M, 0.8%; and others, 0.9%. AL was the most common subtype in most organs, including the liver, lung, kidney, lower urinary tract, bone marrow, gastrointestinal tract, and skin/subcutaneous tissue. ATTR was the most common subtype in the heart, carpal tunnel, and peripheral nerves. AH was the second most common subtype in renal biopsy. Three or more amyloidosis subtypes were detected in each organ. In conclusion, AL was the most common subtype in most biopsy sites except the heart, carpal tunnel, and peripheral nerve, in which ATTR was more common. Because several types of amyloidogenic protein were detected in each organ, amyloid typing must be pursued, no matter the site from where biopsy was obtained.

Macrophage activation syndrome in adult dermatomyositis: a case-based review.

Macrophage activation syndrome (MAS) is a severe and life-threatening syndrome associated with autoimmune diseases, characterized by fever, hepatosplenomegaly, and pancytopenia. Dermatomyositis (DM) is one of the causes of MAS; however, its clinical characteristics in DM patients remain unclear. This study aimed to present a case of anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive DM complicated by MAS in a 29-year-old woman and to review the literatures including similar cases. Even though symptoms and cytopenia of our patient were refractory to combination therapy, including glucocorticoids, immunosuppressants, and plasma exchange, the administration of rituximab (RTX) resulted in rapid clinical improvement and glucocorticoid reduction. The literature review revealed 18 adult patients with DM associated MAS. Most patients developed MAS within 3 months from DM onset. A monotherapy of glucocorticoid was insufficient to control the disease, and the mortality of MAS in DM was higher than that of MAS in other rheumatic diseases, despite being treated by various means. RTX may be an effective treatment for patients with DM complicated by MAS who are refractory to conventional therapy. Anti-MDA5 antibody could influence the development of MAS; however, further investigations are needed to elucidate the association between myositis-specific antibody and MAS.

A case of spheroid-type localized lactoferrin amyloidosis in the bronchus.

We report a case of localized bronchial lactoferrin amyloidosis. A 47-year-old man presented with a complaint of persistent dry cough for two months. Chest computed-tomography revealed a calcification shadow of the right main bronchus; hence, a biopsy was performed, showing layered spheroid-type eosinophilic deposits in the bronchial wall. These deposits were positive for Congo red staining, exhibiting apple-green birefringence under polarized light. In addition, an electron microscopic examination demonstrated that this layered structure was formed by very thin cord-like amyloid deposits. By proteomics analysis using liquid chromatography-tandem mass spectrometry and immunohistochemistry, we confirmed that the deposited amyloid was composed of lactoferrin. While lactoferrin is known to be a precursor protein of localized corneal and seminal vesicle amyloidosis, localized lactoferrin amyloidosis of the bronchus has not been reported in the English literature. Our pathological findings suggested that localized lactoferrin amyloidosis may be caused by long-term tissue damage, and the characteristic spheroid-type appearance is thought to be associated with unique, thin cord-like amyloid deposits.

Nationwide survey on cerebrotendinous xanthomatosis in Japan.

Cerebrotendinous xanthomatosis (CTX) is likely to be underdiagnosed and precise epidemiological characteristics of CTX are largely unknown as knowledge on the disorder is based mainly on case reports. We conducted a nationwide survey on CTX to elucidate the frequency, clinical picture, and molecular biological background of Japanese CTX patients. In this first Japanese nationwide survey on CTX, 2541 questionnaires were sent to clinical departments across Japan. A total of 1032 (40.6%) responses were returned completed for further analysis. Forty patients with CTX (50.0% male) were identified between September 2012 and August 2015. The mean age of onset was 24.5 ± 13.6 years, mean age at diagnosis was 41.0 ± 11.6 years, and corresponding mean duration of illness from onset to diagnosis was 16.5 ± 13.5 years. The most common initial symptom was tendon xanthoma, followed next by spastic paraplegia, cognitive dysfunction, cataract, ataxia, and epilepsy. The most predominant mutations in the CYP27A1 gene were c.1214G> A (p.R405Q, 31.6%), c.1421G> A (p.R474Q, 26.3%), and c.435G> T (p.G145=, 15.8%). Therapeutic interventions that included chenodeoxycholic acid, HMG-CoA reductase inhibitor, and LDL apheresis reduced serum cholestanol level in all patients and improved clinical symptoms in 40.5% of patients. Although CTX is a treatable neurodegenerative disorder, our nationwide survey revealed an average 16.5-year diagnostic delay. CTX may be underdiagnosed in Japan, especially during childhood. Early diagnosis and treatment are essential to improve the prognosis of CTX.

Visualization of multiple organ amyloid involvement in systemic amyloidosis using 11C-PiB PET imaging.

PURPOSE: To investigate the utility of Pittsburgh compound B (PiB) positron emission tomography (PET) imaging for evaluating whole-body amyloid involvement in patients with systemic amyloidosis. METHODS: Whole-body 11C-PiB PET was performed in seven patients with systemic immunoglobulin light-chain (AL) amyloidosis, seven patients with hereditary transthyretin (ATTRm) amyloidosis, one asymptomatic TTR mutation carrier and three healthy controls. The correlations between clinical organ involvement, radiological 11C-PiB uptake and histopathological findings were analysed for each organ. RESULTS: Organ involvement on 11C-PiB PET imaging showed good correlations with the clinical findings for the heart and stomach. Abnormal tracer uptake was also observed in the spleen, lachrymal gland, submandibular gland, sublingual gland, lymph node, brain, scalp, extraocular muscles, nasal mucosa, pharynx, tongue and nuchal muscles, most of which were asymptomatic. Physiological tracer uptake was universally observed in the urinary tract (kidney, renal pelvis, ureter and bladder) and enterohepatic circulatory system (liver, gallbladder, bile duct and small intestine) in all participants. Most of the patients and one healthy control subject showed asymptomatic tracer uptake in the lung and parotid gland. The peripheral nervous system did not show any tracer uptake even in patients with apparent peripheral neuropathy. Histological amyloid deposition was confirmed in biopsied myocardium and gastric mucosa where abnormal 11C-PiB retention was observed. CONCLUSIONS: 11C-PiB PET imaging can be used clinically in the systemic evaluation of amyloid distribution in patients with AL and ATTRm amyloidosis. Quantitative analysis of 11C-PiB PET images may be useful in therapy evaluation and will reveal whether amyloid clearance is correlated with clinical response.

Hereditary Fibrinogen Aα-Chain Amyloidosis in Asia: Clinical and Molecular Characteristics.

Hereditary fibrinogen Aα-chain amyloidosis (Aα-chain amyloidosis) is a type of autosomal dominant systemic amyloidosis caused by mutations in fibrinogen Aα-chain gene (FGA). Patients with Aα-chain amyloidosis have been mainly reported in Western countries but have been rarely reported in Asia, with only five patients with Aα-chain amyloidosis being reported in Korea, China, and Japan. Clinically, the most prominent manifestation in Asian patients with Aα-chain amyloidosis is progressive nephropathy caused by excessive amyloid deposition in the glomeruli, which is similar to that observed in patients with Aα-chain amyloidosis in Western countries. In molecular features in Asian Aα-chain amyloidosis, the most common variant, E526V, was found in only one Chinese kindred, and other four kindred each had a different variant, which have not been identified in other countries. These variants are located in the C-terminal region (amino acid residues 517-555) of mature Aα-chain, which was similar to that observed in patients with Aα-chain amyloidosis in other countries. The precise number of Asian patients with Aα-chain amyloidosis is unclear. However, patients with Aα-chain amyloidosis do exist in Asian countries, and the majority of these patients may be diagnosed with other types of systemic amyloidosis.

[Recurrence of Waldenström macroglobulinemia accompanied by factor X deficiency].

A medical check-up revealed severe anemia in an 85-year-old man who had been diagnosed with Waldenström macroglobulinemia 11 years previously. On the other hand, prolonged PT and aPTT were demonstrated on admission, and were attributed to a significant decrease in factor X activity. These abnormalities were all considered to be have been caused by an exacerbation of the underlying disease and, thus, chemotherapy with the RCD regimen (rituximab, cyclophosphamide, dexamethasone) was started. No significant improvement was obtained and the patient died suddenly on day 154. AL amyloidosis was diagnosed by histopathological examinations and also confirmed by a sequence analysis of amyloid protein. This case with Waldenström macroglobulinemia complicated by AL amyloidosis and recurrent factor X deficiency is quite rare.

Pathological, biochemical, and biophysical characteristics of the transthyretin variant Y114H (p.Y134H) explain its very mild clinical phenotype.

Transthyretin (TTR) is a homotetrameric protein that must misfold in order to form amyloid fibrils. Misfolding includes rate limiting tetramer dissociation, followed by fast tertiary structural changes of the monomer that enable aggregation. Hereditary ATTR amyloidosis is an autosomal dominant genetic disorder with systemic deposition of amyloid fibrils induced by TTR gene mutation. We identified a rare Y114H (p.Y134H) TTR variant in a Japanese patient presenting with late-onset, very mild clinical course. The patient had an extremely low serum variant TTR concentration (18% of total TTR), whereas the composition of variant TTR was 55% in amyloid fibrils in tenosynovial tissues obtained at carpal tunnel release surgery. The amyloid fibril deposits in the ATTR Y114H patient had an altered structure compared with that in wild-type ATTR patients, as determined by luminescent conjugated poly/oligo-thiophene fluorescence spectroscopy. Biophysical studies using recombinant protein showed that Y114H TTR was markedly destabilized both thermodynamically and kinetically and was highly amyloidogenic in vitro. These data suggest that extremely low serum variant Y114H TTR concentration, probably due to endoplasmic reticulum-associated degradation of unstable variant TTR protein, protected this patient from severe amyloidosis, as self-assembly of the amyloidogenic intermediate is a concentration-dependent process.

Genetic counselling for at-risk family members with hereditary transthyretin amyloidosis: data from a single-centre study.

BACKGROUND: Hereditary transthyretin-related amyloidosis is an autosomal dominant disorder. Recently, disease-modifying therapies (DMTs) have been developed. For at-risk individuals, genetic analysis aids in the early administration of medical care; however, few studies have evaluated the current status of genetic counselling and management of presymptomatic carriers of amyloidogenic variants. METHODS: We retrospectively evaluated the medical records of 202 consecutive participants. RESULTS: A total of 103 clients who received genetic counselling for predictive testing were at-risk, and 83 underwent predictive testing. Genetic testing results were positive in 33 patients, 11 of whom had confirmed amyloid deposition and were administered DMTs. For presymptomatic V30M (p.V50M) carriers, 32.0 ± 2.4 years (median ± standard error) was the age when amyloid deposition was first identified (95% confidence interval 27.4-36.6). Serum transthyretin (TTR) levels decreased serially with an estimated slope of -1.2 mg/dL/year. CONCLUSIONS: Our study suggests the clinical utility of management using a combination of predictive testing and monitoring methods. Psychosocial support should be considered with collaboration between geneticists/genetic counsellors and psychologists. For a more optimised protocol for monitoring and designing future interventional trials in presymptomatic carriers, prospective cohort studies are necessary to clarify the natural history, particularly in the early stages of the disease.

Long-term Observation of a Japanese Patient with a Multiple-system Neurodegenerative Disorder with a Uniallelic de novo Missense Variant in KIF1A.

We encountered a 37-year-old Japanese man with KIF1A-associated neurological disorder (KAND) who exhibited motor developmental delay, intellectual disability, and slowly progressive cerebellar ataxia, hypotonia, and optic neuropathy. Pyramidal tract signs were evident late in this case. At 30 years old, the patient developed a neurogenic bladder. A molecular diagnosis revealed a uniallelic missense de novo variant (p.L278P) of KIF1A. Serial neuroradiological studies revealed atrophy of the cerebellum at an early age, and cerebral hemisphere atrophy progressed slowly over a 22-year observation period. Our study suggests that the primary etiology of KAND may be acquired, long-standing neurodegeneration rather than congenital hypoplasia.

Severe Cerebral Small Vessel Disease Caused by the Uniallelic p.A252T Variant of HTRA1.

Objective: To investigate the clinical effect of a heterozygous missense variant of HTRA1 on cerebral small vessel disease (CSVD) in a large Japanese family with a p.A252T variant. Methods: We performed clinical, laboratory, radiologic, and genetic evaluations of members of a previously reported family with cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). Results: Two family members were previously reported patients with CARASIL. Among 6 uniallelic p.A252T carriers, 2 had neurologic symptoms with brain MRI abnormalities, 2 showed CSVD on the MRI only, and the other 2 were unaffected. Clinical phenotypes of 2 heterozygous patients were comparable with those of patients with CARASIL, whereas the other 3 heterozygous patients had developed milder and later-onset CSVD. One heterozygous carrier was asymptomatic. Discussion: Previous studies have suggested that uniallelic p.A252T causes disease. However, our study revealed that patients with uniallelic p.A252T can have severe and young-onset CSVD. The clinical manifestations of uniallelic variant carriers were highly variable, even within the same family. Male and atherosclerotic risk factors were considered to be additional factors in the severity of neurologic symptoms in uniallelic p.A252T carriers, suggesting that strict control of vascular risk factors can prevent vascular events in uniallelic HTRA1 carriers.

Lysinuric protein intolerance exhibiting renal tubular acidosis/Fanconi syndrome in a Japanese woman.

Lysinuric protein intolerance (LPI), caused by pathogenic variants of SLC7A7, is characterized by protein aversion, failure to thrive, hyperammonemia, and hepatomegaly. Recent studies have reported that LPI can cause multiple organ dysfunctions, including kidney disease, autoimmune deficiency, pulmonary alveolar proteinosis, and osteoporosis. We report the case of a 47-year-old Japanese woman who was initially diagnosed with renal tubular acidosis (RTA), Fanconi syndrome, and rickets. At the age of 3 years, she demonstrated a failure to thrive. Urinary amino acid analysis revealed elevated lysine and arginine levels, which were masked by pan-amino aciduria. She was subsequently diagnosed with rickets at 5 years of age and RTA/Fanconi syndrome at 15 years of age. She was continuously treated with supplementation of vitamin D3, phosphate, and bicarbonate. A renal biopsy at 18 years of age demonstrated diffuse proximal and distal tubular damage with endocytosis-lysosome pathway abnormalities. Distinctive symptoms of LPI, such as protein aversion and postprandial hyperammonemia were not observed throughout the patient's clinical course. The patient underwent a panel-based comprehensive genetic testing and was diagnosed with LPI. As the complications of LPI involve many organs, patients lacking distinctive symptoms may develop various diseases, including RTA/Fanconi syndrome. Our case indicates that proximal and distal tubular damages are notable findings in patients with LPI. The possibility of LPI should be carefully considered in the management of RTA/Fanconi syndrome and/or incomprehensible pathological tubular damage, even in the absence of distinctive symptoms; furthermore, a comprehensive genetic analysis is useful for diagnosing LPI.

Ocular findings in patients with acquired ATTRv amyloidosis following domino liver transplantation.

PURPOSE: To investigate the presence of amyloidosis-related ocular findings in patients who received domino liver transplantation from ATTRv amyloidosis donors. METHODS: We reviewed the ocular findings in patients who had previously undergone domino liver transplantation and received ophthalmologic examinations between January 2009 and March 2023. The presence of amyloidosis-related ocular findings was retrospectively assessed by two ophthalmologists. RESULTS: During the study period, a total of 7 patients with 14 eyes were examined. All patients were considered as acquired ATTRv amyloidosis. The mean age at the final visit was 64.6±8.4 years (52-75 years), and the mean time since domino liver transplantation was 167.6±76.2 months (69-257 months). The two evaluators' assessments for amyloidosis-related ocular findings were completely identical. No amyloid fibril deposition was observed in the pupil, lens, or vitreous. Five patients (10 eyes) had a Schirmer test result of 5mm or less than 5 mm, and four patients with a total of 8 eyes underwent fluorescein angiography and indocyanine green angiography, and no evidence of retinal amyloid angiopathy was found on fluorescein angiography. However, three patients with 6 eyes showed choroidal amyloid angiopathy on indocyanine green angiography. CONCLUSION: While cases of choroidal amyloid angiopathy were observed, serious amyloidosis-related ocular complications such as vitreous opacity or secondary glaucoma did not occur even in the long term after domino liver transplantation.

CSF/plasma levels, transthyretin stabilisation and safety of multiple doses of tolcapone in subjects with hereditary ATTR amyloidosis.

PURPOSE: To investigate the effect of tolcapone on cerebrospinal fluid (CSF) transthyretin (TTR) tetramer stability in patients with hereditary transthyretin (ATTRv) amyloidosis. METHODS: A total of 9 patients were enrolled in the study (3 men, 50.3 ± 14.4 years old). Three patients had central nervous system (CNS) involvement. Patients were assigned to receive tolcapone 300 mg/day or 600 mg/day for 7 days. Plasma and CSF were collected at baseline and 2 h after the final tolcapone dose. RESULTS: The mean CSF tolcapone and 3-O-Methyltolcapone (3-OMT) concentration were 39.4 ± 36.3 ng/mL and 26.0 ± 4.9 ng/mL, respectively, after 7 days of tolcapone dosing. Tolcapone and 3-OMT were detected in the CSF of patients with or without CNS symptoms. The mean total study drug (tolcapone + 3-OMT) to TTR molar ratio in CSF was 1.15 ± 0.59. Orally administered tolcapone significantly increased CSF TTR concentration and decreased monomer content under semi-denaturing conditions. Eight adverse events (AEs) were reported in 6 patients. All AEs were mild in severity and resolved. CONCLUSIONS: Tolcapone was able to cross the blood brain-barrier, highlighting its potential to decrease CNS manifestations of ATTRv amyloidosis. Tolcapone was well tolerated by patients with ATTRv amyloidosis.

Giant Hepatomegaly with Spleno-testicular Enlargement in a Patient with Apolipoprotein A-I Amyloidosis: An Uncommon Type of Amyloidosis in Japan.

Hereditary systemic amyloidosis aside from transthyretin-related familial amyloid polyneuropathy is quite uncommon in Japan. We herein report a sporadic case of hereditary apolipoprotein A-I (apoAI) amyloidosis. The patient was a 43-year-old Japanese man who exhibited marked hepatomegaly with spleno-testicular enlargement. While he was initially thought to have primary AL amyloidosis, a proteomics analysis revealed that the amyloid was composed of variant apoAI with an E34K variant. To date, only one patient with apoAI amyloidosis has been reported in Japan. However, our study suggests that more patients may be present in Japan, and the majority may have been diagnosed with other types of amyloidosis due to its clinical similarity.

A Rare Case of Localized Esophageal Amyloidosis.

A 72-year-old man without any symptoms was referred to our hospital. Esophagogastroduodenoscopy revealed an elevated esophageal lesion that was covered with normal mucosa. The examination of biopsy specimens from the lesion revealed amyloid light-chain (AL) (λ) type amyloid deposits, but there were no amyloid deposits elsewhere in the gastrointestinal tract. Further examinations did not indicate systemic amyloidosis. Thus, this case was diagnosed as a localized esophageal amyloidosis. As the clinical outcome of localized amyloidosis is favorable, this case was scheduled for close follow-up. Localized amyloidosis should be considered in the differential diagnosis of esophageal submucosal tumors.

Dialysis-related amyloidosis associated with a novel ß2-microglobulin variant.

Till date, there had been no reported case of dialysis-related amyloidosis (DRA) associated with a ß2-microglobulin variant. We report here a 41-year-old haemodialysis patient with systemic amyloidosis, exhibiting macroglossia and swelling salivary glands, uncommon clinical manifestations for DRA. Molecular analysis showed that the patient had a new variant of ß2-microglobulin (V27M). Extracted amyloid protein was predominantly composed of variant ß2-microglobulin. In vitro analysis revealed that this variant ß2-microglobulin had a strong amyloidogenic propensity, probably owing to the decreased stability caused by a bulky methionine residue. Our data clearly show that V27M variant is amyloidogenic and this mutation results in unusual clinical manifestations. To date, only one amyloidogenic ß2-microglobulin variant (D76N) has been reported in non-dialysis patients. It is noteworthy that the V27M and D76N variants show substantial differences in both clinical phenotypes and pathomechanical features. This is the first case of DRA associated with a naturally occurring ß2-microglobulin variant.