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.

Enterocolic granulomatous phlebitis associated with epidermal growth factor-containing fibulin-like extracellular matrix protein 1 deposition and focal amyloid properties: A case report.

A woman in her 60s with rheumatoid arthritis was admitted with fever and abdominal pain. Laparoscopic examination with the differential diagnosis of peritoneal neoplasm and infection revealed granulomatous phlebitis in the resected greater omentum. Amorphous eosinophilic deposits observed in the resected tissue exhibited focal, weak positivity for Congo red but were strongly positive for thioflavin S, confirming their focal amyloid properties. Marked degeneration of elastic fibers was also evident. Electron microscopy revealed deposits around the affected elastic fibers. Immunohistochemistry revealed the deposition of epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) along with T-cell-predominant lymphocytic inflammation. The definitive diagnosis was granulomatous enterocolic lymphocytic phlebitis (ELP) associated with EFEMP1 deposition exhibiting focal amyloid properties (EFEMP1/AEFEMP1), supported by proteomics analysis. This type of vasculitis is similar to amyloid-ß-related angiitis of the central nervous system. Thus, we speculate that granulomatous ELP also results from an immune response that recognizes EFEMP1/AEFEMP1 deposits as foreign material and attempts to remove them. Confirmation of EFEMP1/AEFEMP1 deposition with Congo red staining is challenging, particularly in the presence of inflammation, and warrants comprehensive evaluation.

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.

Variables for differential diagnosis of familial Mediterranean fever: multiple correspondence analysis of a large Japanese cohort.

OBJECTIVES: We investigated differential diagnoses that should be noted with familial Mediterranean fever (FMF) and useful variables for differentiation in a large Japanese cohort. METHODS: Patients aged ≥13 years who were clinically suspected of having FMF by Livneh criteria were studied 1 year after MEFV genetic testing. Patients ultimately diagnosed with other diseases were studied, and the association among each disease, patient characteristics, and clinical variables were analyzed using multiple correspondence analysis. RESULTS: In total, 504 patients were included in this study; 34 (6.7%) were diagnosed with a disease other than FMF. The most common diagnosis was Behçet's disease, followed by periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome, inflammatory bowel disease, myelodysplastic syndromes (MDS), and infectious diseases. Although none of the non-FMF patients had exon 10 variants, some responded to colchicine treatment. Multiple correspondence analysis suggested that atypical symptoms such as stomatitis were associated with Behçet's disease and PFAPA syndrome, whereas characteristic situations such as disease onset ≥40 years were associated with MDS and infectious diseases. CONCLUSION: Careful follow-ups and reanalysis of the diagnosis should be performed for patients with atypical findings and no exon 10 variants, even if their symptoms meet the clinical criteria for FMF.

Light and heavy chain deposition disease with focal amyloid deposition diagnosed with mass spectrometry: a case report.

BACKGROUND: Light and heavy chain deposition disease (LHCDD) is a rare condition characterised by the deposition of immunoglobulin components in the kidneys. Similarly, Amyloidosis is also caused by the deposition of light chain and/or heavy chain components of immunoglobulins which are folded into amyloid fibrils characterised by Congophilic deposits that exhibit apple-green birefringence under polarised light. Only a handful of reports describing LHCDD with amyloid fibril deposition have been previously published, however, none have characterized the composition of the deposited immunoglobulin components via mass spectrometry. CASE PRESENTATION: We report a case of a 79-year-old Japanese woman with nephrotic syndrome. Bone marrow aspiration revealed a slight proliferation of plasma cells (under 10%). Immunofluorescence assessment of renal biopsy showed amyloid-like deposits in the glomerulus that were positive for IgA and kappa. Further, the Congo red staining of the deposits was faintly positive, and only a slight birefringence was detected. Electron microscopy confirmed fine fibrillar structures and non-amyloid deposits. Finally, mass spectrometry revealed that the deposits were composed of abundant amounts of light chain with small amounts of heavy chain. Therefore, the patient was diagnosed with LHCDD and focal amyloid deposition. Chemotherapy was subsequently initiated, which resulted in haematological and renal response. Under polarised light, faint birefringence with Congo red staining and periodic acid-methenamine silver positivity indicated that the deposits were mostly non-amyloid fibrils with a small component of amyloid fibrils. Generally, the diagnosis of heavy- and light-chain amyloidosis is defined by greater heavy chain deposition compared to the light chain. However, in our case, contrary to the definition, the light-chain deposition was far greater than that of the heavy-chain. CONCLUSIONS: This is the first case of LHCDD with focal amyloid deposition diagnosed by analysing the glomerular deposits by mass spectrometry.

Citrin Deficiency: Clinical and Nutritional Features.

SLC25A13 gene mutations are responsible for diseases related to citrin deficiency (CD), such as neonatal intrahepatic cholestasis caused by citrin deficiency and adult-onset type II citrullinemia (CTLN2). From childhood to adulthood, CD patients are apparently healthy due to metabolic compensation with peculiar dietary habits-disliking high-carbohydrate foods and liking fat and protein-rich foods. Carbohydrate overload and alcohol consumption may trigger the sudden onset of CTLN2, inducing hyperammonemia and consciousness disturbance. Well-compensated asymptomatic CD patients are sometimes diagnosed as having non-obese (lean) non-alcoholic fatty liver disease and steatohepatitis, which have the risk of developing into liver cirrhosis and hepatocellular carcinoma. CD-induced fatty liver demonstrates significant suppression of peroxisome proliferator-activated receptor α and its downstream enzymes/proteins involved in fatty acid transport and oxidation and triglyceride secretion as a very low-density lipoprotein. Nutritional therapy is an essential and important treatment of CD, and medium-chain triglycerides oil and sodium pyruvate are useful for preventing hyperammonemia. We need to avoid the use of glycerol for treating brain edema by hyperammonemia. This review summarizes the clinical and nutritional features of CD-associated fatty liver disease and promising nutritional interventions.

Anterior horn damage in brachial multisegmental amyotrophy with superficial siderosis and dural tear: an autopsy case report.

BACKGROUND: Patients with superficial siderosis (SS) rarely show brachial multisegmental amyotrophy with ventral intraspinal fluid collection accompanied with dural tear. CASE PRESENTATION: We describe spinal cord pathology of a 58-year-old man who developed brachial multisegmental amyotrophy with ventral intraspinal fluid collection from the cervical to lumbar spinal levels accompanied with SS, dural tear, and snake-eyes appearance on magnetic resonance imaging (MRI). Radiological and pathological analyses detected diffuse and prominent superficial deposition of hemosiderin in the central nervous system. Snake-eyes appearance on MRI expanded from the C3 to C7 spinal levels without apparent cervical canal stenosis. Pathologically, severe neuronal loss at both anterior horns and intermediate zone was expanded from the upper cervical (C3) to middle thoracic (Th5) spinal gray matter, and these findings were similar to compressive myelopathy. CONCLUSION: Extensive damage of the anterior horns in our patient may be due to dynamic compression induced by ventral intraspinal fluid collection.

Renal Function in Aged C57BL/6J Mice Is Impaired by Deposition of Age-Related Apolipoprotein A-II Amyloid Independent of Kidney Aging.

Spontaneous and age-related amyloidosis has been reported in C57BL/6J mice. However, the biochemical characteristics of age-related amyloidosis remain unclear. Herein, the age-related prevalence of amyloidosis, the types of amyloid fibril proteins, and the effects of amyloid deposition were investigated in renal function in C57BL/6J mice. The results obtained revealed a high incidence of amyloidosis in C57BL/6J mice originating from The Jackson Laboratory as well as the deposition of large amounts of amyloid in the glomeruli of aged mice. The amyloid fibril protein was identified as wild-type apolipoprotein A-II (ApoA-II). Induction of amyloid deposition in 40-week-old mice, equivalent to that of spontaneous development in 80-week-old mice, to rule out the effects of aging, revealed subsequent damage to kidney function by amyloid deposits. Furthermore, amyloid deposition in the mesangial region decreased podocyte density, compromised foot processes, and led to the accumulation of fibroblast growth factor 2 in glomeruli. Collectively, these results suggest that ApoA-II deposition is a general pathology in aged C57BL/6J mice and is dependent on supplier colonies. Therefore, the effects of age-related amyloid deposition need to be considered in research on aging in mice.

Transthyretin Variant Amyloidosis with a TTR A97D (p.A117D) Mutation Manifesting Remarkable Asymmetric Neuropathy.

We herein report a 68-year-old Japanese man with sporadic variant transthyretin (ATTRv) amyloidosis harboring the novel variant A97D (p.A117D) in TTR. He had slow development of asymmetric neuropathy, unintentional weight loss, mild autonomic failure and mild cardiomyopathy. TTR amyloid deposition on the gastric duodenal mucosa was detected. In silico analyses predicted that TTR A97D (p.A117D) altered the structure and function of the TTR protein. ATTRv amyloidosis is often difficult to diagnose in non-endemic regions due to its diverse phenotypes, such as atypical peripheral nerve involvement and a rare family history.

Macrophages in the reticuloendothelial system inhibit early induction stages of mouse apolipoprotein A-II amyloidosis.

Amyloidosis refers to a group of degenerative diseases that are characterized by the deposition of misfolded protein fibrils in various organs. Deposited amyloid may be removed by a phagocyte-dependent innate immune system; however, the precise mechanisms during disease progression remain unclear. We herein investigated the properties of macrophages that contribute to amyloid degradation and disease progression using inducible apolipoprotein A-II amyloidosis model mice. Intravenously injected AApoAII amyloid was efficiently engulfed by reticuloendothelial macrophages in the liver and spleen and disappeared by 24 h. While cultured murine macrophages degraded AApoAII via the endosomal-lysosomal pathway, AApoAII fibrils reduced cell viability and phagocytic capacity. Furthermore, the depletion of reticuloendothelial macrophages before the induction of AApoAII markedly increased hepatic and splenic AApoAII deposition. These results highlight the physiological role of reticuloendothelial macrophages in the early stages of pathogenesis and suggest the maintenance of phagocytic integrity as a therapeutic strategy to inhibit disease progression.

Distribution and progression of cerebral amyloid angiopathy in early-onset V30M (p.V50M) hereditary ATTR amyloidosis.

BACKGROUND: Cerebral amyloid angiopathy (CAA) is becoming the most common and serious complications in long-lived hereditary ATTR amyloidosis patients. It is therefore imperative to elucidate the characteristics of ATTR-type CAA and develop useful biomarkers. METHODS: We enrolled 34 ATTRv amyloidosis patients with the V30M (p.V50M) variant for analysis with three-dimensional stereotactic surface projection z score imaging of Pittsburgh compound B (PiB)-PET. RESULTS: Eight patients exhibited central nervous system (CNS) symptoms. Seven patients suffered transient focal neurologic episodes, and 2 patients each experienced cerebellar haemorrhages or cognitive decline. The amount of 11C-PiB accumulation increased as a function of disease duration. 11C-PiB-PET abnormalities were seen at 8 years from onset and were associated with CNS manifestations from 12 years. The annual increase rate of the standardised uptake value ratio (SUVR) in female patients was significantly higher than in male patients. CNS amyloid deposition started in the upper middle surface of the cerebellar cortex, and then spread out over the entire surface of the cerebellum, Sylvian fissure, and anterior part of the longitudinal fissure of the cerebrum. CONCLUSIONS: PiB-PET is a useful biomarker for the early detection and treatment evaluation of ATTR-type CAA. Female gender is associated with more rapid progression of ATTR-type CAA.

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.

Reversible Leukoencephalopathy in a Man with Childhood-onset Hyperornithinemia-Hyperammonemia-Homocitrullinuria Syndrome.

A 49-year-old Japanese man had shown developmental delay, learning difficulties, epilepsy, and slowly progressive gait disturbance in elementary school. At 46 years old, he experienced repeated drowsiness with or without generalized convulsions, and hyperammonemia was detected. Brain magnetic resonance imaging detected multiple cerebral white matter lesions. An electroencephalogram showed diffuse slow basic activities with 2- to 3-Hz δ waves. Genetic tests confirmed a diagnosis of hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome. Leukoencephalopathy was resolved following the administration of L-arginine and lactulose with a decrease in plasma ammonia levels and glutamine-glutamate peak on magnetic resonance spectroscopy. Leukoencephalopathy in HHH syndrome may be reversible with the resolution of hyperammonemia-induced glutamine toxicity.

Food Preferences of Patients with Citrin Deficiency.

Citrin deficiency is characterized by a wide range of symptoms from infancy through adulthood and presents a distinct preference for a diet composed of high protein, high fat, and low carbohydrate. The present study elucidates the important criteria by patients with citrin deficiency for food selection through detailed analysis of their food preferences. The survey was conducted in 70 citrin-deficient patients aged 2-63 years and 55 control subjects aged 2-74 years and inquired about their preference for 435 food items using a scale of 1-4 (the higher, the more favored). The results showed that the foods marked as "dislike" accounted for 36.5% in the patient group, significantly higher than the 16.0% in the controls. The results also showed that patients clearly disliked foods with 20-24 (% of energy) or less protein, 45-54% (of energy) or less fat, and 30-39% (of energy) or more carbohydrate. Multiple regression analysis showed carbohydrates had the strongest influence on patients' food preference (ß = -0.503). It also showed female patients had a stronger aversion to foods with high carbohydrates than males. The protein, fat, and carbohydrate energy ratio (PFC) of highly favored foods among patients was almost the same as the average PFC ratio of their daily diet (protein 20-22: fat 47-51: carbohydrates 28-32). The data strongly suggest that from early infancy, patients start aspiring to a nutritional balance that can compensate for the metabolism dissonance caused by citrin deficiency in every food.

Saccharopinuria accompanied by hyperammonemia and hypercitrullinemia presented with elderly-onset epilepsy, progressive cognitive decline, and gait ataxia.

We report a case of saccharopinuria with hyperammonemia and hypercitrullinemia in a Japanese woman who presented with elderly-onset epilepsy, progressive cognitive decline, and gait ataxia. Blood amino acid analysis revealed an increase in citrulline, cystine, and lysine levels, and urine amino acid analysis showed increased citrulline and cystine levels. Urine metabolomics revealed an increased saccharopine level, leading to the definitive diagnosis of saccharopinuria. In western blots of liver biopsy samples, normal citrin levels were observed, suggesting that adult-onset citrullinemia type 2 (CTLN2) was not present. In addition, decreased argininosuccinate synthetase (ASS) levels were observed, and ASS1 gene, a causative gene for citrullinemia type 1 (CTLN1), was analyzed, but no gene mutations were found. Because the causes of hypercitrullinemia were not clear, it might be secondary to saccharopinuria. Muscle biopsy findings of the biceps brachii revealed diminished cytochrome c oxidase (COX) activity, mitochondrial abnormalities on electron microscopy and p62- positive structures in immunohistochemical analyses. Saccharopinuria is generally considered a benign metabolic variant, but our case showed elevated lysine and saccharopine levels causing ornithine circuit damage, mitochondrial dysfunction, and autophagy disorders. This may lead to so far unknown neurological disorders.