Nephrotic syndrome in adults is defined as nephrotic-range (≥3.5g/24h) proteinuria with low serum albumin, usually associated with edema, hyperlipidemia, and lipiduria. The 3.5g/24h threshold was selected arbitrarily and might not be reached in certain cases despite severe defects in glomerular permeability. We describe the case of a 57-year-old male who presented with progressively worsening swelling involving his limbs and abdomen. He also reported decreased urine output and fatigue. Physical examination was notable for severe pitting edema over legs, arms, and abdomen, in addition to peri-orbital puffiness. Labs revealed low serum albumin (1.3 g/dL), moderate proteinuria (2.3g/24h), and elevated total cholesterol (334 mg/dL). Renal biopsy showed amyloid light chain (AL) amyloidosis and bone marrow biopsy confirmed the presence of lambda-restricted plasma cells. Computed tomography, ultrasound, elastography, and laboratory findings were congruent with those seen in hepatic amyloidosis. A diagnosis of nephrotic syndrome caused by systemic AL amyloidosis was made despite the absence of nephrotic range proteinuria. The primary abnormality in nephrotic syndrome is increased glomerular permeability, leading to severe proteinuria causing low serum albumin, decreased oncotic pressure, and increased water retention by kidneys due to activation of the epithelial sodium channel (ENaC). The amount of albuminuria is influenced by both the extent of glomerular permeability and the rates of glomerular filtration and albumin synthesis. In cases where albumin synthesis is decreased secondary to concurrent liver disease, as in our case, a steady state of renal protein excretion may be reached at a lower threshold than 3.5g/24h despite severe defects in glomerular permeability.

Calcifications on mammography from systemic disease at times meet diagnostic criteria for histologic sampling to exclude malignancy. We present a case of bilateral groups of new calcifications on mammography that yielded amyloidosis on core biopsy. Awareness of our patient\'s known diagnosis of systemic light chain amyloidosis (AL) prompted use of Congo red staining to confirm the histologic diagnosis. Knowledge of systemic diseases with possible manifestations on mammography can facilitate cogent and clinically relevant radiology-pathology correlation.

Deposition and accumulation of amyloid fibrils is a hallmark of a group of diseases called amyloidosis and neurodegenerative disorders. Although polypeptides potentially have a fibril-forming propensity, native proteins have evolved into proper functional conformations to avoid aggregation and fibril formation. Understanding the mechanism for regulation of fibril formation of native proteins provides clues for the rational design of molecules for inhibiting fibril formation. Although fibril formation is a complex multistep reaction, experimentally obtained fibril formation curves can be fitted with the Finke-Watzky (F-W) two-step model for homogeneous nucleation followed by autocatalytic fibril growth. The resultant F-W rate constants for nucleation and fibril formation provide information on the chemical kinetics of fibril formation. Using the F-W two-step model analysis, we investigated the physicochemical mechanisms of fibril formation of a Parkinson\'s disease protein α-synuclein (αS) and a systemic amyloidosis protein apolipoprotein A-I (apoA-I). The results indicate that the C-terminal region of αS enthalpically and entropically suppresses nucleation through the intramolecular interaction with the N-terminal region and the intermolecular interaction with existing fibrils. In contrast, the nucleation of the N-terminal fragment of apoA-I is entropically driven likely due to dehydration of large hydrophobic segments in the molecule. Based on our recent findings, we discuss the similarity and difference of the fibril formation mechanisms of αS and the N-terminal fragment of apoA-I from the physicochemical viewpoints.

Systemic amyloidosis is a rare protein misfolding and deposition disorder leading to progressive organ failure. Waldenström macroglobulinemia (WM) with systemic amyloidosis as the main manifestation is even rarer. The patient in this study presented with recurrent diarrhea and had not been diagnosed in other hospitals on multiple occasions. Later, his diarrhea worsened and was accompanied by sunken edema of both lower limbs and dizziness. Renal biopsy showed deposits of PAS light-staining material in the glomeruli, interstitium, and small arteries, which stained positively with Congo red. Cardiac ultrasound showed interventricular septum thickening of 17 mm, right ventricular wall myocardial thickening of approximately 0.6 cm, and septal thickening of approximately 0.5 cm, considering myocardial amyloidosis. Electromyography showed abnormal peripheral nerve conduction. Lymphoplasmacytic cells were found in the bone marrow. Taken together, he was diagnosed with WM. He was treated with a BR (Bendamustine + Rituximab) regimen. After 6 courses, the patient\'s discomfort was relieved, his weight gained 5 kg, the level of serum IgM and dFLC decreased, and cardiac and renal assessments were more relieved. The patient has been followed up for more than 1 month.

Peripheral and autonomic neuropathy are common disease manifestations in systemic amyloidosis. The neurofilament light chain (NfL), a neuron-specific biomarker, is released into the blood and cerebrospinal fluid after neuronal damage. There is a need for an early and sensitive blood biomarker for polyneuropathy, and this systematic review provides an overview on the value of NfL in the early detection of neuropathy, central nervous system involvement, the monitoring of neuropathy progression, and treatment effects in systemic amyloidosis. A literature search in PubMed, Embase, and Web of Science was performed on 14 February 2024 for studies investigating NfL levels in patients with systemic amyloidosis and transthyretin gene-variant (TTRv) carriers. Only studies containing original data were included. Included were thirteen full-text articles and five abstracts describing 1604 participants: 298 controls and 1306 TTRv carriers or patients with or without polyneuropathy. Patients with polyneuropathy demonstrated higher NfL levels compared to healthy controls and asymptomatic carriers. Disease onset was marked by rising NfL levels. Following the initiation of transthyretin gene-silencer treatment, NfL levels decreased and remained stable over an extended period. NfL is not an outcome biomarker, but an early and sensitive disease-process biomarker for neuropathy in systemic amyloidosis. Therefore, NfL has the potential to be used for the early detection of neuropathy, monitoring treatment effects, and monitoring disease progression in patients with systemic amyloidosis.

UNASSIGNED: Amyloidosis is an infiltrative disease caused by the deposition of abnormal proteins. While cardiac amyloidosis is relatively common, gastrointestinal (GI) tract involvement is less frequent. In this case, the authors report a delayed diagnosis of systemic amyloidosis presenting mainly with digestive symptoms.
UNASSIGNED: An 81-year-old male presented with the complaint of persistent diarrhoea for over a year and the progressive development of edemas during the last 4 months. Echocardiogram findings revealed the presence of the characteristic sparkling sign. The diagnosis of amyloidosis was confirmed by histopathological biopsies taken from the duodenum. Serum electrophoresis findings strongly suggested the possibility of plasma cell dyscrasia.
UNASSIGNED: What distinguishes this case is that the suspicion of amyloidosis as the underlying cause of the diarrhoea did not arise until an incidental echocardiogram revealed cardiac hypertrophy and a sparkling appearance.
UNASSIGNED: This case reminds us to consider amyloidosis as a possible underlying cause for unexplained gastrointestinal symptoms such as diarrhoea, especially in bad economic situations where the diagnosis of rare diseases may be delayed.

Aggregation of leukocyte cell-derived chemotaxin 2 (LECT2) causes ALECT2, a systemic amyloidosis that affects the kidney and liver. Previous studies established that LECT2 fibrillogenesis is accelerated by the loss of its bound zinc ion and stirring/shaking. These forms of agitation create heterogeneous shear conditions, including air-liquid interfaces that denature proteins, that are not present in the body. Here, we determined the extent to which a more physiological form of mechanical stress-shear generated by fluid flow through a network of narrow channels-drives LECT2 fibrillogenesis. To mimic blood flow through the kidney, where LECT2 and other proteins form amyloid deposits, we developed a microfluidic device consisting of progressively branched channels narrowing from 5 mm to 20 μm in width. Shear was particularly pronounced at the branch points and in the smallest capillaries. Aggregation was induced within 24 h by shear levels that were in the physiological range and well below those required to unfold globular proteins such as LECT2. EM images suggested the resulting fibril ultrastructures were different when generated by laminar flow shear versus shaking/stirring. Importantly, results from the microfluidic device showed the first evidence that the I40V mutation accelerated fibril formation and increased both the size and the density of the aggregates. These findings suggest that kidney-like flow shear, in combination with zinc loss, acts in combination with the I40V mutation to trigger LECT2 amyloidogenesis. These microfluidic devices may be of general use for uncovering mechanisms by which blood flow induces misfolding and amyloidosis of circulating proteins.

Although AA amyloidosis is primarily caused by inflammatory conditions, associations between AA amyloidosis and solid cancers have occasionally been described. Herein, we report the case of a 48-year-old man in whom resection of a proliferating pilomatricoma with deposition of AA amyloid resulted in remission of concomitant AA gastrointestinal amyloidosis. A rapidly growing, giant, reddish, ulcerated tumor measuring 16 × 13 cm in size was identified on the upper left arm on a visit to our hospital. Gastrointestinal AA amyloidosis was diagnosed from colorectal mucosal biopsy at the same time, and weight loss and profuse diarrhea were clinically evident. As treatment, the tumor was resected with a 10-mm surgical margin. Histologically, the tumor predominantly comprised a lobular proliferation of basophilic cells peripherally, filled with eosinophilic, cornified material and shadow cells with mitoses observed in basophilic cells. Specimens revealed eosinophilic, homogeneous deposits around tumor nests, which were confirmed as amyloid deposits by positive staining with Congo red stain. These deposits were immunohistochemically positive on staining with anti-serum amyloid A antibody. Collectively, proliferating pilomatricoma with AA amyloidosis was diagnosed. After tumor resection, chronic diarrhea resolved and no amyloid deposition was apparent in colorectal biopsy. It is important to remember that if amyloid deposition is present in a tumor, aggressive tumor excision may alleviate systemic amyloidosis.

UNASSIGNED: To evaluate serum neurofilament light chain (sNfL) as biomarker of disease onset, progression and treatment effect in hereditary transthyretin (ATTRv) amyloidosis patients and TTR variant (TTRv) carriers.
UNASSIGNED: sNfL levels were assessed longitudinally in persistently asymptomatic TTRv carriers (N = 12), persistently asymptomatic ATTRv amyloidosis patients (defined as asymptomatic patients but with amyloid detectable in subcutaneous abdominal fat tissue) (N = 8), in TTRv carriers who developed polyneuropathy (N = 7) and in ATTRv amyloidosis patients with polyneuropathy on treatment (TTR-stabiliser (N = 20) or TTR-silencer (N = 18)). Polyneuropathy was confirmed by nerve conduction studies or quantitative sensory testing. sNfL was analysed using a single-molecule array assay.
UNASSIGNED: sNfL increased over 2 years in persistently asymptomatic ATTRv amyloidosis patients, but did not change in persistently asymptomatic TTRv carriers. In all TTRv carriers who developed polyneuropathy, sNfL increased from 8.4 to 49.8 pg/mL before the onset of symptoms and before polyneuropathy could be confirmed neurophysiologically. In symptomatic ATTRv amyloidosis patients on a TTR-stabiliser, sNfL remained stable over 2 years. In patients on a TTR-silencer, sNfL decreased after 1 year of treatment.
UNASSIGNED: sNfL is a biomarker of early neuronal damage in ATTRv amyloidosis already before the onset of polyneuropathy. Current data support the use of sNfL in screening asymptomatic TTRv carriers and in monitoring of disease progression and treatment effect.

OBJECTIVE: Defining the epidemiology of systemic and cardiac amyloidosis (CA) is a contemporary challenge. The present study aimed to estimate incidence and time trends in amyloidosis-related hospitalizations (AH) in Veneto Region (5 million inhabitants, Northeastern Italy).
METHODS: International Classification of Diseases (ICD-9) codes were used to identify AH in Veneto from 2010 to 2020. AH were defined as any hospitalization with a discharge summary reporting an ICD-9 code for systemic amyloidosis. Hospitalization for CA was defined as records with ICD-9 code for systemic amyloidosis and ICD-9 code for heart failure,cardiomyopathy or arrhythmia. Hospital/outpatient encounters for carpal tunnel syndrome (CTS) surgeries also were extracted. AH incidence was estimated using a buffer of 5 years.
RESULTS: In the time range 2015-2020, the incidence rate of AH was 23.5 cases per 106 (95% confidence interval, CI, 21.8; 25.3), mainly affecting patients>65 years (76.2%) and males (63.5%), with a progressively increasing trend (percent annual increase 17%, 95% CI 12; 22%). The 10 year prevalence of AH in 2020 was 124.5 per 106 (95% CI 114.9; 134.8). In 2020, annual hospitalized prevalent cases of CA were about 70% of all cases (159/228), mainly patients >65 years and males. Among patients with multiple CTS surgeries, a subsequent code for cardiac disease was found in 913 after a median of 3.9 years, more frequently in men than in women (463/6.526 7.1% versus 450/11.406 3.9%).
CONCLUSIONS: In Veneto, we recorded a significantly increasing trend in the incidence of AH, with concordant increasing prevalence estimates.