Epidemiological study of the subtype frequency of systemic amyloidosis listed in the Annual of the Pathological Autopsy Cases in Japan.

Clinical presentation of systemic amyloidosis differs among subtypes, and accurate subtype classification is important for choosing the treatment. Amyloid transthyretin (ATTR) amyloidosis was the predominant among the recently consulted amyloidosis cases in Japan. To reveal the latest subtype frequency of systemic amyloidosis among autopsy cases in Japan. We analyzed systemic amyloidosis cases autopsied from January 2017 to December 2018, that were listed in the Annuals of the Pathological Autopsy Cases in Japan, Volumes 60 and 61. When the subtype was unclear, we performed a questionnaire survey, immunohistochemistry with in-house rabbit polyclonal anti-κ116 - 133 , anti-λ118 -134 , and anti-transthyretin115 -124 antibodies, and proteomic analysis. Out of 481 systemic amyloidosis cases listed in the Annuals, 411 cases were available for analysis (85.4%). We classified 399 of these systemic amyloidosis cases. ATTR was the most common subtype (44.4%, n = 177), followed by amyloid immunoglobulin light chain (AL) (38.8%, n = 155). Amyloid A and amyloid ß2 -microglobulin were 9.3% (n = 37) and 6.0% (n = 24), respectively. Double deposition of amyloid was identified in 1.6% (n = 6). In 168 cases (42.1%), systemic amyloidosis was the main cause of death. Of these cases, AL was the most common subtype (47.6%, n = 80), followed by ATTR (41.1%, n = 69). ATTR is the most predominant subtype among the current autopsy cases in Japan.

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.

Autopsy case with concurrent transthyretin and immunoglobulin amyloidosis.

An 85-year-old man with a history of aortic dissection suddenly fainted, underwent cardiac heart arrest, and died. An autopsy was performed, but the cause of death was not grossly identified. Congo red staining detected amyloid deposits in systemic organs, including the heart, lungs, liver, and kidneys. Immunohistochemical (IHC) analysis revealed immunoglobulin (Ig) λ light chain (-λ) in systemic blood vessels and transthyretin (TTR) in the heart and lungs. Ig-λ was predominantly positive in the blood vessels of the lungs, while TTR was detected in the alveolar septum. In the heart, Ig-λ was positive in the endocardium and blood vessels, and TTR was positive in nodular deposits between cardiomyocytes. The concurrent deposition of Ig-λ and TTR in the heart was further substantiated by laser microdissection (LMD)-liquid chromatography-tandem mass spectrometry (LC-MS/MS) at each deposition site. Despite systemic deposition of Ig-λ, bone marrow biopsy findings were not diagnostic for multiple myeloma. In summary, we present an autopsy case of concurrent Ig-λ and TTR deposition as revealed by IHC and LC-MS/MS. When Congo red staining and IHC results are indeterminate due to the deposition of multiple amyloid proteins, LMD-LC-MS/MS is useful for determining the precursor protein.

Possible mechanisms of polyphosphate-induced amyloid fibril formation of ß2-microglobulin.

Polyphosphate (polyP), which is found in various microorganisms and human cells, is an anionic biopolymer consisting of inorganic phosphates linked by high-energy phosphate bonds. Previous studies revealed that polyPs strongly promoted the amyloid formation of several amyloidogenic proteins; however, the mechanism of polyP-induced amyloid formation remains unclear. In the present study using ß2-microglobulin (ß2m), a protein responsible for dialysis-related amyloidosis, we investigated amyloid formation in the presence of various chain lengths of polyPs at different concentrations under both acidic (pH 2.0 to 2.5) and neutral pH (pH 7.0 to 7.5) conditions. We found that the amyloid formation of ß2m at acidic pH was significantly accelerated by the addition of polyPs at an optimal polyP concentration, which decreased with an increase in chain length. The results obtained indicated that electrostatic interactions between positively charged ß2m and negatively charged polyPs play a major role in amyloid formation. Under neutral pH conditions, long polyP with 60 to 70 phosphates induced the amyloid formation of ß2m at several micromoles per liter, a similar concentration range to that in vivo. Since ß2m with an isoelectric point of 6.4 has a slightly negative net charge at pH 7, polyPs were unlikely to interact with ß2m electrostatically. PolyPs appear to dehydrate water molecules around ß2m under the unfolded conformation, leading to the preferential stabilization of less water-exposed amyloid fibrils. These results not only revealed the pH-dependent mechanism of the amyloid formation of ß2m but also suggested that polyPs play an important role in the development of dialysis-related amyloidosis.

Abdominal Fat Pad Fine-Needle Aspiration for Diagnosis of Cardiac Amyloidosis in Patients with Non-Ischemic Cardiomyopathy.

The diagnosis of cardiac amyloidosis is frequently delayed because histological confirmation is often challenging. Few studies have attempted to clarify the utility and safety of abdominal fat pad fine-needle aspiration (FPFNA) for an initial screening test in patients with suspected cardiac amyloidosis.This study included 77 consecutive patients with suspected non-ischemic cardiomyopathy who had left ventricular dysfunction and/or hypertrophy. All patients underwent abdominal FPFNA and an endomyocardial biopsy. In all patients, the abdominal FPFNA could be performed within less than 5 minutes with no complications; however, in 1 patient (1.3%), the obtained specimen was too small to evaluate. Among the remaining 76 patients, 5 (6.6%) were positive for amyloid (FPFNA[+]) and 7 (9.2%), including the 5 FPFNA[+], were diagnosed with cardiac amyloidosis (AL = 1, ATTR = 6) by endomyocardial biopsy. Positive abdominal FPFNAs indicated cardiac amyloidosis with high accuracy (sensitivity, 71.4%; specificity, 100%).Positive abdominal FPFNAs are directly linked to diagnoses of cardiac amyloidosis. Abdominal FPFNA is simple and useful for the initial screening test for cardiac amyloidosis in patients with non-ischemic cardiomyopathy.

Heating during agitation of ß2-microglobulin reveals that supersaturation breakdown is required for amyloid fibril formation at neutral pH.

Amyloidosis-associated amyloid fibrils are formed by denatured proteins when supersaturation of denatured proteins is broken. ß2-Microglobulin (ß2m) forms amyloid fibrils and causes dialysis-related amyloidosis in patients receiving long-term hemodialysis. Although amyloid fibrils of ß2m in patients are observed at neutral pH, formation of ß2m amyloids in vitro has been difficult to discern at neutral pH because of the amyloid-resistant native structure. Here, to further understand the mechanism underlying in vivo amyloid formation, we investigated the relationship between protein folding/unfolding and misfolding leading to amyloid formation. Using thioflavin T assays, CD spectroscopy, and transmission EM analyses, we found that ß2m efficiently forms amyloid fibrils even at neutral pH by heating with agitation at high-salt conditions. We constructed temperature- and NaCl concentration-dependent conformational phase diagrams in the presence or absence of agitation, revealing how amyloid formation under neutral pH conditions is related to thermal unfolding and breakdown of supersaturation. Of note, after supersaturation breakdown and following the law of mass action, the ß2m monomer equilibrium shifted to the unfolded state, destabilizing the native state and thereby enabling amyloid formation even under physiological conditions with a low amount of unfolded precursor. The amyloid fibrils depolymerized at both lower and higher temperatures, resembling cold- or heat-induced denaturation of globular proteins. Our results suggest an important role for heating in the onset of dialysis-related amyloidosis and related amyloidoses.

Chronic hypoxia exacerbates diabetic glomerulosclerosis through mesangiolysis and podocyte injury in db/db mice.

BACKGROUND: Chronic hypoxia may play a pivotal role in the development of diabetic nephropathy (DN). However, the precise mechanisms underlying progressive hypoxia-induced glomerular injury remain unclear. METHODS: We housed db/db mice in a hypoxia chamber (12% O2) for up to 16 weeks beginning at 8 weeks of age. Various urine, serum and kidney abnormalities and glomerular messenger RNA (mRNA) expression were compared with those in age-matched db/db mice housed under normoxia. RESULTS: Levels of urinary albumin and podocalyxin (PCX) were significantly higher in hypoxic mice early during hypoxia. Ultracentrifugation of urine samples revealed that podocytes in the hypoxic mice shed PCX-positive microparticles into the urine. After 16 weeks of hypoxia, the mice also had higher hematocrits with lower serum glucose and various degrees of mesangiolytic glomerulosclerosis with microaneurysms and the infrequent occurrence of nodular lesions. Immunohistologically, hypoxic mice showed significantly decreased endothelial cell densities early during hypoxia and decreased podocyte densities later. In both hypoxic and normoxic mice, glomerular macrophage and transforming growth factor-ß1 (TGF-ß1) staining significantly increased with aging, without changes in vascular endothelial growth factor or endothelial nitric oxide synthase (eNOS). Glomerular mRNA expression of monocyte chemoattractant protein-1, eNOS and TGF-ß1 was significantly enhanced in the hypoxic mice. CONCLUSIONS: These results indicate that chronic hypoxia induces advanced glomerulosclerosis with accelerated albuminuria triggered by mesangiolysis and podocyte injury in a murine model of DN.

Human amyloidosis, still intractable but becoming curable: The essential role of pathological diagnosis in the selection of type-specific therapeutics.

The molecular pathogenesis of human amyloidosis has been elucidated greatly during the last 20 years. Based on the understanding of the molecular mechanisms of amyloid fibril formation and deposition, various kinds of new drugs and therapeutics have been emerging to improve the prognosis of amyloidosis and even cure this disease. In this review article, we first summarize the pathogenesis and state-of-the-art therapeutics of representative types of systemic human amyloidosis, that is, immunoglobulin light chain-related, transthyretin-related, amyloid A-associated and ß2 -microglobulin-related amyloidosis. Next, we describe the essential roles of pathological diagnosis, especially the typing diagnosis of amyloidosis to appropriately guide type-specific therapies of amyloidosis patients. Finally, we introduce the activities of the government-funded group for surveys and research of amyloidosis in Japan, especially the nation-wide pathology consultation system of amyloidosis, which started in April 2018. The nation-wide improvement of the typing diagnosis of amyloidosis is essential for the appropriate treatment and care of amyloidosis patients in Japan.

Amyloid Formation under Complicated Conditions in Which ß2-Microglobulin Coexists with Its Proteolytic Fragments.

Amyloid formation in vivo occurs under complicated conditions in which various amyloidogenic and non-amyloidogenic components coexist, often under crowding. Controversy surrounds the role of additional components under complicated conditions. They have been suggested to accelerate amyloid formation because molecular crowding or interactions with additives increase effective concentrations and, thus, break the supersaturation of amyloidogenic proteins. On the other hand, cellular crowding conditions with various heterogeneous components may retard or prevent amyloid formation because they impede homologous amyloidogenic associations. To elucidate the roles of these additional components, we examined the amyloid formation of ß2-microglobulin (ß2m), a protein responsible for dialysis-related amyloidosis, with a simplified model system in which intact ß2m and its proteolytic peptides coexist. Among the nine proteolytic peptides of ß2m produced in vitro with lysyl endopeptidase, the 22-residue K3 peptide is highly amyloidogenic. The amyloid formation of the K3 peptide, which occurred with a lag time of 1 h at pH 2 and 37 °C, was significantly retarded by the coexistence of ß2m or a mixture of the proteolytic digests. To identify the sites of inhibitory interactions, we performed paramagnetic relaxation enhancement measurements using spin-labeled K3 and uniformly 15N-labeled ß2m with nuclear magnetic resonance detection. The results revealed that K3 interacted weakly with a broad cluster of the hydrophobic residues of ß2m, which accommodated the residues located in some distant sequence, leading to competitive inhibition. The results showed that relatively weak and broad interactions formed a nonproductive complex, implying a role for heterogeneous interactions under complicated conditions.

Aggregation-phase diagrams of ß2-microglobulin reveal temperature and salt effects on competitive formation of amyloids versus amorphous aggregates.

Several serious diseases are associated with crystal-like amyloid fibrils or glass-like amorphous aggregates of denatured proteins. However, protein aggregation involving both types of aggregates has not yet been elucidated in much detail. Using a protein associated with dialysis-related amyloidosis, ß2-microglobulin (ß2m), we previously demonstrated that amyloid fibrils and amorphous aggregates form competitively depending on salt (NaCl) concentration. To examine the generality of the underlying competitive mechanisms, we herein investigated the effects of heat on acid-denatured ß2m at pH 2. Using thioflavin fluorescence, CD, and light scattering analysis along with atomic force microscopy imaging, we found that the temperature-dependent aggregation of ß2m markedly depends on NaCl concentration. Stepwise transitions from monomers to amyloids and then back to monomers were observed at low NaCl concentrations. Amorphous aggregates formed rapidly at ambient temperatures at high NaCl concentrations, but the transition from amorphous aggregates to amyloids occurred only as the temperature increased. Combining the data from the temperature- and NaCl-dependent transitions, we constructed a unified phase diagram of conformational states, indicating a parabolic solubility curve with a minimum NaCl concentration at ambient temperatures. Although amyloid fibrils formed above this solubility boundary, amorphous aggregates dominated in regions distant from this boundary. Kinetic competition between supersaturation-limited slow amyloid fibrillation and supersaturation-unlimited fast amorphous aggregation deformed the phase diagram, with amyloid regions disappearing with fast titration rates. We conclude that phase diagrams combining thermodynamics and kinetics data provide a comprehensive view of ß2m aggregation exhibiting severe hysteresis depending on the heat- or salt-titration rates.

C-terminal sequence of amyloid-resistant type F apolipoprotein A-II inhibits amyloid fibril formation of apolipoprotein A-II in mice.

In murine senile amyloidosis, misfolded serum apolipoprotein (apo) A-II deposits as amyloid fibrils (AApoAII) in a process associated with aging. Mouse strains carrying type C apoA-II (APOA2C) protein exhibit a high incidence of severe systemic amyloidosis. Previously, we showed that N- and C-terminal sequences of apoA-II protein are critical for polymerization into amyloid fibrils in vitro. Here, we demonstrate that congenic mouse strains carrying type F apoA-II (APOA2F) protein, which contains four amino acid substitutions in the amyloidogenic regions of APOA2C, were absolutely resistant to amyloidosis, even after induction of amyloidosis by injection of AApoAII. In vitro fibril formation tests showed that N- and C-terminal APOA2F peptides did not polymerize into amyloid fibrils. Moreover, a C-terminal APOA2F peptide was a strong inhibitor of nucleation and extension of amyloid fibrils during polymerization. Importantly, after the induction of amyloidosis, we succeeded in suppressing amyloid deposition in senile amyloidosis-susceptible mice by treatment with the C-terminal APOA2F peptide. We suggest that the C-terminal APOA2F peptide might inhibit further extension of amyloid fibrils by blocking the active ends of nuclei (seeds). We present a previously unidentified model system for investigating inhibitory mechanisms against amyloidosis in vivo and in vitro and believe that this system will be useful for the development of novel therapies.

Tubulointerstitial Nephritis with IgM-Positive Plasma Cells.

Infiltration by IgG-positive plasma cells is a common finding in tubulointerstitial nephritis. Indeed, it has been thought that CD138-positive mature plasma cells secrete mainly IgG, and the occurrence of tubulointerstitial nephritis with CD138-positive plasma cells secreting IgM has rarely been reported. Routine immunofluorescence of fresh frozen sections is considered the gold standard for detection of immune deposits. However, the immunoenzyme method with formalin-fixed, paraffin-embedded sections is superior for detecting IgM- or IgG-positive cells within the renal interstitium, thus histologic variants may often go undetected. We recently discovered a case of tubulointerstitial nephritis showing IgM-positive plasma cell accumulation within the interstitium. To further explore the morphologic and clinical features of such cases, we performed a nationwide search for patients with biopsy-proven tubulointerstitial nephritis and high serum IgM levels. We identified 13 patients with tubulointerstitial nephritis and IgM-positive plasma cell infiltration confirmed with the immunoenzyme method. The clinical findings for these patients included a high prevalence of distal renal tubular acidosis (100%), Fanconi syndrome (92%), and anti-mitochondrial antibodies (82%). The pathologic findings were interstitial nephritis with diffusely distributed CD3-positive T lymphocytes and colocalized IgM-positive plasma cells, as well as tubulitis with CD3-positive T lymphocytes in the proximal tubules and collecting ducts. Additionally, levels of H+-ATPase, H+, K+-ATPase, and the HCO3--Cl- anion exchanger were markedly decreased in the collecting ducts. We propose to designate this group of cases, which have a common histologic and clinical form, as IgM-positive plasma cell-tubulointerstitial nephritis.

Treatment with Geranylgeranylacetone Induces Heat Shock Protein 70 and Attenuates Neonatal Hyperoxic Lung Injury in a Model of Bronchopulmonary Dysplasia.

PURPOSE: Bronchopulmonary dysplasia (BPD) is a respiratory complication characterized by abnormal alveolar development in premature infants. Geranylgeranylacetone (GGA) can induce heat shock protein (HSP) 70, which has cytoprotective effects against various stressors. Here, we investigated whether GGA protected neonatal lungs from hyperoxic stress in a murine BPD model, and measured the serum HSP70 levels in preterm humans treated with oxygen. METHODS: Newborn mice were exposed to >90% oxygen and administered GGA or vehicle alone orally on days 1, 2, and 3 of life. At 2 days of age, HSP70 expression in the lung was determined by western blotting. At 8 days of age, the lungs were processed for histological analysis. Radial alveolar count (RAC) and mean linear intercept (MLI) were measured as parameters of alveolarization. Apoptosis was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method and cleaved caspase-3 immunohistochemistry. Serum HSP70 levels in preterm humans treated with oxygen were measured by enzyme-linked immunosorbent assay. RESULTS: GGA administration enhanced the HSP70 expression to two-fold compared with normoxia-exposed and vehicle-treated mice. Hyperoxia reduced HSP70 expression, whereas GGA abrogated the effects. Hyperoxia-exposed mice exhibited more apoptotic cells in lung parenchyma and a more simplified alveolar structure with less RAC and larger MLI than normoxia-exposed mice. GGA suppressed the increase in apoptotic cells and the structural changes of the lungs induced by hyperoxia. Serum HSP70 levels of preterm human infants gradually decreased with age. CONCLUSIONS: GGA may attenuate hyperoxic injury in neonatal lungs and thereby may prevent the development of BPD.

Newly recognized cerebral infarctions on postmortem imaging: a report of three cases with systemic infectious disease.

BACKGROUND: Postmortem imaging (PMI) refers to the imaging of cadavers by computed tomography (CT) and/or magnetic resonance imaging (MRI). Three cases of cerebral infarctions that were not found during life but were newly recognized on PMI and were associated with severe systemic infections are presented. CASE PRESENTATIONS: An 81-year-old woman with a pacemaker and slightly impaired liver function presented with fever. Imaging suggested interstitial pneumonia and an iliopsoas abscess, and blood tests showed liver dysfunction and disseminated intravascular coagulation (DIC). Despite three-agent combined therapy for tuberculosis, she died 32 days after hospitalization. PMI showed multiple fresh cerebral and cerebellar infarctions and diffuse ground-glass shadows in bilateral lungs. On autopsy, the diagnosis of miliary tuberculosis was made, and non-bacterial thrombotic endocarditis that involved the aortic valve may have caused the cerebral infarctions. A 74-year-old man on steroid therapy for systemic lupus erythematosus presented with severe anemia, melena with no obvious source, and DIC. Imaging suggested intestinal perforation. The patient was treated with antibiotics and drainage of ascites. However, he developed adult respiratory distress syndrome, worsening DIC, and renal dysfunction and died 2 months after admission. PMI showed infiltrative lung shadow, ascites, an abdominal aortic aneurysm, a wide infarction in the right parietal lobe, and multiple new cerebral infarctions. Autopsy examination showed purulent ascites, diffuse peritonitis, invasive bronchopulmonary aspergillosis, and non-bacterial thrombotic endocarditis that likely caused the cerebral infarctions. A 65-year-old man with an old pontine infarction presented with a fever and neutropenia. Despite appropriate treatment, his fever persisted. CT showed bilateral upper lobe pneumonia, pain appeared in both femoral regions, and intramuscular abscesses of both shoulders developed. His pneumonia worsened, his level of consciousness decreased, right hemiplegia developed, and he died. PMI showed a newly diagnosed cerebral infarction in the left parietal lobe. The autopsy revealed bilateral bronchopneumonia, right-sided pleuritis with effusion, an intramuscular abscess in the right thigh, and fresh multiple organ infarctions. Systemic fibrin thrombosis and DIC were also found. Postmortem cultures showed E. coli and Burkholderia cepacia. CONCLUSION: Cerebral infarction that is newly recognized on PMI might suggest the presence of severe systemic infection.

Heat of supersaturation-limited amyloid burst directly monitored by isothermal titration calorimetry.

Amyloid fibrils form in supersaturated solutions via a nucleation and growth mechanism. Although the structural features of amyloid fibrils have become increasingly clearer, knowledge on the thermodynamics of fibrillation is limited. Furthermore, protein aggregation is not a target of calorimetry, one of the most powerful approaches used to study proteins. Here, with ß2-microglobulin, a protein responsible for dialysis-related amyloidosis, we show direct heat measurements of the formation of amyloid fibrils using isothermal titration calorimetry (ITC). The spontaneous fibrillation after a lag phase was accompanied by exothermic heat. The thermodynamic parameters of fibrillation obtained under various protein concentrations and temperatures were consistent with the main-chain dominated structural model of fibrils, in which overall packing was less than that of the native structures. We also characterized the thermodynamics of amorphous aggregation, enabling the comparison of protein folding, amyloid fibrillation, and amorphous aggregation. These results indicate that ITC will become a promising approach for clarifying comprehensively the thermodynamics of protein folding and misfolding.

Molecular pathogenesis of human amyloidosis: Lessons from ß2 -microglobulin-related amyloidosis.

Amyloidosis refers to a group of diseases with amyloid fibrils deposited in various organs and is classified into more than 30 diseases in humans based on the kind of amyloid protein. In order to elucidate the molecular pathogenesis of human amyloidosis, we studied the molecular mechanism of amyloid fibril formation in vitro. We first developed a novel fluorometric method to determine amyloid fibrils in vitro based on the unique characteristics of thioflavin T. We next proposed a nucleation-dependent polymerization model to explain the general mechanism of amyloid fibril formation in vitro. Based on this model, we characterized the biological molecular interactions that promote or inhibit amyloid fibril formation in vitro and developed models of pathological molecular environment for inducing human ß2-microglobulin-related amyloidosis in long-term hemodialysis patients. We also proposed a novel and attractive cytotoxic mechanism of ß2-microglobulin amyloid fibrils, that is, the disruption of endosomal/lysosomal membranes by endocytosed amyloid fibrils. These findings may be useful to elucidate the molecular pathogenesis of other kinds of human amyloidosis.

Supersaturation-Limited and Unlimited Phase Spaces Compete to Produce Maximal Amyloid Fibrillation near the Critical Micelle Concentration of Sodium Dodecyl Sulfate.

Although various natural and synthetic compounds have been shown to accelerate or inhibit the formation of amyloid fibrils, the mechanisms by which they achieve these adverse effects in a concentration-dependent manner currently remain unclear. Sodium dodecyl sulfate (SDS), one of the compounds that has adverse effects on fibrillation, is the most intensively studied. Here we examined the effects of a series of detergents including SDS on the amyloid fibrillation of ß2-microglobulin at pH 7.0, a protein responsible for dialysis-related amyloidosis. In all the detergents examined (i.e., SDS, sodium decyl sulfate, sodium octyl sulfate, and sodium deoxycholate), amyloid fibrillation was accelerated and inhibited at concentrations near the critical micelle concentration (CMC) and higher than CMC, respectively. The most stable conformation changed from monomers with a ß-structure to amyloid fibrils with a ß-structure and then to α-helical complexes with micelles with an increase in detergent concentrations. These results suggest that competition between supersaturation-limited fibrillation and unlimited mixed micelle formation between proteins and micelles underlies the detergent concentration-dependent complexity of amyloid fibrillation.

A heterozygous female with Fabry disease due to a novel α-galactosidase A mutation exhibits a unique synaptopodin distribution in vacuolated podocytes.

We report the case of a 42-yearold woman diagnosed with heterozygous Fabry disease (FD) due to a novel α-galactosidase A Pro210Ser mutation and exhibiting a unique distribution of synaptopodin within podocytes. The patient was referred to our hospital with moderate proteinuria, and a renal biopsy was performed. Light microscopic examination of the specimen revealed diffuse global enlargement of podocytes, which also showed foamy changes. Electron microscopy revealed abundant myeloid bodies in podocytes and focal mitochondrial abnormalities within the tubules. The patient exhibited none of the characteristic symptoms of FD except hypohidrosis and had no obvious family history. Genetic analysis revealed a novel missense mutation (Pro210Ser) in the α-galactosidase A gene. She was ultimately diagnosed with FD based on immunohistochemical staining indicating large amounts of accumulated globotriaosylceramide in her podocytes, detection of urinary globotriaosylceramide secretion using high-performance thin-layer chromatography/ immunostaining, and structural modeling of the mutated α-galactosidase A (Pro210Ser). Immunostaining of the swollen and foamy podocytes using podocyte-associated antibodies (against podocalyxin, Wilms tumor-1, vimentin, and synaptopodin) revealed a unique distribution of synaptopodin surrounding globotriaosylceramide. To our knowledge, this is the first report of immunohistologically detected synaptopodin upregulation in foamy podocytes in a patient with FD.

HBME-1 and CD15 immunocytochemistry in the follicular variant of thyroid papillary carcinoma.

Papillary carcinoma is the most common thyroid malignancy. As the cytological diagnosis of papillary carcinoma is not difficult in patients with the usual type of lesion, fine-needle aspiration (FNA) cytology is an effective method for preoperative evaluation. However, this modality is often ineffective in identifying the follicular variant of papillary thyroid carcinoma (FVPTC) due to its similarity to other follicular lesions and the incompleteness of typical nuclear features. Therefore, we investigated the expression of immunocytochemical markers of papillary carcinoma in cytological specimens of FVPTC and evaluated their utilities. The immunoreactivity of HBME-1 and CD15 was investigated using 50 imprint smear cytological specimens obtained from thyroid lesions, including 13 FVPTC. The sensitivity and specificity of HBME-1 for FVPTC were 92% and 89%, respectively, while those of CD15 were 23% and 100%, respectively. In conclusion, HBME-1 is a sensitive marker of papillary carcinoma, including both usual type and FVPTC, in cytological specimens. Therefore, using HBME-1 immunocytochemistry in FNA cytology will lead to reduction of the incidence of false-negative diagnoses of FVPTC. Although CD15 is apparently inferior in terms of sensitivity for FVPTC, its excellent specificity will support the definitive diagnosis of thyroid malignancies, including FVPTC, after screening with HBME-1.