The Association of Hashimoto Disease and Congo Red Negative Amyloidosis

Light chain deposition disease presenting with gastrointestinal disorder as primary manifestation: report of two cases and literature review

Light chain deposition disease (LCDD) is an under-recognized condition characterized by deposition of abnormal monoclonal light chains in tissues, leading to organ dysfunction. LCDD involving the gastrointestinal tract is very uncommon, and its diagnosis is challenging. We herein report two cases of LCDD that manifested as inflammatory bowel disease-like symptoms and protein-losing gastroenteropathy. Both patients were women in their early 60s. Tissue biopsies from the gastrointestinal mucosa demonstrated extracellular deposits, which were negative by Congo red staining but positive for κ-light chain by immunohistochemistry. The recent literature on LCDD was reviewed. When patients unexpectedly show extracellular deposits in gastrointestinal biopsy specimens, evaluation of immunoglobulin chains is recommended for diagnosis of LCDD after systemic amyloidosis has been excluded.

Downregulation of SLC27A6 by DNA Hypermethylation Promotes Proliferation but Suppresses Metastasis of Nasopharyngeal Carcinoma Through Modulating Lipid Metabolism

Lipid is the building block and an important source of energy, contributing to the malignant behavior of tumor cells. Recent studies suggested that lipid droplets (LDs) accumulations were associated with nasopharyngeal carcinoma (NPC) progression. Solute carrier family 27 member 6 (SLC27A6) mediates the cellular uptake of long-chain fatty acid (LCFA), a necessary lipid component. However, the functions of SLC27A6 in NPC remain unknown. Here, we found a significant reduction of SLC27A6 mRNA in NPC tissues compared with normal nasopharyngeal epithelia (NNE). The promoter methylation ratio of SLC27A6 was greater in NPC than in non-cancerous tissues. The demethylation reagent 5-aza-2'-deoxycytidine (5-aza-dC) remarkably restored the mRNA expression of SLC27A6, suggesting that this gene was downregulated in NPC owing to DNA promoter hypermethylation. Furthermore, SLC27A6 overexpression level in NPC cell lines led to significant suppression of cell proliferation, clonogenicity in vitro, and tumorigenesis in vivo. Higher SLC27A6 expression, on the other hand, promoted NPC cell migration and invasion. In particular, re-expression of SLC27A6 faciliated epithelial-mesenchymal transition (EMT) signals in xenograft tumors. Furthermore, we observed that SLC27A6 enhanced the intracellular amount of triglyceride (TG) and total cholesterol (T-CHO) in NPC cells, contributing to lipid biosynthesis and increasing metastatic potential. Notably, the mRNA level of SLC27A6 was positively correlated with cancer stem cell (CSC) markers, CD24 and CD44. In summary, DNA promoter hypermethylation downregulated the expression of SLC27A6. Furthermore, re-expression of SLC27A6 inhibited the growth capacity of NPC cells but strengthened the CSC markers. Our findings revealed the dual role of SLC27A6 in NPC and shed novel light on the link between lipid metabolism and CSC maintenance.

Early detection of prion protein aggregation with a fluorescent pentameric oligothiophene probe using spectral confocal microscopy

Misfolding of the prion protein (PrP) and templating of its pathological conformation onto cognate proteins causes a number of lethal disorders of central nervous system in humans and animals, such as Creutzfeldt-Jacob disease, chronic wasting disease and bovine spongiform encephalopathy. Structural rearrangement of PrP^C into PrP^Sc promotes aggregation of misfolded proteins into β-sheet-rich fibrils, which can be visualized by conformationally sensitive fluorescent probes. Early detection of prion misfolding and deposition might provide useful insights into its pathophysiology. Pentameric formyl thiophene acetic acid (pFTAA) is a novel amyloid probe that was shown to sensitively detect various misfolded proteins, including PrP. Here, we compared sensitivity of pFTAA staining and spectral microscopy with conventional methods of prion detection in mouse brains infected with mouse-adapted 22L prions. pFTAA bound to prion deposits in mouse brain sections exhibited a red-shifted fluorescence emission spectrum, which quantitatively increased with disease progression. Small prion deposits were detected as early as 50 days post-inoculation, well before appearance of clinical signs. Moreover, we detected significant spectral shifts in the greater brain parenchyma as early as 25 days post-inoculation, rivaling the most sensitive conventional method (real-time quaking-induced conversion). These results showcase the potential of pFTAA staining combined with spectral imaging for screening of prion-infected tissue. Not only does this method have comparable sensitivity to established techniques, it is faster and technically simpler. Finally, this readout provides valuable information about the spatial distribution of prion aggregates across tissue in the earliest stages of infection, potentially providing valuable pathophysiological insight into prion transmission.

Analysis of risk factors for progressive fibrovascular proliferation in proliferative diabetic retinopathy

PURPOSE

To investigate the risk factors associated with progressive fibrovascular proliferation (FVP) in proliferative diabetic retinopathy (PDR).

METHODS

We retrospectively reviewed the clinical data of patients who underwent pars plana vitrectomy for PDR between August 2017 and October 2019 at our department of ophthalmology. The FVP was divided into five grades based on the coverage area of proliferative membrane. Then we compared the patients with different severities of FVP to analyze the risk factors for higher grade of FVP in PDR.

RESULTS

Univariate analysis showed that positive urinary protein (p = 0.007), higher levels of serum blood urea nitrogen (BUN) (p < 0.001) and serum creatinine (p < 0.001), more severe stage of estimated glomerular filtration rate (p < 0.001), age < 45 years (p = 0.005), longer duration of diabetic retinopathy (p = 0.007), history of hypertension (p = 0.034) and smoking (p = 0.008) were related to FVP grade ≥ 3. Multivariate analysis showed that the level of BUN, age < 45 years and smoking were independent risk factors for FVP grade ≥ 3 in PDR patients.

CONCLUSION

This study demonstrated that BUN (odds ratio [OR] = 1.318, 95% confidence interval [CI] = 1.150-1.511, p < 0.001), age ≤ 45 years (OR = 3.774, 95% CI = 1.762-8.082, p = 0.001) and smoking (OR = 2.111, 95% CI = 1.040-4.288, p = 0.039) were independent risk factors for progressive FVP in PDR among northeastern Chinese patients.

Amyloid Goiter Secondary to Ulcerative Colitis

Diffuse amyloid goiter (AG) is an entity characterized by the deposition of amyloid in the thyroid gland. AG may be associated with either primary or secondary amyloidosis. Secondary amyloidosis is rarely caused by inflammatory bowel diseases. Secondary amyloidosis is relatively more common in the patients with Crohn's disease, whereas it is highly rare in patients with ulcerative colitis. Diffuse amyloid goiter caused by ulcerative colitis is also a rare condition. In the presence of amyloid in the thyroid gland, medullary thyroid cancer should be kept in mind in the differential diagnosis. Imaging techniques and biochemical tests are not very helpful in the diagnosis of secondary amyloid goiter and the definitive diagnosis is established based on the histopathologic analysis and histochemical staining techniques. In this report, we present a 35-year-old male patient with diffuse amyloid goiter caused by secondary amyloidosis associated with ulcerative colitis.

Coexistent findings of renal glomerular disease with Hashimoto's thyroiditis

AIM AND BACKGROUND

Hashimoto's thyroiditis (HT) is a common autoimmune thyroid disease with a female preponderance. Renal involvement in HT is not uncommon. In the present study, we aimed to define the frequency and characteristics of the glomerular diseases associated with HT and further the understanding of any common pathogenesis between HT and glomerular disease.

MATERIALS AND METHODS

We reviewed retrospectively 28 patients with HT who were referred to our Department because of unexplained haematuria, proteinuria or renal impairment from 2007 to 2011. Routine laboratory investigations including blood count, serum biochemistry, urinalysis and 24-h urinary protein excretion were performed on all patients. Renal biopsy was performed in 20 patients with HT, and the specimens were examined by light microscopy and immunofluorescence staining.

RESULTS

We detected four cases of focal segmental glomerulosclerosis (FSGS), four membranous glomerulonephritis (MGN), two minimal-change disease (MCD), three immunoglobulin A nephritis (IgAN), three chronic glomerulonephritis (CGN) and one amyloidosis. In three patients, the renal biopsy findings were nonspecific. Daily urinary protein excretion and glomerular filtration rates were found to be independent of the level of thyroid hormone and thyroid-specific autoantibodies.

CONCLUSION

Glomerular pathologies associated with HT are similar to those in the general population, the most common lesions being MGN, FSGS and IgA nephritis.

Binding mode of Thioflavin T and other molecular probes in the context of amyloid fibrils-current status

Because understanding amyloid fibrillation in molecular detail is essential for development of strategies to control amyloid formation and overcome neurodegenerative disorders, increased understanding of present molecular probes as well as development of new probes are of utmost importance. To date, the binding modes of these molecular probes to amyloid fibrils are by no means adequately described or understood, and the large number of studies on Thioflavin T (ThT) and Congo Red (CR) binding have resulted in models that are incomplete and conflicting. Different types of binding sites are likely to be present in amyloid fibrils with differences in binding modes. ThT may bind in channels running parallel to the long axis of the fibril. In the channels, ThT may bind in either a monomeric or dimeric form of which the molecular conformation is likely to be planar. CR may bind in grooves formed along the β-sheets as a planar molecule in either a monomeric or supramolecular form.

[Peritoneal AA amyloidosis simulating peritoneal carcinomatosis: a case report]

Amyloidosis is a group of deposition diseases that are classified according to the type of fibers accumulated and their characteristics. It can affect any organ. The clinical presentation depends on the organs and systems involved. We present the case of a patient with a history of Hashimoto's thyroiditis and systemic symptoms who presented with abdominal pain. Physical examination detected a palpable mass in the umbilical region. CT showed thickening of the wall of the colon with infiltration of the adjacent peritoneum and extension to the root of the mesentery with abundant ascites. The histological diagnosis was peritoneal AA amyloidosis.