scholarly journals Pathology and Proteomics-Based Diagnosis of Localized Light-Chain Amyloidosis in Dogs and Cats

2020 ◽  
Vol 57 (5) ◽  
pp. 658-665
Author(s):  
Ayumi Kadota ◽  
Susumu Iwaide ◽  
Shinya Miyazaki ◽  
Ikki Mitsui ◽  
Noboru Machida ◽  
...  

Amyloidosis is classified according to the amyloid precursor protein, and accurate diagnosis of the amyloidosis type may guide appropriate treatment. Immunohistochemistry and Congo red staining are the most frequently used methods used to distinguish types of amyloidosis, but problems with specificity and sensitivity indicate the need for an alternative diagnostic method. In this study, we evaluated laser microdissection-liquid chromatography-tandem mass spectrometry (LMD-LC-MS/MS) for the diagnosis of amyloid light-chain (AL) amyloidosis in animals. Plasmacytomas with amyloid deposits from 15 dogs and 2 cats were subjected to Congo red staining with or without potassium permanganate pretreatment, immunohistochemistry for kappa and lambda light chains, and LMD-LC-MS/MS. Congo red staining was diagnostic in 12 of 17 cases based on resistance to potassium permanganate pretreatment, but in 5 of 17 cases the pretreatment unexpectedly reduced Congo red staining or abrogated the birefringence and a definitive diagnosis could not be reached. Immunohistochemistry detected kappa or lambda light chains in 6 of 17 cases. With LMD-LC-MS/MS, immunoglobulin lambda light chain was detected in all 17 cases. The amyloid signature proteins ApoA-I, ApoA-IV, and ApoE were detected in 9, 1, and 3 of the 15 canine cases by LMD-LC-MS/MS, but not in the feline cases. In conclusion, LMD-LC-MS/MS consistently determined the amyloid type in all examined specimens, while Congo red staining after potassium permanganate treatment and immunohistochemistry were less sensitive tests.

2018 ◽  
Vol 12 (2) ◽  
pp. 317-321 ◽  
Author(s):  
Matthew Hoscheit ◽  
Afrin Kamal ◽  
Michael Cline

Systemic amyloidosis is a group of complex disorders characterized by the extracellular deposition of nonbranching fibrils in various tissues, ultimately leading to a variety of clinical presentations including isolated or multiorgan dysfunction. Amyloid involvement of the gastrointestinal tract is common depending on the subtype of this disease; light chain primary amyloidosis (AL) and secondary amyloidosis (AA) affect the gastrointestinal tract in unique ways due to differing pathophysiology. A case is reported of gastroparesis associated with AL amyloidosis diagnosed by esophagogastroduodenoscopy and study of gastric emptying, then subsequently confirmed by Congo red staining performed on endoscopic biopsies.


1996 ◽  
Vol 33 (4) ◽  
pp. 428-430 ◽  
Author(s):  
A. D. Gruber ◽  
R. P. Linke

Generalized amyloidosis was found to be the cause of death in a female adult insectivorous pipistrelle bat ( Pipistrellus pipistrellus) after chronic wound inflammation. Large amounts of amyloid were detected in liver, spleen, kidneys, stomach, intestine, lymphatic tissues, and endocrine and salivary glands. Congo red staining and green birefringence identified amyloid; the Congo red staining was sensitive to potassium permanganate oxidation. The amyloid was further classified immunohistochemically. The deposits reacted with two anti-human-AA-amyloid monoclonal antibodies in a peroxidase-antiperoxidase reaction, whereas no reaction was found with antibodies specific for other types of amyloid. Thus, the bat amyloid deposits were identified as generalized reactive AA-amyloidosis.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3571
Author(s):  
Gareth J. Morgan

Inhibition of amyloid fibril formation could benefit patients with systemic amyloidosis. In this group of diseases, deposition of amyloid fibrils derived from normally soluble proteins leads to progressive tissue damage and organ failure. Amyloid formation is a complex process, where several individual steps could be targeted. Several small molecules have been proposed as inhibitors of amyloid formation. However, the exact mechanism of action for a molecule is often not known, which impedes medicinal chemistry efforts to develop more potent molecules. Furthermore, commonly used assays are prone to artifacts that must be controlled for. Here, potential mechanisms by which small molecules could inhibit aggregation of immunoglobulin light-chain dimers, the precursor proteins for amyloid light-chain (AL) amyloidosis, are studied in assays that recapitulate different aspects of amyloidogenesis in vitro. One molecule reduced unfolding-coupled proteolysis of light chains, but no molecules inhibited aggregation of light chains or disrupted pre-formed amyloid fibrils. This work demonstrates the challenges associated with drug development for amyloidosis, but also highlights the potential to combine therapies that target different aspects of amyloidosis.


2009 ◽  
Vol 55 (3) ◽  
pp. 499-504 ◽  
Author(s):  
Giovanni Palladini ◽  
Paola Russo ◽  
Tiziana Bosoni ◽  
Laura Verga ◽  
Gabriele Sarais ◽  
...  

Abstract Background: The diagnosis of systemic immunoglobulin light-chain (AL) amyloidosis requires demonstration of amyloid deposits in a tissue biopsy and amyloidogenic monoclonal light chains. The optimal strategy to identify the amyloidogenic clone has not been established. We prospectively assessed the diagnostic sensitivity of the serum free light chain (FLC) κ/λ ratio, a commercial serum and urine agarose gel electrophoresis immunofixation (IFE), and the high-resolution agarose gel electrophoresis immunofixation (HR-IFE) developed at our referral center in patients with AL amyloidosis, in whom the amyloidogenic light chain was unequivocally identified in the amyloid deposits. Methods: The amyloidogenic light chain was identified in 121 consecutive patients with AL amyloidosis by immunoelectron microscopy analysis of abdominal fat aspirates and/or organ biopsies. We characterized the monoclonal light chain by using IFE and HR-IFE in serum and urine and the FLC κ/λ ratio in serum. We then compared the diagnostic sensitivities of the 3 assays. Results: The HR-IFE of serum and urine identified the amyloidogenic light chain in all 115 patients with a monoclonal gammopathy. Six patients with a biclonal gammopathy were omitted from the statistical analysis. The diagnostic sensitivity of commercial serum and urine IFE was greater than that of the FLC κ/λ ratio (96% vs 76%). The combination of serum IFE and the FLC assay detected the amyloidogenic light chain in 96% of patients. The combination of IFE of both serum and urine with the FLC κ/λ ratio had a 100% sensitivity. Conclusions: The identification of amyloidogenic light chains cannot rely on a single test and requires the combination of a commercially available FLC assay with immunofixation of both serum and urine.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 5007-5007 ◽  
Author(s):  
Andrew J Cowan ◽  
Martha Skinner ◽  
J. Mark Sloan ◽  
John L Berk ◽  
Carl J O'Hara ◽  
...  

Abstract Abstract 5007 Introduction: Amyloidosis is characterized by extracellular deposition of abnormal insoluble fibrillar proteins. The two most frequent systemic amyloidoses are the light-chain (AL amyloidosis) and familial transthyretin (ATTR) forms. Clinical presentations often vary between the two types. Macroglossia is viewed as pathognomic of AL amyloidosis, and has not previously been described in patients with hereditary TTR amyloidosis. Here, we describe two cases of systemic amyloidosis with macroglossia in which immuno-electron microscopy diagnosed ATTR in one and AL in the other. Case Presentations: A 61 year old woman presented initially to her general internist with weight loss, difficulty swallowing, and tongue numbness. Her clinical exam revealed macroglossia and peripheral neuropathy. Tongue and axillary lymph node biopsies demonstrated amyloid deposits by Congo red staining. There was no evidence of renal, cardiac or other vital organ involvement. She had no evidence of a plasma cell dyscrasia with negative serum and urine immunofixation electrophoresis, normal serum free light chain concentration and ratio as well as polytypic plasma cells in the bone marrow. Immuno-electron microscopy using gold-labeled antibodies was performed on the tongue biopsy. The fibrils were immunoreactive with anti-TTR but not anti-kappa, anti-lambda, or anti-AA antibodies. DNA sequencing identified a known amyloidogenic T60A TTR mutation in exon 3 of chromosome 18, confirming the diagnosis of ATTR with amyloidotic polyneuropathy and macroglossia. The second case involved a 59 year old man with renal insufficiency. He complained of fatigue, weight loss, and tongue swelling. Physical examination was significant for macroglossia and submandibular gland enlargement. Tongue biopsy demonstrated amyloid deposits by Congo red staining. As in the previous case, markers of plasma cell dyscrasia with clonal plasma cells in the bone marrow, blood, and urine were absent. Immuno-electron microscopy of the tongue biopsy documented antibody reactivity to lambda light chain and not TTR, kappa light chain or AA proteins, confirming the diagnosis of AL amyloidosis. He subsequently underwent treatment with high dose intravenous melphalan followed by stem cell transplantation achieving a good clinical response sustained for 2 years to date. Discussion: While macroglossia is thought to be pathognomonic of AL amyloidosis, we report a case of macroglossia with fibrillar ATTR amyloid deposits diagnosed by immuno-electron microscopy. This is contrasted with a clinical presentation consistent with AL in which routine laboratory testing failed to identify evidence of a plasma cell dyscrasia. In both cases, electron microscopy demonstrated immunoreactivity for the fibrils of a single pathogenic protein. The first case was confirmed by DNA sequencing, and the second had a typical response to anti-plasma cell chemotherapy, in spite of the lack of identifiable markers of disease. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 14 (4) ◽  
pp. e241282
Author(s):  
Karen Tsai ◽  
Alice Chen Yu ◽  
Masha J Livhits ◽  
Dipti Sajed ◽  
Angela M Leung ◽  
...  

A 74-year-old woman with a history of primary hyperparathyroidism, thyroid nodules, atrial fibrillation and pacemaker placement for sick sinus syndrome presented with fatigue, constipation and persistent lower extremity oedema. She underwent subtotal parathyroidectomy and left thyroid lobectomy. Histopathology revealed amyloidosis affecting the thyroidand parathyroids confirmed by Congo Red Staining with Mayo Clinic subtyping of light chain kappa-type amyloidosis. She was found to have combined systolic and diastolic cardiac dysfunction, carpal tunnel neuropathy and pre-diabetes suggestive of systemic amyloidosis with involvement of the heart, nerves and pancreas. Congo red stain was positive for amyloidosis on bone marrow biopsy suggestive of a diagnosis of systemic amyloidosis. She was treated with daratumumab with good clinical response. This case illustrates the necessity of considering systemic amyloidosis in patients with incidentally discovered diffuse amyloid deposits on biopsy of an endocrine organ, as endocrine effects are a rare but likely underdiagnosed consequence of systemic amyloidosis.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4375-4375 ◽  
Author(s):  
Faye Amelia Sharpley ◽  
Hannah Victoria Giles ◽  
Richa Manwani ◽  
Shameem Mahmood ◽  
Sajitha Sachchithanantham ◽  
...  

Introduction Early diagnosis, effective therapy and precise monitoring are central for improving clinical outcomes in systemic light chain (AL) amyloidosis. Diagnosis and disease response assessment is primarily based on the presence of monoclonal immunoglobulins and free light chains (FLC). The ideal goal of therapy associated with best outcomes is a complete responses (CR), defined by the absence of serological clonal markers. In both instances, detection of the monoclonal component (M-component) is based on serum FLC assessment together with traditional serum and urine electrophoretic approaches, which present inherent limitations and lack sensitivity particularly in AL where the levels are typically low. Novel mass spectrometry methods provide sensitive, accurate identification of the M-component and may prove instrumental in the timely management of patients with low-level amyloidogenic light chain production. Here we assess the performance of quantitative immunoprecipitation FLC mass spectrometry (QIP-FLC-MS) at diagnosis and during monitoring of AL amyloidosis patients treated with bortezomib-based regimens. Methods We included 46 serial patients with systemic AL amyloidosis diagnosed and treated at the UK National Amyloidosis Centre (UK-NAC). All patients had detailed baseline assessments of organ function and serum FLC measurements. Baseline, +6- and +12-month serum samples were retrospectively analysed by QIP-FLC-MS. Briefly, magnetic microparticles were covalently coated with modified polyclonal sheep antibodies monospecific for free kappa light chains (anti-free κ) and free lambda light chains (anti-free λ). The microparticles were incubated with patient sera, washed and treated with acetic acid (5% v/v) containing TCEP (20 mM) in order to elute FLC in monomeric form. Mass spectra were acquired on a MALDI-TOF-MS system (Bruker, GmbH). Results were compared to serum FLC measurements (Freelite®, The Binding Site Group Ltd), as well as electrophoretic assessment of serum and urine proteins (SPE, sIFE, UPE and uIFE). Results Cardiac (37(80%) patients) and renal (31(67%) patients) involvement were most common; 25(54%) patients presented with both. Other organs involved included liver (n=12), soft tissue (n=4), gastrointestinal tract (n=3) and peripheral nervous system (n=2). Baseline Freelite, SPE, sIFE and uIFE measurements identified a monoclonal protein in 42(91%), 22(48%), 34(74%) and 21(46%) patients, respectively. A panel consisting of Freelite + sIFE identified the M-component in 100% of the samples. QIP-FLC-MS alone also identified an M-component in 100% of the samples and was 100% concordant with Freelite for typing the monoclonal FLC (8 kappa, 34 lambda). In 4 patients, QIP-FLC-MS identified an additional M-protein that was not detected by the other techniques. In addition, 4/8(50%) kappa and 4/38(11%) lambda patients showed a glycosylation pattern of monoclonal FLCs at baseline by mass spectrometry. Interestingly, the frequency of renal involvement was significantly lower for patients with non-glycosylated forms (25% vs 76%, p=0.01), while no similar relationship was found for any other organs. During the 1-year follow-up period, 17 patients achieved a CR; QIP-FLC-MS identified serum residual disease in 13(76%) of these patients. Conclusion In our series, QIP-FLC-MS was concordant with current serum methods for identifying the amyloidogenic light chain type and provided, against all other individual tests, improved sensitivity for the detection of the monoclonal protein at diagnosis and during monitoring. The ability to measure the unique molecular mass of each monoclonal protein offers clone-specific tracking over time. Glycosylation of free light chains is over-represented in AL patients which may allow earlier diagnosis and better risk-assessment of organ involvement. Persistence of QIP-FLC-MS positive M component in patients otherwise in CR may allow targeted therapy. Overall, QIP-FLC-MS demonstrates potential to be exploited as a single serum test for precise serial assessment of monoclonal proteins in patients with AL amyloidosis. Disclosures Wechalekar: GSK: Honoraria; Janssen-Cilag: Honoraria; Amgen: Research Funding; Takeda: Honoraria; Celgene: Honoraria.


1981 ◽  
Vol 18 (2) ◽  
pp. 181-187 ◽  
Author(s):  
B. L. Yano ◽  
K. H. Johnson ◽  
D. W. Hayden

Amyloid in islets of Langerhans from 48 domestic cats, one human, one non-human primate, and one raccoon was compared with secondary systemic amyloid from three domestic cats, one dog, one human, and one cow to determine affinity for Congo red dye after treatment of paraffin-embedded tissue sections with potassium permanganate and dilute sulfuric acid. Insular amyloid from all six species was resistant to pretreatment with potassium permanganate, i.e., affinity for Congo red was retained, whereas secondary systemic amyloid from all species was sensitive to the potassium permanganate pretreatment. Other stains did not distinguish between insular and secondary systemic amyloid. The potassium permanganate-Congo red staining procedure thus can be used to differentiate insular from secondary systemic amyloid in the cat and other species. The results also indicate that insular amyloid and secondary systemic amyloid are of different chemical composition and pathogenesis.


2006 ◽  
Vol 6 ◽  
pp. 154-168 ◽  
Author(s):  
M. Bély

Amyloidosis is characterized by extracellular deposition of protein fibrils of chemically heterogeneous composition. Early recognition and identification of amyloid deposits allows an early start of therapy, which may entail a better prognosis. Congo red staining according to Romhányi (1971) is a highly specific and sensitive method for early microscopic recognition of amyloidosis. The main and most important types of amyloidosis may be distinguished by classic histochemical methods of performate pretreatment according to Romhányi (1979), or by KMnO4oxidation according to Wright (1977) followed by Congo red staining and viewed under polarized light. Differences in the speed of breakdown (disintegration) of amyloid deposits according to Bély and Apáthy allow a more precise distinction of various types of amyloid.


2019 ◽  
Vol 141 (2) ◽  
pp. 93-106 ◽  
Author(s):  
Iuliana Vaxman ◽  
Morie Gertz

The term amyloidosis refers to a group of disorders in which protein fibrils accumulate in certain organs, disrupt their tissue architecture, and impair the function of the effected organ. The clinical manifestations and prognosis vary widely depending on the specific type of the affected protein. Immunoglobulin light-chain (AL) amyloidosis is the most common form of systemic amyloidosis, characterized by deposition of a misfolded monoclonal light-chain that is secreted from a plasma cell clone. Demonstrating amyloid deposits in a tissue biopsy stained with Congo red is mandatory for the diagnosis. Novel agents (proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, venetoclax) and autologous stem cell transplantation, used for eliminating the underlying plasma cell clone, have improved the outcome for low- and intermediate-risk patients, but the prognosis for high-risk patients is still grave. Randomized studies evaluating antibodies that target the amyloid deposits (PRONTO, VITAL) were recently stopped due to futility and currently there is an intensive search for novel treatment approaches to AL amyloidosis. Early diagnosis is of paramount importance for effective treatment and prognosis, due to the progressive nature of this disease.


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