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1.
Kidney Int ; 97(3): 589-601, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32001067

RESUMO

IgG (mainly IgG3) is the most commonly involved isotype in proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID). Here we describe the first series of PGNMID with deposition of monoclonal immunoglobulin light chain only (PGNMID-light chain). This multicenter cohort of 17 patients presented with nephritic or nephrotic syndrome with underlying hematologic conditions of monoclonal gammopathy of renal significance (71%) or multiple myeloma (29%). Monoclonal immunoglobulin was identified by serum and urine immunofixation in 65% and 73%, respectively, with abnormal serum free light chain in 83%, and a detectable bone marrow plasma cell clone in 88% of patients. Renal biopsy showed a membranoproliferative pattern in most patients. By immunofluorescence, deposits were restricted to glomeruli and composed of restricted light chain (kappa in 71%) and C3, with granular appearance and subendothelial, mesangial and subepithelial distribution by electron microscopy. Proteomic analysis in four cases of kappa PGNMID-light chain revealed spectra for kappa constant and variable domains, without evidence of Ig heavy chains; spectra for proteins of the alternative pathway of complement and terminal complex were detected in three. The classical pathway was not detected in three cases. After median follow up of 70 months, the renal response was dependent on a hematologic response and occurred in six of ten patients treated with plasma cell-directed chemotherapy but none of five patients receiving other therapies. Thus, PGNMID-light chain differs from PGNMID-IgG by higher frequency of a detectable pathogenic plasma cell clone. Hence, proper recognition is crucial as anti-myeloma agents may improve renal prognosis. Activation of an alternative pathway of complement by monoclonal immunoglobulin light chain likely plays a role in its pathogenesis.

3.
Blood Cancer J ; 9(3): 30, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30837451

RESUMO

The amyloidoses are a group of disorders with overlapping clinical presentations, characterized by aggregation and tissue deposition of misfolded proteins. The nature and source of the amyloidogenic protein determines therapy, therefore correct subtyping is critical to patient management. We report the clinicopathologic features of nine patients diagnosed with two amyloid types confirmed by liquid chromatography-coupled tandem mass spectrometry. The most common types were transthyrethin (n = 9) and immunoglobulin-derived (n = 7). Two patients did not have immunoglobulin-derived amyloidosis despite the presence of a monoclonal gammopathy. Eight patients were diagnosed with two types concurrently, and one patient had an 11-year interval between diagnoses. Histopathological distribution of amyloid was variable with vascular, interstitial, and periosteal deposits seen. Identification of a second type was incidental in seven patients, but led to genetic counselling in one patient and therapy directed at both amyloid subtypes in another. With longer survival of myeloma and AL amyloidosis patients and increasing prevalence of patients with wild-type transthyretin amyloidosis due to an aging population, the phenomenon of two amyloid types in a single patient will be encountered more frequently. In light of revolutionary new therapies for transthyretin amyloidosis (patisiran, tafamidis, and inotersen), recognition of dual amyloid types is highly clinically relevant.


Assuntos
Amiloidose/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Cromatografia Líquida , Diagnóstico Diferencial , Feminino , Humanos , Microdissecção e Captura a Laser , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Especificidade de Órgãos , Avaliação de Sintomas
4.
Kidney Int Rep ; 3(5): 1193-1201, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30197986

RESUMO

Introduction: Apolipoprotein CII amyloidosis (AApoCII) is a rare form of amyloidosis. Here, we report a novel mutation associated with AApoCII amyloidosis in 5 patients and describe their clinical, renal biopsy, and mass spectrometry findings. Methods: Five patients with renal AApoCII p.Lys41Thr amyloidosis were identified from our amyloid mass spectrometry cohort. Clinical features, kidney biopsy, and mass spectrometry findings were analyzed in this rare type of amyloidosis. Results: The patients were older adults (mean age of 71.6 years at diagnosis), presented with nephrotic-range proteinuria, and often had declining renal function. All renal biopsy specimens showed massive mesangial nodules composed of weakly eosinophilic, periodic acid-Schiff negative, Congo red-positive amyloid deposits. There were no interstitial, vascular, or medullary deposits. In all cases, immunofluorescence studies were negative for Igs and electron microscopy showed amyloid fibrils. Proteomic analysis of Congo red-positive amyloid deposits detected large amounts of apolipoprotein CII (APOC2) protein. We also detected APOC2 p.Lys41Thr mutant protein in amyloid deposits of all patients. DNA sequencing in 1 patient confirmed the presence of the mutation. Both mutant and wild-type forms of APOC2 were detected in amyloid deposits of all patients. Molecular dynamic simulations showed the variant mediating a collapse of the native structure of APOC2, thereby destabilizing the protein. Conclusion: We propose that AApoCII p.Lys41Thr amyloidosis is a new form of amyloidosis seen in elderly individuals, histologically exhibiting massive glomerular involvement, leading to nephrotic-range proteinuria and progressive chronic kidney disease.

5.
Mayo Clin Proc ; 93(11): 1678-1682, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30093168

RESUMO

Hereditary amyloidosis represents a group of diseases in which mutant proteins are deposited in various organs leading to their dysfunction. Correct identification of the amyloid-causing protein is critical because this will determine the optimal therapy for the patient. The most common type of hereditary amyloidosis is due to mutant transthyretin (ATTRm) deposition and often presents with heart failure or peripheral neuropathy. We report the first known case of a patient who had amyloidosis both due to a mutant transthyretin (p.Val122Ile) and due to a novel variant in the gelsolin gene (p.Ala578Pro). Both mutant proteins were identified by mass spectrometry analysis of amyloid deposits as well as sequencing of the genes. Molecular dynamic simulations suggest that the gelsolin p.Ala578Pro variant is likely amyloidogenic.


Assuntos
Neuropatias Amiloides Familiares/diagnóstico , Neuropatias Amiloides Familiares/genética , Proteínas Amiloidogênicas/genética , Proteínas Amiloidogênicas/isolamento & purificação , Dispneia/etiologia , Gelsolina/genética , Mutação em Linhagem Germinativa , Humanos , Masculino , Pessoa de Meia-Idade , Proteômica
6.
J Am Soc Nephrol ; 29(1): 51-56, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29097623

RESUMO

Fibrillary GN (FGN) is a rare primary glomerular disease. Histologic and histochemical features of FGN overlap with those of other glomerular diseases, and no unique histologic biomarkers for diagnosing FGN have been identified. We analyzed the proteomic content of glomeruli in patient biopsy specimens and detected DnaJ heat shock protein family (Hsp40) member B9 (DNAJB9) as the fourth most abundant protein in FGN glomeruli. Compared with amyloidosis glomeruli, FGN glomeruli exhibited a >6-fold overexpression of DNAJB9 protein. Sanger sequencing and protein sequence coverage maps showed that the DNAJB9 protein deposited in FGN glomeruli did not have any major sequence or structural alterations. Notably, we detected DNAJB9 in all patients with FGN but not in healthy glomeruli or in 19 types of non-FGN glomerular diseases. We also observed the codeposition of DNAJB9 and Ig-γ Overall, these findings indicate that DNAJB9 is an FGN marker with 100% sensitivity and 100% specificity. The magnitude and specificity of DNAJB9 overabundance in FGN also suggests that this protein has a role in FGN pathogenesis. With this evidence, we propose that DNAJB9 is a strong biomarker for rapid diagnosis of FGN in renal biopsy specimens.


Assuntos
Glomerulonefrite/diagnóstico , Glomerulonefrite/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Membrana/metabolismo , Chaperonas Moleculares/metabolismo , Biomarcadores/metabolismo , Biópsia , Estudos de Casos e Controles , Glomerulonefrite/patologia , Proteínas de Choque Térmico HSP40/genética , Humanos , Imunoglobulina G/metabolismo , Cadeias gama de Imunoglobulina/metabolismo , Glomérulos Renais/patologia , Glomérulos Renais/ultraestrutura , Proteínas de Membrana/genética , Chaperonas Moleculares/genética , Proteoma , Sensibilidade e Especificidade
7.
J Nephrol ; 31(3): 343-350, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-28828707

RESUMO

Renal amyloidosis is characterized by acellular Congo red positive deposits in the glomeruli, interstitium and/or arteries. Light chain restriction on immunofluorescence studies is present in AL-amyloidosis, the most common type of amyloidosis involving the kidney. The detection of Congo red positive deposits coupled with negative immunofluorescence studies is highly suggestive of non-AL amyloidosis. Some of the non-AL amyloidosis are common while others are relatively rare. The clinical features, laboratory and renal pathology findings are helpful in the diagnosis and typing of non-AL amyloidosis. Thus, ALECT2 amyloidosis is characterized by diffuse cortical interstitial amyloid deposits, AA amyloidosis shows vascular deposits in addition to the glomerular deposits, AFib amyloidosis is characterized by massive amyloid accumulation limited to the glomeruli resulting in the obliteration of glomerular architecture, AApoA1 and AApoAIV are characterized by large amyloid deposits restricted to the medulla, and AGel shows swirling patterns of amyloid fibrils on electron microscopy. While light microscopy is very helpful, accurate typing of non-AL amyloidosis then requires immunohistochemical or laser microdissection/mass spectrometry studies of the Congo red positive deposits. Immunohistochemical studies are available for some of the non-AL amyloidosis. On the other hand, mass spectrometry analysis is a one stop methodology for confirmation and typing of amyloidosis. The diagnosis and typing of amyloidosis by mass spectrometry is based on finding the signature amyloid peptides, apolipoprotein E and serum amyloid-P component, followed by detection of precursor amyloidogenic protein such as LECT2, fibrinogen-α, gelsolin, etc. To, summarize, non-AL amyloidosis is a group of amyloidosis with distinctive clinical, laboratory and renal pathology findings. Typing of the amyloidosis is best performed using mass spectrometry methodology. Accurate typing of non-AL amyloidosis is imperative for correct management, prognosis, and genetic counseling.


Assuntos
Amiloidose/diagnóstico , Amiloidose/patologia , Apolipoproteínas/metabolismo , Cadeias Pesadas de Imunoglobulinas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteína Amiloide A Sérica/metabolismo , Amiloidose/metabolismo , Corantes , Vermelho Congo , Fibrinogênio/metabolismo , Gelsolina/metabolismo , Humanos , Microdissecção e Captura a Laser , Espectrometria de Massas
8.
Nephrol Dial Transplant ; 32(suppl_1): i139-i145, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28391334

RESUMO

Background: Complement activation plays an important role in the pathophysiology of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), although it remains unclear which pathway is activated. Whether pauci-immune necrotizing crescentic glomerulonephritis (pauci-immune GN) with negative ANCA serology is part of the spectrum of AAV or a different disease entity is essentially unknown. Methods: We used proteomic analysis to delineate the complement profile in a series of 13 kidney biopsies of patients with pauci-immune GN, with either proteinase 3 (PR3) (five patients) or myeloperoxidase (MPO) antibodies (four patients) or with consistently negative ANCA serology (four patients). Immunofluorescence staining of glomeruli was essentially negative in the PR3-ANCA and MPO-ANCA groups, while a mild staining for C3 was seen in the ANCA-negative cases. No electron-dense deposits were found in the PR3-ANCA and MPO-ANCA groups, but mesangial and few subepithelial deposits were clearly present in the ANCA-negative specimens. Results: Mass spectrometry revealed low spectra numbers for C3 and immunoglobulins in both PR3-positive and MPO-positive patients with minimal or no C4 and C9. In contrast, larger spectra numbers for C3, moderate spectra numbers for C9, complement factor H-related protein-1 and low spectra numbers for C4, C5 and immunoglobulins were found in the ANCA-negative cases. Conclusion: While complement activation is noted in AAV, the complement activation appears to be more prominent in the ANCA-negative glomerulonephritis. The larger amount of C3 and moderate amount of C9 in the ANCA-negative glomerulonephritis implies activation of the alternate and terminal pathway of complement, suggesting that this entity may be caused or promoted by a genetic or acquired defect in the alternative pathway.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/imunologia , Ativação do Complemento/imunologia , Glomerulonefrite/imunologia , Glomerulonefrite/patologia , Mieloblastina/imunologia , Peroxidase/imunologia , Proteoma/análise , Adolescente , Adulto , Idoso , Biomarcadores/metabolismo , Feminino , Glomerulonefrite/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Proteômica/métodos , Adulto Jovem
11.
Kidney Int ; 91(4): 964-971, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28139293

RESUMO

Gelsolin amyloidosis is a rare type of amyloidosis typically involving the cranial and peripheral nerves, but rarely the kidney. Here we report the clinical, kidney biopsy, and mass spectrometry findings in 12 cases of renal gelsolin amyloidosis. Of the 12 patients, five were men and seven were women with mean age at diagnosis of 63.8 years. Gelsolin amyloidosis was most common in Caucasians (six patients) and Asians (four patients), and included one each African-American and Hispanic patients. Nephrotic syndrome was the most common cause of biopsy, although most patients also had progressive loss of kidney function. Hematological and serological evaluation was negative in 11 patients, while one patient had a monoclonal gammopathy. The renal biopsy showed large amounts of pale eosinophilic Congo red-positive amyloid deposits typically restricted to the glomeruli. Immunofluorescence studies were negative for immunoglobulins in nine cases with three cases of smudgy glomerular staining for IgG. Electron microscopy showed mostly random arrangement of amyloid fibrils with focally parallel bundles/sheets of amyloid fibrils present. Laser microdissection of the amyloid deposits followed by mass spectrometry showed large spectra numbers for gelsolin, serum amyloid P component, and apolipoproteins E and AIV. Furthermore, the p. Asn211Lys gelsolin mutation on mass spectrometry studies was detected in three patients by mass spectrometry, which appears to represent a renal-limited form of gelsolin amyloidosis. Thus, renal gelsolin amyloidosis is seen in older patients, presents with nephrotic syndrome and progressive chronic kidney disease, and histologically exhibits glomerular involvement. The diagnosis can be confirmed by mass spectrometry studies.


Assuntos
Amiloidose/diagnóstico , Biópsia , Distrofias Hereditárias da Córnea/diagnóstico , Nefropatias/diagnóstico , Rim/química , Rim/patologia , Espectrometria de Massas em Tandem , Idoso , Amiloidose/complicações , Amiloidose/metabolismo , Amiloidose/patologia , Apolipoproteínas A/análise , Apolipoproteínas E/análise , Biomarcadores/análise , Distrofias Hereditárias da Córnea/complicações , Distrofias Hereditárias da Córnea/metabolismo , Distrofias Hereditárias da Córnea/patologia , Progressão da Doença , Feminino , Gelsolina/análise , Humanos , Imuno-Histoquímica , Rim/ultraestrutura , Nefropatias/complicações , Nefropatias/metabolismo , Nefropatias/patologia , Masculino , Pessoa de Meia-Idade , Síndrome Nefrótica/diagnóstico , Síndrome Nefrótica/etiologia , Valor Preditivo dos Testes , Prognóstico , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/etiologia , Componente Amiloide P Sérico/análise
12.
J Am Soc Nephrol ; 28(2): 431-438, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28049649

RESUMO

Lysozyme amyloidosis (ALys) is a rare form of hereditary amyloidosis that typically manifests with renal impairment, gastrointestinal (GI) symptoms, and sicca syndrome, whereas cardiac involvement is exceedingly rare and neuropathy has not been reported. Here, we describe a 40-year-old man with renal impairment, cardiac and GI symptoms, and peripheral neuropathy. Renal biopsy specimen analysis revealed amyloidosis with extensive involvement of glomeruli, vessels, and medulla. Amyloid was also detected in the GI tract. Echocardiographic and electrocardiographic findings were consistent with cardiac involvement. Proteomic analysis of Congo red-positive renal and GI amyloid deposits detected abundant lysozyme C protein. DNA sequencing of the lysozyme gene in the patient and his mother detected a heterozygous c.305T>C alteration in exon 3, which causes a leucine to serine substitution at codon 102 (Human Genome Variation Society nomenclature: p.Leu102Ser; legacy designation: L84S). We also detected the mutant peptide in the proband's renal and GI amyloid deposits. PolyPhen analysis predicted that the mutation damages the encoded protein. Molecular dynamics simulations suggested that the pathogenesis of ALys p.Leu102Ser is mediated by shifting the position of the central ß-hairpin coordinated with an antiparallel motion of the C-terminal helix, which may alter the native-state structural ensemble of the molecule, leading to aggregation-prone intermediates.


Assuntos
Amiloidose Familiar/genética , Adulto , Amiloidose Familiar/enzimologia , Humanos , Masculino , Muramidase/metabolismo , Linhagem , Fenótipo
13.
Nephrol Dial Transplant ; 32(3): 459-465, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-27507892

RESUMO

Background: C3 glomerulopathy (C3G) is caused by overactivity of the alternative pathway of complement that results in bright glomerular C3 staining with minimal or no deposition of immunoglobulins on immunofluorescence microscopy. Laser microdissection and mass spectrometry of the two subtypes, C3 glomerulonephritis (C3GN) and dense deposit disease (DDD), have identified C3 as the predominant glomerular complement protein, although lesser amounts of C9, C5, C6, C7 and C8 are detectable. C3 plays a central role in complement activity, with its proteolytic cleavage first generating C3a and C3b, followed by inactivation of C3b generating iC3b (which includes C3α and C3ß), which undergoes further breakdown yielding C3c and terminal breakdown fragment C3dg. The composition of C3 breakdown products in C3G is not known. Methods: In this study, we chose six cases each of C3GN and DDD to analyze the composition of C3 deposits. We analyzed the amino acid sequence of C3 spectra detected by mass spectrometry to determine the relative abundance of C3 fragments in C3G. Thus we were able to determine the amino acid sequences mapping to the various C3 activation products including C3dg, C3α (C3α1 and α2), and C3ß that are part of C3b/iC3b/C3c. Results: C3dg is the predominant cleavage product detected with the highest amino acid coverage. The remaining amino acids map to C3α (C3α1 and α2) and C3ß. Amino acids mapping to C3a and C3f are absent. Taken together, the C3α and C3ß amino acids represent iC3b prior to or after C3c cleavage of C3dg. The C3 spectra for both C3GN and DDD are surprisingly similar. Conclusion: The finding of large amounts of C3dg suggests that C3b deposition in the glomerulus is an active process triggered by thioester binding of C3b to the glycocalyx overlying the glomerular endothelial cells and glomerular basement membrane. Regulatory protein-mediated inactivation of C3b results in the generation of iC3b. After additional cleavages, mostly C3dg remains.


Assuntos
Complemento C3/metabolismo , Glomerulonefrite Membranoproliferativa/metabolismo , Glomerulonefrite/metabolismo , Glomérulos Renais/metabolismo , Adolescente , Adulto , Sequência de Aminoácidos , Biópsia , Criança , Cromatografia Líquida , Complemento C3a/metabolismo , Complemento C3b/metabolismo , Feminino , Glomerulonefrite/patologia , Glomerulonefrite Membranoproliferativa/patologia , Humanos , Glomérulos Renais/ultraestrutura , Masculino , Espectrometria de Massas , Microscopia Eletrônica , Microscopia de Fluorescência , Pessoa de Meia-Idade , Fragmentos de Peptídeos/metabolismo , Adulto Jovem
14.
J Am Soc Nephrol ; 28(2): 439-445, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27297947

RESUMO

Amyloidosis is characterized by extracellular deposition of misfolded proteins as insoluble fibrils. Most renal amyloidosis cases are Ig light chain, AA, or leukocyte chemotactic factor 2 amyloidosis, but rare hereditary forms can also involve the kidneys. Here, we describe the case of a 61-year-old woman who presented with nephrotic syndrome and renal impairment. Examination of the renal biopsy specimen revealed amyloidosis with predominant involvement of glomeruli and medullary interstitium. Proteomic analysis of Congo red-positive deposits detected large amounts of the Apo-CII protein. DNA sequencing of the APOC2 gene in the patient and one of her children detected a heterozygous c.206A→T transition, causing an E69V missense mutation. We also detected the mutant peptide in the proband's renal amyloid deposits. Using proteomics, we identified seven additional elderly patients with Apo-CII-rich amyloid deposits, all of whom had kidney involvement and histologically exhibited nodular glomerular involvement. Although prior in vitro studies have shown that Apo-CII can form amyloid fibrils and that certain mutations in this protein promote amyloid fibrillogenesis, there are no reports of this type of amyloidosis in humans. We propose that this study reveals a new form of hereditary amyloidosis (AApoCII) that is derived from the Apo-CII protein and appears to manifest in the elderly and preferentially affect the kidneys.


Assuntos
Amiloidose/etiologia , Apolipoproteína C-II/fisiologia , Nefropatias/etiologia , Amiloidose/classificação , Feminino , Humanos , Nefropatias/classificação , Pessoa de Meia-Idade
15.
Blood ; 129(3): 299-306, 2017 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-27856462

RESUMO

The goal of this study was to investigate the frequency of use of light-chain variable region (IGVL) genes among patients with systemic (ALS) and localized (ALL) amyloidosis and to assess for associations between IGVL gene usage and organ tropism. We evaluated clinic charts from 821 AL patients seen at the Mayo Clinic who had bone marrow, fat pad, and solid organ tissue samples typed by liquid chromatography tandem mass spectrometry (LC-MS). We identified 701 patients with ALS and 120 with ALL Overall, we were able to identify an IGVL gene in 87 (72%) patients with ALL and 573 (82%) patients with ALS When compared with ALL, LV6-57 was more common, whereas KV3-20 and heavy-chain codeposition were less common in ALS In this large series of ALS, characteristics particular to specific genotypes became apparent. LV6-57 patients were more likely to have renal involvement and to harbor a translocation 11;14. LV3-01 patients were less likely to have advanced cardiac disease and renal involvement. LV2-14 patients were more likely to have peripheral nerve involvement, an intact circulating immunoglobulin, and lower circulating dFLC. LV1-44 patients were more likely to have cardiac involvement. KV1-33 patients had more liver involvement and higher circulating dFLC. Finally, KV1-05 was associated with inferior overall survival but not independently of cardiac stage. IGVL gene usage appears to provide clues about disease pathophysiology and tissue tropism. LC-MS is a high-throughput and low-resource technique that can be used to identify IGVL gene from clinical tissue specimens.


Assuntos
Amiloidose/genética , Genes de Imunoglobulinas , Cardiopatias , Nefropatias , Amiloidose/complicações , Humanos , Cadeias Leves de Imunoglobulina/genética , Região Variável de Imunoglobulina , Espectrometria de Massas em Tandem
16.
Kidney Int ; 90(3): 658-64, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27262366

RESUMO

Apolipoprotein A-IV associated amyloidosis (AApoAIV amyloidosis) is a rare cause of amyloidosis with only a single reported case. Here we describe the clinical, biopsy, and mass spectrometry characteristics of 11 cases of renal AApoAIV amyloidosis encompassing 9 men and 2 women with a mean age at diagnosis of 63.5 years. Progressive chronic kidney disease (mean serum creatinine 2.9 mg/dl) was the most common cause for biopsy with proteinuria absent or minimal in all except one. Hematological and serological evaluation was negative in 9 patients, while 2 had a monoclonal gammopathy. The renal biopsy findings were striking and showed large amounts of eosinophilic Congo-red positive amyloid deposits restricted to the renal medulla with sparing of the renal cortex. In 6 cases, peritubular amyloid was noted in addition to the interstitial involvement. Immunofluorescence studies were negative for immunoglobulins. Electron microscopy showed nonbranching fibrils measuring 7 to 10 nm in diameter. Laser microdissection of the amyloid deposits followed by mass spectrometry showed large spectra number (a semiquantitative measure of abundance) for AApoAIV protein ranging from 49 to 169 (average 85), serum amyloid protein (average 19), and apolipoprotein E (average 48). Importantly, no peptides were detected for any other forms of known amyloidogenic precursor proteins. Thus, renal AApoAIV amyloidosis typically presents with progressive chronic kidney disease and histologically exhibits extensive medullary involvement with sparing of the cortex. The diagnosis is best established by mass spectrometry. Hence, a high degree of suspicion and examination of the renal medulla is required to make the diagnosis.


Assuntos
Amiloide/metabolismo , Amiloidose/diagnóstico , Amiloidose/etiologia , Apolipoproteínas A/metabolismo , Insuficiência Renal Crônica/etiologia , Idoso , Idoso de 80 Anos ou mais , Amiloide/ultraestrutura , Amiloidose/sangue , Amiloidose/patologia , Apolipoproteínas A/ultraestrutura , Apolipoproteínas E/metabolismo , Apolipoproteínas E/ultraestrutura , Biópsia , Creatinina/sangue , Feminino , Humanos , Medula Renal/patologia , Microdissecção e Captura a Laser , Masculino , Espectrometria de Massas , Microscopia Eletrônica , Pessoa de Meia-Idade , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/patologia
17.
Histopathology ; 68(5): 648-56, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26212778

RESUMO

AIMS: Prognostication and treatment selection for cardiac amyloidosis requires accurate amyloid typing. The aim of this study was to investigate the utility of histomorphology for predicting type. METHODS AND RESULTS: Autopsy cases with cardiac amyloidosis (1998-2010) were typed by the use of mass spectrometry-based proteomics. Deposition patterns were correlated with amyloid type. Among 108 decedents (mean age 75 years; 69% men), 107 had a single type, including transthyretin (ATTR) (60 cases), amyloid light chain (AL) (32 λ; 12 κ), amyloid A (AA) (two), and apolipoprotein AIV (AApoAIV) (one). Interstitial deposition was more extensive in AL amyloidosis cases than in ATTR cases [odds ratio (OR) 6.8, P = 0.0004]. Histomorphological patterns of interstitial deposition were mixed in 61% of AL amyloidosis cases and in 61% of ATTR cases, but diffuse pericellular deposits favoured AL amyloidosis (OR 10.7, P = 0.0001), nodular deposits favoured ATTR (OR 3.1, P = 0.0229), and discrete pericellular deposits tended to partially favour ATTR (OR 1.7, P = 0.1970). Arterial and venous deposits each favoured AL amyloidosis (OR ranging from 9.3 to 192.0, P-value ranging from 0.0022 to <0.0001), and were severe in AL amyloidosis. Endocardial deposits favoured AL amyloidosis (OR 46.3, P < 0.0001) and were also more severe in AL amyloidosis. CONCLUSIONS: The extent and distribution of cardiac amyloidosis strongly correlate with amyloid type, suggesting fundamental differences in the pathobiology of deposition. The tendency for mixed patterns to occur limits the practicality and accuracy of using histopathology for amyloid typing.


Assuntos
Amiloide/metabolismo , Amiloidose/metabolismo , Cardiopatias/metabolismo , Proteômica , Adulto , Idoso , Idoso de 80 Anos ou mais , Amiloidose/patologia , Autopsia , Cromatografia Líquida , Estudos de Coortes , Feminino , Cardiopatias/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Minnesota , Espectrometria de Massas em Tandem
18.
J Proteome Res ; 14(4): 1957-67, 2015 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-25734799

RESUMO

Immunoglobulin light chain (LC) amyloidosis (AL) is caused by deposition of clonal LCs produced by an underlying plasma cell neoplasm. The clonotypic LC sequences are unique to each patient, and they cannot be reliably detected by either immunoassays or standard proteomic workflows that target the constant regions of LCs. We addressed this issue by developing a novel sequence template-based workflow to detect LC variable (LCV) region peptides directly from AL amyloid deposits. The workflow was implemented in a CAP/CLIA compliant clinical laboratory dedicated to proteomic subtyping of amyloid deposits extracted from either formalin-fixed paraffin-embedded tissues or subcutaneous fat aspirates. We evaluated the performance of the workflow on a validation cohort of 30 AL patients, whose amyloidogenic clone was identified using a novel proteogenomics method, and 30 controls. The recall and negative predictive values of the workflow, when identifying the gene family of the AL clone, were 93 and 98%, respectively. Application of the workflow on a clinical cohort of 500 AL amyloidosis samples highlighted a bias in the LCV gene families used by the AL clones. We also detected similarity between AL clones deposited in multiple organs of systemic AL patients. In summary, AL proteomic data sets are rich in LCV region peptides of potential clinical significance that are recoverable with advanced bioinformatics.


Assuntos
Amiloide/metabolismo , Amiloidose/diagnóstico , Amiloidose/metabolismo , Cadeias Leves de Imunoglobulina/metabolismo , Região Variável de Imunoglobulina/metabolismo , Peptídeos/isolamento & purificação , Proteômica/métodos , Estudos de Coortes , Biologia Computacional , Humanos , Peptídeos/metabolismo
19.
J Clin Pathol ; 68(4): 314-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25637636

RESUMO

Amyloidosis is caused by deposition in tissues of abnormal protein in a characteristic fibrillar form. There are many types of amyloidosis, classified according to the soluble protein precursor from which the amyloid fibrils are derived. Accurate identification of amyloid type is critical in every case since therapy for systemic amyloidosis is type specific. In ∼20-25% cases, however, immunohistochemistry (IHC) fails to prove the amyloid type and further tests are required. Laser microdissection and mass spectrometry (LDMS) is a powerful tool for identifying proteins from formalin-fixed paraffin-embedded tissues. We undertook a blinded comparison of IHC, performed at the UK National Amyloidosis Centre, and LDMS, performed at the Mayo Clinic, in 142 consecutive biopsy specimens from 38 different tissue types. There was 100% concordance between positive IHC and LDMS, and the latter increased diagnostic accuracy from 76% to 94%. LDMS in expert hands is a valuable tool for amyloid diagnosis.


Assuntos
Amiloide/análise , Amiloidose/diagnóstico , Fixadores , Formaldeído , Imuno-Histoquímica , Proteômica/métodos , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Fixação de Tecidos/métodos , Amiloidose/metabolismo , Biomarcadores/análise , Biópsia , Humanos , Microdissecção e Captura a Laser , Inclusão em Parafina , Valor Preditivo dos Testes
20.
Am J Cardiol ; 114(9): 1396-9, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25217455

RESUMO

To determine the impact of amyloid on the prognosis of patients with hypertrophic cardiomyopathy (HC), we reviewed outcomes of patients who underwent septal myectomy for HC from March 7, 1996, to October 9, 2012, with amyloid deposits identified in operative specimens. Amyloid subtypes were differentiated by mass spectrometry-based proteomics. The survival rate was compared with that of an age-matched population (2:1) without amyloid who underwent septal myectomy for HC. Sixteen patients (mean age ± SD 71 ± 8 years; 12 men) met study criteria. All 16 had intraventricular peak systolic gradients reduced intraoperatively from 105 ± 53 mm Hg to 3 ± 7 mm Hg (p <0.001). Amyloid deposits in specimens ranged from minimal to mild. Nine patients had senile (transthyretin-type) amyloidosis, 4 had immunoglobulin-associated amyloidosis, 2 had apolipoprotein A4 amyloidosis type, and 1 had serum amyloid A type. There were no deaths before 30 days. Twelve patients had New York Heart Association class III or IV function preoperatively, and at last follow-up (median 3 years), class I or II. Only 1 patient received postoperative amyloidosis treatment. The postoperative survival rate at 2 and 4 years was 100% (n = 11 at risk) and 91% (n = 6 at risk), respectively, similar to that of the age-matched population with HC without amyloid who underwent myectomy (p = 0.13). Patients undergoing septal myectomy for HC who have histologic evidence of mild amyloidosis have early outcomes and midterm survival similar to those of patients with HC without amyloidosis who undergo myectomy. In conclusion, although longer follow-up is necessary, small amounts of amyloid, regardless of subtype, do not confer a poor prognosis on patients with HC who undergo septal myectomy.


Assuntos
Amiloide/metabolismo , Amiloidose/diagnóstico , Procedimentos Cirúrgicos Cardíacos/métodos , Cardiomiopatia Hipertrófica/complicações , Septos Cardíacos/cirurgia , Achados Incidentais , Obstrução do Fluxo Ventricular Externo/cirurgia , Idoso , Idoso de 80 Anos ou mais , Amiloidose/complicações , Cardiomiopatia Hipertrófica/diagnóstico , Cardiomiopatia Hipertrófica/cirurgia , Diagnóstico Diferencial , Eletrocardiografia , Feminino , Seguimentos , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Miocárdio/metabolismo , Miocárdio/patologia , Prognóstico , Estudos Retrospectivos , Fatores de Tempo , Obstrução do Fluxo Ventricular Externo/diagnóstico , Obstrução do Fluxo Ventricular Externo/etiologia
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