Biochemical profile of renal amyloidosis in a Latin American cohort.

BACKGROUND: Two-thirds of patients with immunoglobulin light chain (AL) amyloidosis have renal involvement. The biochemical profile of kidney damage is poorly described. METHODS: A cross-sectional study was conducted involving patients diagnosed with AL amyloidosis and renal involvement between January 1, 2010, and April 30, 2022 at the Hospital Italiano de Buenos Aires. Participants were retrospectively identified from the Institutional Amyloidosis Registry. Patients diagnosed with AL amyloidosis and evidence of renal involvement were included. Individuals with other types of amyloidosis were excluded. The selection process involved a thorough review of medical records and registry data to ensure accurate identification and inclusion of eligible participants. RESULTS: Seventy-seven patients were included. At diagnosis, 90% of the subjects had proteinuria, with a median of 4.3 g/24 h, 61% had renal failure, and 47% presented nephrotic syndrome. Semi-automated urinary electrophoresis revealed 55% with non-selective and 21% with moderately selective glomerular proteinuria. Urine immunofixation indicated 64% with lambda monoclonal free light chains and 12% with kappa. Serum immunofixation demonstrated 48% with lambda monoclonal type and 25% with lambda IgG. At the time of diagnosis of AL amyloidosis, the median age was 66 years (IQR 53-72) and 49% were men. In addition to kidney involvement, other organs were also affected: heart in 53%, gastrointestinal system in 19%, peripheral nervous system in 16%, and liver in 16% of patients. CONCLUSION: Our study provides a biochemical profile in renal amyloidosis due to immunoglobulin light chains in a Latin American population. Proteinuria emerged as the most common finding in this cohort with frequent multiorgan involvement.

Reporte de un caso de amiloidosis sistémica al en un varón de 65 años con diarrea crónica y hemolacria / Report of case of systemic al amyloidosis in a 65-year-old man with chronic diarrhea and hemolacria

RESUMEN Se describe el caso de un varón de 65 años con diarrea crónica, equimosis palpebral y hemolacria. Se realizaron estudios de laboratorio, biopsia y análisis inmunohistoquímico para confirmar el diagnóstico. La variable dependiente fue el diagnóstico confirmado de amiloidosis AL, mientras que las variables independientes incluyeron los síntomas clínicos y los resultados de las pruebas diagnósticas. Se emplearon técnicas descriptivas para analizar los datos clínicos y de laboratorio. El paciente presentó diarrea crónica sin respuesta al tratamiento convencional, equimosis palpebral y hemolacria. Los estudios diagnósticos revelaron depósitos de amiloide en los tejidos. El análisis inmunohistoquímico confirmó amiloidosis sistémica de cadenas ligeras tipo AL. Se inició tratamiento específico, mejorando parcialmente los síntomas y estabilizando la condición del paciente. La amiloidosis sistémica de tipo AL requiere un alto índice de sospecha clínica para su diagnóstico oportuno. La combinación de estudios diagnósticos y tratamiento precoz puede mejorar el pronóstico de estos pacientes.

ABSTRACT The case of a 65-year-old male with chronic diarrhea, periorbital ecchymosis, and hemolacria is described. Laboratory studies, biopsy, and immunohistochemical analysis were performed to confirm the diagnosis. The dependent variable was the confirmed diagnosis of AL amyloidosis, while the independent variables included clinical symptoms and diagnostic test results. Descriptive techniques were used to analyze the clinical and laboratory data. The patient presented with chronic diarrhea unresponsive to conventional treatment, periorbital ecchymosis, and hemolacria. Diagnostic studies revealed amyloid deposits in the tissues. Immunohistochemical analysis confirmed systemic light chain AL amyloidosis. Specific treatment was initiated, partially improving the symptoms and stabilizing the patient's condition. Systemic AL amyloidosis requires a high index of clinical suspicion for timely diagnosis. The combination of diagnostic studies and early treatment can improve the prognosis of these patients.

¿Qué hay de nuevo en el diagnóstico de amiloidosis? / What is new in diagnosis of amyloidosis?

La amiloidosis siempre ha representado un desafío diagnóstico. En el año 2020, el Grupo de Estudio de Amiloidosis (GEA), confeccionó la Guía de Práctica Clínica para el Diagnóstico de Amiloidosis. Nuevas líneas de investigación se han desarrollado posteriormente. Esta revisión narrativa tiene como intención explorar el estado del arte en el diagnóstico de la amiloidosis. En pacientes con amiloidosis se recomienda la tipificación de la proteína mediante espectrometría de masa, técnica de difícil ejecución por requerir de microdisectores láser para la preparación de la muestra. Algunas publicaciones recientes proponen otros métodos para obtener la muestra de amiloide que se va a analizar, permitiendo prescindir de la microdisección. Por otra parte, en pacientes con Amiloidosis ATTR confirmada, la recomendación de secuenciar el gen amiloidogénico se encontraba destinada a los casos sospechosos de ATTR hereditaria (ATTRv,), pero actualmente esta se ha extendido a todos los pacientes sin importar la edad. En lo que respecta a los estudios complementarios orientados al diagnóstico de compromiso cardíaco, se ha propuesto el uso de la inteligencia artificial para su interpretación, permitiendo la detección temprana de la enfermedad y el correcto diagnóstico diferencial. Para el diagnóstico de neuropatía, las últimas publicaciones proponen el uso de la cadena ligera de neurofilamento sérica, que también podría resultar un indicador útil para seguimiento. Finalmente, con referencia a la amiloidosis AL, la comunidad científica se encuentra interesada en definir qué características determinan el carácter amiloidogénico de las cadenas livianas. La N-glicosilación de dichas proteínas impresiona ser uno de los determinantes en cuestión. (AU)

Amyloidosis has always represented a diagnostic challenge. In 2020, the Amyloidosis Study Group (ASG) developed the "Clinical Practice Guideline for the Diagnosis of Amyloidosis". New lines of research have subsequently emerged. This narrative review aims to explore the state of the art in the diagnosis of amyloidosis diagnosis. In patients with amyloidosis, protein typing by mass spectrometry is recommended, a technique hard to perform because it requires laser microdissection for sample preparation. Recent publications propose other methods to obtain the amyloid sample to be analyzed, making it possible to dispense with microdissection. On the other hand, in patients with confirmed TTR amyloidosis (aTTR), the recommendation to sequence the amyloidogenic gene was intended for suspected cases of hereditary aTTR but has now been extended to all patients regardless of age. (AU)

Trasplante cardíaco y autólogo de células progenitoras hematopoyéticas en pacientes con amiloidosis AL / Cardiac and autologous stem cell transplantation hematopoietic in patients with AL amyloidosis

Resumen Objetivo: Describir la evolución de las cadenas livianas libres séricas (CLL) en el período comprendido entre el trasplante cardíaco ortotópico (TCO) y el trasplante de células progenitoras hematopoyéticas (TCPH), la respuesta hematológica al año tras el TCPH y el tratamiento quimioterápico e inmunosupresor en pacientes con amiloidosis AL. Método: Serie de casos de pacientes consecutivos con diagnóstico de amiloidosis AL que recibieron TCO seguido de TCPH del Registro Institucional de Amiloidosis del Hospital Italiano de Buenos Aires, entre enero de 2010 y noviembre de 2021. Se reportaron los valores de CLL entre trasplantes y al año del TCPH. Las variables cuantitativas se describieron como mediana e intervalo intercuartil, y las variables categóricas como frecuencias absolutas y relativas. Resultados: De 106 pacientes con amiloidosis AL, seis tuvieron TCO seguido de TCPH. La mediana de edad fue de 55 años. La mayoría eran hombres (n = 5). En el período entre trasplantes, la CLL involucrada disminuyó en dos pacientes y se mantuvo estable en tres. Todos lograron la remisión hematológica completa al año del TCPH. Un solo paciente presentó recaída en el órgano sólido trasplantado. Tacrolimus, micofenolato de mofetilo y corticoides fue el esquema inmunosupresor utilizado después del TCO. Conclusiones: El TCO representa una opción de tratamiento en pacientes con falla cardíaca grave por amiloidosis, permitiendo luego un tratamiento intensivo con quimioterapia de inducción y TCPH. Si bien faltan estudios, la terapia inmunosupresora después del TCO podría tener algún efecto sobre las células plasmáticas clonales.

Abstract Objective: To describe the evolution of serum free light chains (FLC) in the period between orthotopic heart transplantation (OHT) and autologous stem cell transplantation (ASCT), the hematological response one year after ASCT and chemotherapy and immunosuppressive treatment in patients with AL amyloidosis. Method: Case series of consecutive patients diagnosed with AL amyloidosis who received OHT followed by ASCT from the Institutional Registry of Amyloidosis of the Italian Hospital of Buenos Aires, between January 2010 and November 2021. FLC values between transplants and at year post ASCT. Quantitative variables were described with their median and interquartile range. Categorical variables as absolute and relative frequencies. Results: Of 106 patients with AL amyloidosis, 6 had an OHT followed by ASCT. The median age was 55 years. Most were men (n = 5). In the period between transplants, the involved CLL decreased in two patients and remained stable in three. All achieved complete hematologic remission 1 year after ASCT. A single patient presented relapse in the transplanted solid organ. Tacrolimus, mycophenolate mofetil, and corticosteroids were the immunosuppressive regimen used after OHT. Conclusions: OHT represents a treatment option in patients with severe heart failure due to amyloidosis, allowing later intensive treatment with induction chemotherapy and ASCT. Although studies are lacking, immunosuppressive therapy after OHT might have some effect on clonal plasma cells.

Clinical characterization and outcomes of a cohort of colombian patients with AL Amyloidosis.

Background: Amyloid light chain (AL) amyloidosis is characterized by amyloid fibril deposition derived from monoclonal immunoglobulin light chains, resulting in multiorgan dysfunction. Limited data exist on the clinical features of AL amyloidosis. Objective: This study aims to describe the clinical characteristics, treatments, and outcomes in Colombian patients with AL amyloidosis. Methods: A retrospective descriptive study was conducted at three high-complexity centers in Medellín, Colombia. Adults with AL amyloidosis diagnosed between 2012 and 2022 were included. Clinical, laboratory, histological, treatment, and survival data were analyzed. Results: The study included 63 patients. Renal involvement was most prevalent (66%), followed by cardiac involvement (61%). Multiorgan involvement occurred in 61% of patients. Amyloid deposition was most commonly detected in renal biopsy (40%). Bortezomib-based therapy was used in 68%, and 23.8% received high-dose chemotherapy with autologous hematopoietic stem cell transplantation (HDCT-ASCT). Hematological response was observed in 95% of patients with available data. Cardiac and renal organ responses were 15% and 14%, respectively. Median overall survival was 45.1 months (95% CI: 22.2-63.8). In multivariate analysis, cardiac involvement was significantly associated with inferior overall survival (HR 3.27; 95% CI: 1.23-8.73; p=0.018), HDCT-ASCT had a non-significant trend towards improved overall survival (HR 0.25; 95% CI: 0.06-1.09; p=0.065). Conclusions: In this study of Colombian patients with AL amyloidosis, renal involvement was more frequent than cardiac involvement. Overall survival and multiorgan involvement were consistent with data from other regions of the world. Multivariate analysis identified cardiac involvement and HDCT-AHCT as possible prognostic factors.

Antecedentes: La amiloidosis por amiloide de cadenas ligeras (AL) se caracteriza por el depósito de fibrillas amiloides derivadas de cadenas ligeras de inmunoglobulinas monoclonales, lo que resulta en disfunción multiorgánica. Existen datos limitados sobre las características clínicas de la amiloidosis AL. Objetivo: Este estudio tiene como objetivo describir las características clínicas, tratamientos y desenlaces en pacientes colombianos con amiloidosis AL. Métodos: Se llevó a cabo un estudio descriptivo retrospectivo en tres centros de alta complejidad en Medellín, Colombia. Se incluyeron adultos con diagnóstico de amiloidosis AL entre 2012 y 2022. Se analizaron datos clínicos, de laboratorio, histológicos, de tratamiento y de supervivencia. Resultados: El estudio incluyó 63 pacientes. La afectación renal fue más prevalente (66%), seguida de la afectación cardíaca (61%). El 61% de los pacientes presentaron afectación multiorgánica. El depósito amiloide se detectó con mayor frecuencia en la biopsia renal (40%). El tratamiento basado en bortezomib se utilizó en el 68%, y el 23.8% recibió altas dosis de quimioterapia con trasplante autólogo de progenitores hematopoyéticos (ADQT-TAPH). Se observó respuesta hematológica en el 95% de los pacientes con datos disponibles. La respuesta de órgano cardíaca y renal fue del 15% y 14%, respectivamente. La mediana de la supervivencia global fue de 45.1 meses (IC del 95%: 22.2-63.8). En el análisis multivariado, la afectación cardíaca se asoció significativamente con una supervivencia global inferior (HR 3.27; IC del 95%: 1.23-8.73; p=0.018), ADQT-TAPH mostró una tendencia no significativa hacia una mejora en la supervivencia global (HR 0.25; IC 95%: 0.06-1.09; p=0.065). Conclusiones: En este estudio de pacientes colombianos con amiloidosis AL, la afectación renal fue más frecuente que la afectación cardíaca. La supervivencia global y la afectación multiorgánica fueron consistentes con datos de otras regiones del mundo. El análisis multivariado identificó la afectación cardíaca y ADQT-TAPH como posibles factores pronósticos.

Cardiac and autologous stem cell transplantation hematopoietic in patients with AL amyloidosis.

OBJECTIVE: To describe the evolution of serum free light chains (FLC) in the period between orthotopic heart transplantation (OHT) and autologous stem cell transplantation (ASCT), the hematological response one year after ASCT and chemotherapy and immunosuppressive treatment in patients with AL amyloidosis. METHOD: Case series of consecutive patients diagnosed with AL amyloidosis who received OHT followed by ASCT from the Institutional Registry of Amyloidosis of the Italian Hospital of Buenos Aires, between January 2010 and November 2021. FLC values between transplants and at year post ASCT. Quantitative variables were described with their median and interquartile range. Categorical variables as absolute and relative frequencies. RESULTS: Of 106 patients with AL amyloidosis, 6 had an OHT followed by ASCT. The median age was 55 years. Most were men (n = 5). In the period between transplants, the involved CLL decreased in two patients and remained stable in three. All achieved complete hematologic remission 1 year after ASCT. A single patient presented relapse in the transplanted solid organ. Tacrolimus, mycophenolate mofetil, and corticosteroids were the immunosuppressive regimen used after OHT. CONCLUSIONS: OHT represents a treatment option in patients with severe heart failure due to amyloidosis, allowing later intensive treatment with induction chemotherapy and ASCT. Although studies are lacking, immunosuppressive therapy after OHT might have some effect on clonal plasma cells.

OBJETIVO: Describir la evolución de las cadenas livianas libres séricas (CLL) en el período comprendido entre el trasplante cardíaco ortotópico (TCO) y el trasplante de células progenitoras hematopoyéticas (TCPH), la respuesta hematológica al año tras el TCPH y el tratamiento quimioterápico e inmunosupresor en pacientes con amiloidosis AL. MÉTODO: Serie de casos de pacientes consecutivos con diagnóstico de amiloidosis AL que recibieron TCO seguido de TCPH del Registro Institucional de Amiloidosis del Hospital Italiano de Buenos Aires, entre enero de 2010 y noviembre de 2021. Se reportaron los valores de CLL entre trasplantes y al año del TCPH. Las variables cuantitativas se describieron como mediana e intervalo intercuartil, y las variables categóricas como frecuencias absolutas y relativas. RESULTADOS: De 106 pacientes con amiloidosis AL, seis tuvieron TCO seguido de TCPH. La mediana de edad fue de 55 años. La mayoría eran hombres (n = 5). En el período entre trasplantes, la CLL involucrada disminuyó en dos pacientes y se mantuvo estable en tres. Todos lograron la remisión hematológica completa al año del TCPH. Un solo paciente presentó recaída en el órgano sólido trasplantado. Tacrolimus, micofenolato de mofetilo y corticoides fue el esquema inmunosupresor utilizado después del TCO. CONCLUSIONES: El TCO representa una opción de tratamiento en pacientes con falla cardíaca grave por amiloidosis, permitiendo luego un tratamiento intensivo con quimioterapia de inducción y TCPH. Si bien faltan estudios, la terapia inmunosupresora después del TCO podría tener algún efecto sobre las células plasmáticas clonales.

Epidural Extramedullary Plasmacytoma Successfully Treated with Surgical Excision and Bortezomib, Cyclophosphamide and Dexamethasone.

Plasma cell neoplasms are common, accounting for more than 1% of all malignancies. Its most common form is multiple myeloma, but others, such as extramedullary plasmacytoma (EMP), exist. Spinal cord compression secondary to these pathologies is not uncommon, however, adjacent bone involvement is usually present. Spinal cord compression caused by isolated epidural EMP is extremely rare, with only one case reported to date. We describe the case of a 75-year-old female patient that presented with paraparesis, due to an isolated epidural EMP associated with light chain amyloidosis. She was treated with surgical decompression and neoadjuvant chemotherapy, and is currently with a 15-month disease-free period.

Clinical characterization and outcomes of a cohort of colombian patients with AL Amyloidosis

Background: Amyloid light chain (AL) amyloidosis is characterized by amyloid fibril deposition derived from monoclonal immunoglobulin light chains, resulting in multiorgan dysfunction. Limited data exist on the clinical features of AL amyloidosis. Objective: This study aims to describe the clinical characteristics, treatments, and outcomes in Colombian patients with AL amyloidosis. Methods: A retrospective descriptive study was conducted at three high-complexity centers in Medellín, Colombia. Adults with AL amyloidosis diagnosed between 2012 and 2022 were included. Clinical, laboratory, histological, treatment, and survival data were analyzed. Results: The study included 63 patients. Renal involvement was most prevalent (66%), followed by cardiac involvement (61%). Multiorgan involvement occurred in 61% of patients. Amyloid deposition was most commonly detected in renal biopsy (40%). Bortezomib-based therapy was used in 68%, and 23.8% received high-dose chemotherapy with autologous hematopoietic stem cell transplantation (HDCT-ASCT). Hematological response was observed in 95% of patients with available data. Cardiac and renal organ responses were 15% and 14%, respectively. Median overall survival was 45.1 months (95% CI: 22.2-63.8). In multivariate analysis, cardiac involvement was significantly associated with inferior overall survival (HR 3.27; 95% CI: 1.23-8.73; p=0.018), HDCT-ASCT had a non-significant trend towards improved overall survival (HR 0.25; 95% CI: 0.06-1.09; p=0.065). Conclusions: In this study of Colombian patients with AL amyloidosis, renal involvement was more frequent than cardiac involvement. Overall survival and multiorgan involvement were consistent with data from other regions of the world. Multivariate analysis identified cardiac involvement and HDCT-AHCT as possible prognostic factors.

Antecedentes: La amiloidosis por amiloide de cadenas ligeras (AL) se caracteriza por el depósito de fibrillas amiloides derivadas de cadenas ligeras de inmunoglobulinas monoclonales, lo que resulta en disfunción multiorgánica. Existen datos limitados sobre las características clínicas de la amiloidosis AL. Objetivo: Este estudio tiene como objetivo describir las características clínicas, tratamientos y desenlaces en pacientes colombianos con amiloidosis AL. Métodos: Se llevó a cabo un estudio descriptivo retrospectivo en tres centros de alta complejidad en Medellín, Colombia. Se incluyeron adultos con diagnóstico de amiloidosis AL entre 2012 y 2022. Se analizaron datos clínicos, de laboratorio, histológicos, de tratamiento y de supervivencia. Resultados: El estudio incluyó 63 pacientes. La afectación renal fue más prevalente (66%), seguida de la afectación cardíaca (61%). El 61% de los pacientes presentaron afectación multiorgánica. El depósito amiloide se detectó con mayor frecuencia en la biopsia renal (40%). El tratamiento basado en bortezomib se utilizó en el 68%, y el 23.8% recibió altas dosis de quimioterapia con trasplante autólogo de progenitores hematopoyéticos (ADQT-TAPH). Se observó respuesta hematológica en el 95% de los pacientes con datos disponibles. La respuesta de órgano cardíaca y renal fue del 15% y 14%, respectivamente. La mediana de la supervivencia global fue de 45.1 meses (IC del 95%: 22.2-63.8). En el análisis multivariado, la afectación cardíaca se asoció significativamente con una supervivencia global inferior (HR 3.27; IC del 95%: 1.23-8.73; p=0.018), ADQT-TAPH mostró una tendencia no significativa hacia una mejora en la supervivencia global (HR 0.25; IC 95%: 0.06-1.09; p=0.065). Conclusiones: En este estudio de pacientes colombianos con amiloidosis AL, la afectación renal fue más frecuente que la afectación cardíaca. La supervivencia global y la afectación multiorgánica fueron consistentes con datos de otras regiones del mundo. El análisis multivariado identificó la afectación cardíaca y ADQT-TAPH como posibles factores pronósticos.

A Case of Wild-type Cardiac Transthyretin Amyloidosis Diagnosed by Non-invasive Methods.

INTRODUCTION: Transthyretin amyloid cardiomyopathy was considered a rare pathology. However, recent studies show a significant prevalence in patients with degenerative aortic stenosis and heart failure with preserved ejection fraction. CASE PRESENTATION: An 85-year-old woman presented with a four-month history of pain in the rib cage with a history of diffuse large B-cell lymphoma of the oral cavity, essential thrombocytosis and dyslipidemia. She had no significant family history. A transthoracic echocardiogram showed degenerative aortic stenosis and normal systolic function with preserved left ventricular ejection fraction of 70%. Bone-avid tracer cardiac scintigraphy with technetium-99m-labeled hydroxymethylene diphosphonate with SPECT-CT documented grade two myocardial uptake according to the Perugini scale. MRI evidenced late patchy enhancement in the myocardium associated with diffuse subendocardial enhancement. Laboratory tests showed the absence of mutation in the transthyretin (TTR) gene, serum and urine immunofixation electrophoresis (IFE) negative for monoclonal protein and serum-free light chain (sFLC) assay with a normal kappa/lambda (K/L) ratio. All these findings were compatible with a non-invasive diagnosis of wild-type cardiac amyloidosis. CONCLUSION: The accepted criteria for the definitive non-invasive diagnosis of amyloid cardiomyopathy are based on myocardial uptake by scintigraphy (with SPECT), serum and urine immunofixation electrophoresis, serum-free light chain assay and suggestive findings on echocardiography and/or MRI. Genetic testing should differentiate between ATTRv (v for variant) and ATTRwt (wt for wild type) forms.

[Recommendations for the treatment of AL amyloidosis]. / Recomendaciones para el tratamiento de la amiloidosis AL.

INTRODUCTION: Immunoglobulin light chain (AL) amyloidosis is a rare disease. Treatment is challenging, justified in part by systemic compromise and limited scientific evidence. OBJECTIVES: Develop evidencebased recommendations that allow adequate treatment of patients with amyloidosis AL. METHODS: A list of PICO format questions focused on the effectiveness and safety of amyloidosis AL treatment was generated. PubMed, Cochrane and Epistemonikos were searched. The levels of evidence and grades of recommendation were based on the GRADE system. RESULTS: 11 recommendations were generated. In selected patients with amyloidosis AL, autologous hematopoietic stem cell transplantation (ASCT) is recommended after induction with bortezomibbased regimens and conditioning with melphalan, since it could deepen the hematological and organ response, its durability and improve survival. In patients not eligible for ASCT, first-line treatment with bortezomib-based regimens is recommended, since it is likely to achieve a higher rate of hematological and organ response and improve survival. In patients with a contraindication or inaccessibility to bortezomib, treatment with alkylating agents and corticosteroids is recommended, since they are likely to achieve haematological and organ response and improve survival. DISCUSSION: These treatment recommendations are based on the available evidence and the experience of the panel of experts, in a scenario of limited available resources, according to developing countries.

Introducción: La amiloidosis por cadenas livianas de inmunoglobulinas (AL) es una enfermedad poco frecuente. El tratamiento implica un desafío, justificado en parte por el compromiso sistémico y la evidencia científica escasa. Objetivos: Elaborar recomendaciones basadas en la evidencia que permitan realizar un adecuado tratamiento de pacientes con amiloidosis AL. Métodos: Se generó un listado de preguntas con formato PICO centradas en la efectividad y seguridad del tratamiento de la amiloidosis AL. Se realizó la búsqueda en PubMed, Cochrane y Epistemonikos. Los niveles de evidencia y los grados de recomendación se basaron en el sistema GRADE. Resultados: Se generaron 11 recomendaciones. En pacientes con amiloidosis AL seleccionados, se recomienda el trasplante autólogo de células progenitoras hematopoyéticas (TCPH) posterior a una inducción con esquemas basados en bortezomib y el acondicionamiento con melfalán, ya que podría profundizar la respuesta hematológica, de órgano, su durabilidad y mejorar la supervivencia. En pacientes no elegibles para TCPH, se recomienda el tratamiento de primera línea con esquemas basados en bortezomib, dado que es probable que logre mayor tasa de respuesta hematológica, de órgano y mejore la supervivencia. En pacientes con contraindicación o inaccesibilidad al bortezomib, se recomienda el tratamiento con agentes alquilantes y corticoides, dado que es probable que logren la respuesta hematológica, de órgano y mejoren la supervivencia. Discusión: Estas recomendaciones de tratamiento se basan en la evidencia disponible y la experiencia del panel de expertos, en un escenario de recursos disponibles limitados, acorde a los países en vías de desarrollo.

Recomendaciones para el tratamiento de la Amiloidosis AL / Recommendations for the treatment of AL amyloidosis

Immunoglobulin light chain (AL) amyloidosis is a rare disease. Treatment is challenging, justified in part by systemic compromise and limited scientific evidence. Develop evidencebased recommendations that allow adequate treatment of patients with amyloidosis AL. A list of PICO format questions focused on the effectiveness and safety of amyloidosis AL treatment was generated. PubMed, Cochrane and Epistemonikos were searched. The levels of evidence and grades of recommendation were based on the GRADE system.11 recommendations were generated. In selected patients with amyloidosis AL, autologous hematopoietic stem cell transplantation (ASCT) is recommended after induction with bortezomibbased regimens and conditioning with melphalan, since it could deepen the hematological and organ response, its durability and improve survival. In patients not eligible for ASCT, first-line treatment with bortezomib-based regimens is recommended, since it is likely to achieve a higher rate of hematological and organ response and improve survival. In patients with a contraindication or inaccessibility to bortezomib, treatment with alkylating agents and corticosteroids is recommended, since they are likely to achieve haematological and organ response and improve survival. These treatment recommendations are based on the available evidence and the experience of the panel of experts, in a scenario of limited available resources, according to developing countries.

La amiloidosis por cadenas livianas de inmunoglobulinas (AL) es una enfermedad poco frecuente. El tratamiento implica un desafío, justificado en parte por el compromiso sistémico y la evidencia científica escasa. Objetivos: Elaborar recomendaciones basadas en la evidencia que permitan realizar un adecuado tratamiento de pacientes con amiloidosis AL. Métodos: Se generó un listado de preguntas con formato PICO centradas en la efectividad y seguridad del tratamiento de la amiloidosis AL. Se realizó la búsqueda en PubMed, Cochrane y Epistemonikos. Los niveles de evidencia y los grados de recomendación se basaron en el sistema GRADE. Resultados: Se generaron 11 recomendaciones. En pacientes con amiloidosis AL seleccionados, se recomienda el trasplante autólogo de células progenitoras hematopoyéticas (TCPH) posterior a una inducción con esquemas basados en bortezomib y el acondicionamiento con melfalán, ya que podría profundizar la respuesta hematológica, de órgano, su durabilidad y mejorar la supervivencia. En pacientes no elegibles para TCPH, se recomienda el tratamiento de primera línea con esquemas basados en bortezomib, dado que es probable que logre mayor tasa de respuesta hematológica, de órgano y mejore la supervivencia. En pacientes con contraindicación o inaccesibilidad al bortezomib, se recomienda el tratamiento con agentes alquilantes y corticoides, dado que es probable que logren la respuesta hematológica, de órgano y mejoren la supervivencia. Discusión: Estas recomendaciones de tratamiento se basan en la evidencia disponible y la experiencia del panel de expertos, en un escenario de recursos disponibles limitados, acorde a los países en vías de desarrollo.

Features and evolution of patients with systemic amyloidosis and cardiac involvement / Características y evolución de los pacientes con amiloidosis sistémica y compromiso cardíaco.

Objective: To estimate the prevalence of cardiac amyloidosis in patients with systemic amyloidosis. Compare survival rates based on whether they show cardiac involvement. Methods: A retrospective cohort study of patients with systemic amyloidosis from the Institutional Amyloidosis Registry of the Hospital Italian of Buenos Aires from 2010 to 2019. Heart involvement is considered to be the presence of symptoms and/or images consistent with amyloidosis, and there is no other reason to explain it. All deaths due to causes were evaluated. The survival rate was estimated by Kaplan-Meier. Cox regression model was used to evaluate factors related to mortality. Heart transplantation was evaluated in a competitive risk regression model. Results: The prevalence of heart involvement is 63%. For the group with heart damage, the death rate was 14/1,000 person-months, and for patients without damage, the death rate was 5/1,000 person-months. The 5-year overall survival rate for patients with heart involvement was 44%, while that for patients without damage was 67% (p = 0.02). The original HR for heart involvement was 2.09 (p = 0.02). Age showed that HRa was 1.06 (p <0.01). The sub-HR estimated by the competitive risk regression model are 1.86 (95% CI 0.99-3.49) p = 0.05. Conclusion: Cardiac involvement is an important prognostic factor in patients with amyloidosis.

Objetivos: Determinar la prevalencia de amiloidosis cardíaca en pacientes con amiloidosis sistémica. Comparar la supervivencia según sea que presenten o no compromiso cardíaco. Métodos: Cohorte retrospectiva de pacientes con amiloidosis sistémica del Registro Institucional de Amiloidosis del Hospital Italiano de Buenos Aires, entre 2010 y 2019. Se consideró como compromiso cardíaco la presencia de síntomas o imágenes consistentes con amiloidosis no explicado por otras causas. Se evaluó la muerte por todas las causas. Se calculó la sobrevida mediante Kaplan-Meier. Los factores relacionados con mortalidad se evaluaron con un modelo de regresión de Cox. Se evaluó el trasplante cardíaco en un modelo de regresión de riesgo competitivo. Resultados: La prevalencia de compromiso cardíaco fue del 63%. La incidencia de muerte fue de 14/1,000 personas-meses para el grupo con compromiso cardíaco y de 5/1,000 personas-meses para los pacientes sin compromiso. Los pacientes con compromiso cardíaco tuvieron una sobrevida global a los cinco años de 44% contra 67% en los que no tenían compromiso (p = 0.02). El HR crudo para el compromiso cardíaco fue de 2.09 (p = 0.02). La edad mostró un HR ajustado de 1.06 (p <0.01). El modelo de regresión de riesgos competitivos estableció un sub-HR de 1.86 (IC95%, 0.99-3.49; p = 0.05). Conclusiones: El compromiso cardíaco es un factor pronóstico importante en pacientes con amiloidosis.

Amiloidose pulmonar com apresentação traqueobrônquica: relato de caso clínico / Pulmonary amyloidosis with tracheobronchial presentation: clinical case report

Introdução: Amiloidose é o termo utilizado para designar doenças que fazem deposição extracelular de proteínas fibrilares patológicas em órgãos e tecidos, podendo ser sistêmica ou restrita a um único órgão. As manifestações clínicas são diversas, como cardiomiopatia, falência renal, esplenomegalia, problemas intestinais, neuropatias, problemas pulmonares, entre outros. Objetivo: relatar um caso clínico de paciente com amiloidose traqueobrônquica. Metodologia: revisão de bibliografias em comparação ao relato de caso, o qual foi descrito a partir de dados retirados do prontuário e de exames complementares da paciente. Caso clínico: paciente do sexo feminino, 70 anos, procurou assistência médica por dorsalgia, apresentando também chiado, tosse seca, dispneia paroxística noturna e ortopneia. Realizou-se investigação diagnóstica durante a internação, na qual biópsia da mucosa traqueobrônquica e coleta de lavado alveolar foram positivos para o teste Vermelho Congo, o que confirmou o diagnóstico de amiloidose. A paciente, então, foi encaminhada para terapia de ablação a laser. Conclusão: portanto, diante de um paciente com quadro clínico inespecífico e suspeita diagnóstica principal de amiloidose pulmonar, é imprescindível investigar e descartar diagnósticos diferenciais como neoplasia ou discrasia de células plasmáticas. Para isso, é necessário que haja alta precisão na análise dos exames de imagem, de modo a sugerir esse diagnóstico, o qual deve ser confirmado através da fibrobroncoscopia com biópsia de tecido brônquico, que através da coloração Vermelho do Congo, evidenciará presença de substância amorfa e birrefringente, compatível com substância amiloide [au]

Introduction: Amyloidosis is the term used to describe diseases that cause extracellular deposition of pathological fibrillar proteins in organs and tissues, which can be systemic or restricted to a single organ. The clinical manifestations are diverse, such as cardiomyopathy, renal failure, splenomegaly, intestinal problems, neuropathies, lung problems, among others. Objective: to report a clinical case of a patient with pulmonary amioloidosis. Methodology: review of bibliographies in comparison to the case report, which was described based on data taken from the patient's record and complementary exams. Clinical case: a seventy-year-old female patient sought medical assistance because of back pain, also presenting wheezing, dry cough, paroxysmal nocturnal dyspnea and orthopnea. Diagnostic investigation was carried out during hospitalization, in which biopsy of the tracheobronchial mucosa and collection of alveolar lavage were positive for the Congo Red test,wich confirmed the amyloidosis diagnosis. The patient was then referred for laser ablation therapy.Conclusion: hence, in a patient with a nonspecific clinical presentation and main diagnostic suspicion of pulmonary amyloidosis, it is essential to investigate and rule out differential diagnoses such as malignancy or plasma cell dyscrasia. Therefore, it is necessary to use high precision in the analysis of image exams in order to suggest this diagnosis, which should be confirmed through fibrobronchoscopy with bronchial tissue biopsy, that through the Congo Red dye, will show the presence of amorphous and birefringent substance, compatible with amyloid substance [au]

Amiloidosis cardiaca secundaria a macroglobulinemia de Waldenström / Cardiac amyloidosis secondary to Waldenström macroglobulinemia

Introducción: La macroglobulinemia de Waldenström constituye una neoplasia hematológica del grupo de las gammapatías monoclonales, que incluye síntomas sistémicos y relacionados al incremento de la paraproteína M. Objetivo: Describir un caso de amiloidosis cardiaca asociada a macroglobulinemia. Caso clínico: Paciente masculino que fue admitido por astenia, disfonía, y durante su evolución desarrolló disnea progresiva, insuficiencia cardiaca y efusión pleural. Adicionalmente, la ecocardiografía mostró patrón granular miocárdico, y la biopsia pleural resultó positiva para la tinción rojo congo. Posteriormente, recibió tratamiento con bortezomib, dexametasona y rituximab con evolución favorable. Conclusiones: En esta enfermedad el diagnóstico temprano es una ventaja importante para la supervivencia. Es por esa razón, que su manejo es paliativo de las manifestaciones cardiacas. El presente caso pone en manifiesto un reto diagnóstico, en el cual se deben tomar en cuenta las etiologías menos frecuentes de insuficiencia cardiaca(AU)

Introduction: Waldenström's macroglobulinemia is a hematological neoplasm belonging to the group of monoclonal gammopathies, which includes systemic symptoms and those related to an increase in M paraprotein. Objective: To describe a case of cardiac amyloidosis associated with macroglobulinemia. Clinical case: Male patient who was admitted for asthenia, dysphonia, and who, during his evolution, developed progressive dyspnea, heart failure and pleural effusion. Additionally, echocardiography showed myocardial granular pattern, while pleural biopsy was positive for Congo red staining. Subsequently, he received treatment with bortezomib, dexamethasone and rituximab, with favorable evolution. Conclusions: In this disease, early diagnosis is an important advantage for survival. Therefore, its management is palliative of cardiac manifestations. The present case shows a diagnostic challenge, in which the less frequent etiologies of heart failure must be taken into account(AU)

Amiloidosis AL y mieloma múltiple: macroglosia como primera manifestación de una combinación infrecuente / AL amyloidosis and multiple myeloma: macroglossia as first manifestation of a rare combination

El diagnóstico diferencial de la macroglosia es amplio y puede estar en el contexto de una patología localizada o una enfermedad sistémica. Dentro de las enfermedades sistémicas que se manifiestan con macroglosia se describe la amiloidosis, caracterizada por un depósito irreversible de una proteína amorfa y fibrilar El compromiso de esta patología en el territorio de cabeza y cuello es infrecuente y su depósito en la lengua corresponde a menos del 9% de los casos. Se presenta el caso de un paciente que consultó por dolor en hemilengua derecha, disfagia y baja de peso. Se estudió inicialmente con exámenes de laboratorio y nasofibroscopía, sin hallazgos concluyentes. Dado persistencia de síntomas se realizó resonancia nuclear magnética (RM) que mostraba signos sugerentes de enfermedad de depósito, confirmándose mediante estudios histopatológicos una amiloidosis sistémica secundaria. El paciente fue derivado a hematología para completar estudio e iniciar el tratamiento. La amiloidosis sistémica es un diagnóstico infrecuente, que debe ser considerado por su mal pronóstico vital. El diagnóstico en etapas iniciales puede mejorar sustancialmente la sobrevida y calidad de vida de aquellos que padecen la enfermedad. Por lo anterior, es necesario completar un estudio acabado de la patología, apoyándose en métodos no invasivos como la RM.

The differential diagnosis of macroglossia is broad, and it may be present in the context of a localized pathology or a systemic disease. One of the systemic diseases that present macroglossia is amyloidosis, which is characterized by an irreversible deposit of an amorphous and fibrillar protein. The manifestation of this pathology in head and neck territory is infrequent, and its deposit in the tongue represents less than 9% of all types of amyloidosis. We present the case of a patient, who consulted with pain in the tongue, dysphagia, and weight loss. He was initially studied with laboratory tests and a nasofibroscopy with no conclusive findings. Given the persistence of symptoms, magnetic resonance imaging (MRI) was performed, showing signs of an infiltrative disease, which was confirmed as secondary systemic amyloidosis through histopathological studies. Given the above, the patient was referred to hematology to start treatment. Systemic amyloidosis is an uncommon diagnosis that should be suspected since it implies a poor vital prognosis. Moreover, an early diagnosis can substantially improve the survival rate and quality of life of those who suffer this disease. Therefore, a comprehensive study of this condition is needed, complementing with non-invasive methods such as MRI.

Crystal structure of 6aJL2-R24G light chain variable domain: Does crystal packing explain amyloid fibril formation?

Light chain amyloidosis is one of the most common systemic amyloidosis, characterized by the deposition of immunoglobulin light variable domain as insoluble amyloid fibrils in vital organs, leading to the death of patients. Germline λ6a is closely related with this disease and has been reported that 25% of proteins encoded by this germline have a change at position 24 where an Arg is replaced by a Gly (R24G). This germline variant reduces protein stability and increases the propensity to form amyloid fibrils. In this work, the crystal structure of 6aJL2-R24G has been determined to 2.0 Šresolution by molecular replacement. Crystal belongs to space group I212121 (PDB ID 5JPJ) and there are two molecules in the asymmetric unit. This 6aJL2-R24G structure as several related in PDB (PDB entries: 5C9K, 2W0K, 5IR3 and 1PW3) presents by crystal packing the formation of an octameric assembly in a helicoidal arrangement, which has been proposed as an important early stage in amyloid fibril aggregation. However, other structures of other protein variants in PDB (PDB entries: 3B5G, 3BDX, 2W0L, 1CD0 and 2CD0) do not make the octameric assembly, regardless their capacity to form fibers in vitro or in vivo. The analysis presented here shows that the ability to form the octameric assembly in a helicoidal arrangement in crystallized light chain immunoglobulin proteins is not required for amyloid fibril formation in vitro. In addition, the fundamental role of partially folded states in the amyloid fibril formation in vitro, is not described in any crystallographic structure published or analyzed here, being those structures, in any case examples of proteins in their native states. Those partially folded states have been recently described by cryo-EM studies, showing the necessity of structural changes in the variants before the amyloid fiber formation process starts.

Different Dynamics in 6aJL2 Proteins Associated with AL Amyloidosis, a Conformational Disease.

Light-chain amyloidosis (AL) is the most common systemic amyloidosis and is caused by the deposition of mainly insoluble immunoglobulin light chain amyloid fibrils in multiple organs, causing organ failure and eventually death. The germ-line λ6a has been implicated in AL, where a single point mutant at amino acid 24 (6aJL2-R24G) has been observed in around 25% of patient samples. Structural analysis has shown only subtle differences between both proteins; nevertheless, 6aJL2-R24G is more prone to form amyloid fibrils. To improve our understanding of the role of protein flexibility in amyloid fibril formation, we have used a combination of solution nuclear magnetic resonance spectroscopy and molecular dynamics simulations to complement the structural insight with dynamic knowledge. Fast timescale dynamics (ps-ns) were equivalent for both proteins, but suggested exchange events for some residues. Even though most of the intermediate dynamics (µs-ms) occurred at a similar region for both proteins, the specific characteristics are very different. A minor population detected in the dispersion experiments could be associated with the formation of an off-pathway intermediate that protects from fiber formation more efficiently in the germ-line protein. Moreover, we found that the hydrogen bond patterns for both proteins are similar, but the lifetime for the mutant is significantly reduced; as a consequence, there is a decrease in the stability of the tertiary structure that extends throughout the protein and leads to an increase in the propensity to form amyloid fibers.

Solution structure of 6aJL2 and 6aJL2-R24G amyloidogenics light chain proteins.

AL amyloidosis is the most common amyloid systemic disease and it is characterized by the deposition of immunoglobulin light chain amyloid fibers in different organs, causing organ failure. The immunoglobulin light chain germinal line 6a has been observed to over-express in AL patients, moreover, it was observed that, out of these amyloidogenic proteins, 25% present a mutation of an Arg to Gly in position 24. In vitro studies have shown that this mutation produces proteins with a higher amyloid fiber propensity. It was proposed that this difference was due, in part, to the formation of a non-canonical structural element. In order to get a more detailed understanding of the structural and dynamic properties that govern the amyloid fibers formation process, we have determined the solution structure by NMR for the two constructs, showing that the difference in amyloid fibril formation is not due to sequence or structure.