Emerging treatment approaches for the systemic amyloidoses

Cardiac Amyloidosis and its New Clinical Phenotype: Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is now an emerging cardiovascular epidemic, being identified as the main phenotype observed in clinical practice. It is more associated with female gender, advanced age and comorbidities such as hypertension, diabetes, obesity and chronic kidney disease. Amyloidosis is a clinical disorder characterized by the deposition of aggregates of insoluble fibrils originating from proteins that exhibit anomalous folding. Recently, pictures of senile amyloidosis have been described in patients with HFpEF, demonstrating the need for clinical cardiologists to investigate this etiology in suspect cases. The clinical suspicion of amyloidosis should be increased in cases of HFPS where the cardio imaging methods are compatible with infiltrative cardiomyopathy. Advances in cardio imaging methods combined with the possibility of performing genetic tests and identification of the type of amyloid material allow the diagnosis to be made. The management of the diagnosed patients can be done in partnership with centers specialized in the study of amyloidosis, which, together with the new technologies, investigate the possibility of organ or bone marrow transplantation and also the involvement of patients in clinical studies that evaluate the action of the new emerging drugs.

Clinical improvement of renal amyloidosis in a patient with systemic-onset juvenile idiopathic arthritis who received tocilizumab treatment: a case report and literature review

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a common rheumatic disease in children and adolescents. Although JIA may cause secondary amyloidosis, this is a rare complication in patients with JIA and other rheumatic diseases. Many previous studies have revealed that common heterozygous or homozygous mutations in the MEFV gene are associated with systemic-onset JIA (SJIA).

CASE PRESENTATION

We herein report a case involving a 19-year-old female patient with difficult-to-control SJIA. She developed progressive proteinuria without clinical signs or symptoms of edema. Renal amyloidosis was diagnosed by renal pathologic examination, which demonstrated deposition of eosinophilic amorphous material in the interlobular arteries, arterioles, and interstitium. Electron microscopy showed fibrillary material deposits with a diameter of 8 to 10 nm. A heterozygous E148Q mutation in the MEFV gene was identified. Conventional disease-modifying anti-rheumatic drugs and etanercept had been used to treat the SJIA, but the disease could not be controlled. Therefore, we decided to start tocilizumab to control the disease activity. However, the patient was unable to receive a standard dose of tocilizumab in the early period of treatment because of socioeconomic limitations. Her disease course was still active, and proteinuria was found. Therefore, tocilizumab was increased to a dose of 8 mg/kg every 2 weeks (standard dose of SJIA), and the patient exhibited a clinical response within 3 months.

CONCLUSION

Refractory SJIA associated with renal amyloidosis is an uncommon cause of proteinuria in adolescents. Tocilizumab may be a beneficial treatment for renal amyloidosis in patients with SJIA.

Clinicopathological features of renal amyloidosis: a single-center study on 47 cases

The correlations between the clinicopathological features and the long-term outcomes of renal amyloidosis (RA) were analyzed with a view to develop strategies for improving diagnosis and prognosis of RA. We retrospectively reviewed the clinicopathological characteristics of 47 patients diagnosed with RA between 2004 and 2014 at the Wuhan Union Hospital. The data on the renal histology, clinical manifestations, and prognosis of RA patients were retrieved from the hospital records and characteristic patterns were identified. The histological changes in the kidneys were correlated with the clinical manifestations of RA. Additionally, most RA patients in this study had decreased serum levels of κ light chain and increased urine levels of κ and λ light chains as well as presence of M-protein in the urine and serum. Patients with early RA showed no specific pathognomonic symptoms. Bleeding associated with diagnostic renal biopsy was rare. We recommend that the routine work-up of patients aged over 40 years and presenting with non-diabetic nephropathy includes the non-invasive tests for the measurement of serum and urine levels of κ and λ light chains as well as protein electrophoresis tests for the presence of urinary and serum M-protein. Additionally, such patients should undergo renal biopsy screening with Cong-red staining to ensure early diagnosis of RA and improve their survival, since the risk of hemorrhage related to renal biopsy screening is low at early stages of RA.

Lymphadenopathy as a manifestation of amyloidosis: a case series

Lymphadenopathy as a manifestation of amyloidosis is rare. Of 3008 new patients with amyloidosis evaluated from 1994 to 2013 at a single center, 47 (1.6%) presented with lymph node enlargement leading to a biopsy and the diagnosis. We conducted a retrospective review of the initial presentation, time to progression, and treatment outcomes for these patients. Upon initial evaluation, 14 (30%) had isolated lymphadenopathy while 33 (70%) had evidence of vital organ involvement. Thirty-nine patients (83%) had systemic AL amyloidosis at initial evaluation or developed it on follow up; there was a single case each of AA, wtTTR and V122ITTR and one untyped amyloidosis. Eleven patients (23%) had IgM monoclonal gammopathy and 3 (6%) had histology consistent with lymphoplasmacytic lymphoma. Of the 14 patients with isolated lymphadenopathy, 10 (71%) eventually progressed to other organ disease requiring treatment at a median time of 10 months (range 4-71). This series demonstrates that patients presenting with amyloid lymphadenopathy usually have AL amyloidosis, and should have a thorough evaluation for other organ involvement at diagnosis. If present, treatment should be similar to that of other patients with systemic AL amyloidosis, but if not, patients should be monitored regularly for development of other organ disease over time.

High dose melphalan and autologous peripheral blood stem cell transplantation in AL amyloidosis

AL amyloidosis is the most common form of systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. It is often difficult to recognize because of its many manifestations. Recent diagnostic and prognostic advances include the serum-free light chain assay, cardiac MRI, and serologic cardiac biomarkers. Treatment strategies that have evolved during the past decade are prolonging survival and preserving organ function. This article outlines the role of high-dose melphalan and stem cell transplantation. This year marks the 20th anniversary for the first patient who underwent successful stem cell transplantation for this disease at Boston Medical Center.

Decreasing incidence of AA amyloidosis in Spain

BACKGROUND

The main objectives of our study were to review all cases of amyloidosis diagnosed by renal biopsy in Spain from 1994 to 2009 and to analyse variations in the incidence over time.

MATERIALS AND METHODS

We analysed all biopsies from native kidneys included in the Spanish Registry of Glomerulonephritis. A total of 120 centres provided 17 680 biopsies over 16 years. Follow-up was divided in four periods.

RESULTS

We collected 653 cases of renal amyloidosis. In 438 cases (67%), amyloidosis type was specified, [AA amyloidosis, 253 cases (57·8%); AL amyloidosis, 185 cases (42·2%)]. Mean age was 60 (17·8) years; 51·4% of patients were younger than 65. Overall incidence was 3·7%. In patients < 65, AA amyloidosis was present in 66·1% and AL amyloidosis in 33·9% (P < 0·01). No differences were found in patients > 65. Patients with AA amyloidosis were younger (56·8 vs. 64·0, P < 0·01) and had worse creatinine clearance (35 vs. 57 mL/min, P < 0·01). We found a decrease in the incidence among biopsies collected during each of the 4 study periods (4·2%, 3·9%, 3·5% and 3·2%, respectively, P < 0·001).

CONCLUSIONS

This is the largest series of renal amyloidosis in kidney biopsies published to date. We found amyloidosis to be decreasing slowly in Spain. This decrease affects both types and is confirmed in all cases marked in patients < 65 and in AA type. AA amyloidosis was the most frequent in our series. Patients affected by it were younger and had worse kidney function, with no differences in the level of proteinuria.

Amyloidosis of the gastrointestinal tract: a 13-year, single-center, referral experience

Amyloidosis of the gastrointestinal tract, with biopsy-proven disease, is rare. We reviewed a series of patients who presented with biopsy-proven gastrointestinal amyloidosis and report their clinical characteristics, treatments, and survival. This is a retrospective review of data prospectively collected from January 1998 to December 2011 in a tertiary referral center; 2,334 patients with all types of amyloidosis were evaluated during this period. Seventy-six patients (3.2%) had biopsy-proven amyloid involvement of the gastrointestinal tract. Their median age was 61 years (range, 34-79). Systemic amyloidosis with dominant gastrointestinal involvement was present in 60 (79%) patients, whereas the other 16 (21%) patients had amyloidosis localized to the gastrointestinal tract without evidence of an associated plasma cell dyscrasia or other organ involvement. Of the 60 systemic cases, 50 (83%) had immunoglobulin light-chain, five (8%) had familial lysozyme, three (5%) had wild-type transthyretin, and two (3%) had mutant transthyretin amyloidosis. The most frequent symptoms for all patients were weight loss in 33 (45%) and gastrointestinal bleeding in 27 (36%). Incidental identification of amyloidosis on routine endoscopic surveillance played a role in the diagnosis of seven patients with systemic immunoglobulin light-chain, and four patients with immunoglobulin light-chain localized to the gastrointestinal tract. Amyloid protein subtyping was performed in 12 of the cases of localized disease, and all had lambda light chain disease. Of the 50 patients with systemic immunoglobulin light-chain amyloidosis, 45 were treated with anti-plasma cell therapy. The median survival has not been reached for this group. For the 16 patients with localized gastrointestinal amyloidosis, supportive care was the mainstay of treatment; none received anti-plasma cell therapy. All 16 are alive at a median follow-up of 36 months (range, 1-143). Patients with biopsy-proven gastrointestinal amyloidosis often present with weight loss and bleeding. In localized cases, all that underwent typing were due to lambda light chain amyloidosis and none progressed to systemic disease during the period of follow-up. Most patients with systemic disease had immunoglobulin light-chain, and their tolerance of therapy and median survival were excellent. Although a rare manifestation of amyloidosis, staining for amyloid should be considered in patients undergoing gastrointestinal biopsy who have unexplained chronic gastrointestinal symptoms.

AA amyloidosis in the renal allograft: a report of two cases and review of the literature

AA amyloidosis is a disorder characterized by the abnormal formation, accumulation and systemic deposition of fibrillary material that frequently involves the kidney. Recurrent AA amyloidosis in the renal allograft has been documented in patients with tuberculosis, familial Mediterranean fever, ankylosing spondylitis, chronic pyelonephritis and rheumatoid arthritis. De novo AA amyloidosis is rarely described. We report two cases of AA amyloidosis in the renal allograft. Our first case is a 47-year-old male with a history of ankylosing spondylitis who developed end-stage renal disease reportedly from tubulointerstitial nephritis from non-steroidal anti-inflammatory agent use. A biopsy was never performed. One year after transplantation, AA amyloidosis was identified in the femoral head and 8 years post-transplantation, AA amyloidosis was identified in the renal allograft. He was treated with colchicine and adalimumab and has stable renal function at 1 year-follow-up. Our second case is a 57-year-old male with a long history of intravenous drug use and hepatitis C infection who developed end-stage kidney disease due to AA amyloidosis. Our second patient's course was complicated by renal adenovirus, pulmonary aspergillosis and hepatitis C with AA amyloidosis subsequently being identified in the allograft 2.5 years post-transplantation. Renal allograft function remains stable 4-years post-transplantation. These reports describe clinical and pathologic features of two cases of AA amyloidosis presenting with proteinuria and focal involvement of the renal allograft.

[Amyloidosis]

The term amyloidosis refers to the extracellular deposition of fibrils composed of different types of plasma proteins. Various clinical symptoms are caused by the tissue damage related to the deposited fibrillary material. Except of the brain, all organs can be affected: kidney, liver, spleen, lung, gastrointestinal tract, endocrine organs, skin, heart and autonomous nervous system. Diagnosis is confirmed by specific histological methods (congo red stain, polarized and electron microscopy, immunohistochemistry) and genetic testing. Scintigraphy with radioisotope labeled serum amyloid P-component is helpful in the localization of the process and in the assessment of therapeutic effect. In the majority of cases the underlying disease is a plasma cell disorder, light chains aggregate to amyloid fibrils. Therefore chemotherapy and - in selected patients - stem cell transplantation is the choice of treatment. Another common type of amyloidosis is caused by chronic inflammatory diseases (amyloid fibrils are composed of elevated serum amyloid A being related to C reactive protein), or by some hereditary fever syndromes. Treatment of the underlying disorder may bring resolution of the amyloid burden. In 10% of the cases, amyloid fibrils are composed of genetically modified proteins. Depending on the source of the mutant protein liver transplantation, hepatorenal or cardiorenal transplantation may cure the disease.

Structural typing of systemic amyloidoses by luminescent-conjugated polymer spectroscopy

Most systemic amyloidoses are progressive and lethal, and their therapy depends on the identification of the offending proteins. Here we report that luminescent-conjugated thiophene polymers (LCP) sensitively detect amyloid deposits. The heterodisperse polythiophene acetic acid derivatives, polythiophene acetic acid (PTAA) and trimeric PTAA, emitted yellow-red fluorescence on binding to amyloid deposits, whereas chemically homogeneous pentameric formic thiophene acetic acid emitted green-yellow fluorescence. The geometry of LCPs modulates the spectral composition of the emitted light, thereby reporting ligand-induced steric changes. Accordingly, a screen of PTAA-stained amyloid deposits in histological tissue arrays revealed striking spectral differences between specimens. Blinded cluster assignments of spectral profiles of tissue samples from 108 tissue samples derived from 96 patients identified three nonoverlapping classes, which were found to match AA, AL, and ATTR immunotyping. We conclude that LCP spectroscopy is a sensitive and powerful tool for identifying and characterizing amyloid deposits.

Light chains: heavy burden in kidney transplantation

Plasma cell dyscrasias are frequently encountered malignancies which are often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Recent advances in the field include the availability of an assay for free light chains, the introduction of new agents which more effectively target malignant plasma cells, and refinements in the application of stem-cell transplantation. Well-selected patients with plasma cell dyscrasias whose monoclonal Ig is well controlled may be candidates for kidney transplantation. Kidney transplant patients with allograft dysfunction from recurrent or de novo monoclonal Ig deposition can be successfully identified and treated with these new approaches.

An overview of high-dose melphalan and stem cell transplantation in the treatment of AL amyloidosis

AL amyloidosis is the most common form of systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. This review outlines an overview of high-dose intravenous melphalan and stem cell transplantation in the treatment of AL amyloidosis. An algorithm of our recommendations for the treatment of AL amyloidosis is also outlined.

New insights into systemic amyloidosis: the importance of diagnosis of specific type

PURPOSE OF REVIEW

This review aims to summarize recent developments in the area of systemic amyloidoses with emphasis on pathologic diagnosis.

RECENT FINDINGS

In recent years, management of amyloidosis has shifted from a purely supportive approach to quite diverse, radical and aggressive treatments. The central issue is the understanding that treatment of systemic amyloidoses depends on the molecular type of the amyloid protein. In the United States and the Western world, AL-amyloidosis is the most prevalent type of systemic amyloidosis, but hereditary amyloidoses are being diagnosed with increasing frequency; genetics also plays a role in a subset of familial AA amyloidoses. The biggest challenge is in the diagnosis of AL-type with confidence and in differentiation of AL and hereditary amyloidoses. While careful clinico-pathologic correlation is recommended for all patients with amyloidosis, it is, in itself, not a substitute for amyloid typing.

SUMMARY

The diagnosis of the amyloid type ultimately depends on the examination of the amyloid protein within the deposits. The role of immunohistochemistry - the current standard of care in amyloid typing - is evolving with emergence of alternative biochemical methods. Amyloid, being essentially a protein disorder, presents an attractive venue for the application of proteomics methodologies, despite their inherent complexities.

Role of B-type natriuretic peptide in cardiovascular state monitoring in a hemodialysis patient with primary amyloidosis

BACKGROUND

Cardiac involvement occurs in up to 50% of patients with primary or A amyloidosis (ALA) and is associated with very poor prognosis. B-type natriuretic peptide (BNP) has been proposed as a guide for treatment of heart failure patients and as an index of myocardial dysfunction in patients with ALA. Data about BNP dosage for cardiovascular monitoring of patients with ALA on renal replacement therapy are lacking.

CASE

A 64 year old Caucasian man was admitted because of nephrotic syndrome in July 2003. Renal diagnosis was ALA. Melphalan and prednisolone were given but renal function worsened and in April 2004 standard bicarbonate hemodialysis was started. In March 2004 thalidomide was added to his therapy. During the follow-up ejection fraction was stable and was 65% on the contrary E/A ratio gradually increased and overtook 1. BNP plasma levels were increased and the values recorded during the follow-up were: 2505 pg/mL in October 2003 (normal reference values<100), 1827 in April 2004, 4006 in June 2004, 5000 in September 2004, 3750 in January 2005 and 1920 in April 2005. In September 2005 BNP was 3380 pg/mL. The patient was still alive after a follow-up longer than two years.

CONCLUSION

In ALA patients a powerful prognostic role of BNP has been reported whose expression is increased in ventricular myocytes of patients with cardiac involvement. BNP level monitoring does not appear to be superior to standard echocardiography in evaluating cardiovascular status of uremic patients with ALA.

Amyloidosis-associated kidney disease

The amyloidoses are a group of disorders in which soluble proteins aggregate and deposit extracellularly in tissues as insoluble fibrils, causing progressive organ dysfunction. The kidney is one of the most frequent sites of amyloid deposition in AL, AA, and several of the hereditary amyloidoses. Amyloid fibril formation begins with the misfolding of an amyloidogenic precursor protein. The misfolded variants self-aggregate in a highly ordered manner, generating protofilaments that interact to form fibrils. The fibrils have a characteristic appearance by electron microscopy and generate birefringence under polarized light when stained with Congo red dye. Advances in elucidating the mechanisms of amyloid fibril formation, tissue deposition, and tissue injury have led to new and more aggressive treatment approaches for these disorders. This article reviews the pathogenesis, diagnosis, clinical manifestations, and treatment of the amyloidoses, focusing heavily on the renal aspects of each of these areas.

Light-chain (AL) amyloidosis: diagnosis and treatment

Light-chain (AL) amyloidosis is the most common form of systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. The disease often is difficult to recognize because of its broad range of manifestations and what often are vague symptoms. The clinical syndromes at presentation include nephrotic-range proteinuria with or without renal dysfunction, hepatomegaly, congestive heart failure, and autonomic or sensory neuropathy. Recent diagnostic and prognostic advances include the serum free light-chain assay, cardiac magnetic resonance imaging, and serologic cardiac biomarkers. Treatment strategies that have evolved during the past decade are prolonging survival and preserving organ function in patients with this disease. This review outlines approaches to diagnosis, assessment of disease severity, and treatment of AL amyloidosis.