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.
Stem cell transplantation compared with melphalan plus dexamethasone in the treatment of immunoglobulin light‐chain amyloidosis
Cancer | May 4, 2016 | Volume: 122 | Issue: 14 | Pages: 2197-2205
AbstractCarfilzomib, a second‐generation proteasome inhibitor, has been increasingly used in relapsed/refractory multiple myeloma (MM) since its approval by the American food and drug administration (FDA) in the summer of 2012. The drug is active as a single agent and in combination with other antimyeloma agents. As a result of its efficacy and safety in the relapsed/refractory setting, carfilzomib is being evaluated in patients with newly diagnosed MM as well as in high‐risk smoldering MM. This review will give a comprehensive summary of the drug, including its mechanism of action, the evaluated doses and schedules as well as a summary of the main clinical trials in the relapsed/refractory and newly diagnosed settings. A focus will be placed upon certain subgroups of interest as well as a description of the toxicity associated with carfilzomib use and a clinical perspective on toxicity management.
First-in-Human Phase I/II Study of NEOD001 in Patients With Light Chain Amyloidosis and Persistent Organ Dysfunction
Journal of Clinical Oncology | February 8, 2016 | Volume: 34 | Issue: 10 | Pages: 1097-1103
Purpose Light chain (AL) amyloidosis is caused by the accumulation of misfolded proteins, which induces the dysfunction of vital organs. NEOD001 is a monoclonal antibody targeting these misfolded proteins. We report interim data from a phase I/II dose-escalation/expansion study of NEOD001 in patients with AL amyloidosis and persistent organ dysfunction (NCT01707264). Patients and Methods Patients who had completed at least one previous anti–plasma cell-directed therapy, had partial hematologic response or better, and had persistent organ dysfunction received NEOD001 intravenously every 28 days. Dose levels of 0.5, 1, 2, 4, 8, 16, and 24 mg/kg were evaluated (3 + 3 study design). Primary objectives were to determine the maximum tolerated dose and the recommended dose for future studies and to evaluate safety/tolerability. Secondary and exploratory objectives included pharmacokinetics, immunogenicity, and organ responses on the basis of published consensus criteria. Results Twenty-seven patients were enrolled in seven cohorts (dose-escalation component). No drug-related serious adverse events (AEs), discontinuations because of drug-related AEs, dose-limiting toxicities, or antidrug antibodies were reported. The most frequent AEs were fatigue, upper respiratory tract infection, cough, and dyspnea. Recommended dosing was 24 mg/kg. Pharmacokinetics support intravenous dosing every 28 days. Of 14 cardiac-evaluable patients, eight (57%) met the criteria for cardiac response and six (43%) had stable disease. Of 15 renal-evaluable patients, nine (60%) met the criteria for renal response and six (40%) had stable disease. Conclusion Monthly infusions of NEOD001 were safe and well tolerated. Recommended future dosing was 24 mg/kg. Organ response rates compared favorably with those reported previously for chemotherapy. A phase II expansion is ongoing. A global phase III study (NCT02312206) has been initiated. Antibody therapy targeting misfolded proteins is a potential new therapy for the management of AL amyloidosis.
Clinical characteristics and outcomes in biclonal gammopathies
American Journal of Hematology | February 3, 2016 | Volume: 91 | Issue: 5 | Pages: 473-475
Hyperviscosity syndrome is clinically manifested by oronasal bleeding, retinal hemorrhages, and variable neurological symptoms. It occurs when resistance to flow of blood increases sharply, resulting in impaired transit through the microcirculatory system. The most common cause of hyperviscosity is increased concentrations of gamma globulins, either monoclonal in malignant disease or polyclonal, usually seen with rheumatic disorders. Increased numbers of red blood cells, as in polycythemia vera, can result in viscous blood. Extreme increases in concentrations of mature and immature white blood cells can also produce hyperviscosity. Treatment with plasma exchange is required when the clinical syndrome is symptomatic. Although plasma exchange is not a completely benign procedure, it represents the most effective method of controlling hyperviscosity.