How I treat amyloidosis

Abstract

Amyloidosis is an uncommon disorder in which proteins change conformation, aggregate, and form fibrils that infiltrate tissues, leading to organ failure and death. The most frequent types are light-chain (AL) derived from monoclonal B-cell disorders producing amyloidogenic immunoglobulin light chains, and the hereditary and "senile systemic" (ATTR) variants from mutant and wild-type transthyretin (TTR). Diagnosis requires tissue biopsy. AL is more frequent and causes more organ disease than ATTR. Although both can cause cardiomyopathy and heart failure, AL progresses more quickly, so survival depends on timely diagnosis. Typing is usually based on clinical and laboratory findings with monoclonal gammopathy evaluation and, if indicated, TTR gene testing. Direct tissue typing is required when one patient has 2 potential amyloid-forming proteins. In coming years, widespread use of definitive proteomics will improve typing. New therapies are in testing for ATTR, whereas those for AL have followed multiple myeloma, leading to improved survival. Challenges of diagnosing and caring for patients with amyloidosis include determination of type, counseling, and delivery of prompt therapy often while managing multisystem disease. Recent advances grew from clinical research and advocacy in many countries, and global husbandry of such efforts will reap future benefits for families and patients with amyloidosis. (Blood. 2009;114:3147-3157) IntroductionLess than 50 years ago, the composition of AL amyloid fibrils was a matter of controversy. [1][2][3] The connection between a monoclonal gammopathy (itself a powerful concept of that era) and amyloid was not clearly comprehended. 4 Investigators were caught in a logical conundrum: amyloid fibrils were composed of an aberrant protein but not always of the same one. 5 There were different types of amyloid as in Table 1. 6 Since that time, investigators developed a taxonomy based on the several dozen precursor proteins that cause amyloidosis. We now confront the problem of diagnostic confidence in typing amyloid, knowing that different therapies exist for different types. [7][8][9] We also struggle with the core clinical issue: the heart of the matter is that amyloidosis often attacks the heart. 10 How I treat amyloidosis begins with typing the disease, determining the extent of organ (particularly heart) involvement, and deciding on appropriate therapy, whenever feasible on a clinical trial. Effective therapy requires a comprehensive approach, monitoring both the precursor protein we seek to reduce or eliminate and the markers of organ disease, while providing best supportive care. In this report, I use a case-and-comments approach focused on AL, the type afflicting 10 patients per million personyears, including 10% to 15% of patients with myeloma or Waldenström macroglobulinemia. 11Case 1: a woman with hepatosplenomegaly, proteinuria, and bleeding A 49-year-old woman presented with early satiety, right upper quadrant fullness, hepatosplenomegaly, alkaline phosphatase 380 U/L (norm...

Immunoglobulin Light Chain Amyloidosis (AL) Presenting as Periorbital Purpura in A 39 Years Female Patient

“…1 Light Chain Amyloidosis is considered a rare disease, with approximately 6 to 10 cases per million person-years and more common in older adults, with a slight male preponderance. Less than 5% of the cases are in patients younger than 40 years.…”

Amiloidosis extrema asociada a mieloma múltiple e insuficiencia renal terminal: Caso clínico

“…Para ello se ha propuesto utilizar altas dosis de melfalán y trasplante autó logo de progenitores hematopoyé-ticos (TPH), con respuesta hematológica completa en 25-50% 13,14 . La enfermedad renal y/o hepática avanzada contraindicaría la terapia y el inconveniente es la alta toxicidad, con mortalidad de 12-14%, mayor cuando existe compromiso cardiaco.…”

Superior efficacy but higher cost of plerixafor and abbreviated-course G-CSF for mobilizing hematopoietic progenitor cells (HPC) in AL amyloidosis

“…[2][3][4] Use of G-CSF has become the standard method for hematopoietic progenitor cell (HPC) mobilization in AL amyloidosis as chemotherapy-based mobilization in this setting has largely been abandoned owing to the high risk of cardiac events, infections, bleeding complications and mortality. [5][6][7] However, significant morbidity, including death has also been reported during or immediately after G-CSF-based mobilization in AL amyloidosis patients. 8,9 In addition, significant weight gain and mobilization failure are other important complications with this approach.…”