AL amyloidosis and progression to multiple myeloma with gain(1q)

Gain of chromosome 1q21 is an independent adverse prognostic factor in light chain amyloidosis patients treated with melphalan/dexamethasone

Chromosomal aberrations of plasma cells are well established pathogenetic and prognostic factors in multiple myeloma, but their prognostic implication in systemic light chain (AL) amyloidosis is unclear. Therefore, the aim of this study was to identify prognostic cytogenetic risk factors by interphase FISH in a series of 103 consecutive AL amyloidosis patients treated uniformly with melphalan/dexamethasone as first-line therapy. Detection of gain of 1q21 was predictive for a poor overall survival (OS) (median 12.5 versus 38.2 months, p = 0.002). Hematologic event free survival (hem EFS) for gain of 1q21 was 5.0 versus 8.5 months in median (p = 0.08) and haematologic remission rates (≥VGPR) after three cycles were 5% versus 25% (p = 0.06). Most important, in multivariate concordance analyses the adverse prognosis carried by gain of 1q21 was retained as an independent prognostic factor (OS: p = 0.003, average hazard ratio (AHR) = 3.64, hemEFS: p = 0.008, AHR = 2.35), along with the well established Mayo cardiac staging. Patients with t(11;14) had a longer median OS with 38.2 months versus 17.5 months, though no statistical significance was reached. Deletion 13q14 and hyperdiploidy turned out to be prognostically neutral. In conclusion, we have identified gain of 1q21 as an independent adverse prognostic factor in AL amyloidosis patients treated with standard chemotherapy.

The prognostic value of diagnosing concurrent multiple myeloma in immunoglobulin light chain amyloidosis

The prevalence and prognostic value of a concomitant diagnosis of symptomatic or asymptomatic multiple myeloma (MM), as defined by the current International Myeloma Working Group (IMWG) criteria, in patients with immunoglobulin light chain amyloidosis (AL), are unknown. We studied 46 consecutive patients with AL who underwent quantification of serum M-protein and clonal bone marrow plasma cells, as well as a comprehensive evaluation for end organ damage by MM. Using standard morphology and CD138 immunohistochemical staining, 57% and 80% of patients were found to have concomitant MM, respectively. Nine patients exhibited end organ damage consistent with a diagnosis of symptomatic MM. While overall survival was similar between AL patients with or without concurrent myeloma (1-year overall survival 68% vs. 87%; P = 0.27), a diagnosis of symptomatic myeloma was associated with inferior outcome (1-year overall survival 39% vs. 81%; P = 0.005). Quantification of bone marrow plasma cells by both standard morphology and CD138 immunohistochemistry identified a much higher prevalence of concurrent MM in patients with AL than previously reported. Evaluation of bone marrow plasma cell infiltration and presence of myeloma associated end organ damage could be clinically useful for prognostication of patients with AL.

The challenge of systemic immunoglobulin light-chain amyloidosis (Al)

The cardiac involvement and associated mortality that occur in systemic AL amyloidosis remain among the most challenging aspects of the systemic amyloid-related diseases. Monoclonal immunoglobulin light chains produced by a clone of plasma cells are usually the cause of symptoms and organ dysfunction via both poorly understood toxic effects of misfolded species and accumulation of interstitial amyloid fibrils in key viscera. Treatment is aimed at eliminating the clonal cells in order to eliminate toxic light chain production. Recent advances in therapy have helped many patients with AL achieve complete hematologic responses and significant reversal of organ damage but these benefits do not extend to that 10-15 % who present with advanced cardiac involvement. Even with cardiac transplant followed by effective therapy such as stem cell transplant, outcomes for these patients remain promising at best.

The neuromuscular manifestations of amyloidosis

Amyloidosis is a systemic disease that may be acquired or hereditary and which results in the deposition of amyloid fibrils in a variety of tissues causing their progressive dysfunction. Although the clinical presentation often is dominated by cardiac or renal failure, peripheral neuropathy may be a significant or the initial manifestation, resulting in presentation to the neurologist. Diagnosis often is challenging and may require multiple diagnostic procedures, including more than one biopsy. Acquired and hereditary amyloidosis can be definitively distinguished from one another only by immunohistochemical staining or molecular genetic testing. Treatment remains a challenge, although chemotherapy and autologous stem cell transplantation offer hope for those with primary systemic amyloidosis, whereas liver transplantation is effective for some forms of hereditary amyloid neuropathy. Much less commonly, myopathy may be a clinically significant manifestation of amyloidosis.

How I treat amyloidosis

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.