Immunoglobulin Light-Chain Amyloidosis: Clinical Presentations and Diagnostic Approach

Abstract

Systemic immunoglobulin light-chain (AL) amyloidosis is a rare disorder arising from a plasma cell clone that produces misfolded immunoglobulin light chains, which are deposited in various tissues and organs as amyloid fibrils. Signs and symptoms are typically vague and overlap with those arising from other common diseases; consequently, diagnosis of AL amyloidosis is challenging for clinicians. Substantial delays between onset of symptoms and diagnosis are common, and result in poorer outcomes, particularly in patients with cardiac AL amyloidosis and others who develop advanced organ dysfunction. With the need to identify AL amyloidosis as early as possible, it is important for health-care practitioners, including advanced practice clinicians and nurses, to be aware of the hallmark presenting signs and symptoms, as well as the latest practice for evaluation and diagnosis. Increased awareness of signs and symptoms associated with AL amyloidosis, particularly relating to the most frequently involved organs, the heart and kidneys, represents an opportunity for achieving earlier diagnosis. Here we review these issues in AL amyloidosis, summarize the key presenting symptoms that clinicians need to be alert to, and discuss the latest diagnostic tests, with the aim of expediting patient identification and diagnosis with the goal of improving patient outcomes.

Figure 1.

Diagnostic algorithm for AL amyloidosis. Reproduced with permission from Gertz MA. Blood Cancer J. 8 (2018) 44. http://creativecommons.org/licenses/by/4.0/. AL = amyloid light-chain; MGUS = monoclonal gammopathy of undetermined significance; FLC = free light-chain; Pyp = technetium-99m stannous pyrophosphate; TTR = transthyretin-related; GI = gastrointestinal; Ig = immunoglobulin; wt = wild type; NT-proBNP = N-terminal pro-brain natriuretic peptide.