AL Amyloidosis: Understanding the Clinical Prodrome and Delays in Diagnosis

Introduction: Light-chain amyloidosis (ALA) is a rare plasma cell disorder characterized by multiorgan involvement. Patients often present with non-specific symptoms, which can lead to a delay in diagnosis. This is associated with progressive organ involvement and shorter survival. Reducing the time from symptom onset to diagnosis is a critical step in improving outcomes. This study was designed to evaluate the clinical prodrome and challenges associated with the diagnosis of ALA from the patient perspective.

Methods: This retrospective study surveyed patients with ALA through the online HealthTree® Cure Hub platform, which helps patients navigate their disease in a holistic way. The survey consisted of 32 questions, including 23 multiple-choice, 7 date-entry, and two free-response questions. Data on diagnosis and demographics were extracted from the electronic health record and self-reported data linked to HealthTree® Cure Hub. Results were reported as numbers and percentages, and comparisons were made by age (≥70 vs. <70 years) and sex. The following statistical methods were used: Fisher’s exact test for categorical data, two-sample t-test and F-test for normally distributed continuous data, Wilcoxon rank-sum test for skewed data and Spearman correlation coefficient.

Results: We surveyed 248 patients. Of those, a total of 87 patients with a self-reported diagnosis of ALA completed the questionnaire between March 12, 2023, and May 8, 2024. The median age was 66 years; 55% were female, and 91% were white. The most common initial symptoms prompting patients to seek medical evaluation were fatigue/weakness (47%), swelling (38%), shortness of breath (28%), chest pain (23%), and foamy urine (22%). Pain in hands/feet, carpal tunnel syndrome, loss of appetite, hoarseness, macroglossia, diarrhea, periorbital puffiness, nail changes, and erectile dysfunction each accounted for <10% of cases. Signs and symptoms were first detected by patients themselves in 58% of cases, by a physician in 33% and by a family member or friend for the rest. The median number of symptoms per individual was 2; 31% reported only one symptom, 37% 2-3, 18% 4-6, and 14% >6; with chest pain being the most common (39%), followed by swelling (22%), shortness of breath (13%), and foamy urine (13%); one patient reported erectile dysfunction and another reported arrhythmias as their only symptom. There was a correlation between hoarseness and nail changes (ρ=0.71), and carpal tunnel syndrome and orthostatic hypotension (ρ=0.63). Only 16% were aware of ALA as a condition prior to symptom onset. Thirty six percent presented to a general practitioner for initial evaluation; about 50% sought a specialist, including a myeloma/amyloid specialist (21%), and 14% were first evaluated in the emergency department. While most patients (45%) were diagnosed by a hematologist/oncologist, patients reported seeing a median of 3 physicians (range: 1-10) before the diagnosis was established. Among responders, 61% reported having myeloma at the time of testing. After diagnosis, about 50% were referred to a center specialized in ALA, and 72% met with a stem cell transplant specialist. Most patients reported receiving multidisciplinary care, with a median of 3 additional specialists participating in ALA care (range: 0-16). More than half of patients (59%) felt the diagnosis was delayed; among those, 42%, 24%, 24%, and 11% reported a delay of 1-6, 7-12, 13-24, and >24 months, respectively. The proportion of patients reporting >12-month delay was higher among older patients (54% vs. 27%, P=0.02). A quarter of responders felt their treatment was delayed. Half of patients felt the diagnostic delay contributed to a decrease in treatment efficacy and 48% did not feel that all medical professionals were knowledgeable about ALA. Only 38% felt the diagnostic process was simple and easy within their healthcare system.

Conclusion: Most patients with AL amyloidosis initially present with non-specific symptoms, with fatigue/weakness being the most common. Over a third were evaluated first by a general practitioner, and about a third reported a diagnostic delay of >12 months. The diagnostic process is associated with high healthcare utilization, even among patients with concurrent multiple myeloma. Increasing disease awareness among patients and medical providers may shorten the time to diagnosis and contribute to improved outcomes.