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Page 6 of 11 Verriello et al. Vessel Plus 2021;5:51 https://dx.doi.org/10.20517/2574-1209.2021.69

Table 2. Mimics of ATTRv amyloidosis with polyneuropathy, diagnostic pitfalls, and red flags
Mimics Diagnostic pitfalls Red flags
Chronic axonal idiopathic Axonal PN in the elderly who seems idiopathic Rapidly progressive and disabling
polyneuropathy Difficulties in walking
CIDP Decreased NCV Pain
Albuminocytologic dissociation Dysautonomia
Negative tissue biopsy No response to immunotherapy
Lumbar spinal stenosis Progressive walking difficulties Worsening despite of surgery
Lumbar spine stenosis on imaging studies Abnormal NCS
AL amyloidosis Occurrence of monoclonal gammopathy Family history
False immunolabeling of amyloid deposits Multiorgan involvement
Diabetic neuropathy Length-dependent PN with involvement of small Rapidly progressive
fibers Difficulties in walking
Dysautonomia
Motor neuron disease Bulbar signs (tongue atrophy, dysarthria, and No symptoms and signs of upper motor neuron
dysphagia) involvement
Hand weakness

PN: Polyneuropathy; CIDP: chronic inflammatory demyelinating polyneuropathy; NCS: nerve conduction velocity.

Figure 1. Clues for diagnosis of ATTRv amyloidosis with polyneuropathy in patients with chronic peripheral neuropathy.

Several scales can be used for the assessment. The main one is the Coutinho staging system that classifies
ATTRv amyloidosis with polyneuropathy into three stages, from 0 (asymptomatic) to 3 (patient confined to
wheelchair) [Table 3].
[39]
Dysautonomic involvement can be assessed by administering the Composite Autonomic Symptom score 31
(COMPASS 31) , a self-reported questionnaire.
[40]
Apolipoprotein A1-related amyloidosis
Apolipoprotein A1 is a protein released by the liver and the small intestine. It represents the major
constituent of high-density lipoproteins and plays a role in reverse cholesterol transport.

Hereditary amyloidosis with mutation of apolipoprotein A1 is rarely encountered.

The disease typically begins around 40 years and affects mainly the liver, gastrointestinal tract, and kidneys,
frequently inducing organ failure.

There are sixteen already-discovered mutations of apo-A1 gene. Among them, Gly26Arg mutation may
induce a length dependent polyneuropathy .
[41]

Gelsolin-related amyloidosis
The so-called Finnish type amyloidosis or hereditary gelsolin amyloidosis is a rare autosomal dominant
disorder.

Generally, the disease begins around 30 years of age, with various clinical features, including cranial and
peripheral neuropathy, cutis laxa, and corneal lattice dystrophy, variably associated with systemic
symptoms .
[42]