Key Information
Abstract
Background and aims
Hereditary transthyretin amyloidosis (ATTRv) should be considered in patients diagnosed with intravenous immunoglobulin (IVIg)-resistant chronic inflammatory demyelinating polyradiculoneuropathy (IVIg-NR CIDP). In this 1-year long, retrospective, multicentric study, an online questionnaire was sent to 1100 French healthcare professionals (HCPs) investigating: (i) how many IVIg-NR CIDP patients they followed; (ii) how many IVIg-NR CIDP patients had undergone TTR gene analysis; and (iii) how many IVIg-NR CIDP patients were eventually diagnosed with ATTRv. The questionnaire was sent every 3 months for 1 year and contained information on ATTRv clinical manifestations and diagnosis.
Results
One-hundred and ten (10%) HCPs responded. A total of 2131 patients with CIDP were identified, including 315 (22.1%) with IVIg-NR CIDP. TTR gene analysis was performed in 144 patients and was positive in 43 cases (29.9%).
Conclusions
This study demonstrates that ATTRv should be investigated systematically in patients diagnosed with IVIg-NR CIDP. HCP-directed information campaigns are useful for modifying diagnostic practices.
Supplementary Information
The online version contains supplementary material available at 10.1186/s13023-025-03589-4.
Keywords: Chronic inflammatory demyelinating polyradiculoneuropathy, Hereditary transthyretin amyloidosis, Intravenous immunoglobulins
Background
Chronic inflammatory demyelinating-like polyradiculoneuropathy (CIDP) is an autoimmune disease of the peripheral nervous system affecting myelin. CIDP is rare, with a reported prevalence ranging from 0.15 to 8.9 cases/100 000 individuals [1external link, opens in a new tab–3external link, opens in a new tab] and may present at any age. The typical form is characterized by a symmetrical proximal-distal sensorimotor deficit of the upper and lower limbs with gradual onset over at least 8 weeks [1external link, opens in a new tab]. The clinical course of CIDP varies and can be either progressive or relapsing-remitting.
The diagnosis of CIDP is based on a combination of clinical, electrophysiological, biological and paraclinical data [4external link, opens in a new tab, 5external link, opens in a new tab]. According to the 2021 criteria of the European Academy of Neurology/Peripheral Nerve Society (EAN/PNS), the spectrum of CIDP now includes typical CIDP and four variants: distal, multifocal/focal, motor and sensory CIDP [4external link, opens in a new tab]. CIDP variants are more difficult to diagnose, especially focal and multifocal variants, leading to diagnostic delays [4external link, opens in a new tab, 6external link, opens in a new tab]. In an attempt to simplify the diagnosis, the levels of diagnostic certainty have been reduced from three (definite, probable, possible CIDP) to two (CIDP and possible CIDP) since there was no difference in the diagnostic accuracy of criteria for probable and definite CIDP [4external link, opens in a new tab].