Atypical CIDP: diagnostic criteria, progression and treatment response. Data from the Italian CIDP Database

Abstract

ObjectivesA few variants of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) have been described, but their frequency and evolution to typical CIDP remain unclear. To determine the frequency and characteristics of the CIDP variants, their possible evolution to typical CIDP, and treatment response.MethodsWe applied a set of diagnostic criteria to 460 patients included in a database of Italian patients with CIDP. Clinical characteristics and treatment response were reviewed for each patient. The Kaplan-Meier curve was used to estimate the progression rate from atypical to typical CIDP.ResultsAt the time of inclusion, 376 (82%) patients had a diagnosis of typical CIDP while 84 (18%) had atypical CIDP, including 34 (7%) with distal acquired demyelinating symmetric neuropathy (DADS), 17 (4%) with purely motor, 17 (4%) with Lewis-Sumner syndrome (LSS) and 16 (3.5%) with purely sensory CIDP. Based on retrospective review of the symptoms and signs present at onset and for at least 1 year, 180 (39%) patients had an initial diagnosis compatible with atypical CIDP that in 96 (53%) patients evolved to typical CIDP. Mean disease duration was longer in patients evolving to typical CIDP than in those not evolving (p=0.0016). Patients with DADS and LSS had a less frequent response to immunoglobulin than those with typical CIDP, while patients with purely motor and sensory CIDP had a similar treatment response.ConclusionsThe proportion of patients with atypical CIDP varies during the disease course. DADS and LSS have a less frequent response to intravenous immunoglobulin compared with typical CIDP, raising the possibility of a different underlying pathogenetic mechanism.

The Misdiagnosis of CIDP: A Review

“…Sensory CIDP may occur in 3.5-14% of patients, while the motor variant has been reported in 4-9% of all patients with CIDP. Similar estimates have been described for asymmetric CIDP, ranging between 4 and 14% of the entire pool of CIDP patients [21,22]. Considering the rarity of CIDP to begin with, it is not a practical expectation for clinicians without substantial familiarity with CIDP to be able to recognize the rare variants of this rare disease with any high degree of certainty.…”

“…The rarity of ''atypical'' CIDP also presents challenges. Although between 31 and 48% of patients may have an ''atypical'' phenotype early in the disease course, substantial numbers evolve to a ''typical'' phenotype such that over time ''atypical'' patterns may represent only 18% of the full pool of CIDP patients [21,22]. The individual ''atypical'' variants hence become even scarcer and harder to identify.…”

Antibodies to neurofascin, contactin-1, and contactin-associated protein 1 in CIDP

“…The response rates to treatments were reported to be heterogeneous in subgroups of patients, and the availability of specific biomarkers could provide guidance for patient-tailored immunotherapeutic options. 1 Antibodies to cell adhesion molecules of the paranodal complex, neurofascin-155 (Nfasc155), contactin-1 (CNTN1), and contactin-associated protein 1 (Caspr1), and to nodal neurofascin-140/186 (Nfasc140/186) have been identified in various percentages of patients with CIDP, with IgG4 being the predominant isotype of these antibodies. [2][3][4][5][6][7][8] Moreover, IgG4seropositive patients show specific clinical features and a poor response to IVIG.…”

Atypical chronic inflammatory demyelinating polyneuropathies

“…In their JNNP paper, Donuddu and colleagues7 reported the results of an Italian multicentre database study involving a total of 460 patients with CIDP . At the time of registration more than 1 year after onset, 82% of them had typical CIDP, and the remaining 18% had atypical CIDP.…”