TY - JOUR T1 - Atypical CIDP: diagnostic criteria, progression and treatment response. Data from the Italian CIDP Database JF - Journal of Neurology, Neurosurgery & Psychiatry JO - J Neurol Neurosurg Psychiatry SP - 125 LP - 132 DO - 10.1136/jnnp-2018-318714 VL - 90 IS - 2 AU - Pietro Emiliano Doneddu AU - Dario Cocito AU - Fiore Manganelli AU - Raffaella Fazio AU - Chiara Briani AU - Massimiliano Filosto AU - Luana Benedetti AU - Anna Mazzeo AU - Girolama Alessandra Marfia AU - Andrea Cortese AU - Brigida Fierro AU - Stefano Jann AU - Ettore Beghi AU - Angelo Maurizio Clerici AU - Marinella Carpo AU - Angelo Schenone AU - Marco Luigetti AU - Giuseppe Lauria AU - Giovanni Antonini AU - Tiziana Rosso AU - Gabriele Siciliano AU - Guido Cavaletti AU - Giuseppe Liberatore AU - Lucio Santoro AU - Erdita Peci AU - Stefano Tronci AU - Marta Ruiz AU - Stefano Cotti Piccinelli AU - Antonio Toscano AU - Giorgia Mataluni AU - Laura Piccolo AU - Giuseppe Cosentino AU - Mario Sabatelli AU - Eduardo Nobile-Orazio A2 - , Y1 - 2019/02/01 UR - http://jnnp.bmj.com/content/90/2/125.abstract N2 - Objectives A 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.Methods We 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.Results At 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.Conclusions The 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. ER -