Inter-centre heterogeneity, temporal evolution, and factors associated with treatment selection and outcomes in chronic inflammatory demyelinating polyradiculoneuropathy: a multicentre, combined prospective and retrospective observational study.

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable immune-mediated neuropathy, yet real-world evidence on therapeutic strategies and their evolution over time remains limited. This study aimed to characterise prescription patterns across Italian centres, assess adherence to international guidelines, and identify clinical, structural, and temporal determinants of therapeutic decision-making.

METHODS

This multicentre, combined prospective and retrospective observational study used data from the Italian CIDP registry, including 653 patients from 24 tertiary centres from 2015 to 2025. Detailed treatment histories were collected for induction and maintenance regimens, including intravenous immunoglobulin (IVIg), corticosteroids, plasma exchange (PE), subcutaneous immunoglobulin (SCIg), and immunosuppressants. A structured questionnaire assessed centre-level factors influencing treatment choices.

FINDINGS: Marked inter-centre heterogeneity across all treatment options was observed (p < 0.001). Over time, IVIg and SCIg use increased, while corticosteroids, PE, and traditional immunosuppressants declined. Independent determinants of induction therapy included patient characteristics, treatment period, and treating centre. Lower IVIg induction doses and oral corticosteroids were associated with worse long-term outcomes. Over time, induction response rates, residual disability, and therapy suspension rates improved. Questionnaire data revealed that although guideline recommendations strongly influenced decisions, organisational constraints, local prescribing culture, and patient preferences independently shaped treatment allocation.

INTERPRETATION: CIDP management in routine clinical practice is highly heterogeneous and influenced by both clinical and structural factors. These findings underscore the need for standardised, evidence-based, and sustainable treatment pathways to reduce unwarranted variability and ensure equitable access to optimal care as therapeutic options continue to expand.

FUNDING: Grant from Regione Lombardia, Italy; Grant from Ministero della Salute, Ricerca Finalizzata; Kedrion Biopharma (Italy); CSL Behring (Italy); Humanitas Research Institute (Milan, Italy); GBS-CIDP Foundation International (USA).