[Prognostic and monitoring biomarkers in chronic inflammatory demyelinating polyneuropathy]

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a clinical entity with significant phenotypic variability both in its onset and in its course. Therefore, it is important to have objective biomarkers with which to monitor its evolution. In this review we present clinical, neurophysiological, neuroimaging, blood and cerebrospinal fluid (CSF) biomarkers for the monitoring and prognosis of CIDP.

Different clinical tools have been developed and validated to monitor CIDP by assessing strength and disability. However, the best parameter for monitoring gait remains to be determined. Monitoring by neurophysiological examination is also widespread and the amplitude of the compound muscle action potential is the most commonly used. More recently, the Motor Unit Number Index sum score has been developed, which is an accurate and reproducible technique. The role of nerve ultrasonography is under development and a correlation between clinical evolution and ultrasound findings has been described. Multiple biomarkers have been described in blood and CSF, including antinodal/paranodal antibodies, neurofilament light chain, serum immunoglobulin G levels and CSF sphingomyelin levels. Genetic variants and cytokines associated with prognosis and response to treatment have also been described.

One of the most important challenges in the management of CIDP is the monitoring of clinical changes after treatment initiation. The combination of biomarkers that allow an accurate understanding of the disease is crucial for the optimal management of CIDP.