Blood bile acid profiles in chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated neuropathy with demyelinating features like Guillain-Barréé syndrome (GBS). Despite established diagnostic criteria, the lack of specific blood biomarkers highlights the need for novel markers to improve early diagnosis and disease monitoring. Bile acids (BA), cholesterol-derived molecules with immune modulatory properties, have been explored as biomarkers in immune-mediated diseases. This study investigates BA profiles in CIDP and evaluates their potential for diagnosing CIDP.

Patients with treatment-naïve immune-mediated polyneuropathies (CIDP and GBS) and age-matched healthy controls (HCs) were recruited from a tertiary referral hospital. Their plasma BA profiles were analyzed using liquid chromatography-mass spectrometry. A supervised machine learning model was employed to assess the BA profiles, and a simplified tree-based algorithm was developed based on the feature importance to differentiate CIDP, GBS, and HC.

This study included 36 CIDP patients, 70 GBS patients, and 41 HCs. Compared with HCs, CIDP patients showed elevated levels of glycochenodeoxycholic acid (GCDCA, 1,306.64 vs. 614.16 nM, P < 0.001) and glycohyocholic acid (GHCA, 16.95 vs. 6.04 nM, P < 0.001). CIDP patients also exhibited higher levels of GCDCA (1,306.64 vs. 734.44 nM, P < 0.001) and cholenic acid (8.25 vs. 4.41 nM, P < 0.001) compared to GBS patients. The support vector machine model incorporating BA profiles demonstrated strong discriminatory power (AUROC: 0.878), while a simplified tree-based algorithm using four key features achieved better performance (AUROC: 0.929).

BA profiles have potential as diagnostic biomarkers for CIDP, enabling precise and timely patient management.