A comparison of IL-17 and IL-34 concentrations in the cerebrospinal fluid of patients with acute inflammatory demyelinating neuropathy and chronic inflammatory demyelinating polyneuropathy.

Objective: The role of interleukins, such as IL-17 and IL-34, in the pathogenesis of autoimmune diseases has been established in the literature. In the current study, we aimed to identify the concentrations of IL-17 (IL-17A, IL-17F) and IL-34 in the cerebrospinal fluid (CSF) of patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and acute inflammatory demyelinating neuropathy (AIDN).

Methods: We included in this study 8 patients with CIDP (none of them receiving immunomodulatory or immunosuppressant therapy), 7 patients with Guillain-Barre syndrome (GBS, AIDN), and 7 control subjects. The CIDP and AIDN diagnoses were made by clinical evaluation and electrophysiological investigations according to international criteria. CSF samples were obtained appropriately, and the levels of IL-17A, IL-17F, and IL-34 were measured by ELISA kits.

Results: The concentrations of IL-17A, IL-17F, and IL-34 were higher in those with CIDP and AIDN compared to the controls (p=0.005, p=0.01, and p=0.001, respectively). While IL-34 levels were significantly higher in AIDN patients than in CIDP patients (p=0.04), there were no significant differences between the AIDN and CIDP groups with regard to the levels of IL-17A and IL-17F (p=0.4 and p=0.2, respectively).

Conclusion: Our results indicate that IL-17A, IL-17F, and IL-34 levels may have a role in CIDP and AIDN. Furthermore, the difference in the IL-34 levels of patients with AIDN and CIDP may indicate an important difference between the pathogenesis of these two sets of the disease.