Interleukin-17 and interleukin-23 are elevated in serum and cerebrospinal fluid of patients with ALS: a reflection of Th17 cells activation?

Background - There is evidence that immunological factors may involved in pathogenetic mechanisms of amyotrophic lateral sclerosis (ALS). Th17 cells are characterized by predominant production of IL-17 and are suggested to be crucial in destructive autoimmunity. Interleukin-23 (IL-23) appears to play a supporting role in the continued stimulation and survival of Th17. Patients and methods - We measured by enzyme-like immunosorbent assay (ELISA) serum and cerebrospinal fluid (CSF) levels of IL-17 and IL-23 in 22 patients with ALS and 19 patients with other non-inflammatory neurological disorders (NIND) studied as a control group. IL-17 and IL-23 serum and CSF levels were also correlated with duration of the disease, the disability level and the clinical subtype of the disease onset in patients with ALS. Results - IL-17 and IL-23 serum levels were higher in patients with ALS as compared with patients with NIND (P = 0.015 and P = 0.002 respectively). IL-17 and IL-23 CSF levels were also increased in patients with ALS (P = 0.0006 and P = 0.000001 respectively). IL-17 and IL-23 levels were not correlated with disease duration, disability scale or clinical subtype of the disease onset in ALS patients. Conclusions - Our findings suggest that these molecules may be involved in the pathogenetic mechanisms acting as potential markers of Th17 cells activation in ALS.