Characterization of IL-17AA and IL-17FF in rheumatoid arthritis and multiple sclerosis

IL-17 is thought to play a prominent role in immune disorders. Sensitive and specific IL-17AA and IL-17FF assays were developed and used to determine levels in serum and cerebrospinal fluid (CSF) from patients with rheumatoid arthritis and relapsing remitting multiple sclerosis (RRMS). Results: Qualified assays detected IL-17AA and IL-17FF in healthy and disease samples. Serum IL-17AA was significantly higher in rheumatoid arthritis and RRMS as compared with normal healthy subjects. IL-17AA was also elevated in RRMS CSF as compared with normal healthy subjects; although correlation was observed between serum levels of the two isoforms, no correlation was detected between serum and CSF levels. Conclusion: Reliable determination of IL-17 isoforms in the systemic and CNS compartments sheds light on the involvement of IL-17AA and IL-17FF in autoimmunity.