Elevated levels of soluble CD26 and CD30 in multiple sclerosis

Objective The activation of autoreactive T cells is a major event in the initiation of autoimmune responses in multiple sclerosis ( MS ). In addition to the T cell receptor stimulation, optimal activation of T cells requires various costimulatory molecules, such as CD 26 and CD 30, which has not been extensively studied in MS . Our aim was to explore whether the circulating levels of CD 26 and CD 30 in sera are associated with MS subtypes, inflammatory disease activity and disability in MS patients. Methods The study included 195 participants: 39 relapsing–remitting MS patients, 19 secondary‐progressive MS patients, 19 clinically isolated syndrome patients, 58 controls for sCD 26 analysis and 60 for sCD 30 analysis. The levels of sCD 26 and sCD 30 in sera were analyzed using enzyme‐linked immunosorbent assay, and the levels of interleukin‐10, tumor necrosis factor‐α and interferon‐γ were analyzed with the Luminex assay. Results We observed increased levels of sCD 26 and sCD 30 in relapsing–remitting MS , secondary‐progressive MS , and clinically isolated syndrome patients compared with the controls ( P < 0.05). Furthermore, elevated levels of sCD 30 were noticed in treated relapsing–remitting MS patients than in untreated patients ( P = 0.016), and also in converted CIS patients than in unconverted patients ( P = 0.009). Although sCD 26 and sCD 30 could not associate with clinical measures, such as the disability score or disease activity, the levels of sCD 30 correlated positively with interleukin‐10 levels ( r = 0.583, P < 0.0001) and sCD 26 levels ( r = 0.262, P = 0.046) in MS patients. Conclusion The present results suggest that the elevated levels of sCD 30 are associated with the regulatory immune responses predisposing to clinically stable phase of MS .