Evaluation of CD137 and CD137L Transcript Levels and the Serum sCD137 in Immune-mediated Polyneuropathy.

Background: Abnormal humoral and cellular immune responses have been reported in immune-mediated polyneuropathies. CD137, as a costimulatory molecule and a TNF receptor superfamily member, has been demonstrated to have a key role in the pathogenesis of many autoimmune as well as inflammatory disorders. Objective: To evaluate the transcripts levels of CD137, its ligand (CD137L), and the serum levels of soluble CD137 (sCD137) in patients with immune-mediated polyneuropathy. Methods: A total of 45 patients and 46 sex and age-matched healthy individuals were enrolled in the study. CD137 and CD137L transcript levels were assessed by the Real-Time PCR, and the serum level of sCD137 was measured using the ELISA technique. The Bayesian regression model was used for statistical analysis at the 0.05 significance level in R 4.1.0 statistical environment. Results: Transcript levels of the CD137 and CD137L were higher in polyneuropathy patients in comparison with the healthy subjects (P=0.006 for both). Conversely, the mean level of sCD137 was significantly lower in the sera of patients compared to the controls (P<0.001). Conclusion: Our findings point to the possible role of CD137 and CD137L in immune-mediated polyneuropathy pathogenesis. More investigations are required to clarify the exact contributions of the mentioned molecules to the pathogenesis of immune-mediated polyneuropathies.