Serum Interleukin-40 and Soluble CD40 Ligand as Complementary Biomarkers for Disease Activity in Multiple Sclerosis...

Multiple sclerosis (MS) is a complex autoimmune disease of the central nervous system for which reliable biomarkers of disease activity remain an unmet need. Interleukin-40 (IL-40) and soluble CD40 ligand (sCD40L) have been proposed to play roles in the pathogenesis of autoimmune diseases. This study aimed to evaluate serum levels of IL-40 and sCD40L as biomarkers of disease activity in MS patients, and to compare their diagnostic and monitoring performance between MS patients and healthy controls.

One hundred twenty MS patients were recruited from the Department of MS at the Baghdad Teaching Hospital and divided into two groups based on disease status: active (n=60) and inactive (n=60). Additionally, 57 matched healthy individuals were included as controls. A sandwich enzyme-linked immunosorbent assay was used to measure the serum levels of IL-40 and sCD40L in blood samples from each participant.

Both active and inactive patient cohorts showed significantly higher serum levels of IL-40 (44.25±8.57 ng/mL and 38.98±11.31 ng/mL, respectively) compared with their control group (20.82±14.27 ng/mL) (p=0.005). Likewise, sCD40L concentrations were elevated in both active (2155.59±587.02 pg/mL) and inactive (1885.23±851.32 pg/mL) patients compared with controls (849.79±341.87 pg/mL; p=0.0006). IL-40 correlated positively with sCD40L (r=0.399, p=0.005). The receiver operating characteristic analysis showed high diagnostic performance for IL-40 (area under the curve =0.873; sensitivity 87.5%; specificity 76.7%) and sCD40L (area under the curve =0.901; sensitivity 92.5%; specificity 81.7%).

Both IL-40 and sCD40L are significantly elevated in MS and exhibit promising diagnostic validity. These biomarkers may serve as complementary tools for monitoring MS disease activity and progression, offering potential value in clinical practice and therapeutic decision-making.