High serum APRIL levels strongly correlate with disease severity in pediatric atopic eczema

Background Expression of the tumor necrosis factor ( TNF ) family member APRIL (a proliferation‐inducing ligand) is low in normal tissues but is elevated in various autoimmune diseases. Objectives This study explored serum APRIL in children with atopic eczema ( AE ) during flare and quiescence. Methods A case–control study including 50 patients with AE and 40 control subjects was conducted. The severity of AE was assessed according to each of the Leicester Sign Score ( LSS ), the Simple Scoring System ( SSS ), the SCOR ing of Atopic Dermatitis ( SCORAD ) index, and the Objective SCORAD . Serum measurements of APRIL , total immunoglobulin E, and lactate dehydrogenase were obtained in all subjects. Data were obtained during both flare and quiescence in AE subjects. Data were analyzed using the Mann–Whitney U ‐test and Pearson's correlation coefficient. P‐ values of <0.05 were considered to indicate statistical significance. Results Serum APRIL levels were significantly elevated in children with AE in comparison with control subjects during both flare and quiescence ( P < 0.0001 for both). Serum APRIL levels during AE flare and quiescence were positively correlated ( P < 0.001). Serum APRIL levels and scores on each of the LSS , SSS , and SCORAD showed significant positive correlations ( P < 0.01 for all). Conclusions Serum APRIL levels were significantly elevated in children with AE during both flare and quiescence. This confirms the importance of APRIL in the pathophysiology of pediatric AE . Serum APRIL is a reliable marker of the severity of AE in children. APRIL may be a new target in the treatment of AE .