Elevated serum cytokines in patients. Patients have increased levels of IL-18, IL-18 binding protein (BP), IFN-γ, sCD25, BAFF, and IL12/23p40. No statistical difference was observed between the levels of Fas ligand in the patient and healthy group; however, 3 patients had elevated levels of Fas ligand (>200 pg/mL). Data are represented as mean ± standard deviation; a Mann-Whitney rank sum test was used for statistical evaluation. Multiple samples collected >6 months apart were assayed for P1 and P3. Young healthy male controls (<6 years) are indicated in red and young adult healthy controls in green. L, ligand; ns, not significant; S, soluble.