Enhanced plasma levels of soluble LIGHT in patients with hepatitis C and rheumatoid arthritis. Plasma levels of LIGHT was measured by ELISA in patients with hepatitis C (n = 10), rheumatoid arthritis (n = 22) and 16 healthy controls. Soluble LIGHT concentration was normalized to cell numbers (pg/1 million cells). The data represent the mean ± SD of three independent experiments performed (Figure 7). ***P < 0.0005 vs healthy controls.