IL6 and Restrictive ventilatory defect: In patients with lung involvement, the levels of proinflammatory cytokines such as IFN-γ, tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), interleukin 8 (IL-8), and interleukin-12 are two or three fold increased in comparison to patients without lung involvement, and the IL-8/IL-10 ratio was 3 fold increased the level in restrictive lung disease [50,51].