CALCA and Arthritis: Onset of arthritis before pulmonary manifestation; chronic arthritis: uxtaarticular demineralization, joint space narrowing, joint erosions, pannus formation; mixed cellular inflammation of the lung: granulocytes, lymphocytes, T cells, macrophages in the peribronchial and perivas‐cular areas, increased anti‐CCP antibodies, TNF‐α, BAX, TGF‐β, IL‐6, LPO, 8‐OHdG, and SP‐D.