RBC: Red blood cells; HBG: Haemoglobin; WBC: White blood cells; PLT: Platelets; ANA: anti-nuclear antibody; CCP: anti-cyclic citrullinated peptide; RF: rheumatoid factor; ESR: erythrocyte sedimentation rate; AKA: antikeratin antibody; APF: anti-perinuclear factor; IgG: Immunoglobulin G; PGA: physician global access; TLC: total lung capacity; FVC: forced vital capacity; FEV1: the first second forced expiratory volume; DLCO SB: carbon monoxide diffusion capacity single-breath method;GGO: ground glass opacity;