Connective Tissue Disease-associated Interstitial Lung Diseases (CTD-ILD) Epidemiology Non-interventional Study (NIS)

Inclusion Criteria: For newly data collection: * Male and female Patients. * Patients over 18 years old. * Patient who gives his/her signed informed consent to be able to use information about their condition. * Patient who has the diagnosis of: rheumatoid arthritis, connective tissue disease (CTD) (systemic sclerosis or scleroderma; inflammatory myopathy: antisynthetase, dermatomyositis, polymyositis, mixed connective tissue disease; systemic lupus erythematosus; primary Sjögren syndrome; pulmonary fibrosis associated with non-specific autoimmunity; primary systemic vasculitis; psoriasis, anchylosing spondylitis, reactive arthritis) Spondyloarthritis (SpA) or sarcoidosis, (accordingly with the updated clinical criteria for each pathology). Patient with any interstitial lung diseases (ILD) diagnosed clinically and by a high-resolution computed tomography study with an interstitial pattern (supervised by an expert radiologist). For existing data collection: * Medical Records from patients with whom contact was permanently lost for any reason since 2012 till the study start date. * Medical Records from male and female Patients. * Medical Records from patients over 18 years old. * Medical Records of patients that have at least: patient initials, date of birth, gender, date of diagnosis, full diagnosis of: * Patient who has the diagnosis of: rheumatoid arthritis, CTD (systemic sclerosis or scleroderma; inflammatory myopathy: antisynthetase, dermatomyositis, polymyositis, mixed connective tissue disease; Systemic lupus erythematosus; primary Sjögren syndrome; pulmonary fibrosis associated with non-specific autoimmunity; primary systemic vasculitis; psoriasis, anchylosing spondylitis, reactive arthritis) SpA or Sarcoidosis, (accordingly with the updated clinical criteria for each pathology). * Patient with any ILD diagnosed clinically and by a high-resolution computed tomography study with an interstitial pattern (supervised by an expert radiologist). Exclusion Criteria: * Patient with a biopsy definition of usual interstitial pneumonitis, related to any other non-CTD. * Patient with post-chemotherapy or post-radiotherapy pneumonitis. * Medical Records of patients without full diagnostic of ILD (clinically and by biopsy or high-resolution computed tomography).