Condition | Examples |
Pre-existing lung disease | COPD, asthma, bronchiectasis, lung cancer, smoking, recurrent aspiration with gastro-oesophageal reflux disease, inhaled corticosteroids, pulmonary fibrosis, cystic fibrosis, thoracic deformities such as ankylosing spondylitis, scoliosis, previous tuberculosis, postinfectious residual cavitation, bulla or cyst, pneumoconiosis (silicosis), alveolar proteinosis |
Systemic immune deficiency | HIV infection (in particular peripheral CD4+ cell count <50 μL−1), status after organ transplantation, malignancies (haematological cancer), alcoholism, cachexia, immunosuppressive therapy (e.g. tumour necrosis factor-alpha inhibitors, corticosteroids), teething (in children with cervical lymphadenitis), age (young children and the elderly), male gender#, diabetes mellitus#, renal failure# |
Increased genetic susceptibility due to mutations of the following genes | Interferon gamma receptor gene, interleukin-12 receptor gene, signal transducer and activator of transcription 1 (STAT 1) transmembrane conductance regulator gene (cystic fibrosis), alpha 1-antitrypsin gene |
#: suspected or possible risk factors. Reproduced with permission from the publisher [12].