TABLE 1.
Risk factors/predisposing factors for nontuberculous mycobacterial pulmonary disease
| Risk factor | Examples |
| Exposure | |
| Domestic | Household plumbing fixtures |
| Showerheads | |
| Taps | |
| Humidifiers | |
| Heating/ventilation systems | |
| Homelessness, incarceration or institutionalisation | |
| Occupational | Mining |
| Healthcare | |
| Steel industry | |
| Farming and breeding | |
| Veterinary | |
| Waste collection | |
| Fish farming | |
| Geology and speleology | |
| Recreational | Gardening |
| Camping | |
| Horse-riding | |
| Fishing | |
| Swimming | |
| Hot tubs | |
| Damage substrate | |
| Pre-existing lung disease | CF |
| Non-CF bronchiectasis | |
| Primary ciliary dyskinesia | |
| Previous pulmonary tuberculosis | |
| Asthma | |
| COPD | |
| Alpha-1 antitrypsin deficiency | |
| Pneumoconiosis (especially silicosis) | |
| ILDs (especially pulmonary alveolar proteinosis) | |
| ABPA | |
| Williams–Campbell syndrome | |
| Congenital tracheobronchomegaly (Mounier–Kuhn syndrome) | |
| Demographic and constitutional factors (Lady Windermere syndrome) | Older age (>40–70 years) |
| Female sex | |
| Non-smoking history | |
| Slender body habitus | |
| Low BMI/low body fat | |
| Scoliosis | |
| Pectus excavatum | |
| Flattened thoracic cage (platythorax) | |
| “Straight back syndrome” | |
| Low vitamin D | |
| GORD | |
| Defective immunity | |
| Primary immunodeficiency | Mutations in the IFN-γ/IL-12 pathway (e.g. IFNγ-R1, IFN-γ-R2, IL-12R, STAT, tyrosine kinase 2) |
| Deficiency in NF-κB essential modulator | |
| Defective macrophage and dendritic cell function (e.g. chronic granulomatous disease) | |
| Defective T-cells (e.g. CVID, SCID) | |
| Complement C4 deficiency | |
| Acquired immunodeficiency | HIV-AIDS |
| Acquired neutralising anti-IFN-γ antibodies | |
| Diabetes mellitus | |
| Chronic kidney disease | |
| Malignancy | |
| Alcohol abuse | |
| Medications | Oral corticosteroids |
| Inhaled corticosteroids | |
| TNF-α antagonists | |
| Solid organ transplantation (particularly lung transplant) | |
| Haematopoietic stem cell transplantation | |
| Cancer chemotherapy |
CF: cystic fibrosis; COPD: chronic obstructive pulmonary disease; ILD: interstitial lung disease; ABPA: allergic bronchopulmonary aspergillosis; BMI: body mass index; GORD: gastro-oesophageal reflux disease; IFN: interferon; IL: interleukin; STAT: signal transducer and activator of transcription 1; CVID: common variable immunodeficiency; SCID: severe combined immune deficiency; TNF: tumour necrosis factor.