Overview of different forms of pulmonary alveolar proteinosis (PAP) [5, 7, 10]
| Autoimmune PAP (>90%) | |
| GM-CSF antibodies | |
| Secondary PAP (5–10%) | |
| Toxic inhalation | Inorganic and organic dusts Vapours |
| Haematological disorders | Myelodysplastic syndrome Acute lymphoblastic leukaemia Acute myeloid leukaemia Chronic myeloid leukaemia Hodgkin's lymphoma etc. |
| Infections | Cytomegalovirus Mycobacterium tuberculosis HIV Nocardia Pneumocystis jirovecii |
| Other malignancies | Adenocarcinoma Glioblastoma Melanoma |
| Immunodeficiency | Monoclonal gammopathy Selective IgA deficiency Severe combined immunodeficiency |
| Others | Membranous glomerulonephritis Dermatomyositis Lung transplantation |
| Genetic PAP (2%) | |
| Mutations with involvement of surfactant production (PAP-like diseases) | SFTPB, SFTPC, ABCA3, NKX2-1 |
| Mutations of GM-CSF receptor | CSF2RA and CSF2RB (α or β subunit) |
| Lysinuric protein intolerance | SLC7A7 |
| Mutations in macrophages and degradation of surfactant | GATA2 |
| Mutations in telomerase complex | TERT |
GM-CSF: granulocyte–macrophage colony-stimulating factor.