Classification of enrolled subjects according to their clinical, radiological, laboratory and histopathology features
| History | Age at start of symptoms years | Age at referral years | Fan score | Spirometry | Chest CT | Histopathology | Significant laboratory/BAL findings | Final opinion | |
| 1 | Exposure to doves and chicken | 4 | 9 | 5 | RVD | Consolidation, septal thickening | GLD | Specific Dx: chronic HP | |
| 2 | Exposure to doves and chicken | 2.5 | 3.5 | 2 | Not done# | Reticulations/diffuse micronodules | GLD | Eosinophilia | Specific Dx: chronic HP |
| 3 | Exposure to doves/benzene/hookah | 3.5 | 4 | 3 | Not done# | GGO/consolidation/reticulations | Interstitial inflammation more marked around BVB | Eosinophilia | Specific Dx: subacute HP |
| 4 | Recurrent pneumonias | 1 | 5 | 5 | RVD | GGO/air trapping/septal thickening | GLD | Elevated ESR/DHR: defective response | Specific Dx: CGD (PID) |
| 5 | Recurrent skin abscesses /previous pulmonary TB infection | 6.5 | 10 | 4 | MVD | Multiple findings (figure 2) | Not done | Elevated ESR/DHR: defective response | Specific Dx: CGD (PID) |
| 6 | Recurrent pneumonias | 8 | 13 | 5 | RVD | GGO/air trapping/septal thickening/reticulations/consolidation | GLD | Elevated ESR/DHR: defective response | Specific Dx: CGD (PID) |
| 7 | Recurrent pustular skin lesions | 5 | 8 | 4 | RVD | GGO/air trapping/septal thickening | GLILD | Elevated ESR/low NK cells and CD4/elevated immunoglobulins/negative viral serology | Specific Dx: GLILD (non-CVID related) |
| 8 | Familial death of ILD (uncle)/chILD onset after severe pneumonia | 6 | 8 | 5 | RVD | GGO/honey combing/reticulations | Severe fibrotic NSIP (honeycomb lung) | Negative viral serology and immune studies No evidence of microbial infection (by BAL) | Specific Dx: IP (fibrotic NSIP-honeycomb lung)¶ |
| 9 | Dyspnoea since birth | Since birth | 7 | 5 | RVD | GGO (with predominant affection of lower lobes), microcysts | Mixed fibrotic NSIP and DIP | Specific Dx: IP (NSIP/DIP)¶ | |
| 10 | GDD/familial death of undiagnosed ILD (sibling) | 5.5 | 6 | 2 | Not done# | GGO/air trapping | NSIP (cellular) | Specific Dx: IP (NSIP)¶ | |
| 11 | Familial death of undiagnosed ILD in the 4th decade (grandparent) | Since birth | 11 | 4 | MVD | Emphysema/lower lobes tiny ground-glass nodules (tree-in-bud pattern) | BPIP | Negative immune studies | Specific Dx: IP (BPIP)¶ |
| 12 | Familial death of undiagnosed ILD in the 4th decade (grandparent) | Since birth | 5 | 5 | RVD | Air trapping/hyperinflation/lower lobes tiny ground-glass nodules (tree-in-bud pattern) | Parents refused (cases 11 and 12 are siblings) | Negative immune studies | Suggestive Dx: familial ILD of unidentified aetiology |
| 13 | GDD | Since birth | 8 | 4 | Not done# | GGO/air trapping | Chronic bronchiolitis/interstitial chronic inflammation | Specific Dx: chILD related to SAD with background IP+ | |
| 14 | GDD | 0.25 | 5 | 4 | Normal | Ground-glass nodules 2–3 mm (centrilobular and peri-bronchial distribution) | Chronic bronchiolitis/interstitial chronic inflammation | Specific Dx: chILD related to SAD with background IP+ | |
| 15 | NICU admission at birth for 2 months/full term | Since birth | 14 | 2 | MVD | GGO (a few show crazy paving) | Chronic bronchiolitis/interstitial chronic inflammation | Specific Dx: chILD related to SAD with background IP+ | |
| 16 | Puffy fingers/digital tip ulcers/sclerodactyly/induration proximal to MCP (late) | 4 | 8 | 4 | Not done# | Bibasilar GGO | BPIP + focal OP | Abnormal nail-fold capillaries | Specific Dx: Systemic sclerosis |
| 17 | Haemoptysis/admitted twice for blood transfusion for severe microcytic anaemia | 4 | 5 | 2 | Normal | GGO | Not done | BAL: HLM >60% of cells/other causes of DAH were excluded | Specific Dx: IPH |
| 18 | Haemoptysis/admitted six times for blood transfusion for severe microcytic anaemia | 5.5 | 7 | 2 | RVD | GGO | Not done | BAL: HLM >45% of cells/other causes of DAH were excluded | Specific Dx: IPH |
| 19 | Progressive dyspnoea over 2 months | 11 | 11 | 5 | Not done# | Cysts (sparing CPA)/GGO/tiny nodules | Death before any invasive tests | Suggestive Dx: LCH | |
| 20 | 1 | 3.5 | 4 | Not done# | Cysts (sparing CPA)/GGO | Dropped out | Suggestive Dx: LCH | ||
| 21 | History of pulmonary TB | 3.5 | 4.5 | 5 | Not done# | GGO/reticulations/atelectatic bands | Clinically improving (not done) | Negative immune studies | Specific Dx: post-infectious chILD (post-TB) |
| 22 | Start of disease following attack of severe pneumonia | 6 | 6 | 4 | RVD | GGO | OP and reactive fibrous pleuritis | Negative immune studies | Specific Dx: post-infectious chILD (OP) |
CT: computed tomography; BAL: bronchoalveolar lavage; RVD: restrictive ventilatory dysfunction; GLD: granulomatous lung disease; Dx: diagnosis; HP: hypersensitivity pneumonitis; GGO: ground-glass opacities; BVB: bronchovascular bundles; ESR: erythrocyte sedimentation rate; DHR: dihydrorhodamine test; CGD: chronic granulomatous disease; PID: primary immune deficiency; TB: tuberculosis; MVD: mixed ventilatory dysfunction; GLILD: granulomatous lymphocytic interstitial lung disease; NK: natural killer; CVID: common variable immune deficiency; ILD: interstitial lung disease; chILD: childhood interstitial and diffuse lung diseases; NSIP: nonspecific interstitial pneumonia; IP: interstitial pneumonia; DIP: desquamative interstitial pneumonia; GDD: global developmental delay; BPIP: bronchiolocentric pattern of interstitial pneumonias; SAD: small airways disease; NICU: neonatal intensive care unit; MCP: metacarpophalangeal joint; OP: organising pneumonia; HLM: haemosiderin-laden macrophages; DAH: diffuse alveolar haemorrhage; IPH: idiopathic pulmonary haemosiderosis; CPA: costophrenic angle; LCH: Langerhans cell histiocytosis. #: too young or too dyspnoeic to do the test or suffering from global delay (noncooperative); ¶: further genetic testing required to exclude surfactant dysfunction mutation; +: future genetic studies are also warranted for this group, as symptom onset was at birth or shortly after birth.