Table 2.

Classification criteria for interstitial pneumonia with autoimmune features [adapted from Fischer et al. (3)].

A. Clinical domain	B. Serologic domain	C. Morphologic domain
1. Distal digital fissuring (mechanic hands) 2. Distal digital tip ulceration 3. Inflammatory arthritis or polyarticular morning joint stiffness >60 min 4. Palmar telangiectasia 5. Raynaud's phenomenon 6. Unexplained digital oedema 7. Unexplained fixed rash on the digital extensor surfaces (Gottron's sign)	1. ANA ≥1: 320 titer, diffuse, speckled, homogeneous patterns or   a) ANA nucleolar pattern (any titer) or   b) ANA centromere pattern (any titer) 2. Rheumatoid factor ≥2× upper limit of normal 3. Anti-CCP 4. Anti-dsDNA 5. Anti-Ro (SS-A) 6. Anti-La (SS-B) 7. Anti-ribonucleoprotein 8. Anti-Smith 9. Anti-topoisomerase (Scl-70) 10. Anti-tRNA synthetase (e.g., Jo-1, PL-7, PL-12; others are: EJ, OJ, KS, Zo, tRS) 11. Anti-PM-Scl 12. Anti-MDA-5	1. Suggestive radiology patterns by high-resolution computed tomography (HRCT):   a) NSIP   b) OP   c) NSIP with OP overlap   d) LIP 2. Histopathology patterns or features by surgical lung biopsy:   a) NSIP   b) OP   c) NSIP with OP overlap   d) LIP   e) Interstitial lymphoid aggregates with germinal centers   f) Diffuse lymphoplasmacytic infiltration (with or without lymphoid follicles) 3. Multi-compartment involvement (in addition to interstitial pneumonia):   a) Unexplained pleural effusion or thickening   b) Unexplained pericardial effusion or thickening   c) Unexplained intrinsic airways disease   d) Unexplained pulmonary vasculopathy

ANA, antinuclear antibody; HRCT, high-resolution computed tomography; IPAF, interstitial pneumonia with autoimmune features; LIP, lymphoid interstitial pneumonia; NSIP, non-specific interstitial pneumonia; OP, organizing pneumonia; PFT, pulmonary function testing.