TABLE 1

Classification criteria of interstitial pneumonia with autoimmune features

  • 1. Presence of an interstitial pneumonia (by HRCT or surgical lung biopsy), and

  • 2. Exclusion of alternative aetiologies, and

  • 3. Does not meet criteria of a defined connective tissue disease, and

  • 4. At least one feature from at least two of these domains:

  •   A. clinical domain

  •   B. serological domain

  •   C. morphological domain

A. Clinical domain
  •   1. Distal digital fissuring (i.e. “mechanic's hands”)

  •   2. Distal digital tip ulceration

  •   3. Inflammatory arthritis or polyarticular morning 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)

B. Serological domain
  •   1. ANA ≥1:320 titre, diffuse, speckled, homogeneous patterns or any titre for nuclear and centromere pattern

  •   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, EJ, OJ, KS, Zo, tRS)

  •   11. Anti-PM/Scl

  •   12. Anti-MDA-5

C. Morphological domain
 1. Suggestive radiology patterns by 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 centres

  •    f.  Diffuse lymphoplasmacytic infiltration (with or without lymphoid follicles)

 3. Multicompartment involvement (in addition to interstitial pneumonia):
  •    a. Unexplained pleural effusion or thickening

  •    b. Unexplained pericardial effusion or thickening

  •    c. Unexplained intrinsic airways disease# (by PFT, imaging or pathology)

  •    d. Unexplained pulmonary vasculopathy

HRCT: high-resolution computed tomography; ANA: antinuclear antibody; ds: double-stranded; SS: Sjögren syndrome; NSIP: nonspecific interstitial pneumonia; OP: organising pneumonia; LIP: lymphoid interstitial pneumonia; PFT: pulmonary function testing. #: includes airflow obstruction, bronchiolitis or bronchiectasis. Reproduced from [6] with permission.