Clinical spectrum time course of interstitial pneumonia with autoimmune features in patients positive for antisynthetase antibodies

- Classification criteria for antisyntehase syndrome (ASSD) are lacking.
- Lung involvement is common in antisynthetase Ab (anti-ARS) positive patients.
- Several patients diagnosed with ASSD satisfy IPAF classification criteria.
- Clinical spectrum time course heterogeneity is common in anti-ARS positive patients.
- The establishment of new classification criteria for ASSD is mandatory.