General Concepts in CTDS-ILD

Lessons from the New Classification of Idiopathic Interstitial Pneumonias 

Episodes of rapid deterioration have been described in idiopathic NSIP and more recently in CTDs-ILD, resembling acute exacerbations of IPF and featuring DAD superimposed UIP or fibrotic NSIP (21). In a recent study, acute exacerbations occmred in 4 of 93 patients with histologically proven CTDs-ILD including 3 with RA-UIP and 1 with SSc-NSIP (21). The estimated one-year frequency was 5.6% among aU patients with CTDs-UIP, but was higher in those with RA-UIP. As in IIPs, the outcome was poor. 

A detailed history, review of systems, and physical examination are critical in the recognition of occult CTD (1). The measurement of muscle enzymes should be part of routine investigation. Appropriate immunological laboratory tests include rheumatoid factor (RF), antinuclear antibodies (ANA), and extractable nuclear antigens, a panel that measures the most common antigens that are responsible for a positive ANA (1). 

It should be recognized that the borders between IIPs and CTDs-ILD are often blurred. ILD may precede the systemic manifestations of CTD by several months or years, especially in RA or DM/DM (1). Even in the absence of a 

The detection and management of the CTDs-ILD is usefully conceptualized as a series of key questions. 

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