Interstitial lung disease (ILD) is a relatively frequent manifestation
of systemic autoimmune rheumatic disorders (SARDs), including systemic
sclerosis (SSc), rheumatoid arthritis (RA), idiopathic inflammatory
myopathies (IIM), systemic lupus erythematosus (SLE), primary Sjogren's
syndrome (pSS), and anti-neutrophil cytoplasmic antibody (ANCA)
associated vasculitis. Interstitial pneumonia with autoimmune features
(IPAF) has been proposed to describe patients with ILD who have clinical
or serological findings compatible with SARDs but they are not
sufficient for a definite diagnosis. ILD may present with different
patterns among patients with SARDs, but most commonly as nonspecific
interstitial pneumonia (NSIP), with the exception of RA and ANCA
vasculitis that more often present with usual interstitial pneumonia
(UIP). The natural history of ILD is quite variable, even among patients
with the same SARD. It may present with subclinical features following a
slow progressively course or with acute manifestations and clinically
significant rapid progression leading to severe deterioration of
pulmonary function and respiratory failure. The radiographic pattern of
ILD, the extent of the disease, the baseline pulmonary function, the
pulmonary function deterioration rate over time and clinical variables
related to the primary SARD, such as age, sex and the clinical
phenotype, are considered prognostic factors for SARDs-ILD associated
with adverse outcomes and increased mortality. Different modalities can
be employed for ILD detection including clinical evaluation, pulmonary
function tests, high resolution computed tomography and novel techniques
such as lung ultrasound and serum biomarkers. ILD may determine the
clinical outcome of SARDs, since it is associated with significant
morbidity and mortality and therefore screening of patients with SARDs
for ILD is of great clinical importance