As published in NEJM, 2006, 345:25 2655-2709. Limited or diffuse SSL with lung involvement defined as active alveolitis on bronchoalveolar lavage (BAL) or ground-glass opacity on CT, a DLCO < 80% predicted or decrease in lung function (DLCO/VA,DLCO, FVC) of 10% or more in last 12 months.