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Introduction Interstitial lung disease (ILD) is associated with dcSSc but may be observed in lcSSc, with features not clearly defined, but antiScl70.Material and Methods To characterize risk factors and prognosis of lcSSc-ILD, the retrospective study CP175 included EUSTAR patients arrayed according to skin subset and presence/absence of ILD on HRCT at enrollment (baseline). Disease features were analyzed for risk factors and survival of lcSSc patients with: (i) ILD at baseline (multivariable logistic), (ii) incident ILD during follow-up (Cox models), and (iii) progressive-ILD.Results Baseline HRCT was available in 5953/8153 (73%) lcSSc cases (vs 3248/3974[81%] dcSSc; p<0.001), more frequently with coexisting anti-Scl70 (OR 1.5, CI 1.3-1.8), lower FVC and DLCO (OR 0.99 both), but less frequently with serum ACA (OR 0.7, CI 0.6-0.8).At baseline (figure 1), 36% (2127/5953) lcSSc patients had ILD, in association with older age (OR 1.03, CI 1.02-1.03), digital ulcers (OR 1.18, CI 1.00-1.38), skin thickening proximal to metacarpophalangeal joints (OR 1.14, CI 1.01-1.29), esophageal involvement (OR 1.18, CI 1.04-1.34), anti-Scl70 (OR 1.98, CI 1.7-2.3), lower FVC (OR 0.99, CI 0.98–0.99) and DLCO (OR 0.98, CI 0.97-0.98). Serum ACA were protective (OR 0.28, CI 0.24-0.32), also with coexisting anti-Scl70+ or anti-RNAPOL+ (OR 0.3, CI 0.2-0.4).Among ACA+ lcSSc cases, skin fibrosis proximal to metacarpophalangeal (OR 1.3, CI 1.03-1.6) and concurrent anti-Scl70 (OR 2.4, CI 1.7-3.4) were risk factors for ILD. Among anti-Scl70+ lcSSc patients, digital ulcers increased ILD risk (OR 1.5, CI 1.1-2.0). In lcSSc, ILD extension>20% (19% vs 31%) and honeycombing (14% vs 22%) were less frequent with ACA.Among 3826 lcSSc without baseline ILD, 443 developed it during follow-up [incidence rate 6% person-years: highest with anti-Scl70 (14%), lowest with ACA (4%)]. Risk factors included age (HR 1.03, CI 1.02-1.04), male sex (HR 1.4, CI 1.1-1.9), anti-Scl70 (HR 1.7, CI 1.3-2.1), lower FVC and DLCO (HR 0.99 both); telangiectasias (HR 0.6, CI 0.5-0.8) and ACA (HR 0.4, CI 0.4-0.6) were protective (figure 2).Among lcSSc, overall survival was significantly impacted by ILD; patients with lcSSc-ILD had better survival than dcSSc-ILD.Of 472 ILD patients with available follow-up, 64 (14%) were progressors within the first year, showing significantly worse survival compared to non-progressors.Conclusions ILD is found in 36% lcSSc patients, the incidence rate being 6% person-years, carries a poor prognosis and may progress over time. Early identification is crucial for establishing proper treatment, supporting the inclusion of lcSSc-ILD patients in trials and underscoring the need for risk-adapted screening/monitoring protocols.Abstract OC.02 Figure 1Risk factors for ILD at baseline in IcSScAbstract OC.02 Figure 2Risk factors for incident ILD in IcSSc