PT  - JOURNAL ARTICLE
AU  - Showalter, Kimberly
AU  - Hoffmann, Aileen
AU  - Rouleau, Gerald
AU  - Aaby, David
AU  - Lee, Jungwha
AU  - Richardson, Carrie
AU  - Dematte, Jane
AU  - Agrawal, Rishi
AU  - Chang, Rowland W.
AU  - Hinchcliff, Monique
TI  - Performance of Forced Vital Capacity and Lung Diffusion Cutpoints for Associated Radiographic Interstitial Lung Disease in Systemic Sclerosis
AID  - 10.3899/jrheum.171362
DP  - 2018 Nov 01
TA  - The Journal of Rheumatology
PG  - 1572--1576
VI  - 45
IP  - 11
4099  - http://www.jrheum.org/content/45/11/1572.short
4100  - http://www.jrheum.org/content/45/11/1572.full
SO  - J Rheumatol2018 Nov 01; 45
AB  - Objective. Forced vital capacity (FVC) and DLCO are used for screening of systemic sclerosis–associated interstitial lung disease (SSc-ILD). The study purpose was to determine the sensitivity, specificity, and negative predictive value (NPV) (proportion of true negative screening tests) of FVC and DLCO thresholds for SSc-ILD on chest high-resolution computed tomography (HRCT) scans.Methods. Patients fulfilling American College of Rheumatology 2013 SSc criteria with a chest HRCT scan and pulmonary function tests (PFT) were studied. A thoracic radiologist quantified radiographic ILD. Optimal FVC and DLCO % predicted thresholds for ILD were identified using receiver-operating characteristic curves. The FVC and DLCO combinations with greatest sensitivity and specificity were also determined. Subanalysis was performed in patients with positive Scl-70 autoantibodies.Results. The study included 265 patients. Of 188 (71%) with radiographic ILD, 59 (31%) had “normal” FVC (≥ 80% predicted), and 65 out of 151 (43%) had “normal” DLCO (≥ 60% predicted). FVC < 80% (sensitivity 0.69, specificity 0.73), and DLCO < 62% (sensitivity 0.60, specificity 0.70) were optimal thresholds for radiographic SSc-ILD. All FVC and DLCO threshold combinations evaluated had NPV < 0.70. The NPV for radiographic ILD for FVC < 80% was lower in patients with positive Scl-70 autoantibody (NPV = 0.05) compared to negative Scl-70 autoantibody (NPV = 0.57).Conclusion. Radiographic ILD is prevalent in SSc despite “normal” PFT. No % predicted FVC or DLCO threshold combinations yielded high NPV for SSc-ILD screening. “Normal” FVC and DLCO in patients with SSc, especially those with positive Scl-70 autoantibodies, should not obviate consideration of HRCT for ILD evaluation.