Alevizos MK, Danoff SK, Pappas DA, et al. - Findings demonstrate an association of %HAA (percentage of lung parenchyma with high attenuation areas), evaluated using quantitative lung densitometry (qLD), with various known risk factors for rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Furthermore, it could be a more quantitative tool to detect RA-ILD and track progression, compared with expert radiologist interpretation.

• Multi-detector row computed tomography scans of RA patients were analyzed with qLD for %HAA (the percentage of voxels of -600 to -250 Hounsfield units).

• In 193 RA patients, baseline %HAA was evaluated, and repeat qLD assessment was performed in 106 patients.

• A correlation of %HAA with Expert Read Score was evident, and female gender, higher pack-years of smoking, higher body mass index, and anti-CCP ≥ 200 units were revealed as significant indicators of high baseline %HAA (>10% of lung parenchyma with high attenuation), conjointly offering an area under the receiver operator curve (AUROC)=0.88.

• Higher baseline %HAA, presence of MUC5B minor allele, and absence of HLA-DRB1 shared epitope (AUC-ROC = 0.69) were identified as the predictors of %HAA increase.

• In males and those with higher cumulative smoking, a higher association of the MUC5B minor allele with %HAA change was identified.

• A significant correlation of anti-CCP level with a greater increase in %HAA was observed within the group with increased %HAA.