The potential utility of anterior upper lobe honeycomb-like lesion in interstitial lung disease associated with connective tissue disease.

BACKGROUND

Interstitial lung disease (ILD) is associated with high morbidity and mortality in patients with connective tissue disease (CTD). Because some patients with CTD overlap present with ILD first, with CTD diagnosed later, specific radiologic signs are needed to help differentiate each CTD or CTD-ILD from idiopathic ILD.

OBJECTIVES

To determine whether specific CT findings can help differentiate CTD as rheumatoid arthritis (RA), systemic sclerosis (SSc), or polymyositis/dermatomyositis (PM/DM).

METHODS

We analyzed 143 consecutive ILD patients with RA, SSc, or PM/DM. We assessed diagnostic accuracy of CT findings of CTD-ILD, CT pattern, and signs including "anterior upper lobe honeycomb-like lesion" and "low attenuation area (LAA) within an interstitial abnormality" for each CTD-ILD. Prognostic predictors were determined using Cox regression models.

RESULTS

Subjects were 78 patients with RA-ILD, 38 with SSc-ILD, 24 with PM/DM-ILD, and 3 with overlapping CTD-ILD. High frequency of anterior upper lobe honeycomb-like lesion suggests that CTD-ILD is due to RA-ILD (22%) rather than SSc-ILD (8%) or PM/DM-ILD (8%), whereas LAA within an interstitial abnormality suggests that CTD-ILD is due to SSc-ILD (26%) rather than RA-ILD (4%) or PM/DM-ILD (0%). Multivariate analysis showed that while not associated with survival, current or ex-smoker, honeycombing, and acute exacerbation were negative prognostic factors of mortality.

CONCLUSIONS

The tendency is high for RA-ILD, in which anterior upper lobe honeycomb-like lesion is a specific feature, to show UIP or NSIP/UIP pattern, combined emphysema, and honeycombing; SSc-ILD to show NSIP pattern and LAA within an interstitial abnormality; and PM/DM-ILD to show NSIP pattern and non-honeycombing.