Longitudinal association between nailfold capillaroscopy and incident interstitial lung disease: A EUSTAR database analysis.

Objectives: To evaluate (1) the association between nailfold capillaroscopy pattern and 5-year risk for incident interstitial lung disease and (2) the association between transition in nailfold capillaroscopy pattern and risk of incident interstitial lung disease.

Methods: Data of adult patients from the EUSTAR database fulfilling the ACR-EULAR criteria with a disease duration ⩽5 years, having a scleroderma pattern at nailfold capillaroscopy with high-resolution computed tomography confirmed absence of interstitial lung disease (i.e. baseline) was used. Interstitial lung disease-free survival was assessed for up to 5 years of follow-up with a Cox proportional hazards model stratified on nailfold capillaroscopy pattern at baseline. The association of annual transition in nailfold capillaroscopy pattern on the risk to develop interstitial lung disease was assessed with a mixed logistic regression analysis.

Results: Out of 771 eligible patients, 283 (37%) had an early pattern, 377 (49%) had an active pattern, and 111 (14%) had a late pattern. The Cox proportional hazard model including the identified confounders did not show an association between severity of nailfold capillaroscopy pattern at baseline and increased risk for interstitial lung disease during 5-year follow-up (hazard ratio (95 confidence interval; p value): 1.09 (0.86-1.39; 0.47)). The mixed logistic regression analysis revealed an increased annual risk for incident interstitial lung disease with increasing severity of capillaroscopic pattern (odds ratio (95% confidence interval); p value 3.76 (1.99-7.11; <0.01)).

Conclusion: Our study shows that worsening of nailfold capillaroscopy has a strong association with an increased annual risk to develop interstitial lung disease. Of note, a worse scleroderma pattern at nailfold capillaroscopy is not associated with the long-term risk to develop interstitial lung disease.