Relationship between nailfold capillaroscopy findings and the etiology and prognosis of interstitial lung disease

Connective tissue-associated interstitial lung diseases (CTD-ILD) are believed to be caused by microvascular damage. The objective of this study was to assess the nailfold capillaroscopy (NFC) pattern in patients diagnosed with both CTD-ILD and non-CTD-ILD to identify microvascular changes and determine the relation between capillaroscopic parameters, clinical variables, and disease-related measurements.

This cross-sectional study included 95 patients with interstitial lung disease who applied to our Rheumatology and Chest Clinics between September 2021 and July 2023. The patients were divided into two groups based on their diagnosis: non-CTD-ILD (group 1) and CTD-ILD (group 2). Nailfold capillaroscopy was performed.

Ninety-five patients, 49 (51% female, mean age 62.31 ± 11.027 years) in group 1 and 46 (69.6% female, mean age 62.09 ± 10.887 years) in group 2, were included in the study. Abnormal capillary morphologies were both detected in the CTD-ILD group and the non-CTD-ILD groups. In patients with a usual interstitial pneumonia (UIP) pattern on chest computed tomography (CT), tortuosity was higher than in patients with non-specific interstitial pneumonia (NSIP) (P = 0.041), and the proportion of tortuosity increased significantly as the duration of the disease increased (P = 0.016).

Our study highlights capillaroscopic abnormalities alone may not be sufficient to differentiate CTD-ILD (other than systemic sclerosis) from non-CTD-ILD. The presence of NFC abnormalities in non-CTD-ILD may suggest that fibrotic lung disease could potentially play a role in the deterioration of the microvascular structure or abnormal angiogenesis. Our study demonstrated that a multidisciplinary approach, incorporating clinical, morphological, pathological, and serological evaluations, is necessary for interpreting ILD. Key Points • Capillaroscopic abnormalities can also be seen in non-CTD-ILD. • Capillaroscopy findings do not distinguish the non-Ssc etiology of ILD. • Nailfold capillaroscopy may have the potential to serve as a useful tool in predicting prognosis and monitoring the disease progression in patients with idiopathic pulmonary fibrosis (IPF).