Study of the Role of Nailfold Capillaroscopy in the Evaluation of Patients with Interstitial Lung Diseases

Abstract

PURPOSE: Distinguishing between idiopathic interstitial pneumonias (IIPs) and other types of interstitial lung diseases (ILD) such a connective tissue disease (CTD)-related ILD can be challenging. In some patients, the clinical features of autoimmunity are subtle. Abnormal capillaries on nailfold capillaroscopy (NC) predict a higher risk of CTD development and the use of NC is common in the evaluation of patients with Raynaud's phenomenon. NC could help clinicians identify signs of CTD or autoimmune features in patients with ILD, although its clear role in the evaluation of ILD has yet to be defined. This study aims to describe the impact of NC in the evaluation of patients with ILD. METHODS: We retrospectively identified patients with ILD seen in a tertiary care center who underwent a NC as part of their work-up. All diagnoses were established by multidisciplinary consensus according to current guidelines. Patients were categorized into 3 groups according to their final diagnosis: CTD-ILD, interstitial pneumonia with autoimmune features (IPAF) and IIP. RESULTS: NC was performed in twenty-seven patients, 14 of whom were female (52%). There were 11 who had Raynaud's phenomenon (41%), and the majority had positive antinuclear antibodies (89%). Mean forced vital capacity percent predicted and diffusion capacity percent predicted were 76% and 47% respectively. Morphologic capillary changes were observed in 10 patients (37%): a scleroderma pattern was found in 5 of them while the other 5 had minor capillary changes. Patients carrying a final diagnosis of CTD-ILD (40%) or IPAF (63%) were more likely to have NC abnormalities than those with a diagnosis of IIP (16%). Identification of nailfold capillary abnormalities contributed to establishing a multidisciplinary diagnosis of IPAF in all cases. There were no clinical symptoms, serologies or physiologic variables that were predictive of nailfold abnormalities. CONCLUSIONS: In our cohort, NC contributed to the identification of subtle clinical signs of autoimmune features in patient with ILD and influenced multidisciplinary consensus diagnosis. Further, larger studies are needed to validate these findings, and to better understand the prognostic significance of NC abnormalities in patients with ILD.