Is There a Link Between Nailfold Videocapillaroscopy and Pulmonary Function Tests in Systemic Sclerosis Patients? A 24-Month Follow-up Monocentric Study

Background/Objective The aim of this study was to explore the associations between nailfold videocapillaroscopy (NVC) and pulmonary function tests (PFTs) in systemic sclerosis (SSc) patients. Methods This was a longitudinal study with follow-up of unselected Brazilian SSc patients. Baseline clinical examination, serological workup, high-resolution chest tomography, and NVC were performed. Pulmonary function test was performed at baseline and after 24 months. Pulmonary function test worsening over time was defined as either a Delta FVC decline >= 10% or a Delta FVC decline >= 5% and <9%, combined with a Delta DLCO decline >= 15%, at 24 months. The NVC parameters were quantitatively (capillary density number, dimension, morphology, and hemorrhages) and qualitatively (NVC pattern) evaluated according to the consented standardized definitions of the EULAR Study Group on Microcirculation in Rheumatic Diseases. Results Seventy-nine patients were included. Fifty-nine were rated to have a scleroderma pattern (6 early/16 active/37 late). The mean FVC and DLCO were 76.8% and 67.2% at baseline and 73.8% and 64.3% at 24 months, respectively. After multivariate analysis, we found that a reduced baseline FVC was associated with reduced capillary density (odds ratio [OR], 11; 95% confidence interval [CI], 1.5-90.7; p = 0.03) and a reduced baseline DLCO associated with the late scleroderma pattern (OR, 6.75; 95% CI, 1.09-42; p = 0.03). No association between worsening of PFT over time and NVC was found. Conclusions The association between NVC and PFTs might corroborate the link between microangiopathy and interstitial lung disease in patients with SSc. This finding might strengthen the idea of incorporating NVC as a tool to predict progressive interstitial lung disease in these patients in the future.

Automated summary

This study aimed to explore the associations between nailfold videocapillaroscopy (NVC) and pulmonary function tests (PFTs) in systemic sclerosis (SSc) patients. The results showed that the association between NVC and PFTs might be related to interstitial lung disease in SSc patients. This finding may strengthen the idea of using NVC as a tool to predict progressive interstitial lung disease in these patients.