A Comparison of Nailfold Video Capillaroscopy Findings in Mixed Connective Tissue Disease Interstitial Lung Disease vs Systemic Sclerosis Interstitial Lung Disease: A Single-Centre Study.

Objective: To differentiate the nailfold capillaroscopy (NFC) findings in patients with MCTD-ILD and SSc-ILD and correlate the NFC changes and lung functions among them. Methods: In this observational study from Oct 2020 to Oct 2022, 27 patients with MCTD-ILD and 27 patients with SSc-ILD were included. NFC was performed using Jiangsu Jiahua, JH 1004, China. Statistical analysis was conducted using IBM SPSS software, version 26, and tests including Mann-Whitney U-test, student t-test, chi-square test, or Fisher's exact test were used to compare between groups. Results: In this study, major capillaroscopic changes were more frequent in SSc-ILD group (92%) than in MCTD-ILD group (72.3%), with normal capillaries seen in 7.4% of MCTD-ILD cases. The mean FVC was higher in SSc-ILD group compared to MCTD-ILD group, and patients with capillary loss had a lower mean FVC. Loss of capillaries was more frequent in SSc-ILD group, while dilated capillaries were predominantly observed in MCTD-ILD group. A significant association was found between the severity of restriction in spirometry and NFC. Conclusion: There is an important role for NFC in detecting the severity of lung involvement, as the grading of restrictive severity in spirometry is strongly associated with capillaroscopic abnormalities.