Nailfold capillaroscopy and autoimmune connective tissue diseases in patients from a Portuguese nailfold capillaroscopy clinic

Raynaud's phenomenon (RP) is frequent in autoimmune connective tissue diseases (AICTD) and its approach includes nailfold capillaroscopy (NFC), as it is a non-invasive technique that permits direct visualization of the microcirculation. The aim of this study is to analyze and establish clinical correlations between NFC findings and particular aspects of autoimmune disorders. This is a retrospective study. Clinical data from patients attending our NFC clinic were reviewed. Inclusion criteria included AICTD previous diagnosis, which included systemic sclerosis (SSc), mixed connective tissue disease (MCTD), systemic lupus erythematosus (SLE), Sjögren syndrome, inflammatory idiopathic myopathies (IIM), rheumatoid arthritis, undifferentiated connective tissue disease and antiphospholipid syndrome (APS). Videocap^® version 3.0 biomicroscope was used. NFC score was determined. For statistics, SPSS software was utilized. 384 patients were included; most of them were women, with mean age of 47 years. RP was present in 91% of the patients, with greater prevalence in SSc and MCTD. Scleroderma pattern was the most prevalent NFC pattern, mainly in SSc, MCTD and IIM. Mean capillary density was reduced in IIM, SSc and MCTD. NFC score was worse in SSc, IIM and MCTD. In patients with AICTD, RP is related to microvascular damage and worse NFC score. NFC scleroderma pattern correlates with SSc classification criteria score. In MCTD, scleroderma pattern relates to myositis. SLE and APS reveal significant hemorrhages, but not related to APS antibodies. This study highlights the possible role of NFC as biomarker of AICTD, particularly in SSc and IIM.