Nailfold videocapillaroscopy in primary Sjögren's syndrome.

Nailfold videocapillaroscopy was performed in 2 groups of subjects: 14 healthy volunteers (C) and 15 patients with primary Sjögren's syndrome (PSS). This was a controlled clinical trial, matched by age and sex. The aims of this study were to evaluate (1) functional capillary density (number of capillaries with flowing red blood cells per mm(2), FCD); (2) capillary red blood cell velocity at rest (RBV), maximum capillary red blood cell velocity (RBV(max)) after 1 minute ischemia, and the time to reach it (TRBV(max)), taking into account the presence or absence of Raynaud's phenomenon (RP) in the analysis; (3) nailfold capillary morphology; and (4) afferent (AFD), apical (APD), and efferent (EFD) capillary diameters.