Microvascular dynamics at the nailfold in rheumatoid arthritis

Conventional and fluorescence videomicroscopy using Na-fluorescein as tracer was performed in 13 patients with rheumatoid arthritis (RA) and Waaler Rose titers less than 1: 112, 10 patients with titers greater than or equal to 1: 112 and 11 patients with osteoarthritis (OA) (control group). At the nailfold different microvascular diameters, capillary flow pattern, red blood cell velocity and transcapillary diffusion of Na-fluorescein were determined. Mean red blood cell velocity was significantly (p less than 0.02) decreased in patients with RA and high titers (0.23 +/- 0.21 0.21 mm/s) when compared to OA patients (0.59 +/- 0.20 mm/s). Abnormal flow patterns, in 2 cases even a reversal of flow direction, were only observed in RA patients and not in controls. Mean transcapillary and interstitial diffusion of Na-fluorescein was not enhanced at the nailfold in RA-patients. These findings do not exclude increased microvascular permeability in synovial membranes or in RA patients with vasculitis.