OBJECTIVE. To examine capillary permeability in fibromyalgia (FMS)
we studied the nailfold capillaries of 13 unselected patients
with FMS and 9 healthy controls using dynamic fluorescence
METHODS. The transcapillary permeability of a
20% solution of sodium fluorescein injected into an
antecubital vein was assessed by videodensitometric analysis.
The pericapillary and interstitial fluorescent light
intensities (FLI) were calculated at different sites on a
transverse axis crossing the selected capillary.
Fluorescence videomicroscopy revealed no abnormalities in the
pattern of dye distribution around the nailfold capillaries in
the patient group. Videodensitometric analysis showed a trend
to an increased early transcapillary diffusion in patients
with FMS, but the difference was only significant at 3 s from
the first appearance of the dye (p < 0.05). From 10 s to 1 min
after the dye’s appearance, the mean FLI in the patients
equalled that of the controls. The patients with FMS showed an
earlier but lower FLI peak. Moreover, the FLI were
significantly lower in the patients than in the controls from
5 to 30 min after the dye appearance in all of the sites of
the densitometric analysis (p < 0.05). Thirty min after the
first appearance of the dye, the FLI was reduced by more than
50% in the patient group compared to the controls.
Our results indicate that transcapillary permeability and
the interstitial persistence of the tracer in FMS are
significantly reduced compared to controls. This difference
may be caused by the abnormal microvascular dynamics induced
by low capillary flow and/or capillary bed hypotension.
Grassi W, Core P, Carlino G, Salaffi F, Cervini C