Background Previous studies demonstrated functional and morphological microcirculatory abnormalities that may be relevant to the pathophysiology and clinical manifestations of fibromyalgia (FM).
Objectives To ascertain and compare capillary morphology of FM patients with and without Raynaud's phenomenon (RP) using nailfold videocapillaroscopy (NVC).
Methods Patients fulfilling the 2010 American College of Rheumatology Diagnostic Criteria for FM were allocated in 2 groups according to the presence or absence of RP (RP+ or RP-, respectively). All patients with secondary causes of RP other than FM were excluded. One blinded operator performed all the NVC using a 200x amplification digital microscope and analytical software. Capillary parameters evaluated in fingers II-V of both hands included: tortuosity, apex enlargement, branch enlargement, microhemorrhages, giant capillaries, capillary density, capillary branching and architectural derangements. Each parameter was rated 0-3 (0= no changes; 1= <33% abnormalities; 2=33-66% abnormalities; 3= >66% abnormalities) and the mean scores were calculated. The association of RP with the capillary parameters was assessed using multivariate linear regression adjusted for age, FM duration and occupation.
Results Twenty FM patients were enrolled, 10 in each group, however 2 patients RP+ were excluded due to thyroid disease. Included patients were all female, had a mean age of 50.4 years and a mean duration of disease of 12.8 years. In both RP+ and RP- groups, the most frequently found abnormalities were minor dysmorphies, namely tortuosities, apex enlargement and branch enlargement. However, scoring of these parameters showed no significant difference between the 2 groups. More than half of RP+ and RP- patients presented slight focal decreases in capillary density, once again with no difference between groups. The only giant capillaries were found in a RP+ patient with an “early scleroderma pattern” as proposed by Cutolo et al. Hemorrhages were scarce and had a traumatic appearance, except in the previously mentioned patient. Interestingly, RP associated negatively with the capillary branching score. Table 1 summarizes the results.
Conclusions No association was established between RP and microcirculatory abnormalities in FM patients. However, capillary tortuosity and enlargement were present in almost all subjects, supporting previous findings that FM may associate with minor NVC dysmorphies. Some authors suggest that tissue hypoxia arising from repeated autonomic-mediated vasoconstriction might explain these changes, as well as the apparent reduction in capillary density. Studies with a larger sample of FM patients are needed to confirm these results.
Disclosure of Interest : None declared