Antinuclear antibodies and connective tissue disease features in fibromyalgia syndrome: a controlled study

The objective was to investigate the prevalence of antinuclear antibodies (ANA) and of connective tissue disease (CTD) features in patients with fibromyalgia syndrome (FS) compared with healthy, pain-free controls.

One hundred ninety-two patients with FS and 80 pain-free healthy controls were studied by a protocol that included features of FS and those of a CTD, e.g., Raynaud's phenomenon (RP) and dry mouth. ANA was tested by indirect immunofluorescence assay with mouse kidney substrate. Patients with an initial positive ANA were followed after a mean period of 3.3 years.

ANA was positive in 11.5% of all patients, 11.3% of 160 female patients and 10.0% of 80 female controls, with no significant differences between the groups. Among the women, RP was present in 8.8% of patients and 2.5% of controls (p < 0.07), whereas subjective dry mouth without an obvious cause occurred in 12% of patients and none of the controls (p < 0.005). The frequency of other CTD features was similar in both groups. Diagnosis of a CTD was not made in any patient initially or in those seen on followup.

Prevalence of ANA and of CTD features was similar in patients with FS and healthy controls, with the exception of subjective dry mouth, the frequency of which was significantly greater among the patients.