Nailfold capillaroscopic findings in primary Sjögren's syndrome: clinical and serological correlations

To describe the capillaroscopic abnormalities observed in patients with primary Sjögren's Syndrome (pSS), associating them with clinical and serologic features, and comparing these findings to those observed in normal controls.

Sixty-one consecutive patients with pSS were studied by clinical evaluation, serology, and nailfold capillary microscopy (NCM). Twenty-one normal controls were also examined. Capillaroscopic findings were recorded in a standardized way by a blinded observer Capillary loss on NCM was evaluated using a deletion score.

NCM was normal in 59.0% of pSS patients; 29.5% had non-specific abnormalities, and 11.5% presented a SD-like pattern. Patients presented a higher deletion score than controls (p < 0.001). Other capillaroscopic parameters (number of dilated, bizarre, and meandering capillaries; capillary hemorrhages; venous plexus visibility) did not differ significantly between patients and controls. Among patients, the deletion score was higher in those with systemic manifestations (p = 0.022) and Raynaud's phenomenon (p = 0.050). No association between the presence of antinuclear antibodies, rheumatoid factor, anti-SSA/Ro and anti-SSB/La with qualitative or quantitative NCM findings was found. Among the 7 patients with SD-like pattern on NCM, 6 had Raynaud's phenomenon, but only 2 presented autoantibodies related to systemic sclerosis (1 with anticentromere and 1 with low titer antitopoisomerase I). None of these patients met the ACR criteria for SSc.

SD-like pattern on NCM is observed in a small but significant proportion of pSS patients. The association of systemic involvement with a higher deletion score may be related to the hypothesis that these manifestations represent clinical expressions of systemic vasculitis.