Alterations of the nailfold capillary morphology associated with Raynaud phenomenon in patients with systemic lupus erythematosus.

Quantitative analysis of nailfold capillary morphology was performed in age and sex matched groups of 29 patients with systemic lupus erythematosus (SLE) presenting Raynaud phenomenon (RP), 29 RP negative patients with SLE with the same duration of the disease, and 29 healthy controls. Percentages of tortuous, meandering and bushy capillaries were significantly increased in both groups of patients without influence of RP. Capillary density was lower, mean diameters of the capillary loops were higher in patients, especially when RP was present (at the venular branch in microns, mean +/- SD: controls: 15.0 +/- 2.0, RP negative patients with SLE: 17.6 +/- 3.6, RP positive patients with SLE: 20.5 +/- 6.3). In a subgroup of 13 patients with frequent Raynaud's attacks (more than 1/week), diameters were still higher (22.1 +/- 7.1, p to controls less than 0.0005; p to RP negative patients less than 0.05). In patients with SLE, the prevalence of RP seems not to be associated with the increased number of abnormal capillaries but with capillary enlargement, correlating with the frequency of attacks.