Evaluation of the severity of systemic sclerosis by nailfold capillary microscopy in 112 patients

The authors used nailfold capillary microscopy (NCM) to evaluate 112 patients with systemic sclerosis spectrum disorders (SSc). Patients were classified as S1 if they had skin involvement proximal to the metacarpo-phalangeal joints. S2 if they had at least two minor SSc American Rheumatism Association criteria, and S3 if they had at least two CREST criteria (calcinosis, Raynaud's, esophageal motility disorder, sclerodactyly, telangiectases), without S1 or S2 criteria. Disease duration from the first symptom was similar in all groups (7.17 +/- 8.98 years). Disease severity was determined by a total score of seven target organ involvements. S1 patients had a greater degree of skin and pulmonary involvement, with a mean score of 26.2 +/- 17.3. S2 patients had a mean score of 13.8 +/- 12.4, and had mostly vascular and digestive involvement, in comparison with S3 patients (7.2 +/- 7.2; p less than 0.001 and p less than 0.01 respectively). NCM sensitivity for S1 and S2 was 93.6%. NCM correlated with the degree of target organ involvement (p less than 0.01). Three NCM profiles established were: "mild," normal or borderline capillaries; "moderate," other abnormalities with no capillary telangiectases; and "severe," abnormalities other than those of the mild profile, with capillary telangiectases.