Image analysis of nailfold capillaries in patients with undifferentiated connective tissue syndromes

Several studies have reported patients that show nailfold capillary abnormality without fulfilling any of the criteria for rheumatic diseases. Our objective was to define how many patients with undifferentiated connective tissue syndrome (UCTS) have nailfold capillary abnormalities and to determine the correlation between capillary abnormality and clinical findings. We analyzed videograph images of nailfold capillaries in 75 patients with UCTS, comparing them with 22 normal controls (NL) and 55 patients with systemic sclerosis (SS), using standardized canonical discriminant analysis. Sixty patients with UCTS showed the SS type pattern and 15, the NL type pattern. The SS type pattern in patients with UCTS significantly correlated with Raynaud's phenomenon, telangiectasia, and anti-nuclear antibody. The UCTS patients with nailfold capillary abnormalities correlated with symptoms of SS have a possibility of progressing to SS. The follow up study of these patients will show whether progression to SS occurs.