THE PREDICTIVE VALUE OF QUANTITATIVE NAILFOLD CAPILLARY MICROSCOPY INPATIENTS WITH UNDIFFERENTIATED CONNECTIVE-TISSUE DISEASE

The present prospective study was undertaken to follow the natural his tory of patients with Raynaud's phenomenon and to document in these pa tients the frequency with which secondary disorders develop. Seventeen patients with primary Raynaud's phenomenon (PRP) and 43 patients with undifferentiated connective tissue disease (UCTD) were examined after 6-8 years to see whether they had developed into UCTD or systemic scl erosis (SSc), respectively. Their nailfold capillary parameters were a nalysed statistically to ascertain whether they would predict for the development of the diseases into UCTD or SSc. Two patients with PRP (1 2%) developed into UCTD, and 10 patients with UCTD (23%) into SSc. In PRP, all three parameters of the patients who developed into UCTD show ed a tendency to be larger than in those who did not develop UCTD. In UCTD, the apical limb width (P < 0.02), capillary width (P < 0.01) and capillary length (P < 0.01) of the subjects who developed SSc were si gnificantly larger than those who did not. Of the clinicolaboratory fi ndings in patients with UCTD, the occurrence rate of abnormal apical l imb width (relative risk 20.7, P < 0.01), abnormal capillary width (re lative risk 10.7, P < 0.01), abnormal capillary length (relative risk 9.2, P < 0.02) and antinuclear antibody (relative risk 9.6, P < 0.05) showed a significant predictive value for the development of UCTD into SSc. These results indicate that quantitative nailfold capillary micr oscopy, as well as antinuclear antibody, will provide exact predictive information in patients with UCTD in clinical practice.