Outcome of high titer antinuclear antibody positivity in individuals without connective tissue disease: a 10-year follow-up

To ascertain the development of disease in a cohort of connective tissue disease (CTD)-negative patients 10years after testing positive for antinuclear antibody (ANA) in high titer, a telephone survey and serological tests were conducted on a group of CTD-negative patients with high ANA titer identified in a previous study. Thirty-four out of 62 patients (55%) completed only the telephone survey and 27 completed both. The mean length of follow-up was 11.5years. The ages ranged from 27 to 89years with the mean being 58.9years. The sex distribution included 4 (12%) men and 30 (88%) women. Twenty-one out of 27 patients (78%) remained ANA-positive. A total of five patients were diagnosed with CTD with two in the last 5years. Common symptoms described, in order of frequency, were joint pain, Raynaud's phenomenon, and Sicca symptoms. This study shows that a considerable percentage of CTD-negative individuals with an initial high ANA titer continue to maintain their positivity even after an extended period. It is reassuring, however, that only a small number of these individuals go on to develop CTD. It confirms the fact that the ANA test, despite remaining a useful clinical tool, needs to be used in conjunction with other evidence and clinical judgement when attempting to validate the diagnosis of CTD.