Objective. To assess the diagnostic value of positive antinuclear antibody (ANA) test results in children with musculoskeletal or dermatologic problems but without autoimmune disease at presentation.
Design. Retrospective chart review.
Setting. Pediatric rheumatology clinic in a tertiary care center.
Patients. Five hundred charts reviewed, comprising all new patients seen, 1978 to 1993.
Results. Of 500 children seen, 113 had positive ANA test results available at referral. Of those 113 patients, 72 (64%) had an autoimmune condition diagnosed at initial clinic visit; another 10 (9%) were lost to follow-up. Thirty-one children (27%) had no autoimmune condition diagnosed at initial clinic visit and had clinical follow-up over a mean of 37 months. Nonspecific musculoskeletal complaints and hypermobility accounted for the majority of presentations. Routine hematology data were usually normal. Median ANA titer was 1:160; ANA patterns varied. On follow-up, 25 patients (81%) cleared their symptoms; five (16%) had significant improvement. One patient developed an autoimmune disease (autoimmune hepatitis).
Conclusions. Based on our findings, the vast majority of children who have positive ANA test results but do not have autoimmune conditions at initial diagnosis will not develop an autoimmune condition. ANA testing of children who have musculoskeletal or dermatologic problems in the absence of autoimmune conditions does not reveal new diagnoses, and represents unnecessary laboratory time and expense. The prognosis of children who have positive ANA test results in the absence of autoimmune conditions is usually excellent.