Use of the HEp‐2 cell substrate in the detection of antinuclear antibodies in juvenile rheumatoid arthritis

Presence and titer of antinuclear antibodies (ANA) were determined in 217 juvenile rheumatoid arthritis (JRA) patients, by indirect immunofluorescence using HEp‐2 cells as substrate. Positive ANA titers (⩾1:40) were present in 131 (60%) of the JRA patients. All 3 JRA onset types demonstrated increased percentages of ANA positivity compared with healthy children. Sixty‐seven percent of the patients in the polyarticular onset group had positive titers; titers were positive in 62% of the pauciarticular onset group and in 32% of the systemic onset group. ANA were also found in 45% of control patients with other connective tissue diseases. In JRA patients, the speckled pattern occurred most commonly (72%). Fourteen patients (8 with pauciarticular onset and 6 with polyarticular onset) had iridocyclitis; all of them had high titers (⩾1:80) of ANA. The use of HEp‐2 cells provided a sensitive substrate for detecting ANA in JRA. It proved to be of value in differentiating JRA patients from healthy controls, but not from patients with other connective tissue diseases.