Pediatric Rheumatology Online Journal → August 2003 → Miscellaneous Clinical Studies and Case Reports → Abstract #191

DISTRIBUTION OF ANTINUCLEAR ANTIBODY IN HEALTHY CHILDREN AND ADOLESCENTS

M. O. Hilario,¹ L. E. Andrade,² C. A. Len,¹ S. C. Roja,¹ M. T. Terreri.¹

¹Pediatric Rheumatology Unit - Department of Pediatrics, Universidade Federal de Sao Paulo - EPM, Sao Paulo, SP, Brazil; ²Division of Rheumatology - Department of Medicine, Universidade Federal de Sao Paulo, Sao Paulo, SP, Brazil

OBJECTIVE: To characterize the antinuclear antibody (ANA) titer distribution and patterns in healthy subjects and in children with autoimmune rheumatic diseases.
METHODS: Sera from 214 healthy school children and adolescents [108 females (50.5%)> mean age 8.7 years (range 6 months to 20 years), and from 116 aged-matched patients (juvenile idiopathic arthritis [58.0%>, juvenile systemic lupus erythematosus [24.1%>, juvenile dermatomyositis [7.7%>, systemic sclerosis [6.9%> and other autoimmune rheumatic diseases [3.4%>) were assayed for ANA by indirect immunofluorescence using HEp-2 cells as substrate. All slides were examined by two blinded observers. Sera considered positive for the presence of ANA at the starting dilution of 1/80 were further diluted at the following dilutions: 1/160, 1/320, 1/640, 1/1280 and 1/2560.
RESULTS: ANA was present in 27/214 (12.6%) healthy children, most of them with titers 1/160 (63%); however, in 10/27 (37%) they were 1/320, including one child with ANA 1/1280. Although not statistically significant, there was a trend for higher frequency of ANA among children between 5 and 10 y.o.. There was no difference between gender. The most prevalent ANA pattern was fine speckled (79.3%) however, less frequent patterns were observed for 3 children, including the nucleolar pattern (in one), the mitochondrial (in one) and the PCNA pattern (in one). These children have been followed up for 2 years now and remain asymptomatic. ANA was positive in 14/67 (21%) patients with juvenile rheumatoid arthritis, 21/28 (75%) juvenile systemic lupus erythematosus, 4/9 dermatomyositis, and 3/8 systemic sclerosis. Rheumatic patients presented overall higher titers than healthy children.
CONCLUSION: A positive ANA test occurred in a subset of healthy children, mostly at low titer but in some cases as high as 1:1280. Gender did not appear to influence but there was a slightly higher frequency among healthy children aged 5-10 years old.