Aim:

To determine the clinical value of positive antinuclear antibody (ANA) and ANA profile tests in children with autoimmune disorders.

Methodology:

A retrospective chart review was carried out of children less than 16 years of age seen in Child Health Department of Christian Medical College from August 2003 to August 2005 with a positive ANA test (Hep-2 cell substrate, titer> 1:100).

Results:

Of 150 children with a positive ANA test, 138 (92%) had an autoimmune disease and 12 (8%) had non autoimmune disease. Out of 138 children 79 had SLE, 17 had JRA, 12 had ITP, 10 had autoimmune hemolytic anemia, 10 had scleroderma, 6 had MCT/Overlap, 2 had autoimmune hepatitis and juvenile dermatomyositis each. The remaining 12 children did not have identifiable autoimmune disorders. Out of 17 children with JRA children ANA was positive in 12 children with polyarticular, 4 children with oligo articular and 1 child with systemic onset JRA. Others include 5 children with infections, 3 children with no diagnosis, 2 children with lymphoma and one each with abnormal urinary proteinuria and non-specific musculoskeletal pain.

In ANA profile, DsDNA was done for all children with positive ANA but others like U1RNP, SCL 70, SM and centromere were done if clinical suspicion of particular disease is high. Out of 138 children with a positive ANA test in autoimmune disorders, 88 had an ANA profile positive which is statistically significant (p = 0.004). Out of 79 SLE children, 74 (94%) ANA profile positive. Type of ANA did not correlate with specific autoimmune disorders. Speckled type is present alone or with various other types in different diseases.

Children with JRA were readily identified on the basis of the history and physical examination. Children with SLE were therefore compared with children with positive ANA tests who did not have JRA, designated the “comparison group”. Neither the presence nor the titer of ANA served to distinguish children with JRA from children with other musculoskeletal conditions.

Conclusion:

Children with positive ANA (titers> 1:100) had autoimmune disorders. ANA test should remain the mainstay for screening with children with rheumatic disease. ANA profile should be performed along with ANA in those with high index of suspicion for autoimmune disorders because of its relatively high cost. ANA tests are of no diagnostic utility in either making or excluding the diagnosis of JRA.

RCIAPCON 2005 - Conference Abstracts.Pediatric Oncall [serial online] 2006 [cited 15 June 2006(Supplement 6)];3. Available from:
http://www.pediatriconcall.com/fordoctor/Conference_abstracts/
antinucler_antibody.asp