Related Experiment Videos
Persistent antinuclear antibodies in children without identifiable inflammatory rheumatic or autoimmune disease
D A Cabral1, R E Petty, M Fung
1Department of Pediatrics, University of British Columbia, Vancouver, Canada.
Insights
Children with musculoskeletal pain and positive antinuclear antibody (ANA) tests, without signs of autoimmune disease, have a low risk of developing inflammatory conditions. Persistent ANA positivity in these pediatric cases rarely indicates future autoimmune disease.
Area of Science:
- Pediatrics
- Immunology
- Rheumatology
Background:
- Musculoskeletal pain is common in children.
- Autoimmune and inflammatory diseases can present with musculoskeletal pain.
- Antinuclear antibody (ANA) testing is used in the evaluation of pediatric autoimmune conditions.
Purpose of the Study:
- To evaluate the long-term significance of positive ANA tests in children presenting with musculoskeletal pain without clinical evidence of autoimmune disease.
- To determine the risk of developing overt inflammatory or autoimmune disease in this patient cohort.
Main Methods:
- One hundred eight children with musculoskeletal pain underwent ANA testing.
- Positive ANA results were followed over time.
- Patients were tested for specific autoantibodies including anti-DNA, anti-Sm, RNP, Ro (SS-A), and La (SS-B).
- Immunoblotting was used to detect antibodies to core histones.
Main Results:
- Twenty-four of 108 children had positive ANA tests; 21 remained positive over a mean of 38 months.
- No patients initially had anti-DNA antibodies; one later developed elevated anti-DNA (radioimmunoassay) but remained negative on Crithidia luciliae.
- Four patients had antibodies to core histones; none had antibodies to Sm, RNP, Ro (SS-A), or La (SS-B).
- No patient developed overt inflammatory or autoimmune disease during a mean follow-up of 61 months.
Conclusions:
- Pediatric musculoskeletal pain with a positive ANA test, in the absence of clinical signs of autoimmune disease, indicates a low risk of imminent disease development.
- Persistent ANA positivity in this context is generally not associated with the future onset of overt autoimmune conditions.
- Further investigation for specific autoantibodies may be warranted in select cases, but the overall prognosis appears favorable.
Abstract:
One hundred eight children with musculoskeletal pain considered not to be due to an autoimmune or inflammatory disease had an antinuclear antibody (ANA) test performed. Twenty-four of these children were ANA positive on HEp-2 cell substrate at a screening serum dilution of 1:20. A positive ANA test persisted in 21 of 24 of the patients over a mean time period of 38 months (range 1 to 103 months). No sera from any patient at initial evaluation had anti-DNA antibodies by radioimmunoassay or by indirect immunofluorescence on Crithidia luciliae. One patient recently developed elevated anti-DNA (radioimmunoassay) antibodies but still has a negative assay on C luciliae. Four patients had antibodies to core histones by immunoblotting. None had antibodies to Sm, RNP, Ro (SS-A), or La (SS-B) by counterimmunoelectrophoresis. No patient developed an overt inflammatory or autoimmune disease during a mean follow-up period of 61 months (range 13 to 138 months). A child with musculoskeletal pain and a positive test for ANA, but with no clinical evidence at presentation of inflammatory or autoimmune disease, is at low risk of imminently developing such a disease.