Antinuclear antibody positive patients should be grouped as a separate category in the classification of juvenile idiopathic arthritis

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Antinuclear antibody positive patients should be grouped as a separate

category in the classification of juvenile idiopathic arthritis

http://onlinelibrary.wiley.com/doi/10.1002/art.30076/abstract

Abstract

Objective.

We hypothesized that in the International League of Associations for

Rheumatology (ILAR) classification of juvenile idiopathic arthritis (JIA),

patients with similar characteristics are classified into different

categories. We sought to investigate whether ANA-positive patients belonging

to the ILAR categories of oligoarthritis, rheumatoid factor (RF)-negative

polyarthritis, psoriatic arthritis, and undifferentiated arthritis share

homogeneous features and to compare these features with those of

ANA-negative patients in the same categories.

Methods.

We identified JIA patients who were followed up during a 22-year period. ANA

positivity was defined as => 2 positive results at a titer of => 1:160.

Demographic and clinical features were recorded retrospectively and compared

among ANA-positive and ANA-negative patients.

Results.

Of a total of 971 patients, 711 were ANA-positive, 149 were ANA-negative,

and 111 had an indeterminate ANA status. Patients with undetermined ANA were

excluded. All ANA-positive patients were similar in terms of age at disease

presentation, female-to-male ratio, and frequency of asymmetric arthritis

and iridocyclitis.

Compared with ANA-positive patients, ANA-negative patients were older at

disease presentation and had a lesser female prevalence, a lower frequency

of iridocyclitis and asymmetric arthritis, a greater number of affected

joints over time, and a different pattern of arthritis. The close

relationship between the presence of ANA and younger age at disease

presentation, female predilection, asymmetric arthritis, and development of

iridocyclitis was confirmed by multivariate and multiple correspondence

analysis.

Conclusion.

Our findings substantiate the hypothesis that ANA-positive patients

classified into different JIA categories by current ILAR criteria constitute

a homogeneous patient population.