Objective: To investigate whether changes in peripheral blood lymphocytes correlate with changes in disease activity in juvenile dermatomyositis (JDM).
Methods: Clinical changes in disease expression measured by a disease activity score were correlated with changes in percentages of peripheral blood lymphocyte subsets.
Results: Changes in the percentage of peripheral blood CD19 positive lymphocytes (B cells) correlated with changes in disease activity (Spearman rank coefficients = 0.47, p = 0.02). There were no significant correlations in disease activity with changes of T cell subsets or the T cell activation markers CD25 or DR.
Conclusion: Change in the percentage of peripheral blood B cells correlates with change in disease activity in patients with JDM. This variable may be of use as an indicator of immunologic activity and response to therapy.