Correlations between change in disease activity and changes in peripheral blood lymphocyte subsets in patients with juvenile dermatomyositis

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.