A new study published in Cytometry. Part B Clinical Cytometry characterized synovial B and T cells subsets in patients with oligoarticular juvenile idiopathic arthritis oJIA to identify any parameters that could predict a more aggressive course of the disease. Here B and T cells from synovial fluid SF of 39 patients with oJIA were characterized by flow cytometry. In 22 patients SF was analyzed at disease onset Group A while in 17 patients SF was analyzed at articular relapse Group B . All patients in Group A were followed up for at least for 2 years after SF analysis. The findings showed that 13 patients relapsed during the follow up period. When compared among groups the SF analysis demonstrated an activated phenotype in relapsed patients with higher Switched Memory B cells and lower Na ve B cells in Group B. Furthermore patients from Group A who did not relapse showed lower percentages of synovial double negative T cells DNT and 947 948 T cells at the onset compared to Group A patients. Hence it was concluded that in oJIA relapse SF presented an activated B phenotype. From the results it was stated that patients at disease onset with DNTs 1.8 and or 947 948 T cells 16 of CD3 in synovial fluid have longer free disease survival.