Researchers have used an immunophenotyping approach to categorize patients with systemic lupus erythematosus (SLE) into distinct subgroups. Peripheral blood mononuclear cells from 143 patients with SLE and 49 healthy individuals were analyzed by flow cytometry to characterize circulating B cells, T cells and dendritic cells. The resulting immunophenotype was analyzed by use of principal component analysis, and cluster analysis subsequently revealed three distinct subgroups based on T cell heterogeneity, including a T cell-independent group, a T follicular helper (TFH) cell-dominant group and a regulatory T cell-dominant group. The percentage of patients with SLE who were resistant to immunosuppressive treatment was highest among the TFH cell-dominant group.