Peripheral immunophenotypes associated with the flare in the systemic lupus erythematosus patients with low disease activity state

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by clinical heterogeneity and flare unpredictability. It was still unclear for the association between SLE flare and immunophenotypes. Flow cytometric analysis defined the B and T subsets of the low disease activity state (LDAS) patients and healthy controls. Principal components analysis (PCA) and cluster analysis (CA) distinguished the immunophenotypes. Compared with the 66 healthy controls, the 93 LDAS patients had higher proportions of plasma cells, double negative B cells, naïve B cells and CD8⁺T cells, and lower proportions of unswitched memory B cells and CD4⁺T cells. PCA showed the abnormalities of T and B cell axes. CA divided the patients into 3 groups. The memory B cells group had the lower flare risk compared with the non-memory B cells group (including naïve B cells group and T cells group). The immunophenotypes were associated with SLE flare in the LDAS patients.