CD40 and CD72 expression and prognostic values among children with systemic lupus erythematosus: a case-control study

Systemic lupus erythematosus (SLE) is a chronic disease with proven interactions between immune system components, including both humoral- and cell-mediated immunity, as well as co-stimulatory and inhibitory molecules such as CD40 and CD72. Here, we investigated CD40 and CD72 expression on B cells of SLE children and assessed their prognostic values. We conducted a preliminary case-control study in Mansoura University Children's Hospital, Egypt from September 2018 to January 2020 including 27 SLE children and 27 healthy controls. We assessed cases during initial flare and after remission. Flow cytometry analysis was carried out for all participants for CD40 and CD72 expression of B cells. During flare, SLE cases had statistically significant higher CD40 and lower CD72 expression in comparison with controls (p < 0.001). After remission, the number of CD40⁺ B cells significantly decreased (p < 0.001), while the number of CD72⁺ B cells significantly increased (p < 0.001) in comparison with flare. We reported non-significant positive correlations between CD40 expression and SLE Disease Activity Index (SLEDAI; p = 0.347 during flare and p = 0.653 after remission) and negative correlations between CD72 expression and SLEDAI (p = 0.34 during flare and p = 0.044 after remission). No significant differences were detected between renal histopathology classes with regard to CDs expression on B cells (p = 0.45 for CD40 and p = 0.63 for CD72). In conclusion, CD40⁺ B cells and CD72⁺ B cells could be considered as markers of paediatric SLE flare and remission, respectively.