Reduction of bcl-2 in T Cells during Immunosuppressive Therapy in Patients with Severe Juvenile Onset Systemic Lupus Erythematosus

Overexpression of bcl-2 protein has been observed in the cytoplasm of T lymphocytes from adults with systemic lupus erythematosus (SLE). The aims of our study were to investigate the distribution of bcl-2 in T and B cells from patients affected with juvenile onset SLE (JSLE) and to monitor the modification of bcl-2 expression under immunosuppressive therapy. Thirty-two JSLE patients entered the study; 45 pathological and 16 healthy subjects were studied as controls. In SLE patients the disease activity was assessed using SLE disease activity index score. Bcl-2 expression was evaluated by cytofluorimetry. PCR analysis of t(14,18) translocation was performed from genomic DNA isolated from peripheral blood mononuclear cells. An increased bcl-2 expression both on cytoplasm and on cell surface of circulating T lymphocytes in JSLE patients with active disease was found. A variation, under pharmacological treatment, of protein expression during the course of the disease was observed. PCR analyses demonstrated that 14, 18 translocation was not associated with bcl-2 overexpression. Our data show a strong correlation between bcl-2 protein expression and disease activity and suggest an alteration of apoptotic regulation in JSLE patients.