Changes in serum levels of soluble interleukin-2 receptor and fas-ligand expression in relation to disease activity of systemic lupus erythematosus

ABSTRACT

Serum soluble IL-2 receptors [sIL2R] levels and Fas-ligand [Fas-L] expression on peripheral blood mononuclear cells [PBMC] were determined in patients with Systemic Lupus Erythematosus [SLE] to assess whether there was any relationship between them and disease activity. Enzyme Linked Immunosorbant assay [ELISA] technique was done on serum samples collected from 36 SLE patients and 25 healthy controls for determination of sIL2R level. RT-PCR was done also on PBMC samples collected from the same patients and controls for detection ofFas-L mRNA. We found significant increase of sIL2R in the SLE group [327.6 +/- 73.5 pg/ml] compared to healthy controls [119.7 _ 12.6 pg/ml] [p<0.001]. Levels of sIL2R were found to correlate significantly with clinical manifestation and serological markers of active SLE fatigue [p<0.05], renal involvement [p<0.01], pulmonary involvement [p<0.05], high levels ofanti-ds DNA antibody [p<0.001] and high C3 level [p<0.0001]. Fas-L mRNA was expressed in PBMC from [88.9%] SLE patients and not detected in healthy controls. Fas-L positive SLE patients correlate significantly with clinical manifestation and serological markers of active SLE fatigue [p<0.0001], rash [p<0.05], renal affection [p<0.001], high levels ofanti-ds DNA antibody [p<0.0001] and high C3 level [p<0.0001]. Levels ofsIL2R and Fas-L expression correlate significantly with disease activity [p<0.001, 0.001, 0.05, 0.005, respectively]. these findings indicate that sIL2R represent a new early useful serological marker to monitor disease activity in SLE patients. Fas-L expression increased in SLE patients, this increasing was in parallel to disease activity, so it is used as late marker to monitor the severity of the disease