Abstract:

Objective
To determine the serum levels of a proliferation-inducing ligand(APRIL) in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis(RA) and analyze its correlations with immunological parameters and its roles in the development of SLE.Methods The levels of  APRIL  in 48 patients with SLE,16 patients with RA and 16 healthy controls were determined by enzyme linked immunosorbent assay (ELISA),its correlations with SLEDAI and immunological parameters were analyzed.Results The serum levels of APRIL in SLE and RA patients were significantly higher than  that in healthy controls （P<0.01）,and the serum level of APRIL in SLE  patients were significantly higher than that in RA patients（P<0.01）. The serum level of  APRIL in SLE patients with positive anti-Sm antibody was significantly higher than that in the negative ones（P<0.05）.The serum level of APRIL in SLE patients with positive anti-U1RNP antibody was significantly higher than that in the negative ones（P<0.05）.While the serum level of APRIL in SLE patients  didn’t have significant differences between the patients with positive anti-SSA /SSB antibody,anti-ACL antibody,anti-dsDNA antibody and the negative ones.The serum level of APRIL in SLE patients was  negatively correlated with the complements C3 and C4 （r1=－0.819，P1＜0.01；r2=－0.549，P2＜0.01）,but not significantly correlated with SLEDAI and other immunological parameters.Conclusion The serum level of APRIL in SLE patients is specially increased,it may have an important effect on the development of SLE and may be correlated with the activity of SLE .

Key words: systemic lupus erythematosus;rheumatoid arthritis;a proliferation-inducing ligand;enzyme linked immunosorbent assay