Abstract:
Background: BLyS and APRIL are tumor necrosis factor-family cytokines that play an important role in generating and maintaining the mature B-cell pool. Elevated BLyS levels have been implicated in lupus nephritis, and BLyS antagonism has shown to be an effective therapeutic modality in lupus patients. The aim of the study was to assess the correlation between blood BLyS level and the severity of lupus nephritis. APRIL that is thought to be counterbalance of the autoimmunogenic effects of BLyS was also evaluated too. Methods: 52 lupus nephritis patients that underwent kidney biopsy were evaluated prospectively for at least 6 mo. Renal SLEDAI score, anti-dsDNA, complements, blood BLyS and APRIL on biopsy day were assessed for correlation with pathological score. Analysis using a multivariate model was used to adjust the effect of immunosuppressive therapy. All patients are treated with the standard regimen, and will be monitored continuously. Results: Blood BlyS level in the active lupus nephritis patients were lower than the remission group, whereas blood APRIL level in the active lupus nephritis patients were higher. BLyS level was not correlated with renal pathology, renal SLEDAI and anti-dsDNA, except for the complement level, low dose steroid usage and high dose mycophenolate usage. Surprisingly, APRIL level was instead correlated well with activity index, proteinuria and duration of disease. Conclusions: Blood BLyS levels correlate with systemic lupus whereas blood APRIL levels correlate with lupus nephritis.