Aim of the study To assess the relationship between low levels of circulating basophils counts and the activity of lupus nephritis.

Methods We performed a retrospective clinical study, 140 clinical and pathology samples from patients with biopsy-proven LN from were analysed. The renal activity and classification were evaluated according to renal pathology. SLE disease activity was scored using the SLE Disease Activity Index (SLEDAI).The correlations between circulating basophil counts and renal pathology activity index were assessed.

Results Mean age of our patients was 34.63±12,7 years old, 83% were females. Class III, IV and V lupus nephritis accounted for 21%, 58.7% and 11.2% respectively. Circulating basophil counts correlated with total systemic lupus erythematosus disease activity index (SLEDAI) score (r=–0.3), renal SLEDAI score (r=–0.32), activity index (AI) score(r=–0.29), and renal histologic activity parameters (p<0.05, respectively). Compared with systemic lupus erythematosus (SLE) non active LN patients, the active LN group showed lower basophil counts (p=0.002). Moreover, Significant differences were found in circulating basophil counts among LN pathology classification groups (p<0.05). Groups of classes III, IV were more likely to have lower circulating basophil counts when compared with the other classes (p=0.047).

Conclusion According to these results circulating basophil counts might be an interesting marker for renal activity of LN.