Study on the correlation between CD3-CD16+CD56+ nature killer cells and systemic lupus erythematosus activity

Objective To investigate the expression and clinical significance of peripheral CD3-CD16+CD56+ nature killer (NK) cells in systemic lupus erythematosus (SLE) patients. Methods Peripheral blood CD3-CD16+CD56+ NK cells from 134 SLE patients and 90 healthy controls were tested by flow cytometry. Serum anti-nuclear antibodies (ANA), anti-double-stranded deoxyribonucleic acid (dsDNA) antibodies and anti-C1q antibodies were determined by Enzyme-linked immunosorbent assay (ELISA). Logistic multiple stepwise regression was used to analyze the independent risk factors for disease activity in SLE patients, Pearson or Spearman correlation was used to analyze the correlation between CD3-CD16+CD56+ NK cells and clinical indicators of SLE patients, and multiple stepwise regression was used to analyze the independent risk factors affecting CD3-CD16+CD56+ NK cells. Results The count and percentage of CD3-CD16+CD56+ NK cells in peripheral blood of SLE patients [(151±126)%, (10±7)%, n=134] was lower than that of healthy controls [(404±261), (19±9)%, n=90)] (t=-12.218, P<0.01; t=-9.606, P<0.01) . The count and percentage of CD3-CD16+CD56+ NK cells in peripheral blood of SLE patients in active group [(94±67)%, (9+6)%, n=54] was lower than that in inactive group [(189±142)%, (11±6) %, n=80] (t=-4.586, P<0.01; t=-2.241, P=0.027) . The count and percentage of CD3-CD16+CD56+ NK cells in peripheral blood, duration of disease, urine protein quantification, erythrocyte sedimentation rate (ESR) and complement 4(C4) were independently correlated with disease activity in SLE patients (OR=0.990, 0.936, 0.979, 1.813, 1.040, 0.183; P<0.05). And the Systemic lupus erythematosus disease activity index (SLEDAI) score was independently correlated with CD3-CD16+ CD56+ cell count (β=-0.358, P<0.01). Conclusions The count and percentage of CD3-CD16+CD56+ cells in the peripheral blood of SLE patients decrease significantly, which is an independent risk factor for disease activity in SLE patients. The SLEDAI score is independently correlated with the count of CD3-CD16+CD56+ NK cells in SLE patients, suggesting that the decrease of CD3-CD16+CD56+ NK cells might play an important role in the development of SLE. Key words: Lupus erythematosus, systemic; CD3-CD16+CD56+ nature killer cell; Systemic lupus erythematosus disease activity index; Anti-double-stranded deoxyribonucleic acid antibodies