The alterations and clinical significance of serum S100A8/A9 and sRAGE in patients with chronic obstructive pulmonary disease

Abstract

Objective To analyze the alterations and clinical significance of serum calcium binding protein S100A8/A9 and soluble receptor for advanced glycation end products (sRAGE) levels in patients with chronic obstructive pulmonary disease(COPD). Methods Enzyme-linked immonosorbent assay was established to detect serum levels of S100A8/A9 and sRAGE in 203 patients with COPD[male166, female 37, aged 52-92 years, average years(69.72±9.079)] and in 41 smoking elderly non-COPD patients[male 35,female 6, aged 55-89 years, average years(68.66±8.74)], and 167 non-smoking healthy subjects as the control group[male 132, female 35, aged 57-92 years, average years(69.13±7.21)] from April 2018 to January 2019. The relationship between the S100A8/A9, sRAGE and clinical biomarkers [the percentage of fored expiratory volume in one second(FEV1) in the predicted value, FEV1/fored vital capacity(FVC), neutrophile granulocyte(NEU)%, pack-year] were investigated. The diagnostic value of S100A8/A9, sRAGE and their combined detection for COPD was analyzed using the subject operating characteristic curve. Results The serum S100A8/A9 level [(2.70±1.11)μg/ml] in COPD patients was significantly higher than that in the smoking control group [(1.65±0.63) μg/ml] and the non-smoking control group[(0.99±0.48)μg/ml], t=5.807, P<0.000 1; t=18.45, P<0.000 1. The serum S100A8/A9 levels in patients with COPD[GOLD Ⅰ(2.08±1.08) μg/ml, GOLDⅡ (2.58±1.06) μg/ml, GOLD Ⅲ (2.69±1.12) μg/ml, GOLDⅣ (2.95±1.10)μg/ml] were significantly higher than the non-smoking control group(0.99±0.48)μg/ml, t=6.616, P<0.000 1; t=14.56, P<0.000 1; t=17.10, P<0.000 1; t=18.09, P<0.000 1.The serum sRAGE level [(0.29±0.25)ng/ml] in COPD patients was significantly higher than that in the smoking control group[(0.60±0.24)ng/ml] and the non-smoking control group[(0.85±0.35)ng/ml], t=7.367, P<0.000 1; t=18.14, P<0.000 1. The serum sRAGE levels in patients with COPD[GOLD Ⅰ(0.46±0.40),GOLDⅡ (0.28±0.25),GOLD Ⅲ (0.29±0.25),GOLD Ⅳ (0.25±0.19)ng/ml] were significantly lower compared with non-smoking control group[(0.85±0.35)ng/ml], t=3.459, P=0.000 5; t=10.23, P<0.000 1; t=13.95, P<0.000 1; t=11.70, P<0.000 1. Serum S100A8/A9 levels were positively correlated with smoking amount and NEU% (r=0.458 5, P<0.000 1; r=0.228 3, P=0.001 1), negatively correlated with FEV1/FVC, the percentage of FEV1 in the predicted value, and sRAGE(r=-0.190 6, P=0.006 4; r=-0.186 3, P=0.007 8; r=-0.201 7, P=0.003 9). sRAGE levels were negatively correlated with NEU% (r=-0.155 9, P=0.026 4). In the ROC curve, the area under the curve of S100A8/A9, sRAGE and combined detection were 0.922[95%CI(0.897-0.947)], 0.926[95%CI(0.899-0.952)]and 0.966 [95%CI(0.950-0.983)], respectively. Conclusion S100A8/A9 and sRAGE are closely correlated with the degree of airflow constrains and the levels of serum inflammatory mediators, which are expected to be as potential biomarkers of COPD. Key words: Pulmonary disease, chronic obstructive; Calgranulin A; Calgranulin B; Receptor for advanced glycation end products