Correlations between serum amyloid A, C-reactive protein and clinical indices of patients with acutely exacerbated chronic obstructive pulmonary disease

Background: To explore the correlations between SAA, CRP, and clinical indices of patients with acutely exacerbated chronic obstructive pulmonary disease (AECOPD).

Methods: A total of 120 patients with AECOPD and another 120 with remitted COPD were enrolled in an AECOPD group and a COPD remission group, respectively. Meanwhile, 120 healthy subjects were included as a control group. SAA, CRP, PCT, Fbg, IL-8, IL-6, TNF-α, and IP-10 levels were detected. FEV₁ and FEV₁ /FVC were measured.

Results: Compared with control group, the serum levels of SAA, CRP, PCT, Fbg, IL-8, IL-6, TNF-α, and IP-10 significantly increased in COPD remission group (P < 0.05). The levels of AECOPD group significantly exceeded those of COPD remission group (P < 0.05). The levels of AECOPD patients with different GOLD grades were significantly different (P < 0.05). AECOPD group had significantly lower FEV₁ and FEV₁ /FVC than those of COPD remission group (P < 0.05). The CAT score of AECOPD patients was (18.41 ± 2.55) points. The levels of SAA, CRP, PCT, Fbg, IL-8, IL-6, TNF-α, and IP-10 were negatively correlated with FEV₁ and FEV₁ /FVC, and positively correlated with CAT score. The area under receiver operating characteristic curve of SAA was largest (0.931). The cutoff values for SAA, CRP, PCT and Fbg were 18.68 mg/L, 14.70 mg/L, 0.39 μg/L, 3.91 g/L, 0.46 μg/L, 24.17 μg/L, 7.18 mg/L, and 83.19 ng/L, respectively.

Conclusions: Serum levels of SAA, CRP, PCT, Fbg, IL-8, IL-6, TNF-α, and IP-10 in AECOPD patients were elevated, which may undermine pulmonary functions. SAA can be used as an effective index for AECOPD diagnosis and treatment.