Diagnosis values of IL-6 and IL-8 levels in serum and bronchoalveolar lavage fluid for invasive pulmonary aspergillosis in chronic obstructive pulmonary disease

Abstract

Among immunologically normal hosts, patients with chronic obstructive pulmonary disease (COPD) are considered to be at high risk of invasive pulmonary aspergillosis (IPA), and early diagnosis and treatment are the key to improving the prognosis of patients. Here we aimed to evaluate whether interleukin (IL)-6 and IL-8 might be used in the detection and diagnosis of IPA in patients with COPD. We prospectively collected 106 patients with COPD and divided them into non-IPA (n=74), probable/possible IPA (n=26) and proven IPA (n=6). Platelia Aspergillus kit was used to detect galactomannan in bronchoalveolar lavage fluid (BALF), and serum and ELISA kit was used to detect IL-6 and IL-8 levels. Diagnostic efficiency of IL-6, IL-8 and galactomannan in serum and BALF was evaluated by receiver operating characteristic curve. Compared with the non-IPA group, the proven/probable IPA group showed significantly elevated levels of IL-6 and IL-8 in both serum and BALF, which were positively correlated with galactomannan levels. The sensitivity and specificity of IL-6 for diagnosing IPA were 74.32% and 81.25% (cut-off at 92.82 pg/mL, area under the curve (AUC)=0.8366) in serum and 68.92% and 71.88% (cut-off at 229.4 pg/mL, AUC=0.7694) in BALF. The sensitivity and specificity of IL-8 for diagnosing IPA were 83.78% and 81.25% (cut-off at 93.46 pg/mL, AUC=0.8756) in serum and 85.14% and 75.00% (cut-off at 325.4 pg/mL, AUC=0.8252) in BALF. The elevated levels of IL-6 and IL-8 in patients with IPA with COPD could be used as auxiliary indicators to diagnose IPA in addition to galactomannan.