Levels of interleukin (IL)‐6 and IL‐8 are elevated in serum and bronchoalveolar lavage fluid of haematological patients with invasive pulmonary aspergillosis

Aspergillus spp. have been shown to induce T‐helper cell (Th) 1 and Th17 subsets resulting in elevated levels of several cytokines. The objective of this study was to analyse a bundle of cytokines in serum and bronchoalveolar lavage fluid (BALF) in patients with and without invasive pulmonary aspergillosis (IPA). This nested case‐control analysis included 10 patients with probable/proven IPA and 20 matched controls without evidence of IPA, out of a pool of prospectively enrolled (2014‐2017) adult cases with underlying haematological malignancies and suspected pulmonary infection. Serum samples were collected within 24 hours of BALF sampling. All samples were stored at ?70°C for retrospective determination of cytokines. IL‐6 and IL‐8 were significantly associated with IPA in both serum (P = .011 and P = .028) and BALF (P = .006 and P = .012, respectively), and a trend was observed for serum IL‐10 (P = .059). In multivariate conditional logistic regression analysis, IL‐10 remained a significant predictor of IPA in serum and IL‐8 among BALF cytokines. In conclusion, levels of IL‐6 and IL‐8 were significantly associated with probable/proven IPA, and a similar trend was observed for serum IL‐10. Future cohort studies should determine the diagnostic potential of these cytokines for IPA, and evaluate combinations with other IPA biomarkers/diagnostic tests.