Summary
Background. Asthma is a chronic re spiratory disease with heterogeneous pathogenesis and etiology. For better diagnostic it is important to pay attention to new laboratory markers for asthma. YKL-40 is a recently discovered human glycoprotein which could be an adequate marker for the assessment of asthma. How ever, it is not yet clear how YKL-40 works and what immunological mechanism of asthma is more related to the expression of this protein.
Objective and methods.This study aimed to review scientific publications that investigated the association of YKL-40 with different immunological mechanisms of asthma and to evaluate the association of YKL-40 with markers of immune response. The primary outcome measure was YKL-40 level in serum and/or sputum of patients with asthma. A total of 87 articles were found. Overall, 10 articles were in cluded in systematic review that were published 2016–2021. The results of a systematic review revealed that YKL-40 levels were higher in patients with asthma compared with healthy subjects. Some studies showed that higher levels of YKL-40 were detected in allergic asthma compared to healthy subjects or patients with non-allergic asthma. Majority of studies showed no relation between YKL-40 and eosinophils or total immunoglobulin E (IgE), but revealed positive relation between YKL-40 and neutrophil. Some studies showed positive relation between YKL-40 and interleukin (IL)-6, IL-8 level. Majority of studies showed positive relation between YKL-40 level and asthma severity.
Reasults and conclusions. The results of a systematic review suggest that the assessment of YKL-40 level maybe a signifi cant marker in the identification of patients with severe asthma.
