Cathelicidin as a marker of worsening of the course of lung infection

Abstract

Cathelicidin (LL-37) is an antimicrobial peptide, an early defense factor. Transfer of the hCAP-18 / LL-37 gene into the airways of the mouse reduces bacterial contamination and inflammatory response in infection.&nbsp;The main aim of research to determine the content of LL-37 in patients with pneumonia and its degree of influence on the course of lung infection. <b>Materials and Methods:</b> The study involved 40 patients with moderate pneumonia and 40 patients with severe lung infection, 30 patients with mild pneumonia. The comparison group consisted of 30 healthy volunteers. Serum LL-37 levels were determined by ELISA (Cloud-Clone Corp.), serum samples were diluted according to the manufacturer’s instructions. <b>Research results and discussion:</b> The average level of LL37 in patients with lung infection was 6.95 ± 2.48, in the comparison group (without bronchopulmonary pathology) - 1.47 ± 3.65 ng/ml (p&lt;0.001). Patients who had severe pneumonia, the level of LL-37 was significantly higher than in the groups with mild and moderate course (p=0.001). A relationship was found between the level of LL-37 and the etiology of the disease (p=0.0002). For example, patients with a bacterial infection of the lungs had a higher level of LL-37 compared with viral lung lesions (p&lt;0.005). The level of LL-37 was studied in patients with fatal outcome due to pneumonia. In all the deceased, the level of LL-37 was significantly lower, while the patients had no difference in pathogens - 0.82 ± 2.65 ng/ml (p&lt;0.001). Therefore, it can be concluded that a low level of LL-37 is a poor prognostic sign in severe pneumonia, which increases mortality.&nbsp;LL-37 in lung infection deserves special attention and needs more detailed study in diseases.