Importance of mannose-binding lectin2 polymorphism (rs1800450) in infections in children

Purpose Mannose-binding lectin (MBL) is a serine protease belonging to the collectins and an important factor in the inherited immune system. We aimed to reveal the distribution of different MBL2 genotypes in patients diagnosed with acute bronchiolitis and pneumonia. Material and methods A total of 147 patients who applied to Pediatric Emergency between 01.12.2019-31.12.2020 included in the study. Patients were divided into two subgroups: Bronchiolitis and pneumonia. Results AA genotype was found to be significantly higher in healthy controls (p = 0.039). In pneumonia group, both AB/BB genotype was significantly higher compared to healthy controls (p = 0.001). While AA genotype was more common in patients with acute bronchiolitis, AB/BB genotypes were more common in the pneumonia group (p = 0.001). The presence of fever, crepitation, tachypnea, pathological x-ray finding and high leukocyte count are significantly more common in patients with AA genotype, while more than 3 days of follow-up duration and severe clinical picture were more common in patients with AB/BB genotypes (p Conclusions Genotypes with low MBL expression were significantly more common in patients with pneumonia and severe infection. All these results reveal the importance of MBL polymorphisms and expression in infections.