Mannose-binding Lectin Levels in Children with Recurrent Conditions

Mannose-bulding lectin (MBL) is a key component of innate immunity that effective eliminates a wide range of pathogenic microorganisms. In many people, mutations cause low innate MBL production or activity. This potentially increases the risks of severe infections.

Objektive: to explort the activity of MBL in the blood serum of infants and toddlers suffering from recurrent respiratory tract infections.

Methods: 31 children treated for respiratory infections complicated by moderately severe community-acquired pneumonia were included in the study. The patients were divided into two groups: 1) children who had had 7 or more episodes of an acute respiratory disease (ARI) over the year; 2) those who had had fewer than 5 ARI episodes over the period. MBL levels were identified using a standard HBT ELISA test kit for Human MBL (Hyсult biotech).

Results: In both groups, clinical signs included low-grade or regular fever, coughing, shortness of breath. On auscultation, each third patient had decreased lung sounds, fine crackles, and crepitus. Only children from group 1 had more than one lung tissue segment affected. Respiratory failure occurred in 26.4% patients in group 1 and 6.2% in group 2. Pleurisy was present only in 13.3% children in group 1. Some patients in group 1 had had pneumonia for the second (20%) or third (13.3%) time.

Analysis showed that only 12.5% people in group 2 had MBL levels below 0.5µg/l, whereas there were 53.3% such children in group 1, р < 0.02. In group 2, 31.2% patients had an MBL level of above 3µg/l. In group 1, the maximum MBL level was 1.5µg/l.

Conclusion: The study has demonstrated that low MBL levels are associated with a higher predisposition to respiratory diseases in children: a low MBL level was more frequent in patients with recurrent conditions, р < 0.02.