Аннотация:Allergic diseases become increasingly common all over the world and the prevalence of obesity recognized as greatest pandemy of the XXI century, especially threatening children population. Obesity considered as a chronic low-grade inflammation with adaptive and innate immunity involvement, whereas excess adipose tissue can act as potent source of pro-inflammatory cytokines.
We aimed to evaluate the association of clinical and immunological parameters of obesity and allergic diseases in groups of children with different body mass index (BMI).
Materials and methods. We conducted retrospective case-control study of 322 medical histories of children aged 12–17 years with allergic diseases, including 229 with atopic bronchial asthma (ВА), 36 with allergic rhinitis (AR), 29 with atopic dermatitis (AD) and 28 children with both AR and AD, which were categorized in accordance with body mass index (BMI) into groups with normal weight, overweight and obesity. The reference group included 48 healthy children.
Allergic history data and blood allergy tests (sIgE spectrum) have been accessed. In blood serum of 108 children we determined the levels of total IgE , CRP, IL-6, IL-8, TNFα and leptin, using commercial test systems of Vector-Best (Russia) and DBC Can-L-4620 (Canada). Parameters of innate immunity (phagocytosis and complement activity) and main lymphocyte populations were measured in blood samples from 214 children with allergic diseases (AR, AD, BA). We used the chi-square test to compare the characteristics of the participants and estimated odd ratios (ORs), 95% confidence intervals (CIs), and P for trend. «Statistica 7.0» software was used for statistical analysis. The study was approved by Ethic Committee at the Mechnikov Research Institute for Vaccines and Sera, Moscow.
Results: All the patients were divided into 3 groups based on the evaluation of BMI: 122 - normal weight (38%), 102 – overweight (31.6%) and 98 (30.4%) – obesity. Anthropometrical analysis of 322 medical histories revealed that in 62% (2/3 of cases) children aged 12–17 years with allergic diseases were overweight, including obesity that encompassed 50% of cases in total. The frequency of obesity was significantly elevated in 12-14 aged patients and tended to reduce as the age levels increased (OR-9.0; 95% CI:1.56-51.86; p=0,08 and OR-0.27; 95%CI: 0.08-0.94; p=0.04, respectively). We did not observe any associations between BMI and gender in all groups. The odds ratio for sIgE to pollen (grasses, weeds and trees), food and house dust mite allergens was increased in the obese children compared with the parameters in other groups. Within 229 patients with atopic asthma 84 (36.7%) were overweight, 82 (35.5%) – obese and 63 (27.5%) – normal weight. The value of BMI appeared to be directly associated with atopy and was influenced by the type of disease.
Among 93 of non-asthmatic children with allergy 23 (24.7%) were overweight, 18 (19.3%) – were obese and 52 (56%) were with normal BMI. The frequency of obesity and overweight among children with bronchial asthma was 3 times higher, in association with high number of comorbidities than in allergic non-asthmatic group.
In all children with allergic diseases, as the value of body weight increased, the levels of total IgE, NK CD16 + cells, CRP and leptin in blood samples increased, while the activity of phagocytosis decreased. We revealed negative correlations between BMI and the complement levels (r= -0.61) as well as with T cell counts (CD3+ r=-0.73, CD4+ r=-0.65, и CD8+ r=-0.51) and positive correlation with phagocytosis activity (r=0.58) in patients with obese.
The level of total IgE in children with asthma was higher than in groups with allergic rhinitis, and increased in accordance with the body weight (р = 0.05). The leptin content was enhanced in children with obesity in both groups BA and AR+AD, but in the cases with AR+AD its level was significantly higher (p = 0.001). The level of CRP was also increased in obese children, but the highest values we observed in children with asthma (р = 0.04). The concentration of pro-inflammatory cytokines revealed some differences. Thus, the level of IL-6 was increased in children with AR and normal body weight, IL-8 in children with enhanced body weight, and only TNFα was elevated in children with asthma in obesity (р=0.008).
Thus, our study could further confirm the impact of obesity into the pathogenesis of allergic diseases. The overweight and obesity in children with allergic diseases showed association with atopic BA and might be considered as the factors of it’s unfavorable clinical course, associated with higher comorbidity.
МАТЕРИАЛ ПРЕДСТАВЛЕН на 3rd International Conference on Obesity and Chronic Diseases (ICOCD-2018), USA, Los Angeles, July 2015