دراسة العلاقة الترابطية بين الخمج بالفيروس التنفسي المخلوي والفايروس الانفي والتغاير الجيني rs6749704 مع بعض المحركات الخلوية في الربو عند الاطفال

Study the Association of Respiratory Syncytial Virus and Rhinovirus Infection with some cytokines and rs6749704 polymorphism in Pediatric Asthma

abstract

Immunological and molecular study was performed on asthmatic children infected with RSV and HRV to detection the association between Respiratory Syncytial virus (RSV) and Human Rhinovirus (HRV).infections and genetic polymorphism (rs6749704) in CCL20 , and subsequent alteration in immune response with disease and severity.
The present study is a case-control study conducted on 100 in / and outpatient’s distributed between 50 atopic asthma (35 male and 15 female) and 50 non atopic (31 male and 19 female) who attended the consulting clinic for respiratory diseases and asthma in Kerbela Teaching Hospital for Children during the time period extending from February to June 2022 in Kerbela province. Their ages were between 1-6 years. Fifty healthy children (32 male and 18 female) with the same age and sex to the patients, were selected from the local community were considered as the control group. The characteristics and clinical data were collected from consultants, asthmatic children and /or their parents through a questionnaire. In addition, a questionnaire was made to collect the data from healthy control and /or their parents.
Sera of patients’ and healthy control’ blood which were used to qualitative determination of Respiratory Syncytial virus -IgM, Human Rhinovirus -IgM and measure concentrations total serum immunoglobulin E (TSIgE), CCL20, CXCL10, IL-10 and TGF-β for all samples by Enzyme Linked Immuno Sorbent Assay (ELISA) technique. Whilst, the second part of the blood was placed in EDTA tubes to determine complete and differential blood count including percentage of (eosinophil and neutrophils count) by using blood film and (Sysmex XN-350 five differential automated hematology analyzers, and for the genomic DNA extraction. The DNA extraction was used to detect CCL20 (rs6749704) single nucleotide polymorphism (SNP) by Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR- RFLP).

In the present data, a total of 24 child with asthma infected with RSV and HRV, distribution 10 as RSV and 14 as HRV.
The obtained result showed there was a highly significant association between TSIgE concentration in atopic asthmatic patients and mean rank (275.77)IU/mL while in non-atopic was (36.17) IU/mL compared to healthy control(11.153) IU/mL. Regarding, The mean rank of percentage eosinophil and neutrophil in atopic patients were (6.2), (27.87) and mean rank of non-atopic were (2.1), (52.34), there was a highly significant association between atopic, non-atopic asthmatic patients and healthy control(P=0.0001).Whereas in healthy control were (1.7) (48.42) (P=0.0001). Further there was a highly significant association between increasing CCL20 serum concentration in asthmatic patients compared to healthy control, and the mean rank of CCL20 in atopic patients was (52.2 pg/ml), non-atopic patients (35.7pg/ml) and mean rank of healthy control was (23.9pg/ml). Additionally, eosinophil and neutrophil count and TSIgE level were higher in the moderate compared to mild asthma in the atopic and non- atopic(P = < 0.05).
The results of the current study showed significant differences in the distribution of the CC genotype of CCL-20 (-786T>C) between the atopic, non- atopic asthmatic children and control group (P=0.000). Therefore, the CC genotype could be considered a risk factor for developing atopic and non-atopic asthma in Iraqi children. Genotypes analysis by using Hardy-Weinberg distribution showed significant differences between observed and expected patient numbers for CCL-20 (-786T>C) in the non-atopic patients but not in the atopic group. In conclusion, a high incidence of asthma occurred between males compared to females children and suggested that CCL20 (-786T>C) promoter polymorphism may contribute to the predisposition of asthma and there was a significant association among genotype of this gene and level of CCL20 and development of the disease in children infected with RSV and HRV.

A family history of asthma is considered a risk factor. CCL – 20 and CXCL10 are significantly associated with the development of asthma in children infected with RSV and HRV.
An increased risk of asthma was associated with the CC genotype of CCL-20 (-786T > C) that was revealed as an etiological with the risk by their association with high CCL-20 level , high percentage eosinophil and neutrophil count , and distribution in the atopic and non-atopic respectively in asthmatic children more than in the control group.