The relationship between A, D, E vitamin metabolism, beta defensin, cathelicidin levels and recurrent bronchiolitis in the three-year old children

Acute bronchiolitis is an inflammatory injury of the bronchioles, usually caused by viral patogens which results in wheezing, cough, increased respiratory rate, thoracic retractions and prolonged expirium with it's severe course especially in children under 2 years of age. Incidence of the disease, the probable relationship between its recurrent attacks and asthma, and constituting an important reason of infantile disease and death, increase importance of the disease. As the reccurent brochiolitis is an indicator and a risk factor of asthma, recent significant increase in incidence of asthma and allergic diseases, create a further incerase in the importance of this disease. In this study, the relationship between the metabolism of vitamin A, E and D and levels of beta defensin and cathelicidin in patients who had the first bronchiolitis attack, and severity and recurrence of bronchiolitis will be assessed. 152 patients admitted to Celal Bayar University Hospital Pulmonary and Allergy Clinic, who diagnosed as first attack acute bronchiolitis in between 1 month – 3 years of age within 2014 October and 2016 February were included to current study. At the time of the first admission, in order to measure levels of serum vitamin A,E, D, vitamin D receptor, beta defensin, cathelicidin blood samples of patients were taken, centrifuged and kept at -80°C in freezer. Then, throughout 6 months-a year patients were controlled with 3 month's periods and reported as whether the bronchiolitis attacks recurred or not. Besides, at the time of the first admission, any environmental factors that can affect the reccurence and severity of the bronchiolitis (smoking among family, smoker mother during pregnancy, presence of siblings, allergy and temporary wheezing history in family) were asked (to parents) in a survey and recorded. Serum biomarkers, were investigated by ELISA method. In order to assess the relationship between clinical severity and recurrence of bronchiolitis and the serum levels of biomarkers that has been studied on. In 78 patients who included in the study, bronchiolitis recurred and in 74 of them bronchiolitis didn't recurred. 127 of our subjects admitted with mild and 25 of them admitted with moderate bronchiolitis. Those patients who admitted with moderate bronchiolitis, had more recurrence than others. (%68 of them had bronchiolitis recurrence, %32 of them didn't have. p:8.82) When the relationship between the recurrence of the disease and measured serum parameters has been evaluated, levels of parameters other than vitamin E, were founded slightly lower in patients who had bronchiolitis recurrence was detected. (Serum level of vitamin D in recurred bronchiolitis group is 50,5 ± 61,1 nmol/L, in non-reccured group is 53,4 ± 65,9 nmol/L p:0.77, vitamin A in recurred bronchiolitis group is 218,3 ± 98,2mcg/ml, in non-recurred group is 228,5 ± 106,9mcg/ml p: 0.55, vitamin E in recurred bronchiolitis group is 4,2± 1,5mg/dl, in non-recurred group 3,9 ± 1,6mg/dl p: 0.33, cathelidicin in recurred group is 76,7 ± 40,1ng/ml, in non-recurred group is 84,9 ± 52,3ng/ml p: 0,28) However, it doesn't ceate a statistical difference. No significant relationship was detected between the severity of the disease and serum levels of the parameters. There was a significant relationship detected between bronchiolitis recurrence and smoking history in family which is one of the environmental factors that we evaluated in our study which is; in those patients who had smoking history in his/her family, bronchiolitis recurrence was detected. In %59 of recurred bronchiolitis group, there was passive smoke exposure, in %41 of them there wasn't. (p:0.028) There are restrictions in our study, as there wasn't any patients had severe bronchiolitis clinic and a great portion of our patients had mild bronchiolitis, impede us to obtain more accurate results. In addition, longer follow-up of the patients may provide more accurate results to evaluate the effects of prognosis and recurrence of the disease. It's important to know that, patients especially whose symptom scores are above 4, need to be followed for longer durations and they are the risky group for developing asthma. Antioxidants like; vitamin A, E and D play important roles in recurrence of bronchiolitis attacks and asthma development. The efficacy of nutritional vitamin supplements on preventing recurrences should be investigated. Additionally, the effects of antimicrobial peptides that has a wide-spectrum, on pathogens take part in pathogenesis of bronchiolitis and asthma is crucial today, with current bacterial resistance against classical antibiotics is quite high. Further investigations about these antimicrobial peptides are needed.