SERUM LEVEL OF INSULIN LIKE GROWTH FACTOR BINDING PROTEIN 3 (IGBP3) AS A MARKER OF SEVERITY AND REMODELING IN ASTHMATIC CHILDREN

Abstract

SUMMARY A sthma is a heterogeneous chronic disease affecting millions of people all over the world, it affects about 300 million people worldwide, the prevalence of asthma among Egyptian children aged 3 - 15 years was estimated to be 8.2%, sever and chronic asthma leading to airway remodeling causing an alteration of the structure and function of airway that would increase morbidity and mortality. Insulin-like growth factor binding protein 3 (IGFBP-3) is the major circulating IGF binding protein, IGFBP3 is over-expressed in asthma and contributes to airway inflammation and airway hyper-responsiveness and to allergic airway remodeling, its main source is hepatic cells. The aim of this study was to evaluate the level of insulin growth factor binding protein-3 (IGBP3) ng/ml as a member of insulin like growth factor binding proteins that played a role in assessment of severity and airway remodeling in asthmatic children. This case-control study was carried out on 60 asthmatic children (group 1) who were recruited from Pediatric Chest Clinic, Children’s Hospital Ain Shams University. The age of their age ranged between 6-15 years with mean 9.73 ± 2.49 age years with female to male ratio1:1.08. Twenty (20) matched- clinically healthy children (group 2) were collected from outpatient clinic as a control group. The asthmatic children were further subdivided according asthma severity into mild persistent asthma (n=20), moderate persistent asthma (n=20), severe persistent asthma (n=20). They further subdivided according to MMEF75-25 as small airway affection into Moderate to severe small airway affected patients’ group (MMEF7525<60), and mild small airway affected patients’ group (MMEF75/25>60) indicating of the pathological effect of asthma severity on small airways. All studied children were subjected to full medical history, throughout clinical examination including: weight, height and BMI, and spirometric pulmonary function testing. Measurement of serum IgE, complete blood picture (CBC), serum Insulin like growth factor binding protein-3 (IGFBP-3) analysis of samples was done using ELISA technique. Frequency of passive smoking exposure (65%), family history of atopy (56.7) and asthma, frequency of heavy traffic exposure (72%) were statistically significant higher in patients’ group compared to control group. FEV1% of predicted, FVC % of predicted, FEV1/FVC ratio and MMEF75/25% of predicted were statistical significantly of lower values in severe asthma patients’ group compared to mild and moderate asthma patients’ group. A comparison between asthmatics and control group laboratory data showed statistical significant differences as regards Absolute Eosinophil count(AEC) with mean level (6.73 ± 2.60) versus (5.40 ± 1.76) and serum total IgE with mean level (127.62 ± 187.08) versus (19.38 ± 5.95). TLC×103, absolute Eosinophil count (AEC), and serum level of total IgE were statistical significantly higher in severe patients’ group compared to moderate patients’ group and mild patients’ group. Indicating positive correlation between TLC×103, absolute Eosinophil count (AEC), and serum level of total IgE and asthma severity, There was statistical high significant negative correlation between serum level of IGFBP3 (ng/ml) and studied demographic data (Weight of age and sex) with P value 0.006, and (Height of age and sex) with P value 0.002, and Z-score (BMI) values) with p value 0.008, Moreover there was statistical high significant negative correlation between serum level of IGFBP3 (ng/ml) and and studied spirometer values as (FEV% of predicted, FVC % of predicted, FEV/FVC ratio and MMEF75/25% of predicted). Moderate to Severe small airway affection MMEF75/25<60 were statistical significantly higher than Mild small airway affection MMEF75/25>60 as regards serum IGFBP3 with mean (9.89 ± 5.91) versus 2.63 ± 0.58(P Value 0.000). There was a higher serum level of IGFBP3 in moderate to severe small airway affected asthmatics group (3-27) ng/ml when compared to mild small airway asthmatics group (1.5-4) ng/ml with cut-off value >3 with sensitivity (97.50) and specificity (95.00).