A comparative study of two angiogenic factors: vascular endothelial growth factor and angiogenin in induced sputum from asthmatic children in acute attack.
BACKGROUND
Angiogenesis is a prerequisite for airway remodeling in bronchial asthma. Several factors may play important roles in inflammation and angiogenesis through effects on inflammatory cell infiltration or neovascularization.


OBJECTIVE
(1) To determine the levels of vascular endothelial growth factor (VEGF) and angiogenin in sputum supernatants of asthmatic children during the acute attack and 6 weeks after start of therapy; and (2) to correlate their levels with the degree of asthma severity.


METHODS
Twenty asthmatic children with acute attack (mean age, 9.6 +/- 3.5 years [+/- SD]) and 12 sex- and age-matched healthy control children were enrolled in the study. Sputum supernatants were collected for determination of VEGF and angiogenin levels. Serum samples were withdrawn for IgE measurement. The above tests were performed using an enzyme-linked immunosorbent assay. The FEV1 was measured using spirometry. VEGF, angiogenin, and FEV1 estimations were repeated for asthmatic children 6 weeks after start of therapy.


RESULTS
During the acute attack, asthmatic children had significantly higher levels of VEGF and angiogenin than in healthy control children (p < 0.001). VEGF and angiogenin levels showed more elevation with increase in asthma severity (p < 0.001). A significant positive correlation existed between both angiogenic factors (r = 0.98, p < 0.001). A negative significant correlation was found between FEV1 percentage of predicted and both VEGF (r = -0.99, p < 0.001) and angiogenin (r = -0.97, p < 0.001). A nonsignificant correlation was found between serum IgE and sputum VEGF (r = 0.09, p > 0.05). Although there was a significant decrease in the levels of both VEGF and angiogenin after 6 weeks of treatment with corticosteroid inhalation therapy, the levels did not reach normal control levels (p < 0.001 and p < 0.05, respectively).


CONCLUSIONS
Our results show that both VEGF and angiogenin levels were elevated in children with acute asthma. The study also suggests that increased severity of bronchial asthma in children is associated with the expression of both angiogenic factors, which are implicated in asthma pathogenesis. After 6 weeks of therapy, the levels of both angiogenic factors showed significant decrease.
Abdel-Rahman
Azza M O
AMO
Department of Pediatrics, National Research Center. Electronic address: azzaomar74@yahoo.com.
El-Sahrigy
Sally A F
SAF
Department of Pediatrics, National Research Center.
Bakr
Salwa I
SI
Department of Clinical Pathology, Ain Shams University Hospital, Cairo, Egypt.
D000208:Acute Disease; D000293:Adolescent; D043925:Angiogenesis Inducing Agents / Q000032:analysis*; D001249:Asthma / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis; D008297:Male; D012259:Ribonuclease, Pancreatic / Q000032:analysis*; D013183:Sputum / Q000737:chemistry* / Q000166:cytology; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis*
D043925:Angiogenesis Inducing Agents; D042461:Vascular Endothelial Growth Factor A; D007073:Immunoglobulin E; C046366:angiogenin; D012259:Ribonuclease, Pancreatic