02551e49-54f9-4d1a-a797-476104decd03.json

{
 "id": "02551e49-54f9-4d1a-a797-476104decd03",
 "disease": {
  "id": "H00079",
  "names": [
   "Asthma"
  ],
  "dbLinks": {
   "icd10": [
    "J45"
   ],
   "mesh": [
    "D001249"
   ]
  },
  "category": "Immune system disease",
  "description": "Asthma is a complex syndrome with many clinical phenotypes in both adults and children. Its major characteristics include a variable degree of airflow obstruction, bronchial hyperresponsiveness, and airway inflammation. Inhaled allergens encounter antigen presenting cells (APC) that line the airway. Upon recognition of the antigen and activation by APC, naive T cells differentiate into TH2 cells. Activated TH2 stimulate the formation of IgE by B cells. IgE molecules bind to IgE receptors located on mast cells. The crosslinking of mast-cell-bound IgE by allergens leads to the release of biologically active mediators (histamine, leukotrienes) by means of degranulation and, so, to the immediate symptoms of allergy. Mast cells also release chemotactic factors that contribute to the recruitment of inflammatory cells, particularly eosinophils, whose proliferation and differentiation from bone marrow progenitors is promoted by IL-5. The activation of eosinophils leads to release of toxic granules and oxygen free radicals that lead to tissue damage and promote the development of chronic inflammation."
 },
 "article": {
  "id": "17050892",
  "text": "BACKGROUND:\nReduced lung function in early infancy has been associated with later obstructive airway diseases. We assessed whether reduced lung function shortly after birth predicts asthma 10 years later.\n\nMETHODS:\nWe conducted a prospective birth cohort study of healthy infants in which we measured lung function shortly after birth with the use of tidal breathing flow-volume loops (the fraction of expiratory time to peak tidal expiratory flow to total expiratory time [t(PTEF)/t(E)]) in 802 infants and passive respiratory mechanics, including respiratory-system compliance, in 664 infants. At 10 years of age, 616 children (77%) were reassessed by measuring lung function, exercise-induced bronchoconstriction, and bronchial hyperresponsiveness (by means of a methacholine challenge) and by conducting a structured interview to determine whether there was a history of asthma or current asthma.\n\nRESULTS:\nAs compared with children whose t(PTEF)/t(E) shortly after birth was above the median, children whose t(PTEF)/t(E) was at or below the median were more likely at 10 years of age to have a history of asthma (24.3% vs. 16.2%, P=0.01), to have current asthma (14.6% vs. 7.5%, P=0.005), and to have severe bronchial hyperresponsiveness, defined as a methacholine dose of less than 1.0 micromol causing a 20% fall in the forced expiratory volume in 1 second (FEV1) (9.1% vs. 4.9%, P=0.05). As compared with children whose respiratory-system compliance was above the median, children with respiratory compliance at or below the median more often had a history of asthma (27.4% vs. 14.8%; P=0.001) and current asthma (15.0% vs. 7.7%, P=0.009), although this measure was not associated with later measurements of lung function. At 10 years of age, t(PTEF)/t(E) at birth correlated weakly with the maximal midexpiratory flow rate (r=0.10, P=0.01) but not with FEV1 or forced vital capacity.\n\nCONCLUSIONS:\nReduced lung function at birth is associated with an increased risk of asthma by 10 years of age."
 },
 "questions": [
  {
   "id": "a8b372a0-70f9-446c-b705-b229e08cb70e",
   "text": "What are the risk factors of Asthma?",
   "answers": [
    {
     "answer_start": 1907,
     "text": "Reduced lung function at birth"
    },
    {
     "answer_start": 998,
     "text": "children whose t(PTEF)/t(E) was at or below the median"
    },
    {
     "answer_start": 1480,
     "text": "children with respiratory compliance at or below the median"
    }
   ]
  }
 ]
}