05d967dc-437a-463c-9d91-34696585b7a9.json

{
 "id": "05d967dc-437a-463c-9d91-34696585b7a9",
 "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": "16141442",
  "text": "BACKGROUND:\nAlthough research has shown that early life exposure to household endotoxin protects against development of allergies, studies are less clear on the relationship between household endotoxin exposure and prevalence of wheezing and asthma. We assayed 2,552 house dust samples in a representative nationwide sam- ple to explore relationships between endotoxin exposures and risk factors for asthma, asthma symptoms, and medication use.\n\nMETHODS:\nHouse dust was vacuum-sampled from five locations within homes and assayed for endotoxin. Health, demographic, and housing information was assessed through questionnaire and on-site evaluation of 2,456 residents of 831 homes selected to represent the demographics of the United States.\n\nRESULTS:\nEndotoxin concentration (EU/mg) and load (EU/m(2)) were highly correlated (r = 0.73-0.79). Geometric mean endotoxin concentrations were as follows (in EU/mg): bedroom floors, 35.3 (5th-95th percentile, 5.0-260); bedding, 18.7 (2.0-142); family room floors, 63.9 (11.5-331); sofas, 44.8 (6.4-240); and kitchen floors, 80.5 (9.8-512). Multivariate analysis demonstrated significant relationships between increasing endotoxin levels and diagnosed asthma, asthma symptoms in the past year, current use of asthma medications, and wheezing among residents of the homes. These relationships were strongest for bedroom floor and bedding dust and were observed in adults only. Modeling the joint effect of bedding and bedroom floor endotoxin on recent asthma symptoms yielded an adjusted odds ratio of 2.83 (95% confidence interval, 1.01-7.87). When stratified by allergy status, allergic subjects with higher endotoxin exposure were no more likely to have diagnosed asthma or asthma symptoms than nonallergic subjects.\n\nCONCLUSION:\nThis study demonstrates that household endotoxin exposure is a significant risk factor for increased asthma prevalence."
 },
 "questions": [
  {
   "id": "c80ed6a6-6cc7-4559-96f5-4df4be5eb15d",
   "text": "What are the risk factors of Asthma?",
   "answers": [
    {
     "answer_start": 1804,
     "text": "household endotoxin exposure"
    },
    {
     "answer_start": 1153,
     "text": "increasing endotoxin levels"
    }
   ]
  }
 ]
}