Aerobiologia d'espores d'Alternaria atmosfèriques i prevalença de sensibilització a Alternaria alternata en població amb rinitis i/o asma al·lèrgic a Catalunya
There is a wide historic evidence that relates allergy to molds. Hippocratic doctors already described pathologies associated with mold allergy. According to the environmental concentration of mold spores, the exposed population will have more or less chances of sensitization to them. Thats the reason why mold exposure is an important point in the study of mold allergy.
Mold sensitization and ,especially to Alternaria alternata, seems to be a risk factor for the development of asthma, especially in children, according to different epidemiologic studies.
The aim of this study is to obtain objective and reliable data in the knowledge of mold allergy, through the aerometric study of Alternaria in Catalonias atmosphere and the sensitization prevalence to Alternaria alternata in the population exposed , which presents with rhinitis and/or allergic asthma. Five Burkard type collectors situated in Barcelona, Bellaterra, Girona, Lleida and Tarragona were used to obtain Alternaria alternata aerobiologic data, and the spores identification was made using an optic microscope.
The patients in study are population with asthma and/or rhinitis who come to visit asking for a evaluation of the allergic etiology of their disease. Skin tests ( prick test) with Alternaria alternata A extract and Alternaria alternata B extract ,with Alt a1 allergen quantification were performed in all patients. Seric specific IgE testing is made with Pharmacia Cap system.Values obtained are expressed in kU/L.
The aerobiological study of Alternaria alternata spores in the atmosphere of different areas in Catalonia , shows its presence any time of the year, finding the highest peaks of concentration during summer time and early autumn. Country areas show a highest atmospheric concentration of Alternaria.
1056 patients ,in which rhinitis and/or allergic asthma is suspected, are enrolled in the study. 824 of them have a positive cutaneous test to at least one of the common area aeroallergens tested or to the Alternaria alternata extract, what confirms the allergic condition of the patient. That is the reason why the valid population of the study are those 824 patients. The gender distribution is: 332 men and 492 women. The age distribution is : 140 patients were younger than 14 years old and 684 patients were older than 14. 151 patients were sensitized to Alternaria alternata, what represents an 18,3% of all valid patients.
61% of the 103 patients sensitized to Alternaria alternata ,according to the results in prick testing (area bigger than 7mm2 when compared to the negative control), in which a seric specific IgE test to Alternaria alternata is performed, show a value higher than 0.70 kU/L, and 65% of the 103 patients have a value of seric specific IgE above 0.35 kU/L.
Those patients enrolled in the study sensitized to Alternaria alternata , show a higher risk of developing asthma when compared to the population sensitized to any of the other aeroallergens tested.
The children enrolled in the study present a higher incidence of sensitization to Alternaria alternata when comparing to adults and young people.
Prick test to standardized Alternaria alternata extract with Alt a 1 allergen quantification shows a higher sensitivity than seric specific IgE determination when used to test Alternaria alternata sensitization.
Advisor:Cistero Bahima, Anna; Pedro-Botet Montoya, Juan
School:Universitat Autónoma de Barcelona
Source Type:Master's Thesis
Keywords:417 departament de medicina
Date of Publication:07/28/2004