THE DECAY OF HOUSE-DUST MITE ALLERGENS, DER-P-I AND DER-P-II, UNDER NATURAL CONDITIONS

Background Fluctuations in the level of mite allergens in domestic hou se dust are the result of changes in the balance between synthesis, re moval and decay. Purely physical forces as well as enzymatic degradati on, mediated by house dust inhabiting microbes, may contribute to the decay of allergens in domestic dust. Knowledge about the speed of deca y is essential for an understanding of the dynamics of allergen levels . Objective The present study is a quantitative assessment of the spee d of decay at nine combinations of temperature (15 degrees C, 20 degre es C and 25 degrees C) and relative humidity (33%, 55% and 75%). Metho ds Samples of mite infested material of an old rug were stored at thes e temperature/relative humidity-combinations for 6, 12 or 18 months, a fter the mites were killed by either a freezing treatment or an acaric ide (lindane). The microbes living in the rug presumably survive these treatments. Concentrations of Der p I and Der p II + Der f II, in ext racts of the rug material, were measured by a radio immunoassay. Resul ts No significant changes in the levels of Der p I and Der p II + Der f II, could be detected even after 1 1/2 year at a high temperature an d humidity.Conclusion These findings incidate that mite allergens can be extremely stable under normal domestic circumstances.