Guanine Levels in House Dust as a Means of Estimating the Mite Population

: House dust has recently been incriminated as an important causative allergen in bronchial asthma and allergic rhinitis. In particular attention is being focused on the mites contained in house dust. Previously, the number of mites contained in house dust was determined by counting under a microscope. This method is not appropriate, however, for epidemiological investigations which require large numbers of specimens, as it is time-consuming and labor intensive. Guanine makes up about 0.3% of the body weight of mites and is present in large amounts in mite excrement, and by using an improved method for quantifying guanine in house dust we obtained a correlation coefficient of 0.776 between the number of mites and amount of guanine. In addition, because virtually no guanine is contained in human nails and hair, thus eliminating possible sources of error, it became clear that the amount of guanine in house dust can be used to estimate the total amount of mite allergen resulting from the bodies and excrement of the acarids.