Allergenic Implications of Airborne Leptosphaeria Ascospores

In order to investigate potential acroallergens of the Auckland region, a quantitative and qualitative study of the air spora was conducted at three different sites over the 12-month period, September 1979 to August 1980. Burkard volumetric spore traps were operated simultaneously at each of the three sites viz. Mt. Eden, Henderson and Waitakeres, located on a 20-km axis extending westward from Auckland City and encompassing residential, horticultural, agricultural, commercial and forested contexts. In the individual category of ascomycetous fungi, Leptosphaeria ascospores were recorded as an important component of air spora of the two non-forested sites. Ascospores concentration displayed a seasonal peak in late summer (February) and early autumn (March) and a diel periodicity with a distinct nocturnal maxima at all sites, confirming Leptosphaeria to be a component of the “rising air” or “damp-air spora”. The maximum concentration exceeded 4430 m^?3 of air around midnight (24/25 March, early autumn). A comparison of the results from the three sites showed that 61% of the total Leptosphaeria ascospores were trapped at Henderson (a satellite town in a rural setting) 29% at Mt. Eden (commercial/residential area) and 10% at Waitakeres (mainly forest site). Our data for Leptosphaeria ascospores combined with a high regional incidence of respiratory allergic diseases particularly bronchial asthma in late summer and autumn, indicate that a thorough investigation of the role of Leptosphaeria as a potential aeroallergen is warranted.