ALLERGENIC IMPLICATION OF AIRBORNE ULOCLADIUM IN SAUDI-ARABIA

As part of a national programme on the role of inhalant allergens in r espiratory allergic disorders particularly bronchial asthma in the Kin gdom of Saudi Arabia, a qualitative, volumetric and immunological stud y of outdoor aeroallergens was conducted. Among various pollen grains and fungal spores identified, Ulocladium spp. emerged to be one of the major spore categories in the outdoor air spora. Ulocladium data usin g Burkard volumetric sampler from three different sites for 12 months each and for 3 continuous years from one site are presented. In additi on, data for 12 months for two other sites in Riyadh City using person al;volumetric sampler are also presented. The peak mean weekly concent ration of Ulocladium was highest in the populated coastal (Jeddah) wit h > 120 spores m(-3) of air. The data displayed a trend at all sites i n seasonal variations showing winter with higher concentration and sum mer with lower concentration. The maximum concentrations for all sites fluctuated and remained under 300 spores m(-3) except for Jeddah reac hing over 1200 m(-3) in late winter. The percentage of Ulocladium in t he air also varied at all sites with highest composition being 7% of t he total air spora using Burkard trap and 6% using personal volumetric sampler. However, at all sites Ulocladium was found to be among the m ost frequently encountered genera. Extracts of Ulocladium were prepare d from local isolates and tested on 100 allergic patients attending al lergy clinic at investigators hospital. 13% positive SPT result with v arious fungal extracts including 5% by Ulocladium were recorded in the se patients. The study suggets a possible role of Ulocladium as an all ergen in the region and necessitates further investigation of the genu s by inclusion of Ulocladium antigens in all in vivo and in vitro alle rgy diagnostic tests in the Kingdom.