Improved in vitro diagnosis of allergy to Alternaria tenius and Cladosporium herbarum

To improve the in vitro diagnosis of mould allergy 22 children suffering from allergic asthma caused by Alternaria tenius and/or Cladosporium herbarum as proven by bronchial provocation test were investigated. Partially purified, standardized mould preparations were used in radioallergosorbent test (RAST) with conventional and new update mould discs, mould-induced histamine release and immunoblotting. Updated RAST discs were found to be superior to the old-type discs for the detection of Alternaria but not Cladosporium sensitivity. In all patients except one, specific IgE-antibodies to the respective mould were demonstrated by immunoblotting. Mould-induced histamine release failed to prove sensitization in only two patients. No differences were found comparing histamine release from whole blood with release from isolated cells. The results demonstrate a high sensitivity of in vitro tests when purified and standardized extracts are used.