In the past decades a number of techni4iues have been applied for diagnosing Aspergillus fumigatus infection. Indeed the correct diagnosis of Aspergillus infection is made by isolation and identification of the organism from biopsied specimen in the lesion, but it is fairly hard to achieve successfully. Recently serological studies are being applied to this fungal infection. However none of them was fully satisfactory in the sense of specificity, sensitivity, reproducibility and applicability for laboratory and field trial.
In the present study ELISA are carried out with minor modification of Voller´s microplate method for diagnosis of Aspergillus fumigatus infection, where Aspergillus metabolite as antigen, peroxides conjugated antihuman globulin (IgG) as conjugated enzyme and H202-OPD as substrate is used.
The results obtained are as follows:
1. The optimal dilution of conjugate, metabolite antigen and serum are 1/10,000, 60mg/ml and 1/200 respectively.
2. One to two common precipitation is observed on double gel immunodiffusion using metabolite antigen.
3. The ELISA values for aspergillosis is significantly higher than other group, that is, aspergillosis; 0.788±0.296, healthy group; 0.131±0.078, asthma; 0. 158±0.034, pulmonary tuberculosis; 0.184±0.066, bacterial pneumonia; 0.117±0.057, paragonimiasis; 0.231±0.020, (P<0.001).
4. The specificity of ELISA using Aspergillus metabolite antigen as a diagnostic tool is 97.3%.
From the above results it is suggested that the ELISA using Aspergillus metabolite antigen is a useful serologic tool for diagnosis of Aspergillus infection since the technique has high specificity, sensitivity and reproducibility.
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