[Immunodiffusion tests in gel media with the addition of polyethyleneglycol 6000 for the serodiagnosis of mycoses]

Abstract

Different immunodiffusion techniques with and without the addition of polyetilenglycol 6000 (PEG), were studied to determine its effect on the sensitivity of these reactions. One hundred thirteen sera from patients who suffered or had suffered deep mycoses (paracoccidioidomycosis: 49, histoplasmosis: 25, aspergillosis: 25, candidiasis: 8 and coccidioidomycosis: 6) were examined by the quantitative Ouchterlony's immunodiffusion procedure. Regular medium and media with 2% and 4% PEG were used. Eighty two out of the one hundred thirteen sera were positive for the regular medium and 91 for the medium containing 2% of PEG; furthermore, an increase of 1 or 2 two fold dilutions in the titers was observed in 40% of the sera, for the later media. Twenty one sera from aspergillosis cases were examined by agarose gel immunoelectrophoresis, 80% had more precipitin bands in the medium with 2% of PEG. Thirty four serum samples of patients suffering aspergillosis, paracoccidioidomycosis and histoplasmosis were studied using the agarose electroosmophoresis with the secondary immunodiffusion test. An increase in the number of the anodic bands were observed in 55% while 64% presented more catodic bands, when the PEG medium was used. This results would indicate that the addition of 2% PEG 6000 to the regular medium improves the sensitivity of the immunodiffusion tests for mycoses.