In this study, it was shown that the diagnostic accuracy of antibody detection by a counterimmunoelectrophoresis technique could be improved by using cytoplasmic antigens depleted of mannan residues. The specificity of the counterimmunoelectrophoresis increased from 28.6 to 78.6% when cytoplasmic antigens depleted of mannan were used, while the sensitivity slightly decreased from 80 to 70%.