Induction and detection of delayed dermal hypersensitivity in guinea-pig immunized with Blastomyces dermatitidis...

Guinea-pigs were immunized using yeast phase antigens (lysate and filtrate preparations) from two strains of Blastomyces dermatitidis (T-58 and Le). Following a sensitization period, the animals were skin tested on days 40 and 216 using T-58 and Le yeast and mycelial phase lysate and filtrate antigen preparations for the detection of delayed dermal hypersensitivity (DTH). Using the Friedman's analysis of variance by rank test, significant differences were found in the efficacy of the immunogens to induce DTH in the animals when skin tested on both occasions (P < 0.05). Optimal reactivity was observed in guinea-pigs immunized with Le yeast lysate (mean axes of induration ranging from 12.0 to 18.8 mm and 7.0 to 18.5 mm on day 40 and 216, respectively) and T-58 yeast filtrate (mean axes of induration ranging from 7.5 to 18.0 mm and 8.0 to 17.0 mm on day 40 and 216, respectively) when the immunogens were administered with adjuvant. When the same data was analysed using the Friedman's test with regard to evaluating the efficacy of the skin test antigens to detect DTH, significant differences were found between them (P < 0.05) with optimal results using the Le mycelial filtrate and yeast lysate antigens (mean axes of induration ranging from 7.0 to 16.5 mm and 7.5 to 14.5 mm, respectively) when skin testing was done on day 40. When skin testing was done on day 216, the T-58 and Le mycelial lysate antigens gave optimal results (mean axes of induration ranging from 9.0 to 18.5 mm and 7.5 to 15.0 mm, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)