Spherulin, a soluble extract from autolyzed spherules of Coccidioides immitis, was compared with mycelium derived coccidioidin for complement fixing (CF) activity. At optimal dilutions, both reagents were comparable with high titered sera. However, spherulin showed a 31% higher ratio of CF reactors than coccidioidin, among patients having titers of 1:8 or less with coccidioidin. Of 80 sera from subjects with proved or suspected coccidioidomycosis, 63 fixed complement with spherulin but only 47 of these fixed complement with coccidioidin. In no case did coccidioidin detect CF activity when spherulin failed to do so. Titers were frequently higher with spherulin in sera reactive to both antigens. In 3 instances, CF activity was demonstrated by spherulin with sera that did not react with coccidioidin in either the CF or immunodiffusion tests; one of these sera was obtained from a patient with culturally proved coccidioidomycosis.
|Original language||English (US)|
|Title of host publication||AMER.REV.RESP.DIS.|
|Number of pages||5|
|State||Published - 1974|
ASJC Scopus subject areas