Clinical Comparison of Two Mexican Coccidioidins

Abstract

Coccidioidin, an extract from the saprophytic mycelial form of Coccidioides spp., has been a very useful antigen preparation both for skin and serological tests for coccidioidomycosis. Unfortunately, coccidioidin is not currently available for skin testing in the United States. Coccidioidin has been produced commercially in Mexico by a vaccine and reagents laboratory of the Mexican Federal Government. It also has been produced at the Microbiology Laboratory of the Faculty of Medicine, Universidad Nacional Autónoma de México exclusively as an antigen for research projects. The objective of the study was to compare both coccidioidins in their reactivity and safety when applied in humans. One hundred and eighty-four volunteers were tested; median age was 33 (range 14-82). When the cutoff point is set in 5 mm, 88 subjects (47.8%) had a positive test for the commercial coccidioidin and 76 (41.3%; CI(95%) 0.50, 1.15; P = 0.20) were positive with the research antigen. Seventy-five subjects were positive for both antigens and 96 were negative for both. Fifty-nine subjects (31.3%) reported an adverse reaction after the application of the antigen; they were mostly very mild local reactions. Mexican research coccidioidin is a safe and reliable antigen that can be used for the detection of coccidioidomycosis infection in mammals.

Antigens of Coccidioides posadasii as an Important Tool for the Immunodiagnosis of Coccidioidomycosis

“…Many approaches are currently available for laboratory diagnosis of CM: recovery of Coccidioides spp. by culture [9,10]; detection of fungal spherules on clinical specimens by microscopy [11,12]; histopathology [11,12]; molecular-based techniques directly with clinical specimens [13,14] or cultures [15,16]; serology [10,12]; and skin testing [17]. Although a positive culture of Coccidioides spp.…”

Measuring Cellular Immunity in Coccidioidomycosis: The Time is Now

“…In this issue of Mycopathologia, Castañón-Olivares et al [1] report on coccidioidin skin-test antigens prepared in Mexico and their evaluation in subjects living in endemic and non-endemic areas of Mexico.…”