Detection of Coccidioidal Antibodies by 33-kDa Spherule Antigen, Coccidioides EIA, and Standard Serologic Tests in Sera from Patients Evaluated for Coccidioidomycosis

Abstract

During a 9-month study of patients being evaluated for coccidioidomycosis, 1 or more serum samples were obtained from 138 patients with an illness suggestive of recent infection. In this group, standard immunodiffusion tests of unconcentrated sera were positive for 25; 49 additional patients had at least 1 reactive test result by newer enzyme-linked serologic tests. At least 11 of these 49 patients had coccidioidomycosis as determined by culture or subsequent standard serologic tests. Patients with coccidioidomycosis identified only by newer tests had fewer or milder clinical abnormalities than did patients in whom the disease was detected by standard tests. For 31 other patients with illness of a chronic or undetermined duration, newer tests detected only 10 more than the 18 identified by standard tests, suggesting that later in the course of illness, standard testing gains in sensitivity for coccidioidal infection.

Protein Expression Profiling of Coccidioides posadasii by Two-Dimensional Differential In-Gel Electrophoresis and Evaluation of a Newly Recognized Peroxisomal Matrix Protein as a Recombinant Vaccine Candidate

“…To assess whether Pmp1 was recognized by the immune system of naturally infected patients, we assayed for anti-Pmp1 immunoglobulin G (IgG) antibody in several patient populations. Ninety-six-well plates (Polysorp; Nunc, Rochester, NY) were coated with 10 ng rPmp1 in Dulbecco's Enzyme-linked immunosorbent assays (ELISAs) were performed as previously described (53). Serum from individuals with complicated coccidioidal disease was from patients enrolled in a study to examine the effectiveness of new antifungal agents, and represents the earliest available sample from each patient.…”

Recent Advances in Our Understanding of the Environmental, Epidemiological, Immunological, and Clinical Dimensions of Coccidioidomycosis

“…The newest serologic tests are commercial EIA kits, which use proprietary coccidioidal antigens. These assays are more sensitive than the traditional CF, TP, IDCF, and IDTP assays (145)(146)(147) and may detect antibodies earlier in infection (145)(146)(147)(148).…”

Clinical Specificity of the Enzyme Immunoassay Test for Coccidioidomycosis Varies According to the Reason for Its Performance

“…When we focused on patients who had serologic draws for screening purposes and not to evaluate symptoms, 16 of 29 patients (55%) had possible false-reactive results. An alternate explanation to a false-positive test result is that patients with coccidioidomycosis identified only by the newer EIA had fewer or milder clinical abnormalities than did patients in whom the infection was detected by older methods, as supported by a previous study (4).…”

“…The EIA is a useful test because it can be done locally and has demonstrated better sensitivity in early coccidioidal illness than other methods (3,4). Two EIA kits are available commercially, without discernible differences in performance between them; both are easy in use, have a rapid turnaround time, and can be performed in local laboratories.…”

“…In addition, the EIA is more sensitive early in the disease process than are complement fixation (CF) and immunodiffusion (ID) (3,4). However, the EIA has generated some controversy, especially as it pertains to the particular finding of immunoglobulin M (IgM) reactivity in the absence of any immunoglobulin G (IgG) detected (EIA IgM ϩ /IgG Ϫ ).…”