Evaluation of different commercial ELISA methods for the serodiagnosis of systemic candidosis

Abstract

Different commercial enzyme-linked immunsorbent assays (ELISA) were evaluated in a preliminary study for diagnosis of systemic candidosis: Biomerica and Virotech GmbH, which allowed immunoglobulin G detection, and Platelia, which associated total antibody to antigen detection. They were tested with a home-made ELISA and compared with the routine techniques used in the hospital laboratory: indirect immunofluorescence and counter-immunoelectrophoresis. Sera were obtained from patients with probable or proven systemic candidosis (groups 3 and 4, n=8 and n=14, respectively) and from patients without systemic candidosis who were divided into controls (n=10), those hospitalized without Candida isolation (group 1, n=10) and those hospitalized with Candida isolation in a peripheral site (group 2, n=18). The immunoglobulin G ELISAs showed a higher sensitivity associated with lower specificity compared to the indirect immunofluorescence, counter-immunoelectrophoresis and total immunoglobulin ELISAs. Mannan antigen detection showed the highest specificity (78.9%). Its association with the detection of total anti-Candida immunoglobulins was more sensitive than the association of indirect immunofluorescence with counter-immunoelectrophoresis (95.4% versus 59%, respectively) with a specificity of 52.6% (versus 55.2%). Interest in the use of commercial ELISAs, more particularly the Platelia tests, has to be confirmed in a prospective study with follow-up of the patients.

Invasive Fungal Infections and Approaches to Their Diagnosis

“…Serologic tests can provide a rapid means of diagnosing fungal infections, as well as a means to monitor the progression of the infection and the patient's response to therapy by comparing serial determinations of antibody or antigen titers (Alexander & Pfaller, 2006;Lopez-Ribot & Patterson, 2005;Persat et al, 2002;Philip et al, 2005;Saubolle, McKellar, & Sussland, 2007;Sendid et al, 2003;Wheat et al, 1983). Most conventional serologic tests are based on detection of antibodies against specific fungal antigens.…”

“…Antibody tests for Candida and Aspergillus may be performed; however, these tests are frequently unable to distinguish between active and past infection on the one hand and colonisation on the other (Kappe, Schulze-Berge, & Sonntag, 1996;Persat et al, 2002;Philip et al, 2005). Furthermore, a negative serologic test does not rule out infection because immunocompromised patients and some individuals with disseminated infection may not mount an antibody response to the infecting organism.…”

ECIL recommendations for the use of biological markers for the diagnosis of invasive fungal diseases in leukemic patients and hematopoietic SCT recipients

“…[42][43][44][45][46][47][48][49][50][51][52][53][54][55] The number of IC cases per study varied from 7 to 105, with a median of 25. A control group was included in 11 of 14 studies, and most frequently consisted of patients with similar risk factors but without IC, and sometimes with other documented infections.…”

Usefulness of a commercial enzyme-linked immunosorbent assay kit for Candida mannan antigen for detecting Candida in oral rinse solutions

“…Candida mannan antigen detection is a reliable and sensitive method for serological diagnosis of systemic candidiasis, and an assay kit is commercially available. [8][9][10] The Unimedi Candida is a microplate enzyme immunoassay employing affinity-purified polyclonal antibodies against Candida albicans mannan. The detection method is generally prepared with C. albicans antigen, but it allows the detection of antigens against other Candida species.…”