Evaluation of a Monoclonal-based EIA for the Detection of Giardia lamblia and the Identification of the Antigen
I. A number of commercial enzyme immunoassay (EIA) tests are available for the diagnosis of giardiasis. In a time of rising health-care costs, there is a need for diagnostic tests that are rapid, specific, sensitive and inexpensive. In the first phase of this study, I developed a monoclonal-based EIA, the GIARDIA TEST, with these qualities in mind. This assay's performance characteristics were determined by a comparison study using conventional ova and parasite examination, immunofluorescence antibody test (IFA) and other commercial EIA tests. Studies were done in-house at TechLab, Inc. and at various U.S. medical facilities. Results were statistically analyzed to determine sensitivity (ability of the assay to detect a positive result), specificity (amount of cross-reactivity), predictive positive value (the confidence in a positive result), predictive negative value (the confidence in a negative result) and overall correlation with the reference assay.
II. There remain many questions to be answered about the various antigens produced by Giardia lamblia and how they can be utilized as diagnostic markers. In the second phase of this study, I identified and partially characterized the antigen (Ct7 Ag) that reacts with the Ct7 monoclonal antibody (MAb). This MAb is an IgM class mouse immunoglobin that is utilized by the GIARDIA TEST and by an immunofluorence antibody test (IFA) which detects Giardia cysts in water and feces. The results of this study will provide physicians and researchers with detailed information about the Ct7 Ag and why it is a useful marker for giardiasis.