Enzyme-linked immunosorbent disease testing

Diagnostic procedures include dark-field microscopy12, non-treponemal exams10 (i.e., the Venereal Disease Laboratory and the rapid plasma reagin test), and treponemal exams (i.e., enzyme immunoassay, the T. pallidum hemagglutination test, the fluorescent treponemal antibody test, and the enzyme-linked immunosorbent assay). 

Nowadays, antibodies are utilized in numerous immunoanalytical methods. Those widely used in practice, such as radioimmunoassays, fluoroimmunoassays and enzyme-linked immunosorbent assays (ELISA), require labelled reagents. Millions of ELISA tests for diagnostics of various diseases are daily performed in clinical laboratories. The detection of analytes by two-antibody "sandwich" ELISA, is schematically outlined in Figure 3. 

The most commonly used screening method for HIV is an enzyme-linked immunosorbent assay, which detects antibodies against HIV-1 and is both highly sensitive and specific. False positives can occur in multiparous women in recent recipients of hepatitis B, HIV, influenza, or rabies vaccine following multiple blood transfusions and in those with liver disease or renal failure, or undergoing chronic hemodialysis. False negatives may occur if the patient is newly infected and the test is performed before antibody production is adequate. The minimum time to develop antibodies is 3 to 4 weeks from initial exposure. 

The causative agent in Lyme disease is a spirochetal bacterium (Borrelia burgdorferi) that is transmitted directly through the bite of a deer tick. Optic neittopathy can occur due to Lyme disease and manifests as papillitis, retrobulbar neuropathy, or ischemic optic neiu-opathy. Serologic testing may help to identify Lyme infection by use of indirect immunofluorescent assay and enzyme-linked immunosorbent assay.The treatment of Lyme disease includes oral or intravenous peniciUin, doxycycUne, erythromycin, or ceftriaxone. 

Enzyme-linked immunosorbent assay A multistage test offering identification of disease-specific antibodies, the enzyme-linked immunosorbent assay may be useful in identifying infectious etiologies of uveitis, such as toxoplasmosis, toxocariasis, HI ( and Lyme disease. 

Antigen-capture enzyme-linked immunosorbent assay (ELISA) testing, IgM ELISA, polymerase chain reaction (PCR), and virus isolation can be used to diagnose a case of Ebola HF within a few days of the onset of symptoms. Persons tested later in the cour.se of the disease or after recovery can be tested for IgM and IgG antibodies the disease can al.so be diagnosed retrospectively in deceased patients by using iminunohistochemistry testing, virus isolation, or PCR. 

Clinical testing techniques using proteins as the basis for detection of disease include western blotting, immunohistochemical staining, enzyme-linked immunosorbent assay (ELISA), and mass spectrometry. 

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