The first step in determining if an antibody is a cold autoantibody is to perform a series of immunoassays. These tests can include an enzyme-linked immunosorbent assay (ELISA), an immunofluorescence assay (IFA), a complement fixation test (CFT) and a radioimmunoassay (RIA). In addition, a lupus erythematosus (LE) cell test may be used to test for the presence of specific cold autoantibodies.
ELISA
The ELISA test is a biochemical technique used to detect and measure antibodies in a sample. This test is very sensitive and can detect small amounts of antibodies. During the ELISA test, a sample of serum is incubated with an antigen that binds to specific antibodies. If antibodies are present in the sample, they will bind to the antigen and be detected by a labeled enzyme.
IFA
The immunofluorescence assay (IFA) is a type of immunoassay used to detect the presence of antibodies in a sample. During this test, the sample is incubated with a fluorescently labeled antibody specific to a particular antigen. If antibodies are present in the sample, they will bind to the fluorescently labeled antibody and be detected by a microscope.
CFT
The complement fixation test (CFT) is a type of immunoassay used to detect the presence of antibodies in a sample. During this test, the sample is incubated with a complement, a component of the immune system, and an antigen. If antibodies are present in the sample, they will bind to the antigen and activate the complement, resulting in the formation of a visible precipitate.
RIA
Radioimmunoassay (RIA) is a type of immunoassay used to detect the presence of antibodies in a sample. During this test, the sample is incubated with a radiolabeled antibody specific to a particular antigen. If antibodies are present in the sample, they will bind to the radiolabeled antibody and be detected by a Geiger counter.
LE Cell Test
The lupus erythematosus (LE) cell test is a type of immunoassay used to detect the presence of specific cold autoantibodies in a sample. During this test, the sample is incubated with lupus erythematosus cells, which are cells that have been specifically sensitized to recognize certain antigens. If antibodies are present in the sample, they will bind to the lupus erythematosus cells and be detected by a microscope.
