ANA Screening IgG
Enzyme ImmunoAssay (ELISA) for the qualitative determination of IgG auto-antibodies to dsDNA, histones, SSA, SSB, Sm, Sm/RNP, Scl-70, Jo-1, centromere and other antigens extracted from the HEp-2 nucleus, in human plasma and sera.
Autoimmunity is the failure of an organism to recognize its own constituent parts as self, which allows an immune response against its own cells and tissues. Any disease that results from such an aberrant immune response is termed an Autoimmune Disease.
Rheumatoid autoimmune diseases are often associated with auto-antibodies to Nuclear Antigens. We can to distinguish between Anti Nuclear Antibodies (ANA), associate with autoimmune systemic diseases as SLE (Systemic Lupus Erythematosus), RA (Reumatoid Arthritis), Scleroderma, MCDT (Mixed Connective Tissue Disease) and Sjogren’s Syndrome; and Extractable anti Nuclear Antibodies (ENA), associate with autoimmune systemic disease as Polymyositis, SLE, MCDT and Sjogren’s Syndrome.
The serological detection of antinuclear antibodies (ANA) in patient with suspected autoimmune disorders is common practice in every immunological laboratory. When this first diagnostic step is performed with positive results, we can go along with the isolate detection and quantification of the individual antibodies.
Microplates are coated with antigens dsDNA, histones, SSA, SSB, Sm, Sm/RNP, Scl-70, Jo-1, centromere and other antigens extracted from the HEp-2 nucleus.
In the 1st incubation, the solid phase is treated with diluted samples and anti nuclear IgG are captured, if present, by the solid phase.
After washing out all the other components of the sample, in the 2nd incubation bound anti nuclear IgG are detected by the addition of anti hIgG antibody, labeled with peroxidase (HRP).
The enzyme captured on the solid phase, acting on the substrate/chromogen mixture, generates an optical signal that is proportional to the amount of anti nuclear IgG antibodies present in the sample. The presence of IgG in the sample may therefore be determined by means of a cut-off value able to discriminate between negative and positive samples.
- Autoantibody to a nuclear antigen in proliferating cells. K Miyachi, MJ Fritzler, EM Tan – The Journal of Immunology, 1978 – Am Assoc Immnol
- Autoantibodies to nuclear antigens (ANA): their immunobiology and medicine.EM Tan – Advances in immunology, 1982 – ncbi.nlm.nih.gov
- Antinuclear antibody with distinct specificity for polymyositis. JF Wolfe, E Adelstein, GC Sharp – Journal of Clinical Investigation, 1977 – pubmedcentral.nih.gov